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Cited by 590biodegradable polymer synthesis and propertiesAdvanced Drug Delivery SystemsAdvanced Polymer Synthesis and Characterization

Recent advances in the synthesis of aliphatic polyesters by ring-opening polymerization☆

Open access
JEROME, C, LECOMTE, P·2008·Advanced Drug Delivery Reviews
DOI 10.1016/j.addr.2008.02.008
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Abstract

Advanced drug delivery systems rely on the availability of biocompatible materials. Moreover, biodegradability is highly desirable in the design of those systems. Consequently, aliphatic polyesters appear as a class of promising materials since they combine both properties. Nevertheless, their use in practical biomedical systems relies on clinical approval which not only depends on the material itself but also on its reproducible synthesis with the absence of residual toxics. The first sections of this review aim at reporting on the evolution of the initiators/catalytic systems and of the synthesis conditions (particularly the use of supercritical CO(2) as polymerization medium) in order to produce aliphatic polyesters with controlled macromolecular parameters by still "greener" ways. In addition, the further development of delivery systems also depends on the synthesis of materials exhibiting novel properties, such as amphiphilicity or pH-sensitivity that are emerging from the active research in macromolecular engineering. Functionalizing aliphatic polyesters is quite tedious due to their sensitivity towards hydrolytic degradation. The last section of this review is discussing several strategies to obtain functional (co)polyesters of various architectures providing them with novel properties.

AI snapshot

Written from the paper’s full text.

TL;DR

This review surveys how aliphatic polyesters for drug delivery have been synthesized by ring-opening polymerization, emphasizing the move from toxic metal initiators toward greener, metal-free, enzymatic, and supercritical CO₂-based routes. It also reviews strategies for making functional and amphiphilic polyester architectures, while noting that degradability makes post-polymerization modification difficult.

Key findings

  • Initiator/catalyst development has shifted from aluminum and tin alkoxides toward rare-earth, “friendly” metal, supported-metal, enzymatic, and all-organic systems. Aluminum alkoxides give strong selectivity—propagation in LLA/THF at 80 °C is about 100 times faster than bimolecular transesterification—while tin(IV) alkoxides give broader distributions (PDI ~1.5). Rare-earth examples include La with a 45 s half-reaction time and reactivity La > Y >> Yb, and a bimetallic Sm initiator giving PDI ~1.2 at 0 °C.
  • Supercritical CO₂ is presented as a useful medium for synthesis, purification, and particle formation. Tin(IV) alkoxide-initiated ε-CL ROP in scCO₂ at 40 °C and 210–215 bar is slower than in toluene or bulk (about 14× and 33×, respectively); extraction removes 95% ε-CL in about 110 min and 99% in about 175 min. Enzymatic ROP in scCO₂ produced PCL with Mw 74,000, and repolymerizable oligomers (Mn ~500) were converted to PCL with Mn above 80,000.
  • Functionalization routes include polymerizing substituted lactones, derivatizing preformed polyesters, and a two-step precursor approach. Click chemistry is highlighted as mild and often quantitative—poly(αN₃εCL) with Mn 46,000 and Mw/Mn 1.6 reacted completely with propargyl benzoate—whereas atom transfer radical addition is often non-quantitative and can leave copper contamination.
  • Amphiphilic PCL-g-PEO, PLA-g-PEO, diblock, triblock, and related architectures are emphasized for advanced drug delivery; enzymatic ROP can also give stereoselectivity, with enantiomeric purity above 95% for some substituted caprolactones.

Methods

  • Narrative review of the literature, covering ROP mechanisms, initiator/catalyst families, supercritical CO₂ processing, and macromolecular engineering of functional aliphatic polyesters.
  • Draws on cited experimental studies and schemes rather than presenting new primary data; no systematic search strategy, inclusion criteria, or meta-analysis is described.
  • Main analysis is thematic synthesis of reported synthetic approaches, molecular-weight control, toxicity concerns, and functionalization outcomes.

Limitations

  • Stated in the paper: aliphatic polyesters are sensitive to hydrolytic degradation, making functionalization difficult; many functional groups require protection/deprotection; metal residues from Al, Sn, rare-earth, and Cu catalysts can be problematic for biomedical use; enzymatic ROP gives poorer control (Mw/Mn >2); ATRA can be non-quantitative and copper-contaminating; scCO₂ suffers from low polymer solubility and slow kinetics.
  • Evident from the text: as a review, it provides no new experimental validation and no systematic quality assessment of the cited studies, so conclusions depend on selected examples and the authors’ perspective.
  • Evident from the text: clinical translation remains limited, with few synthetic polymer drug delivery systems successfully used in clinics despite decades of research.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.addr.2008.02.008

Cites

168 of 168 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

2 of 146 cited sources checked · 0 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    Aluminum alkoxide initiators can polymerize other cyclic monomers such as adipic anhydride and trimethylene carbonate.

    “This type of initiator can also polymerize other cyclic monomers, such as adipic anhydride and trimethylene carbonate [9]”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [9] 9. D. Mecerreyes, R. Jérôme, P. Dubois, Novel macromolecular architectures based on aliphatic polyesters: relevance of the coordination- insertion ring-opening polymerization, Adv. Polym. Sci. 147 (1999) 1-59. source

      The available indexed passages (ORBi record, no page number) discuss ring-opening polymerization and tin alkoxide initiators, but do not address aluminum alkoxide initiators polymerizing adipic anhydride or trimethylene carbonate. Searches for both named monomers and aluminum alkoxide initiators found no passage establishing the claim. (LLM, conf=0.72)

      Experimental — accuracy not yet measured
  • Premisecitation

    Calcium methoxide is of limited interest because of its low solubility and aggregation.

    “Although commercially available and highly active in ROP of ε-CL and L-LA, calcium methoxide is of limited interest because of its low solubility and aggregation [25].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [25] 25. Z. Zhong, M.J.K. Ankone, P.J. Dijkstra, Ch. Birg, M. Westerhausen, J. Feijen, Calcium methoxide initiated ring-opening polymerization of ε-caprolactone and L-lactide, Polym. Bull. 46 (2001) 51-57. source
  • Premisecitation

    Depending on the nature of the metal, the number of active sites is close to 2.6 or 2.0.

    “Depending on the nature of the metal, the number of active sites is close to 2.6 or 2.0.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [17] 17. N Spassky, V. Simic, L. Hubert-Pfalzgraf, M. Montaudo, Synthesis of aliphatic polyesters by controlled ring-opening polymerization of cyclic esters. Characterization, properties, transesterification reactions, Macromol. Symp. 144 (1999) 257-267. source
  • Premisecitation

    Controlling the composition, morphology, Tg and degradation rate of copolymers allows regulation of the drug release behaviour.

    “Controlling the composition, the morphology, the Tg and degradation rate allows regulation of the drug release behaviour [13].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [13] 13. C. Qing, B. Jianzhong, W. Shenguo, Relationship among drug delivery behaviour, degradation behaviour and morphology of copolylactones derived from glycolide, L-lactide and ε-caprolactone, Polym. Adv. Technol. 13 (2) (2002) 105-111.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Premisecitation

    A large variety of rare earth derivatives have been used to initiate ROP of lactones and lactides.

    “A large variety of rare earth derivatives have been used to initiate ROP of lactones and lactides [14].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14] 14. S. Agarwal, C. Mast, K. Dehnicke, A. Greiner, Rare Earth metal initiated ring-opening polymerization of lactones, Macromol. Rapid Commun. 21 (2000) 195-212. source
  • May combine two claims. 68
  • Classified as probably not a substantial claim. 35
  • The quote only partly states this claim. 1

  • May combine two claims.

    Premisecitation

    The very good control imparted by aluminum alkoxides is a unique platform for macromolecular engineering of aliphatic polyesters, making comb-like, star-shaped, graft and hyperbranched (co)polyesters available.

    “The very good control imparted to ring-opening polymerization by aluminum alkoxides is a unique platform for the macromolecular engineering of aliphatic polyesters, for instance, making comb-like, star-shaped, graft and hyperbranched (co)polyesters available [9].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [9] 9. D. Mecerreyes, R. Jérôme, P. Dubois, Novel macromolecular architectures based on aliphatic polyesters: relevance of the coordination- insertion ring-opening polymerization, Adv. Polym. Sci. 147 (1999) 1-59. source

      The indexed material identifies the cited paper in a publication-record section (Advances in Polymer Science, vol. 147, pp. 1–59), but the retrieved passages do not provide its discussion of aluminum alkoxides. Searches for aluminum alkoxides and for the listed comb-like, star-shaped, graft, and hyperbranched architectures found no passage from the cited paper that establishes the claim; passages describing some architectures belong to other publications listed nearby. (LLM, conf=0.72)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisereasoning

    ROP proceeds mainly via two major mechanisms depending on the organometallic: some act as catalysts and activate the monomer by complexation with the carbonyl group, while others act as initiators through an insertion-coordination mechanism.

    “The ROP proceeds mainly via two major polymerization mechanisms depending on the used organometallics.Some of them acts as catalysts, and activate the monomer by complexation with the carbonyl group (Scheme 4).”
    • Also stated in: § Scheme 3. Synthesis of aliphatic polyesters by step-growth polycondensation. · plain
      “In the second mechanism, the organometallic plays the role of initiator and the polymerization proceeds through an 'insertion-coordination' mechanism (Scheme 5).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    LA polymerization at 180 °C has been studied for a wide range of cations (Na+, K+, Mg2+, Ca2+, Zn2+, Fe2+) with a variety of counter-ions, and zinc lactate gave the best results.

    “The LA polymerization at 180 °C has been studied for a wide range of cations [19,20]: Na + , K + , Mg 2+ , Ca 2+ , Zn 2+ , and Fe 2+ with a variety of counter-ions: chloride, iodide, oxide, hydroxide, carbonate, acetate and higher fatty acids, lactate, tartrate, citrate, α-amino acids and peptides.Zinc lactate gave the best results.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [19] 19. H.R. Kricheldorf, I. Kreiser-Sanders, D.O. Damrau, Resorbable intiators for polymerizations of lactones, Macromol. Symp. 159 (2000) 247-257. source
    • cites [20] 20. H.R. Kricheldorf, I. Kreiser-Sanders, D.O. Damrau, Resorbable intiators for polymerizations of lactones, Macromol. Symp. 144 (1999) 269-276. source

  • May combine two claims.

    Premisecitation

    Fe2(OCH(C6H5)2)6 initiates ROP of LA and ε-CL and imparts good control to the polymerization.

    “Fe 2 (OCH(C 6 H 5 ) 2 ) 6 initiates ROP of LA and ε-CL and imparts a good control to the polymerization [24].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [24] 24. B.J. O'Keefe, L.E. Breyfogle, M.A. Hillmyer, W.B. Tolman, Mechanistic comparison of cyclic ester polymerizations by novel iron(I∏)- alkoxide complexes: single vs multiple site catalysis, J. Am. Chem. Soc. 124 (2002) 4384-4393. source

  • May combine two claims.

    Premisecitation

    Rare earth derivatives usually have high reactivity, as exemplified by the polymerization of β-butyrolactone by Y(OCH2-CH2OMe) at room temperature, in contrast to the long reaction time and high temperature required with aluminum-based initiators.

    “Their usually high reactivity must be emphasized, as exemplified by the polymerization of β-butyrolactone which is polymerized by Y(OCH 2 -CH 2 OMe) at room temperature [15], in contrast to the long reaction time and high temperature required when aluminum-based initiators are used.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [15] 15. A. Le Borgne, C. Pluta, N. Spassky, Highly reactive yttrium alkoxide as new initiator for the polymerization of β-butyrolactone, Macromol. Rapid Commun. 15 (12) (1994) 955-960. source

  • May combine two claims.

    Premisecitation

    Propagation is 100 times faster than bimolecular transesterification in the ring-opening polymerization of LLA in THF at 80 °C, and molecular weight is very well controlled.

    “For instance, propagation is 100 times faster than bimolecular transesterification in the ring-opening polymerization of LLA in THF at 80 °C [8] and molecular weight is very well controlled.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [8] 8. J. Baran, A. Duda, A. Kowalski, R. Szymanski, S. Penczek, Quantitative comparison of selectivities in the polymerization of cyclic esters, Macromol. Symp. 123 (1997) 93-101. source

  • May combine two claims.

    Premisereasoning

    ROP allows good control of polymer characteristics, including predictable molecular weight and narrow molecular weight distribution, and is well-suited for macromolecular engineering of homo- and copolymers of various architectures.

    “Indeed, this mechanism allows quite good control of the polymer characteristics (i.e., predictable molecular weight, narrow molecular weight distribution) and is particularly well-suited for macromolecular engineering with the production of homo-and copolymers of various architectures (i.e., palm-tree, diblock, multiblock, star) (Scheme 2).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: ROP allows good control of polymer characteristics and is well-suited for macromolecular engineering of aliphatic polyesters.

  • May combine two claims.

    Premisecitation

    With Sm, Y and Yb a narrow polydispersity is observed until high conversions, while for La initiator the polydispersity increases with conversion, indicating that transesterification reactions occur.

    “With Sm, Yand Yb a narrow polydispersity is observed until high conversions while for La initiator the polydispersity increases with conversion indicating that transesterification reactions occur.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [17] 17. N Spassky, V. Simic, L. Hubert-Pfalzgraf, M. Montaudo, Synthesis of aliphatic polyesters by controlled ring-opening polymerization of cyclic esters. Characterization, properties, transesterification reactions, Macromol. Symp. 144 (1999) 257-267. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The sharp increase of patents in this field in the early 90s coincides with the clinical success and commercialization of Lupron Depot, the first parenteral sustained-release formulation using PLA, approved in 1989.

    “The sharp increase of the patents number in this field in the early 90s coincides with the clinical success and commercialization of Lupron Depot, the first parenteral sustained-release formulation using PLA, which was approved in 1989 [6].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [6] 6. M. Chaubal, Polylactides/glycolides -excipients for injectable drug, Drug Deliv. Technol. 2 (n°5) (2002).

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationnone given

    The use of aliphatic polyesters in practical biomedical systems depends on clinical approval and on reproducible synthesis without residual toxics.

    “Nevertheless, their use in practical biomedical systems relies on clinical approval which not only depends on the material itself but also on its reproducible synthesis with the absence of residual toxics.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The use of aliphatic polyesters in practical biomedical systems depends on clinical approval and on reproducible synthesis without residual toxics.

  • May combine two claims.

    Premisecitation

    In the Y[N(SiMe3)2]3/alcohol system, Mn can be predicted from the monomer/alcohol molar ratio and the molecular weight distribution is narrow even at high monomer conversion.

    “In addition to Mn, which can be predicted from the monomer/alcohol molar ratio, the molecular weight distribution is narrow even at high monomer conversion.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18] 18. E. Martin, P. Dubois, R. Jérôme, Controlled ring-opening polymerization of ε-caprolactone promoted by "in situ" formed yttrium alkoxides, Macromolecules 33 (5) (2000) 1530-1535. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Tin octoate is probably the most popular polymerization initiator for ROP of aliphatic polyesters.

    “Probably the most popular polymerization initiator for ROP of aliphatic polyester is tin(II) bis-(2ethylhexanoate) also referred as tin octoate (Sn(Oct) 2 ) [10].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [10] 10. A. Stjerndahl, A.F. Wistrand, A.C. Albertsson, Industrial utilization of tin-Initiated resorbable polymers: synthesis on a large scale with a low amount of initiator, Biomacromolecules 8 (2007) 937-940. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Zinc acetate is a friendly analogue of tin octoate.

    “Zinc acetate turned out to be a friendly analogue of tin octoate [23].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [23] 23. A. Kowalski, J. Libiszowski, K. Majerska, A. Duda, S. Penczek, Polymer 48 (2007) 3952-3960.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    The polymerization of lactides and lactones by ring-opening polyaddition is free of the limitations of step-growth polycondensation and is preferred for synthesis with tailor-made properties.

    “The polymerization of lactides and lactones by the ring-opening polyaddition process is free of these limitations and is thus preferred for their synthesis with tailor-made properties.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Step-growth polycondensation has major drawbacks: high temperatures and long reaction times favour side reactions, and short deviations from stoichiometry deleteriously affect molecular weight.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A broad range of anionic, cationic and coordinative initiators or catalysts have been reported for ROP.

    “A broad range of anionic, cationic and coordinative initiators or catalysts have been reported for the ROP [4,5].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [4] 4. S. Penczek, M. Cypryk, A. Duda, P. Kubisa, S. Slomkowski, Living ring-opening polymerisations of heterocyclic monomers, Prog. Polym. Sci. 32 (2007) 247-282. source
    • cites [5] 5. P. Lecomte, R. Jérôme, New developments in the synthesis of aliphatic polyesters by ring-opening polymerization, in: R. Smith (Ed.), Biodegradable Polymers for Polymer Industrial Applications, Woodhead Publishing Ltd, 2005, pp. 77-106.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    The lanthane initiator is the most reactive with a half-reaction time of 45 s, and the reactivity range is La>Y>>Yb.

    “The lanthane initiator is the most reactive with half-reaction time of 45 s, the reactivity range being La>Y>>Yb.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [17] 17. N Spassky, V. Simic, L. Hubert-Pfalzgraf, M. Montaudo, Synthesis of aliphatic polyesters by controlled ring-opening polymerization of cyclic esters. Characterization, properties, transesterification reactions, Macromol. Symp. 144 (1999) 257-267. source

  • May combine two claims.

    Premisecitation

    (THF)2Ca[N(SiMe3)2]2 reacted with isopropanol with in situ formation of Ca isopropoxide; ROP of ε-CL and L-LA is then controlled at room temperature as confirmed by agreement between theoretical and experimental Mn and low Mw/Mn (<1.3).

    “The (THF) 2 Ca[N(SiMe 3 ) 2 ] 2 precursor was indeed reacted with isopropanol with in situ formation of Ca isopropoxide.ROP of ε-CL and L-LA is then controlled at room temperature as confirmed by the agreement between theoretical and experimental Mn and low Mw/Mn(<1.3).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26] 26. Z. Zhong, PJ. Dijkstra, Ch. Birg, M. Westerhausen, J. Feijen, A novel and versatile calcium-based initiator system for the ring-opening polymerization of cyclic esters, Macromolecules 34 (2001) 3863-3868.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    At 0 °C with the bimetallic Sm initiator, the molecular weight distribution is narrow (PDI ~ 1.2), indicating fast initiation compared with propagation and transesterification reactions.

    “At 0 °C, the molecular weight distribution is narrow (PDI ~ 1.2), which indicates a fast initiation compared with propagation and transesterification reactions if any.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [16] 16. P. Ravi, T. Grôb, K. Dehnicke, A. Greiner, Novel [Sm2I(NPPh3)5(DME)] initiator for the living ring-opening polymerization of ε- caprolactone and δ-valerolactone, Macromolecules 34 (2001) 8649-8653. source

  • May combine two claims.

    Premisecitation

    Germanium alkoxides have been studied because of less toxicity than tin alkoxides; however, ROP of ε-CL requires higher temperature, e.g. 140 °C for Ge(OC2H5)4, and the molecular weight distribution is quite broad.

    “Germanium alkoxides because of less toxicity than tin alkoxides have also been studied [31].However, ROP of ε-CL requires higher temperature, e.g.140 °C for Ge(OC 2 H 5 ) 4 ], and the molecular weight distribution is quite broad.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] 31. H.R. Kricheldorf, D. Langanke, Polylactones 54: ring-opening and ring-expansion polymerizations of ε-caprolactone initiated by germanium alkoxides, Polymer 43 (2002) 1973-1977. source

  • May combine two claims.

    Premisecitation

    Based on the extraction constant, 95% of ε-CL is extracted after ca. 110 min, while 99% extraction requires ca. 175 min.

    “Based on the extraction constant, 95% of ε-CL is extracted after ca.110 min, while 99% extraction would require ca.175 min.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [87] 87. R. Jérôme, Ph. Lecomte, New developments in the synthesis of aliphatic polyesters by ring-opening polymerization, Biodegradable Polymers for Industrial Applications, 2005, pp. 77-106.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Zirconium derivatives are 10 times less toxic than tin counterparts, and Zr-containing drugs and cosmetics are accepted by the Food and Drug Administration.

    “Zirconium derivatives being 10 times less toxic than tin counterparts and Zr-containing drugs and cosmetics being accepted by the Food and Drug Administration [27], they were investigated for the polyesters synthesis.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [27] 27. M. Bero, P. Dobrzynski, J. Kasperczyk, Application of zirconium(IV) acetylacetonate to the copolymerization of glycolide with and lactide, Polym. Bull. 42 (1999) 131-139. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    PGSS is highly attractive for elaborating particulate DDS, while it is not yet widely developed.

    “It is thus highly attractive for elaborating particulate DDS, while it is not yet widely developed.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisenone given

    Polyester formed in a high-pressure reactor can be in situ loaded by guest molecules, or collected as micro-particles.

    “For instance, the polyester formed in the high-pressure reactor can be in situ loaded by guest molecules, or collected as micro-particles.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisereasoning

    Because polymers are insoluble in scCO2, the choice of the CO2-philic component is very limited, usually restricted to silicones and fluorinated polymers.

    “Because polymers are insoluble in scCO 2 , the choice of the CO 2 -philic component is very limited, and usually restricted to silicones and fluorinated polymers.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    Fluorinated polymers are inappropriate for biomedical applications.

    “Nevertheless, fluorinated polymers are inappropriate for biomedical applications.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Jérôme and co-workers used an Y alkoxide precursor, Y[N(SiMe3)2]3, reacted with one or two equivalents of isopropanol to form mixed yttrium alkoxide/amide; the unreacted amide functions were then used to graft the Y alkoxide to the support.

    “Jérôme and co-workers tackled this problem by using an Yalkoxide precursor, i.e.Y[N(SiMe 3 ) 2 ] 3 [34], reacting it with one or two equivalent(s) of isopropanol with formation of mixed yttrium alkoxide/amide.The unreacted amide functions were then used to graft the Y alkoxide to the support.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [34] 34. E. Martin, P. Dubois, R. Jérôme, Preparation of supported yttrium alkoxides as catalysts for the polymerization of lactones and oxirane, J. Polym. Sci., Polym. Chem. 41 (2003) 569-578. source

  • May combine two claims.

    Premisecitation

    The grafted alkoxide can participate in a fast exchange with an alcohol added on purpose in the polymerization medium at 40 °C; chains are detached from the support by methanolysis, which restores the Y alkoxides at the surface of the support.

    “The grafted alkoxide can participate in a fast exchange with an alcohol added on purpose in the polymerization medium, at 40 °C.Chains are detached from the support by methanolysis, which restores the Y alkoxides at the surface of the support.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [34] 34. E. Martin, P. Dubois, R. Jérôme, Preparation of supported yttrium alkoxides as catalysts for the polymerization of lactones and oxirane, J. Polym. Sci., Polym. Chem. 41 (2003) 569-578. source

  • May combine two claims.

    Premisecitation

    scCO2 extraction can remove residual monomers and catalysts from aliphatic polyesters, yielding ultra-pure polyesters suitable for biomedical applications.

    “scCO 2 is a valuable vehicle for extracting residual monomers and catalysts leading to ultra-pure aliphatic polyesters as required for applications in the biomedical field.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [87] 87. R. Jérôme, Ph. Lecomte, New developments in the synthesis of aliphatic polyesters by ring-opening polymerization, Biodegradable Polymers for Industrial Applications, 2005, pp. 77-106.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    In ROP of L-LA in scCO2 with PDMS-based stabilizers, block copolymers were effective giving fine and discrete PLLA microparticles, while graft copolymer failed to give enough stabilization due to short polymer-philic chains resulting in hard agglomerates.

    “While block copolymers were effective giving fine and discrete PLLA microparticles, the graft copolymer failed to give enough stabilization due to their short polymer-philic chains resulting in hard agglomerates [95].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [95] 95. H. Ganapathy, H. Subban, S. Ha, Y. Jeong, L. Tae, L. Won-Ki, T. Kwon, Ring-opening polymerization of L-lactide in supercritical carbon dioxide using PDMS based stabilizers, Eur. Polym. J. 43 (1) (2006) 119-126. source

  • May combine two claims.

    Premisecitation

    The kinetic profile of dibutyltin diacetate extraction is quasi-linear and the slope allows the extraction constant to be determined.

    “The kinetic profile is quasi-linear (Fig. 2b) and the slope of the straight line allows the extraction constant to be determined.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [87] 87. R. Jérôme, Ph. Lecomte, New developments in the synthesis of aliphatic polyesters by ring-opening polymerization, Biodegradable Polymers for Industrial Applications, 2005, pp. 77-106.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Because Zr complexes usually aggregate (coordination number=6), benzyl alcohol has been added to Zr(O-n-C3H7)4; Mn is then determined by the monomer/alcohol molar ratio, with low polydispersities.

    “Because Zr complexes usually aggregate (coordination number=6) [29], benzyl alcohol has been advantageously added to Zr(O-n-C 3 H 7 ) 4 [29,30].Mn is then determined by the monomer/alcohol molar ratio, with low polydispersities.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [29] 29. C. Miola-Delaite, T. Hamaide, R. Spitz, Anionic coordinated polymerization of ε-caprolactone with aluminum, zirconium, and some rare earths alkoxides as initiators in the presence of alcohols, Macromol. Chem. Phys. 200 (1999) 1771-1778. source
    • cites [30] 30. C. Miola-Delaite, E. Colomb, E. Pollet, T. Hamaide, Anionic ring opening polymerization of oxygenated heterocycles with supported zirconium and rare earths alkoxides as initiators in protic conditions. Towards a catalytic heterogeneous process, Macromol. Symp. 153 (2000) 275-286. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationnone given

    Even if novel functional aliphatic polyesters have been only scarcely tested in clinics up to now, their unique properties make them promising for DDS of tomorrow.

    “Even if these novel materials have been only scarcely tested in clinics up to now, their unique properties make them promising for the DDS of tomorrow.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationnone given

    Most polymers and pharmaceuticals have poor solubility in scCO2, which limits development of the RESS processing strategy.

    “Unfortunately, most polymers and pharmaceuticals have poor solubility in scCO 2 , which limits the development of such processing strategy.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    This method is free from side reactions and quite reproducible and allows varying the average number of alkoxides per Y (1 or 2).

    “This method, free from side reactions and quite reproducible allows to vary the average number of alkoxides per Y(l or2).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [34] 34. E. Martin, P. Dubois, R. Jérôme, Preparation of supported yttrium alkoxides as catalysts for the polymerization of lactones and oxirane, J. Polym. Sci., Polym. Chem. 41 (2003) 569-578. source

  • May combine two claims.

    Premisenone given

    PGSS process has advantages that the starting material does not have to be soluble in scCO2 and no organic solvents are required during processing.

    “This “particles from gas saturated solutions”, so-called PGSS process, has the advantages that the starting material does not have to be soluble in scCO 2 and that no organic solvents are required during processing.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The second strategy is grafting of functional groups in the α-position of the carbonyl of preformed polyester.

    “The grafting of functional groups in the α-position of the carbonyl of preformed polyester is the second strategy [100].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [100] 100. S. Ponsart, J. Coudane, M. Vert, A novel route to poly(ε-caprolactone)-based copolymers via anionic derivatization, Biomacromolecules 1 (2000) 275-281. source

  • May combine two claims.

    Premisecitation

    A series of lactones substituted by bromides, acrylates, protected hydroxyl groups, protected carboxyl groups, and terminal olefins or containing ketones have been synthesized and homo- or co-polymerized.

    “Later on, a series of lactones substituted by bromides [103,104], acrylates [105], protected hydroxyl goups [106,107] protected carboxyl groups [108][109][110][111][112][113][114][115] and terminal olefins [116,117] or containing ketones [118] have been synthesized and homo-or co-polymerized.”
    Quote in the paperNot a substantial claim0 of 5 sources checked
    • cites [103] 103. Ch. Detrembleur, M. Mazza, O. Halleux, Ph. Lecomte, D. Mecerreyes, J.L. Hedrick, R. Jérôme, Ring-opening polymerization of γ- bromo-ε-caprolactone: a novel route to functionalized aliphatic polyesters, Macromolecules 33 (2000) 14-18.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [104] 104. D. Mecerreyes, B. Atthoff, K.A. Boduch, M. Trollsaas, J.L. Hedrick, Unimolecular combination of an atom transfer radical polymerization initiator and a lactone monomer as a route to new graft copolymers, Macromolecules 32 (1999) 5175-5182. source
    • cites [105] 105. D. Mecerreyes, J. Humes, R.D. Miller, J.L. Hedrick, Ph. Lecomte, Ch. Detrembleur, R. Jérôme, First example of an unsymmetrical difunctional monomer polymerizable by two living/controlled methods, Macromol. Rapid Commun. 21 (2000) 779-784. source
    • cites [106] 106. S. Gautier, V. d'Aloia, O. Halleux, M. Mazza, Ph. Lecomte, R. Jérôme, Amphiphilic copolymers of ε-caprolactone and γ-substituted ε- caprolactone. Synthesis and functionalization of poly(D,L-lactide) nanoparticles, J. Biomater. Sci., Polym. Ed. 14 (2003) 63-85. source
    • cites [107] 107. F. Stassin, O. Halleux, P. Dubois, C. Detrembleur, P. Lecomte, R. Jérôme, Ring opening copolymerization of ε-caprolactone, γ- (triethylsilyloxy)-ε-caprolactone and γ-ethylene ketal-ε-caprolactone: a route to hetero-graft copolyesters, Macromol. Symp. 153 (2000) 27- 39. source

  • May combine two claims.

    Interpretationown data

    Michael-type reaction is not quantitative and has risk of cross-linking through residual acrylic groups.

    “Nevertheless, the Michaeltype reaction is not quantitative; with the risk of cross-linking through the residual acrylic groups.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    DIPAGYL, a glycolide derivative substituted by acetonide, can be partially deprotected into diol.

    “Vert et al. investigated the synthesis and polymerization of 3-(1,2-3,4-tetraoxobutyl-diisopropylidene)dioxane-2,5-dione(DIPAGYL), a derivative of glycolide, substituted by acetonide, which can be partially deprotected into diol [121].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [121] 121. M.K. Benabdillah, J. Coudane, M. Boustta, R. Engel, M. Vert, Synthesis and characterization of novel degradable polyesters derived from D-gluconic and glycolic acids, Macromolecules 32 (1999) 8774-8780. source

  • May combine two claims.

    Premisecitation

    Ketal groups in the γ-ketal lactone polymer are used as protected ketones, whose reduction by sodium borohydride led to pendent hydroxyl groups, together with an increase of the hydrophilic character of the hydroxy-polyester.

    “The ketal groups are used as protected ketones, whose reduction by sodium borohydride led to pendent hydroxyl groups, together with an increase of the hydrophilic character of the hydroxy-polyester.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [101] 101. D. Tian, Ph. Dubois, Ch. Grandfils, R. Jérôme, Ring-opening polymerization of 1,4,8 trioxaspiro[4.-9-undecanone: a new route to aliphatic polyesters bearing functional pendent groups, Macromolecules 30 (1997) 406-409. source

  • May combine two claims.

    Premisecitation

    Carbon dioxide, benzaldehyde and iodine have been respectively grafted along the PCL chain, as precursors of acid, hydroxyl, and iodo moieties.

    “For instance, carbon dioxide [135], benzaldehyde [100] and iodine [137], thus precursors of acid, hydroxyl, iodo moieties, have been respectively grafted along the chain.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [135] 135. S. Gimenez, S. Ponsart, J. Coudane, M. Vert, Synthesis, properties and in vitro degradation of carboxyl-bearing PCL, J. Bioact. Compat. Polym. 16 (2001) 32-46. source
    • cites [100] 100. S. Ponsart, J. Coudane, M. Vert, A novel route to poly(ε-caprolactone)-based copolymers via anionic derivatization, Biomacromolecules 1 (2000) 275-281. source
    • cites [137] 137. B. Nottelet, J. Coudane, M. Vert, Synthesis of an X-ray opaque biodegradable copolyester by chemical modification of poly(ε- caprolactone), Biomaterials 27 (2006) 4948-4954. source

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    Synthesis of substituted lactones is most often a multi-step process with a low final yield.

    “It must be noted that the synthesis of substituted lactones is most often a multi-step process with a low final yield.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    γ-acrylic-ε-CL can be easily synthesized according to a three-step procedure and copolymerized with εCL into poly(γ-acrylic-εCL-co-εCL) copolymers.

    “γ-acrylic-ε-CL can be easily synthesized according to a three-step procedure [144] and copolymerized with εCL into poly (γ-acrylic-εCL-co-εCL) copolymers.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [144] 144. D. Mecerreyes, J. Humes, H.R.D. Miller, J.L. Hedrick, C. Detrembleur, P. Lecomte, R. Jérôme, J. SanRoman, First example of an unsymmetrical difunctional monomer polymerizable by two living/controlled methods, Macromol. Rapid Commun. 21 (2000) 779-784. source

  • May combine two claims.

    Premisecitation

    PEO macromonomer is a lactone substituted by a PEG polymer chain and is a precursor of graft copolymers, e.g. PCL-g-PEO with a palm-tree architecture due to quite divergent reactivity ratios.

    “A very attractive functional lactone is the poly(ethylene oxide) (PEO) (also called polyethylene glycol-PEG) macromonomer, i.e. a lactone substituted by a PEG polymer chain [129].Such macromonomer is precursor of graft copolymers, e.g, poly (ε-caprolactone-g-ethylene oxide) (PCL-g-PEO) with a palm-tree architecture due to quite divergent reactivity ratios (Scheme 2e).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [129] 129. J. Rieger, K.V. Bernaerts, F.E. Du Prez, R. Jérôme, C. Jérôme, Lactone end-capped Poly(ethylene oxide) as a new building block for biomaterials, Macromolecules 37 (26) (2004) 9738-9745. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    Main advantage of Michael addition is that no organometallic catalyst, that might be detrimental to biomedical applications, is needed.

    “The main advantage of the Michael addition is that no organometallic catalyst, that might be detrimental to biomedical applications, is needed.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Hydroxyl groups were grafted onto poly(ε-caprolactone-co-oxepane-1,2-dione) by coupling hydroxyethyl hydrazine with pendant ketones, and pendant hydroxyl groups were used for further derivatization.

    “In another work, hydroxyl groups were grafted onto poly(ε-caprolactone-co-oxepane-1,2-dione) by coupling hydroxyethyl hydrazine with pendant ketones [142], Pendant hydroxyl groups were used for further derivatization [142].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [142] 142. L. Emma, E. Prime, J. Justin, J.J. Cooper-White, G.G. Qiao, Coupling hydrophilic amine-containing molecules to the backbone of poly(ε-caprolactone), Aust. J. Chem. 59 (2006) 534-538.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Amphiphilic PCL-g-PEO copolymers have been prepared and form micelles in water.

    “Amphiphilic PCL-g-PEO copolymers have been accordingly prepared, that form micelles in water [130].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [130] 130. J. Rieger, P. Dubois, R. Jérôme, C. Jérôme, Controlled synthesis and interface properties of new amphiphilic PCL-g-PEO copolymers, Langmuir 22 (18) (2006) 7471-7479. source

  • May combine two claims.

    Interpretationnone given

    The three effective derivatization strategies described are all addition-type reactions that have the advantage to be free of side-products of reactions.

    “These are all addition-type reactions that have the advantages to be free of side-products of reactions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    1,4,8-trioxaspiro[4.6]-9-undecanone is homo-polymerized and copolymerized with ε-caprolactone.

    “This γ-ketal lactone is homo-polymerized [101] and copolymerized [102] with ε-caprolactone.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [101] 101. D. Tian, Ph. Dubois, Ch. Grandfils, R. Jérôme, Ring-opening polymerization of 1,4,8 trioxaspiro[4.-9-undecanone: a new route to aliphatic polyesters bearing functional pendent groups, Macromolecules 30 (1997) 406-409. source
    • cites [102] 102. D. Tian, Ph. Dubois, R. Jérôme, Ring-opening polymerization of 1,4,8-trioxaspiro-[4.-9-undecanone. A route to novel molecular architectures for biodegradable aliphatic polyesters, Macromol. Symp. 130 (1998) 217-227.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Emrick et al. copolymerized ε-caprolactone with an unsaturated derivative, followed by conversion of pendent double bonds into diols; esterification of these hydroxyl groups with PEO end-capped by a carboxylic acid generates amphiphilic graft PCL-g-PEO copolymers.

    “Emrick et al. gave a first example of this strategy by copolymerizing ε-caprolactone with an unsaturated derivative, followed by conversion of the pendent double bonds into diols.Esterification of these hydroxyl groups with PEO end-capped by a carboxylic acid generates again amphiphilic graft PCL-g-PEO copolymers [139].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [139] 139. B. Parrish, T. Emrick, Aliphatic polyesters with pendant cyclopentene groups: controlled synthesis and conversion to polyester-graft- PEG copolymers, Macromolecules 37 (2004) 5863-5865. source

  • May combine two claims.

    Premisecitation

    Brominated poly(ε-caprolactone) homo- or copolymers have been successfully quaternized by pyridine and were found to be efficient degradable polycations in gene delivery systems.

    “Interestingly, brominated poly (ε-caprolactone) homo-or copolymers have been successfully quaternized by pyridine [119] and were found to be efficient degradable polycations in gene delivery systems [ 120].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [119] 119. C. Detrembleur, M. Mazza, X. Lou, O. Halleux, Ph. Lecomte, D. Mecerreyes, J.L. Hedrick, R. Jérôme, New functional aliphatic polyesters by chemical modification of copolymers of ε-caprolactone with γ-(2-Bromo-2-methylpropionate)-ε-caprolactone, γ-Bromo-ε- caprolactone, and a mixture of β-and γ-Ene-ε-caprolactone, Macromolecules 33 (21) (2000) 7751-7760. source
    • cites [120] 120. B. Vroman, M. Mazza, M.R. Fernandez, R. Jérôme, V. Préat, Copolymers of ε-caprolactone and quaternized ε-caprolactone as gene carriers, J. Control. Release 118 (1) (2007) 136-144. source

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    Combination of the two above-described strategies into a two-step process appears as a valuable alternative.

    “Thanks to the efficiency of synthetic strategies which makes some functional lactones readily available, the combination of the two above-described strategies into a two-step process appears as a valuable alternative (Scheme 12).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    Grafting of functional groups onto preformed aliphatic polyesters chains is an appealing strategy because from a single easily available precursor, a wide range of functional groups can be attached in one further step.

    “Grafting of functional groups onto preformed aliphatic polyesters chains is an appealing strategy because from a single easily available precursor, a wide range of functional groups can be attached in one further step.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Interpretationnone given

    No degradation was observed in the Michael-type addition.

    “No degradation was either observed.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Thiol end-capped PEO was added onto pendent acrylic groups of PCL (content 18 mol%) in presence of pyridine, forming PCL-g-PEO graft copolymer as result of 65% conversion of acrylic units.

    “Thiol end-capped PEO was then added onto the pendent acrylic groups of PCL (content of acrylic units = 18 mol%) in the presence of pyridine (THF, room temperature, 300 h [pyridine]/[thiol]/[acrylate]=15/10/1).[145] The PCL-g-PEO graft copolymer was formed as result of 65% conversion of the acrylic units.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [145] 145. J. Rieger, K. Van Butsele, P. Lecomte, C. Detrembleur, R. Jérôme, C. Jérôme, Versatile functionalization and grafting of poly(ε- caprolactone) by Michael-type addition, Chem. Commun. (2005) 274-276. source

  • May combine two claims.

    Interpretationnone given

    Copolymers with a high content of ketone are insoluble in organic solvents, restricting the content of any functional group to low values.

    “Nevertheless, copolymers with a high content of ketone are insoluble in organic solvents, restricting the content of any functional group to low values.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Epoxides are not compatible with tin and aluminum alkoxides, such that they have to be incorporated by postpolymerization oxidation of pendent double bonds, for instance by m-chloroperbenzoic acid (mCPBA).

    “Epoxides are not compatible with tin and aluminum alkoxides, such that they have to be incorporated by postpolymerization oxidation of pendent double bonds, for instance by m-chloroperbenzoic acid (mCPBA) [117][118][119].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [117][118][119]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    αClεCL is copolymerized with εCL in a well-controlled manner, the initiator being a tin(IV) alkoxide.

    “Then, αClεCL is copolymerized with εCL in a well-controlled manner, the initiator being a tin(IV) alkoxide [150].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [150] 150. S. Lenoir, R. Riva, X. Lou, Ch. Detrembleur, R. Jérôme, Ph. Lecomte, Ring-opening polymerization of α-chloro-ε-caprolactone and chemical modification of Poly(α-chloro-ε-caprolactone) by atom transfer radical processes, Macromolecules 37 (2004) 4055-4061. source

  • May combine two claims.

    Premisecitation

    Because aluminum alkoxides can be prepared by reaction of trialkyl aluminum with an alcohol, the variety of alcohols available offers a large choice for the structure of the α end group, including polymerizable end groups of the methacrylate and the norbornenyl types.

    “On the other hand, because aluminum alkoxides can be prepared by reaction of trialkyl aluminum with an alcohol, the variety of alcohols available offers a large choice for the structure of the α end group, including polymerizable end groups of the methacrylate and the norbornenyl types [156,157]”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [156] 156. J.L. Eguiburu, M.J. Fernandez-Berridi, J. San Roman, Ring opening polymerization of L-lactide initiated by oxyethyl methacrylate- aluminum trialkoxides Part 2. End groups exchange, Polymer 41 (2000) 6439-6445. source
    • cites [157] 157. Ph. Dubois, N. Ropson, R. Jérôme, Ph. Teyssié, Macromolecular engineering of polylactones and polylactides. 19. kinetics of ring- opening polymerization of ε-caprolactone initiated with functional aluminum alkoxides, Macromolecules 29 (1996) 1965-1975. source

  • May combine two claims.

    Premisecitation

    In a representative example, poly(αClεCL-co-εCL) (Mn=22,000; Mw/Mn=1.5) was reacted with 5 equivalents of sodium azide in DMF at room temperature overnight; then 5 equivalents of propargyl benzoate were added and the click reaction was quantitative at 35 °C for 3 h; a slight increase in polydispersity index was observed (Mw/Mn=1.7).

    “In a representative example, poly (αClεCL-co-εCL) (Mn=22,000 ; Mw/Mn= 1.5) was reacted with 5 equivalents of sodium azide in DMF at room temperature overnight.5 equivalents of propargyl benzoate were then added to the reaction mixture, and the “click” reaction was quantitative at 35 °C for 3 h.A slight increase in the polydispersity index was observed (Mw/Mn= 1.7).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [153] 153. R. Riva, S. Schmeits, C. Jérôme, R. Jérôme, P. Lecomte, Combination of ring-opening polymerization and "click chemistry": toward functionalization and grafting of Poly(ε-caprolactone), Macromolecules 40 (4) (2007) 796-803. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    Click reaction is actively investigated for macromolecular engineering of aliphatic polyesters.

    “This reaction is actively investigated for macromolecular engineering of aliphatic polyesters.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    α-chlorocyclohexanone is easily converted into parent lactone (αClεCL) by one-step oxidation with m-CPBA with high yield, the chlorine atom of the lactone being activated by proximity of the ester group.

    “α-chlorocyclohexanone is easily converted into the parent lactone (αClεCL) by one-step oxidation with m-CPBA with high yield, the chlorine atom of the lactone being activated by the proximity of the ester group (Scheme 15) [148,149].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [148] 148. R. Riva, S. Lenoir, R. Jérôme, Ph. Lecomte, Functionalization of poly(ε-caprolactone) by pendant hydroxyl, carboxylic acid and epoxide groups by atom transfer radical addition, Polymer 46 (2005) 8511-8518. source
    • cites [149] 149. R. Riva, J. Rieger, R. Jérôme, Ph. Lecomte, Heterograft copolymers of poly(ε-caprolactone) prepared by combination of ATRA "grafting onto" and ATRP "grafting from" processes, J. Polym. Sci., Polym. Chem. 44 (20) (2006) 6015-6024. source

  • May combine two claims.

    Interpretationreasoning

    To be quantitative, higher temperature (85 °C instead of 65 °C) are needed for ATRA, resulting in chains degradation.

    “To be quantitative, higher temperature (85 °C instead of 65 °C) are needed for ATRA, resulting in chains degradation.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    No protection is needed and no chain degradation is observed by SEC in ATRA.

    “Again, no protection is needed and no chain degradation is observed by SEC [148].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [148] 148. R. Riva, S. Lenoir, R. Jérôme, Ph. Lecomte, Functionalization of poly(ε-caprolactone) by pendant hydroxyl, carboxylic acid and epoxide groups by atom transfer radical addition, Polymer 46 (2005) 8511-8518. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Such copolymers are tremendously studied for biomedical applications due to their amphiphilic character and the peculiar properties of the PEO component that makes them unique for injectable DDS.

    “Such copolymers are tremendously studied for biomedical applications due to their amphiphilic character and the peculiar properties of the PEO component that makes them unique for injectable DDS [161].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [161] 161. T. Govender, T. Riley, T. Ehtezazi, M.C. Garnett, S. Stolnik, L. Ilium, S.S. Davis, Defining the drug incorporation properties of PLA- PEG nanoparticles, Int. J. Pharm. 199 (1) (2000) 95-110. source

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Macromolecular engineering provides polyesters with a wide variety of architectures and allows their combination with any other polymers.

    “Macromolecular engineering also provides polyesters with a wide variety of architectures and allows their combination of any other polymers.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Copper catalyzed 1,3-Huisgen's cycloadditions between azides and alkynes are known for quantitative yield, under very mild conditions, from cheap and easily available reagents, and fall in the so-called click reactions.

    “Today, much attention is paid to copper catalyzed 1,3-Huisgen's cycloadditions between azides and alkynes, thus to reactions which are known for quantitative yield, under very mild conditions, from cheap and easily available reagents, i.e. one reaction that falls in the so-called click reactions [151].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [151] 151. V.V. Rostovstev, L.G. Green, V.V. Fokin, K.B. Sharpless, Stepwise cycloaddition process: copper (I) catalyzed regioselective ligation of azides and termival alkynes, Angew. Chem, Int. Ed. 41 (2002) 2596-2599.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    With vinyl acetic acid as olefin, not all chlorinated units are reduced and consequently no ATRA occurs.

    “The situation is even worst when vinyl acetic acid is substituted for 3-buten-1-ol.With this olefin, no all the chlorinated units are reduced and consequently no ATRA occurs.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [149] 149. R. Riva, J. Rieger, R. Jérôme, Ph. Lecomte, Heterograft copolymers of poly(ε-caprolactone) prepared by combination of ATRA "grafting onto" and ATRP "grafting from" processes, J. Polym. Sci., Polym. Chem. 44 (20) (2006) 6015-6024. source

  • May combine two claims.

    Interpretationcitation

    pH-sensitive systems can be built by introduction of an additional pH-responsive block to the structures, leading to emerging smart DDS sensitive to EPR effect for cancer therapy.

    “pH-sensitive systems can also be built by introduction of an additional pH-responsive block to the structures leading to the emerging smart DDS sensitive to EPR effect for cancer therapy [163],”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [163] 163. K. Van Butsele, F. Stoffelbach, R. Jérôme, C. Jérôme, Synthesis of novel amphiphilic and pH-sensitive ABC miktoarm star terpolymers, Macromolecules 39 (17) (2006) 5652-5656. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    Hydrolysis of the alkoxide at the ω-end of polyesters prepared by ROP results in a hydroxyl group that can be used to prepare various macromonomers, e.g. by reaction with acryloyl chloride.

    “As already mentioned, the hydrolysis of the alkoxide at the ω-end of the polyesters prepared by ROP results in the presence of an hydroxyl group that can be used to prepare various macromonomers, e.g. by reaction with acryloyl chloride.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Cycloaddition of both propargyl benzoate mediated by CuI and triethylamine and 3-dimethylaminoethyl-1-propyne mediated by CuI turned out to be quantitative with no significant degradation.

    “Cycloaddition of both propargyl benzoate mediated by Cul and triethylamine (NEt 3 ) and 3-dimethylaminoethyl-1-propyne mediated by Cul turned out to be quantitative with no significant degradation [153] (Scheme 16).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [153] 153. R. Riva, S. Schmeits, C. Jérôme, R. Jérôme, P. Lecomte, Combination of ring-opening polymerization and "click chemistry": toward functionalization and grafting of Poly(ε-caprolactone), Macromolecules 40 (4) (2007) 796-803. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    An additional advantage of click reaction is tolerance towards many organic functions.

    “An additional advantage of this “click” reaction is tolerance towards many organic functions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    This superiority is reinforced by the fact that the additional step, i.e., substitution of chlorides by azides, and the cycloaddition can be carried out in one-pot, thus without isolating the intermediate azide containing copolymer.

    “This superiority is reinforced by the fact that the additional step, i.e., substitution of chlorides by azides, and the cycloaddition can be carried out in one-pot, thus without isolating the intermediate azide containing copolymer.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Emrick et al. reported cycloaddition of an azido-endcapped PEO onto PCL bearing pendent alkynes.

    “Emrick et al. reported on the cycloaddition of an azido-endcapped PEO onto PCL bearing pendent alkynes [152].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [152] 152. B. Parrish, R. Breitenkamp, T. Emrick, PEG-and peptide-grafted aliphatic polyesters by click chemistry, J. Am. Chem. Soc. 127 (2005) 7404-7410. source

  • May combine two claims.

    Premisecitation

    Poly(αClεCL-co-εCL) can be quantitatively converted into azides, followed by click reaction with functional alkynes.

    “Riva et al. described that poly(αClεCL-co-εCL) can be quantitatively converted into azides, followed by “click” reaction with functional alkynes (Scheme 16) [153].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [153] 153. R. Riva, S. Schmeits, C. Jérôme, R. Jérôme, P. Lecomte, Combination of ring-opening polymerization and "click chemistry": toward functionalization and grafting of Poly(ε-caprolactone), Macromolecules 40 (4) (2007) 796-803. source

  • May combine two claims.

    Interpretationreasoning

    Even though click reaction requires an extra step compared to ATRA, it is more effective.

    “Even though the “click reaction” requires an extra step compared to ATRA (comparison of Schemes 15 and 16), it is more effective.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Similar copolymers with functional polyesters are also described.

    “Similar copolymers with functional polyesters are also described [160].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [160] 160. A. Mahmud, X.B. Xiong, A. Lavasanifar, Novel self-associating Poly (ethyleneoxide)-block-poly(ε-caprolactone) block copolymers with functional side groups on the polyester block for drug delivery, Macromolecules 39 (26) (2006) 9419-9428. source

  • May combine two claims.

    Interpretationnone given

    Stoichiometric amount of copper catalyst with respect to activated chlorides, needed in ATRA, contaminates the final polyester and prevents its end-use in biomedical field.

    “Moreover, the stoichiometric amount of the copper catalyst with respect to activated chlorides, which is needed in ATRA, contaminates the final polyester, prevents its end-use in biomedical field.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationnone given

    CuI is used in catalytic amount (0.1 equivalent with respect to azide groups), which is a significant improvement compared to ATRA, which requires a stoichiometric amount of copper catalyst.

    “It is worth noting that Cul is used in catalytic amount (0.1 equivalent with respect to the azide groups), which is a significant improvement compared to ATRA, which requires a stoichiometric amount of copper catalyst.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    PCL-g-PEO were synthesized by reaction of an alkyne end-group of PEO with poly(αN3εCL-co-εCL); grafting efficiency was approximately 30%, in line with yield reported for ATRA, and no degradation was detected.

    “PCL-g-PEO were also synthesized by reaction of an alkyne end-group of PEO (ω-alkyne-PEO) with poly(αN 3 εCL-co-εCL).The grafting efficiency was approximately 30% in line with the yield reported for ATRA.Importantly, no degradation was detected.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [153] 153. R. Riva, S. Schmeits, C. Jérôme, R. Jérôme, P. Lecomte, Combination of ring-opening polymerization and "click chemistry": toward functionalization and grafting of Poly(ε-caprolactone), Macromolecules 40 (4) (2007) 796-803. source

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The spreading development of click chemistry in polymer engineering leads to very rapidly increasing numbers of papers.

    “The spreading development of click chemistry in polymer engineering leads to very rapidly increasing numbers of papers.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    Even if functionalization of aliphatic polyesters is very challenging due to their sensitivity towards degradation, successful strategies have been evidenced and original materials can be synthesized in a highly controlled way.

    “Even if the functionalization of aliphatic polyesters is very challenging due to their sensitivity towards degradation, successful strategies have been evidenced and original materials can be synthesized in a highly controlled way.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    scCO2 technology has been found as a method of choice as far as DDS are concerned.

    “This technology has been found as a method of choice as far as DDS are concerned.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    From quite toxic aluminum and tin initiating systems mainly used in stoichiometric amount, highly reactive rare earth catalysts leading to lower polymer contamination, initiator/catalysts based on friendly metals have been developed.

    “From the quite toxic aluminum and tin initiating systems mainly used in stoichiometric amount, highly reactive rare earth catalysts leading to lower polymer contamination, initiator/catalysts based on friendly metals have been developed.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Lipase catalysis chemoselectively induces ROP of 2-methylene-4-oxa-12-dodecanolide yielding a polyester having the reactive exo-methylene group in the main chain; this polymer cannot be obtained using a conventional chemical initiator.

    “The lipase catalysis chemoselectively induces the ring-opening polymerization of 2-methylene-4-oxa-12-dodecanolide yielding a polyester having the reactive exo-methylene group in the main chain.The present polymer cannot be obtained using a conventional chemical initiator [173].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [173] 173. H. Uyama, S. Kobayashi, M. Morita, S. Habaue, Y. Okamoto, Chemoselective ring-opening polymerization of a lactone having exo- methylene group with lipase catalysis, Macromolecules 34 (2001) 6554-6556. source

  • Classified as probably not a substantial claim.

    Interpretationnone given

    Spreading of non toxic scCO2 technology made possible studies not only on synthesis of aliphatic polyesters in this medium but also on their purification and processing as micro-particles.

    “Simultaneously, the spreading of the non toxic scCO 2 technology made possible studies not only on the synthesis of aliphatic polyesters in this medium but also on their purification and processing as micro-particles.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: scCO2 is non-toxic.

  • May combine two claims.

    Premisecitation

    Polymerization with lipase catalyst successfully yields polymers only through ring-opening process, whereas vinyl groups were further polymerized by anionic and radical initiators to produce a cross-linked polymer gel.

    “Polymerization with the lipase catalyst successfully yields polymers only through the ring-opening process, whereas vinyl groups were further polymerized by anionic and radical initiators to produce a cross-linked polymer gel (Scheme 19) [173,174].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [173] 173. H. Uyama, S. Kobayashi, M. Morita, S. Habaue, Y. Okamoto, Chemoselective ring-opening polymerization of a lactone having exo- methylene group with lipase catalysis, Macromolecules 34 (2001) 6554-6556. source
    • cites [174] 174. S. Habaue, M. Asai, M. Morita, Y. Okammoto, H. Uyama, S. Kobayashi, Chemospecific ring-opening polymerization of α- methylenemacrolides, Polymer 44 (2003) 5195-5200. source

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationreasoning

    These novel materials, even if they have not yet been tested very much in clinical testing, are promising for advanced DDS of tomorrow.

    “These novel materials, even if they have not yet been tested very much in clinical testing are promising for the advanced DDS of tomorrow.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    These requirements have driven the evolution of researches on ROP of aliphatic polyesters.

    “These requirements have driven the evolution of the researches on the ring-opening polymerization of these materials.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Lactones were copolymerized with divinyl esters and glycols using lipase to produce copolyester, not a mixture of homopolymers; two different modes of polymerization, ROP and polycondensation, simultaneously took place through enzymatic polymerization in one-pot to produce the copolyesters.

    “Lactones were also copolymerized with divinyl esters and glycols using lipase to produce the copolyester, not a mixture of homopolymers.Two different modes of polymerization, ring-opening polymerization and polycondensation, simultaneously took place through enzymatic polymerization in one-pot to produce the copolyesters [170].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [170] 170. S. Namekawa, H. Uyama, S. Kobayashi, Enzymatic synthesis of polyesters from lactones, dicarboxylic acid divinyl esters, and glycols through combination of ring-opening polymerization and polycondensation, Biomacromolecules 1 (2000) 335-338.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Interpretationnone given

    Aliphatic polyesters are emerging materials for elaboration of drug delivery systems.

    “Aliphatic polyesters are emerging materials for the elaboration of drug delivery systems.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationnone given

    For demanding applications such as DDS, synthesis of aliphatic polyesters has to avoid use of toxic catalysts and/or initiators and organic solvents that are difficult to remove.

    “For such demanding applications, their synthesis has to avoid the use of toxic catalysts and/or initiators and of organic solvents that are difficult to remove.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Presently, all-organic and enzymatic systems for ROP are the heart of tremendous researches since they are totally metal free.

    “Presently, all-organic and enzymatic systems for ROP are the hart of tremendous researches since they are totally metal free.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    Recent discoveries in disease mechanisms are guidelines for elaboration of novel materials of tailored properties able to build smart DDS with appropriate answer to diseased tissue.

    “Finally, the recent discoveries in disease mechanisms are other guidelines for the elaboration of novel materials of tailored properties able to build smart DDS with the appropriate answer to the diseased tissue.”
    Quote in the paperNot a substantial claim
94 of 94

  • The paper relies on this without support.

    Advanced drug delivery systems require biocompatible materials.

    “Advanced drug delivery systems rely on the availability of biocompatible materials.”

  • The paper relies on this without support.

    Biodegradability is highly desirable in the design of drug delivery systems.

    “Moreover, biodegradability is highly desirable in the design of those systems.”

  • The paper relies on this without support.

    The use of aliphatic polyesters in practical biomedical systems depends on clinical approval and on reproducible synthesis without residual toxics.

    “Nevertheless, their use in practical biomedical systems relies on clinical approval which not only depends on the material itself but also on its reproducible synthesis with the absence of residual toxics.”

  • The paper relies on this without support.

    ROP allows good control of polymer characteristics and is well-suited for macromolecular engineering of aliphatic polyesters.

    “Indeed, this mechanism allows quite good control of the polymer characteristics (i.e., predictable molecular weight, narrow molecular weight distribution) and is particularly well-suited for macromolecular engineering with the production of homo-and copolymers of various architectures (i.e., palm-tree, diblock, multiblock, star) (Scheme 2).”

  • The paper relies on this without support.

    Step-growth polycondensation has major drawbacks: high temperatures and long reaction times favour side reactions, and short deviations from stoichiometry deleteriously affect molecular weight.

    “The major drawbacks of this polycondensation mechanism are the high temperatures and long reaction times generally required that favour the side reactions, together with the deleterious effect on the molecular weight of any short deviation from the reaction stoichiometry.”

  • The paper relies on this without support.

    In favourable cases, ROP of lactones and lactides is a living/controlled process leading to narrow molecular weight distribution with molecular weight predetermined by the monomer-to-initiator molar ratio.

    “In the more favourable cases, the ring-opening polymerization of lactones and lactides is a living/controlled process that leads to polyesters of narrow molecular weight distribution with a molecular weight predetermined by the monomer-to-initiator molar ratio.”

  • The paper relies on this without support.

    Ionic initiators are much reactive and, in polyesters, cause detrimental inter- and intra-molecular transesterification reactions lowering molecular weight and broadening molecular weight distribution.

    “Generally speaking, ionic (non-bulky ion pairs and free ions) initiators are much reactive and, in case of polyesters, are responsible for detrimental inter-and intra-molecular transesterification reactions lowering the molecular weight and broadening the molecular weight distribution of the polymer.”

  • The paper relies on this without support.

    Many organometallic derivatives of metals with d-orbitals of a favourable energy impart control to the polymerization in contrast to their anionic counterparts.

    “Many organometallic derivatives of metals with d-orbitals of a favourable energy, such as Al, Sn, Nd, Y, Yb, Sm, La, Fe, Zn, Zr, Ca, Ti and Mg, are imparting control to the polymerization in contrast to their anionic counter-part.”

  • The paper relies on this without support.

    PLA and PLGA are the most used materials for drug delivery due to their fast and adjustable degradation rate.

    “Among the wide variety of aliphatic polyesters, PLA and PLGA polymers are the most used materials for drug delivery due to their fast and adjustable degradation rate.”

  • The paper relies on this without support.

    Tin octoate and alkoxides are the most widely used organometallic mediators for the ring-opening polymerization of lactones.

    “For the time being, tin octoate and alkoxides were the most widely used organometallic mediators for the ringopening polymerization of lactones even if novel powerful and interesting metal free catalytic systems are emerging as valuable alternatives.”

  • The paper relies on this without support.

    Aluminum alkoxides have high selectivity, which is the major reason for their choice to produce well-defined polyesters for lab studies.

    “The high selectivity of aluminum alkoxides is the major reason for their choice to produce well-defined polyesters for lab studies.”

  • The paper relies on this without support.

    Hydrolysis of the propagating chains systematically results in a ω-hydroxyl end-group.

    “Moreover, the hydrolysis of the propagating chains systematically results in a ω-hydroxyl end-group.”

  • The paper relies on this without support.

    Tin octoate is accepted as a food additive by the US Food and Drug Agency and thus no purification of the polymers is needed for applications such as packaging.

    “It is accepted as a food additive by the US Food and Drug Agency (FDA) and thus no purification of the polymers is needed for applications such as packaging.”

  • The paper relies on this without support.

    Due to tin toxicity, tin octoate has to be avoided in materials used for biomedical application.

    “However, even if tolerated in food regulations, due to tin toxicity, it has to be avoided in materials used for biomedical application.”

  • The paper relies on this without support.

    Rare earth metals have a low level of tolerance in organisms.

    “However, due to low level of tolerance of rare earth metals in the organisms, these catalytic systems are not yet frequently adopted for the preparation of polyesters intended for DDS elaboration.”

  • The paper relies on this without support.

    The availability of aliphatic polyesters uncontaminated with possible toxic metallic residues is essential for biomedical applications.

    “As stressed in the previous sections, the availability of aliphatic polyesters uncontaminated with possible toxic metallic residues is essential for biomedical applications.”

  • The paper relies on this without support.

    Some lipases are known to catalyze (trans)esterification reactions.

    “Some lipases are known to catalyze (trans) esterification reactions.”

  • The paper relies on this without support.

    ε-CL is the most extensively studied lactone with respect to lipase-catalyzed ring-opening polymerization.

    “The seven-membered unsubstituted lactone ε-CL is the most extensively studied with respect to lipase-catalyzed ring-opening polymerization.”

  • The paper relies on this without support.

    Among the available supercritical fluids, supercritical carbon dioxide is the best candidate because of low toxicity, low cost, non-flammability and easily accessible critical parameters.

    “Among the available supercritical fluids, supercritical carbon dioxide (scCO 2 ) is the best candidate because of low toxicity, low cost, non flammability and easily accessible critical parameters (T c =31.4 °C, P c = 73.8bar).”

  • The paper relies on this without support.

    The low solubility of many polymers, including aliphatic polyesters, in scCO2 may be a drawback.

    “The low solubility of many polymers, including aliphatic polyesters, in scCO 2 may be a drawback.”

  • The paper relies on this without support.

    Many polymerizations conducted in scCO2 are precipitation polymerizations, which is less desirable.

    “For example, many polymerization conducted in this medium are precipitation polymerizations which is less desirable.”

  • The paper relies on this without support.

    Plasticization of polymers by scCO2 is beneficial particularly for drug delivery applications because it offers the possibility to incorporate guest molecules under mild conditions.

    “Plasticization of polymers by scCO 2 is also beneficial particularly for drug delivery applications, because it offers the possibility to incorporate guest molecules under mild conditions.”

  • The authors state this as an assumption.

    In the tin(IV) alkoxide-initiated ROP of ε-CL in scCO2, the two alkoxides are active.

    “Nevertheless, the experimental molecular weight increases regularly with conversion and is predetermined by the monomer-to-initiator molar ratio, at least until 20,000 g/mol (Fig. 1), on the assumption that the two alkoxides are active.”

  • The paper relies on this without support.

    scCO2 is non-toxic.

    “Simultaneously, the spreading of the non toxic scCO 2 technology made possible studies not only on the synthesis of aliphatic polyesters in this medium but also on their purification and processing as micro-particles.”

  • The paper relies on this without support.

    The aliphatic polyesters used in drug delivery systems are biodegradable and biocompatible.

    “The previous sections are devoted to the ROP synthesis of the major biodegradable and biocompatible aliphatic polyesters by one-step process from the simplest basic monomers, i.e. ε-caprolactone, lactides and glycolide, all of them being widely used in DDS.”
25 of 25

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • ROP has been the method of choice for the synthesis of tailor-made drug delivery systems where complex architectures and precise molecular weights are essential to their performance.

    “For this reason, ROP has been the method of choice for the synthesis of tailor-made drug delivery systems where complex architectures and precise molecular weights are essential to their performance.269,270”

    From Catalysis as an Enabling Science for Sustainable Polymers (2018) · cites this paper as [270]

  • A variety of initiator/catalyst systems have been developed for ROP of cyclic esters and carbonates.

    “A variety of initiator/catalyst systems have been developed for ROP of cyclic esters and carbonates.268,270”

    From Catalysis as an Enabling Science for Sustainable Polymers (2018) · cites this paper as [270]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Duplicate citation names different solvent isomers

    Minor

    References 40 and 58 identify what appears to be the same article by its authors, journal, year, volume and pages, but give different tetrafluoroethane isomers in its title.

1 of 1

Cites

Flagged first, then by citations

1 of the 169 references couldn’t be matched to a known paper.

Research works printed but not linked: 1

  1. [97]97. S. Slomkowski, Polyester nano-and micro-particles by polymerization and by self-assembly of macromolecules, in: A.J. Domb, Y. Tabata, M.N. V. Ravi Kumar, S. Farber (Eds.), Nanoparticles for Pharmaceutical Applications, 2007, pp. 287-303.

Cited by

Sorted by citations

Related

Authors
JEROME, C., & LECOMTE, P.
Affiliations
University of Liège (BE)
ORCID
LECOMTE, P
Venue
Advanced Drug Delivery Reviews
Publisher
Elsevier BV
Published
2008-06-10
Volume
60
Issue
9
Pages
1056-1076
ISSN
0169-409X (ISSN-L)
DOI
10.1016/j.addr.2008.02.008
OpenAlex
W2043026814
Cited by
590
References
169
Citations by year
2026: 17 · 2025: 24 · 2024: 21 · 2023: 32 · 2022: 37 · 2021: 27 · 2020: 28 · 2019: 40 · 2018: 36 · 2017: 41 · 2016: 40 · 2015: 40 · 2014: 40 · 2013: 37 · 2012: 41
FWCI
1.39
Type
journal article
Language
en
Open access
Licence
www.elsevier.com/tdm/userlicense/1.0/ (tdm)
Locations
  • Advanced Drug Delivery Reviews (publishedVersion)
  • PubMed (publishedVersion)
  • Open Repository and Bibliography (University of Liège) (submittedVersion, other-oa)
Funders
Fonds De La Recherche Scientifique - FNRS
Topics
  • Physical Sciences › Materials Science › Biomaterials › biodegradable polymer synthesis and properties
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmaceutical Science › Advanced Drug Delivery Systems
  • Physical Sciences › Chemistry › Organic Chemistry › Advanced Polymer Synthesis and Characterization
Keywords
aliphatic polyesters, ring-opening polymerization, biodegradable polymers, biomaterials, drug delivery systems, polymerization initiators, catalytic systems, amphiphilic polymers, pH-responsive polymers, macromolecular engineering, hydrolytic degradation
MeSH terms
Carbon Dioxide, Drug Carriers, Polyesters, Technology, Pharmaceutical, Drug Delivery Systems

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-11.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-11.

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