Cited by 337Alzheimer's disease research and treatmentsNanoparticle-Based Drug DeliveryTea Polyphenols and Effects

The DOI matches its Crossref record; 83 of the 87 references it cites were found in a registry or an index.

Dual-drug loaded nanoparticles of Epigallocatechin-3-gallate (EGCG)/Ascorbic acid enhance therapeutic efficacy of EGCG in a APPswe/PS1dE9 Alzheimer's disease mice model

Open access

Abstract

Epigallocatechin-3-gallate (EGCG) is a candidate for treatment of Alzheimer's disease (AD) but its inherent instability limits bioavailability and effectiveness. We found that EGCG displayed increased stability when formulated as dual-drug loaded PEGylated PLGA nanoparticles (EGCG/AA NPs). Oral administration of EGCG/AA NPs in mice resulted in EGCG accumulation in all major organs, including the brain. Pharmacokinetic comparison of plasma and brain accumulation following oral administration of free or EGCG/AA NPs showed that, whilst in both cases initial EGCG concentrations were similar, long-term (5–25 h) concentrations were ca. 5 fold higher with EGCG/AA NPs. No evidence was found that EGCG/AA NPs utilised a specific pathway across the blood-brain barrier (BBB). However, EGCG, empty NPs and EGCG/AA NPs all induced tight junction disruption and opened the BBB in vitro and ex vivo. Oral treatment of APPswe/PS1dE9 (APP/PS1) mice, a familial model of AD, with EGCG/AA NPs resulted in a marked increase in synapses, as judged by synaptophysin (SYP) expression, and reduction of neuroinflammation as well as amyloid β (Aβ) plaque burden and cortical levels of soluble and insoluble Aβ(1-42) peptide. These morphological changes were accompanied by significantly enhanced spatial learning and memory. Mechanistically, we propose that stabilisation of EGCG in NPs complexes and a destabilized BBB led to higher therapeutic EGCG concentrations in the brain. Thus EGCG/AA NPs have the potential to be developed as a safe and strategy for the treatment of AD.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1016/j.jconrel.2019.03.010

Cites

83 of 83 references verified0 citation errors · 0 not checkable

Statistics

Figures

Graphical abstract
Graphical abstract CC BY · PubMed Central
Fig. 1 Results of EGCG/AA NPs optimization study. (A) Response surface of size at fixed value of AA 2.5 mg/ml. Optimized value 124.8 ± 5.2 nm. (B) Response surface of PDI at fixed value of AA 2.5 mg/ml. Optimized value 0.054 ± 0.013. (C) Response surface of ZP at fixed value of EGCG 2.5 mg/ml. Optimized value −15.1 ± 1.7 mV. (D) Response surface of EGCG EE at fixed value of AA 2.5 mg/ml. Optimized value 97.1 ± 2.4 (%).
Fig. 1 Results of EGCG/AA NPs optimization study. (A) Response surface of size at fixed value of AA 2.5 mg/ml. Optimized value 124.8 ± 5.2 nm. (B) Response surface of PDI at fixed value of AA 2.5 mg/ml. Optimized value 0.054 ± 0.013. (C) Response surface of ZP at fixed value of EGCG 2.5 mg/ml. Optimized value −15.1 ± 1.7 mV. (D) Response surface of EGCG EE at fixed value of AA 2.5 mg/ml. Optimized value 97.1 ± 2.4 (%).CC BY · PubMed Central
Fig. 2 Stability and in vitro drug release results. (A) Backscattering profile of EGCG/AA NPs at 25 °C showed nanovehicle instability after 4 months. (B) Backscattering profile of EGCG/AA NPs stored at 4 °C did not show any instability for up to 11 months. (C) EGCG chemical stability in different solutions, formulations and storage temperatures. EGCG showed a significant increase in the stability after the addition of AA to the medium and its incorporation into PEGylated PLGA NPs. (D) In vitro drug release of EGCG/AA NPs and free EGCG. In each condition 25 mg of EGCG were dialysed in a total volume of 150 ml. Thus 0.167 mg/ml was 100% of the maximal equilibrium concentration. Cumulative drug release from EGCG/AA NPs at 24 h = 48.6%. Data shown was from triplicate experiments.
Fig. 2 Stability and in vitro drug release results. (A) Backscattering profile of EGCG/AA NPs at 25 °C showed nanovehicle instability after 4 months. (B) Backscattering profile of EGCG/AA NPs stored at 4 °C did not show any instability for up to 11 months. (C) EGCG chemical stability in different solutions, formulations and storage temperatures. EGCG showed a significant increase in the stability after the addition of AA to the medium and its incorporation into PEGylated PLGA NPs. (D) In vitro drug release of EGCG/AA NPs and free EGCG. In each condition 25 mg of EGCG were dialysed in a total volume of 150 ml. Thus 0.167 mg/ml was 100% of the maximal equilibrium concentration. Cumulative drug release from EGCG/AA NPs at 24 h = 48.6%. Data shown was from triplicate experiments.CC BY · PubMed Central
Fig. 3 In vivo biodistribution and pharmacokinetics of EGCG/AA NPs. 3 months-old C57BL/6 WT mice were treated with a single oral dose of EGCG/AA NPs and EGCG/AA NPs-Rho 40 mg/kg. (A) Histograms show biodistribution of EGCG in brain, liver, stomach, intestine, kidneys, heart, lungs and pancreas of mice after 24 h of EGCG/AA NPs administration. Data expressed as EGCG amount per mg of tissue. Mean administered volume of EGCG/AA NPs was 448 μl (1.120 mg). Mean brain EGCG concentration was 0.6 ng/ml. With mean brain weight of 470 mg this represented 0.025% of administered EGCG. (B) Plasma and (C) brain pharmacokinetic profile of EGCG following single oral dose administration of free EGCG or EGCG/AA NPs (40 mg/kg). Data expressed as EGCG amount per ml of plasma and EGCG amount per mg of tissue, respectively. (D) Rhodamine detection in the dentatus gyrus of the hippocampus and the cortex of mice treated with EGCG/AA NPs-Rho (40 mg/kg) or free Rhodamine (2.7 mg/kg). Scale bar 50 μm.
Fig. 3 In vivo biodistribution and pharmacokinetics of EGCG/AA NPs. 3 months-old C57BL/6 WT mice were treated with a single oral dose of EGCG/AA NPs and EGCG/AA NPs-Rho 40 mg/kg. (A) Histograms show biodistribution of EGCG in brain, liver, stomach, intestine, kidneys, heart, lungs and pancreas of mice after 24 h of EGCG/AA NPs administration. Data expressed as EGCG amount per mg of tissue. Mean administered volume of EGCG/AA NPs was 448 μl (1.120 mg). Mean brain EGCG concentration was 0.6 ng/ml. With mean brain weight of 470 mg this represented 0.025% of administered EGCG. (B) Plasma and (C) brain pharmacokinetic profile of EGCG following single oral dose administration of free EGCG or EGCG/AA NPs (40 mg/kg). Data expressed as EGCG amount per ml of plasma and EGCG amount per mg of tissue, respectively. (D) Rhodamine detection in the dentatus gyrus of the hippocampus and the cortex of mice treated with EGCG/AA NPs-Rho (40 mg/kg) or free Rhodamine (2.7 mg/kg). Scale bar 50 μm.CC BY · PubMed Central
Fig. 4 Effect of EGCG formulations on in vitro models (A) Flux of 15, 50, 150 and 500 μg/ml of EGCG/AA NPs-Rho across primary rat BMVECs within the initial 2 h. Data are showed as mean ± SD. At 1440 min values of each data set showed statistical difference to each of the other groups (p < 0.001, ANOVA). (B) FITC-dextran flux across primary rat BMVECs in the presence of 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs and equivalent amounts of empty NPs. Flux rates in the absence of drug were normalised to 1. Data are showed as mean ± SEM. (C) Normalised TEER real time measurement of BMVCEs monolayer in response to 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs and equivalent amounts of empty NPs (added at 2 h). Shown are mean ± SEM. (D) Claudin-5 (green) and DNA (blue) staining of BMVECs monolayer after exposure to 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs and equivalent amounts of empty NPs for 1 h. Scale bar 10 μm. (E) Evans Blue/Albumin leakage response in ex vivo rat brains treated on the indicated side with 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs or equivalent amounts of empty NPs for 1 h. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
Fig. 4 Effect of EGCG formulations on in vitro models (A) Flux of 15, 50, 150 and 500 μg/ml of EGCG/AA NPs-Rho across primary rat BMVECs within the initial 2 h. Data are showed as mean ± SD. At 1440 min values of each data set showed statistical difference to each of the other groups (p < 0.001, ANOVA). (B) FITC-dextran flux across primary rat BMVECs in the presence of 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs and equivalent amounts of empty NPs. Flux rates in the absence of drug were normalised to 1. Data are showed as mean ± SEM. (C) Normalised TEER real time measurement of BMVCEs monolayer in response to 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs and equivalent amounts of empty NPs (added at 2 h). Shown are mean ± SEM. (D) Claudin-5 (green) and DNA (blue) staining of BMVECs monolayer after exposure to 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs and equivalent amounts of empty NPs for 1 h. Scale bar 10 μm. (E) Evans Blue/Albumin leakage response in ex vivo rat brains treated on the indicated side with 1.5, 5, 15, 50, 150 and 500 μg/ml EGCG, EGCG/AA NPs or equivalent amounts of empty NPs for 1 h. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)CC BY · PubMed Central
Fig. 5 Effect of EGCG treatments on SYN expression. 3 months-old APP/PS1 mice were orally treated with EGCG/AA NPs or free EGCG 40 mg/kg/day for 3 months. At 6 months, animals were sacrificed by perfusion with 4% PFA and brains were cut with a cryostat. SYN immunostaining was performed on 20 μm coronal sections. (A) SYN staining of CA3 hippocampus region. Scale bar 50 μm. (B) 3D surface mapping analysis of SYN staining. Interactive 3D surface Plot v 2.4, Image J. Zones with synaptic labeling of the EGCG/AA NPs treated mice exhibited a tridimensional relief and color intensity higher to those of the WT group.
Fig. 5 Effect of EGCG treatments on SYN expression. 3 months-old APP/PS1 mice were orally treated with EGCG/AA NPs or free EGCG 40 mg/kg/day for 3 months. At 6 months, animals were sacrificed by perfusion with 4% PFA and brains were cut with a cryostat. SYN immunostaining was performed on 20 μm coronal sections. (A) SYN staining of CA3 hippocampus region. Scale bar 50 μm. (B) 3D surface mapping analysis of SYN staining. Interactive 3D surface Plot v 2.4, Image J. Zones with synaptic labeling of the EGCG/AA NPs treated mice exhibited a tridimensional relief and color intensity higher to those of the WT group.CC BY · PubMed Central
Fig. 6 Effect of EGCG treatments on neuroinflammation and Aβ plaque/peptide burden. (A) 3 months-old APP/PS1 mice were orally treated with EGCG/AA NPs or free EGCG 40 mg/kg/day for 3 months. At 6 months, animals were sacrificed by perfusion with 4% PFA and brains were cut with a cryostat. GFAP and ThS immunostaining was performed on 20 μm coronal sections. Dentate gyrus of hippocampus and cortex area are shown. Scale bar 100 μm. Images of ThS staining of 100 μm coronal sections of perfused animals were used for Aβ plaques depositions count. Histograms show Aβ plaques depositions count at (B) hippocampus and (C) cortex area. In ELISA kit, animals were sacrificed by cervical dislocation, and brain cortices were homogenized. Histograms show (D) soluble and (E) insoluble amounts of Aβ(1–42) peptide expressed as pg/mg of total protein. ANOVA analysis of data is included in the table S2 of the supplementary material.
Fig. 6 Effect of EGCG treatments on neuroinflammation and Aβ plaque/peptide burden. (A) 3 months-old APP/PS1 mice were orally treated with EGCG/AA NPs or free EGCG 40 mg/kg/day for 3 months. At 6 months, animals were sacrificed by perfusion with 4% PFA and brains were cut with a cryostat. GFAP and ThS immunostaining was performed on 20 μm coronal sections. Dentate gyrus of hippocampus and cortex area are shown. Scale bar 100 μm. Images of ThS staining of 100 μm coronal sections of perfused animals were used for Aβ plaques depositions count. Histograms show Aβ plaques depositions count at (B) hippocampus and (C) cortex area. In ELISA kit, animals were sacrificed by cervical dislocation, and brain cortices were homogenized. Histograms show (D) soluble and (E) insoluble amounts of Aβ(1–42) peptide expressed as pg/mg of total protein. ANOVA analysis of data is included in the table S2 of the supplementary material.CC BY · PubMed Central
Fig. 7 Behavioural tests results. 3 months-old APP/PS1 mice were orally treated with EGCG/AA NPs or free EGCG 40 mg/kg/day for 3 months and then subjected to MWM and NOR tests. (A, B) Histograms shows the escape latency of learning process (statistics at the end of the training phase) (A) and of the test day (B) of WT, non-treated APP/PS1 and treated APP/PS1 mice. (C, D) Histograms show the time expended in the target quadrant (C) and the time expended at border area (D) the test day. (E) Histograms show the time percentage of investigation of the novel object by WT, non-treated APP/PS1 and treated APP/PS1 mice in the NOR test. ANOVA analysis of data is included in the table S3 of the Supplementary material.
Fig. 7 Behavioural tests results. 3 months-old APP/PS1 mice were orally treated with EGCG/AA NPs or free EGCG 40 mg/kg/day for 3 months and then subjected to MWM and NOR tests. (A, B) Histograms shows the escape latency of learning process (statistics at the end of the training phase) (A) and of the test day (B) of WT, non-treated APP/PS1 and treated APP/PS1 mice. (C, D) Histograms show the time expended in the target quadrant (C) and the time expended at border area (D) the test day. (E) Histograms show the time percentage of investigation of the novel object by WT, non-treated APP/PS1 and treated APP/PS1 mice in the NOR test. ANOVA analysis of data is included in the table S3 of the Supplementary material.CC BY · PubMed Central

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

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?

Self-check

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

The self-check needs the paper’s full text.

Citations

Cites

Show all 87 references

Research works printed but not linked: 1

  1. 2009, Development and validation of in vitro release testing methods for semisolid formulations, vol. 10, 1

Cited by

Sorted by citations

See all 337

Metadata

Authors
Cano, A., Ettcheto, M., Chang, J.-H., Barroso, E., Espina, M., Kühne, B. A., Barenys, M., Auladell, C., Folch, J., Souto, E. B., Camins, A., Turowski, P., & García, M. L.
Affiliations
  • Biomedical Research Networking Center on Neurodegenerative Diseases (ES)
  • University College London (GB)
  • Hospital Sant Joan de Déu Barcelona (ES)
  • Institut de Nanociència i Nanotecnologia de la Universitat de Barcelona (ES)
  • Universitat de Barcelona (ES)
  • University of Coimbra (PT)
Corresponding author
  • Turowski, Patric
  • García, Maria Luisa
Venue
Journal of Controlled Release
Publisher
Elsevier BV
Published
2019-05
Volume
301
Pages
62-75
ISSN
0168-3659 (ISSN-L)
OpenAlex
W2920901214
Cited by
337
References
87
Citations by year
2026: 31 · 2025: 55 · 2024: 45 · 2023: 52 · 2022: 58 · 2021: 49 · 2020: 38 · 2019: 8
FWCI
26.22
Type
journal article
Language
en
Open access
Locations
  • Journal of Controlled Release (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Dipòsit Digital de la Universitat de Barcelona (Universitat de Barcelona) (submittedVersion, cc-by-nc-nd)
  • UCL Discovery (University College London) (submittedVersion)
Funders
  • British Heart Foundation (FS/16/26/32193)
  • Ministerio de Ciencia e Innovación (PI2016/01, SAF2017-84283-R, MAT 2014-59134-R, CB06/05/0024)
  • Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas
  • European Regional Development Fund
  • Generalitat de Catalunya (CVE-DOGC-B-14206020-2014)
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Alzheimer's disease research and treatments
  • Physical Sciences › Materials Science › Biomaterials › Nanoparticle-Based Drug Delivery
  • Life Sciences › Agricultural and Biological Sciences › Food Science › Tea Polyphenols and Effects
Keywords
epigallocatechin gallate, vitamin C, Alzheimer's disease, APP/PS1 mice, blood-brain barrier disruption, tight junctions, oral bioavailability, brain accumulation, amyloid-beta, neuroinflammation, synaptophysin, spatial learning and memory, drug stability
MeSH terms
Polylactic Acid-Polyglycolic Acid Copolymer, Alzheimer Disease, Animals, Antioxidants, Ascorbic Acid, Brain, Catechin, Disease Models, Animal, Drug Carriers, Male, Mice, Inbred C57BL, Mice, Transgenic, Polyethylene Glycols, Amyloid beta-Peptides, Endothelial Cells, Rats, Nanoparticles, Drug Liberation

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.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review