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PreprintCited by 213D Printing in Biomedical ResearchMicrofluidic and Capillary Electrophoresis ApplicationsTissue Engineering and Regenerative Medicine

Gut-liver-axis microphysiological system for studying cellular fluidic shear stress and inter-tissue interaction

Open access
Yang, Jiandong, Hirai, Yoshikazu, Imamura, Satoshi, Tsuchiya, Toshiyuki, Tabata, Osamu, Kamei, Ken-ichiro·2022·Biomicrofluidics
DOI 10.1101/2022.01.31.478467PMC PMC9420048

Preprint — published as 10.1063/5.0088232 · Paper page

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Abstract

Gut-liver-axis (GLA) is a fundamental interaction between the gut and liver for maintaining human health. To clarify the physiological and pathological roles of GLA in the human body, a GLA microphysiological system (GLA-MPS) holds great potential. However, in current GLA-MPS, the importance of a physiologically relevant flow for gut and liver cells’ cultivation is not fully addressed. In addition, the integration of individual organ perfusion, circulation flow, and organ tissue functions in a single device has not been achieved. Here, we introduce a GLA-MPS by integrating two cell culture chambers with individually applied perfusion flows and a circulation channel with an on-chip pneumatic micropump under cell culture chambers via a porous membrane for interconnecting them. We analyzed the fluid shear stress (FSS) with computational fluid dynamics simulations and confirmed that the physiologically relevant FSS (i.e., 8 × 10 −3 and 1.2 × 10 −7 dyne cm −2 ) could be applied for the gut (Caco-2) and liver (HepG2) cells, respectively. Under physiologically relevant flow, the Caco-2 and HepG2 cells in the GLA-MPS maintained a cell survival rate of 95% and 92%, respectively; further, they enhanced the expression of functional proteins such as zonula occludens 1 (ZO-1) and albumin (ALB), respectively. Thus, the presented GLA-MPS can be adapted as an advanced in vitro model in a wide range of applications for disease modeling associated with inter-tissue interactions, such as fatty liver diseases.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper presents a four-layer gut-liver-axis microphysiological system (GLA-MPS) that applies separate perfusion flows to Caco-2 gut and HepG2 liver chambers while connecting them by on-chip micropump-driven circulation through a porous membrane. It reports physiologically relevant fluid shear stress, high cell viability, enhanced functional protein expression, and barrier function under optimized flow.

Key findings

  • CFD estimated apical gut FSS of 8 × 10⁻³ to 2 × 10⁻² dyne cm⁻² under 2–5 μL min⁻¹ perfusion, and basal/circulation FSS of 1 × 10⁻⁸ to 1.2 × 10⁻⁷ dyne cm⁻² through a 20-μm-thick porous membrane.
  • After 8 days with circulation flow, Caco-2 and HepG2 cells showed 95% and 92% viability, respectively.
  • ZO-1 expression in Caco-2 increased with gut perfusion at 5 μL min⁻¹ (FSS = 2 × 10⁻² dyne cm⁻²), while albumin expression in HepG2 increased when circulation flow increased from 0 to 61 nL min⁻¹.
  • The micropump produced 22–61 nL min⁻¹ circulation at 1 Hz and 50–150 kPa, giving a 1.5%–9% exchange ratio in 1 min versus approximately 0.25%–1% in other GLA-MPSs; the device required only 1.5 × 10⁴ cells per chamber versus 3 × 10⁵ for 24-well inserts.

Methods

  • The GLA-MPS was fabricated from four PDMS layers plus glass: a cell-culture layer with chambers (5.3 mm × 2 mm × 360 μm), a porous membrane (5-μm holes, 20-μm pitch and thickness), a circulation layer, and a control layer with an on-chip pneumatic micropump.
  • Caco-2 and HepG2 cells were cultured in separate chambers, with gut apical perfusion and closed-loop circulation; readouts included CFD with COMSOL, microbead flow-rate tracing, cell viability assay, immunocytochemistry for ZO-1 and albumin, and FITC-dextran permeability.
  • Statistical analysis used Tukey-Kramer and asymptotic Wilcoxon signed-rank tests; flow-rate measurements are reported as mean ± SD (n = 10), and permeability assay as n = 3.

Limitations

  • The paper states that the device could be improved by integrating organoid structures, by controlling molecular transport gradients across barrier tissues, and by adding TEER sensors with better accuracy and reproducibility; it also notes that the fluorescent dye used for barrier testing might influence cellular functions.
  • Evident from the text: the study used Caco-2 and HepG2 cell lines rather than patient-derived primary cells, and the authors note that primary cells could have patient-to-patient variation; microbiome and other tissue-cell applications are proposed as future work rather than demonstrated here.

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

Integrity signals

Registry

Crossref · 10.1101/2022.01.31.478467

Cites

48 of 48 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

14 of 49 cited sources checked · 5 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    Reported GLA-MPSs showed better predictive capabilities of organ-to-organ interaction compared to normal static cell-culture models.

    “They showed better predictive capabilities of organ to organ interaction, compared to normal static cell-culture models.”
    Quote in the paperSubstantial claim4 of 6 sources checked
    • cites [3] source
    • cites [7] 2020, Cell Syst source

      The Results section ('Interaction between SCFA, gut and liver MPSs') reports that connecting the gut and liver MPSs changed their phenotypes and gene expression relative to studying them in isolation. This supports the claim that the system reveals organ-to-organ interactions, but the paper does not establish better predictive capability than static cell-culture models; its isolation comparison is not identified as a static-culture comparison. Page numbers are unavailable in our copy. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [8] source

      The Results section on bile-acid synthesis reports gut–liver crosstalk in the integrated system, including higher FGF19 in interacting than isolated tissue controls. But those controls were single-tissue MPSs on the same platform, not conventional static cell cultures. The paper does not establish that the system has better predictive capability than static models. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [9] 2020, Lab Chip source
    • cites [10] source

      The section on recent advances in multi-organ models says static in vitro systems cannot capture multi-organ interactions, while BOC systems can reveal responses not observed with conventional models (page unavailable). That supports the general comparison, but our copy does not establish superior predictive capability specifically for the reported GLA-MPSs. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
    • cites [11] 2021, Micromachines source

      The Introduction says multiorgan MPSs can evaluate interorgan interactions in real time and may improve pharmacokinetic predictions. But the paper studies a KIM-Plate, not a system it calls a GLA-MPS, and does not show better predictive capability than static cell-culture models; its static-culture comparison in Results and Discussion §3.1 concerns cell number and morphology. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Gut epithelial cells require physiologically relevant fluid shear stress (FSS) from the perfusion flow to express their organ cell functions.

    “Practically gut epithelial cells require physiological relevant fluid shear stress (FSS) from the perfusion flow, to express their organ cell functions.14,15”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [14] 2018, Cell. Mol. Gastroenterol. Hepatol source

      The Microfluidic Intestine Chip Models section reports improved drug absorption and metabolic enzyme activity in response to apical fluid shear stress. The Mechanically Active Gut Chip Model section also describes intestinal functions under combined flow and peristalsis-like deformation. Neither establishes that fluid shear stress from perfusion is required for gut epithelial cells to express those functions. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [15] 2018, PLoS One source

      In Results and discussion (page not provided), the paper reports that physiologically relevant perfusion shear appeared to induce Mucin-2 production in Caco-2 cells, unlike static Transwell cultures. That supports a role for flow in expressing one intestinal function, but not the broader claim that gut epithelial cells require it to express their organ functions generally; the Introduction also says Caco-2 cells differentiate and form tight monolayers in static Transwells. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Current GLA-MPSs are based on two approaches: the cell-culture insert in microtiter plates and microfluidic devices.

    “The current GLA-MPSs are based on two approaches: the cell-culture insert in the microtiter plates 7,11 and microfluidic devices.12,13”
    Quote in the paperNot a substantial claim4 of 4 sources checked
    • cites [7] 2020, Cell Syst source
    • cites [11] 2021, Micromachines source
    • cites [12] source
    • cites [13] source
  • Findingnone given

    The circulation flow controlled by the micropump performed closed-loop circulation to interconnect the Caco-2 and HepG2 cell-culture chambers via a porous membrane.

    “The circulation flow controlled by micropump performed closed-loop circulation to interconnect the Caco-2 and HepG2 cell-culture chambers via a porous membrane.”
    Quote in the paperSubstantial claim
  • Findingown data

    Caco-2 cells expressed ZO-1 tight junction protein to form the gut barrier.

    “Caco-2 cells expressed ZO-1 tightjunction protein to form the gut barrier (Figure 6a);”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 21
  • May combine two claims. 23
  • The quote only partly states this claim. 1

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

    Premisecitation

    Gut microbiome plays critical roles in pathophysiological scenarios in the gut and can influence other organs such as the liver and the immune system.

    “Gut microbiome 33 plays critical roles in the pathophysiological scenarios in the gut; they can influence other organs such as the liver 34,35 and the immune system 37 .”
    Quote in the paperSubstantial claim1 of 4 sources checked
    • cites [33] 2020, Acta Pharm. Sin. B source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [34] 2019, Hepatol. Commun source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [35] source
    • cites [37] source

      Checked before — its earlier verdict is held back until a new check runs.

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

    Premisecitation

    In cell-culture insert systems, cellular uptake and transport across the cell barrier can be studied with the porous membrane.

    “For the cell-culture insert system, cellular uptake and transport across the cell barrier (e.g., endothelial cells and intestinal epithelial cells) can be studied with the porous membrane;”
    Quote in the paperNot a substantial claim2 of 2 sources checked
    • cites [7] 2020, Cell Syst source

      The STAR Methods describe intestinal epithelial monolayers grown on porous Transwell inserts, and the Results show that the system was used to study short-chain fatty acid passage across the gut barrier and its consumption by the gut model. The cited paper does not establish the sentence’s endothelial-cell example; its barrier experiments concern intestinal epithelium. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [11] 2021, Micromachines source

      Methods §2.6 describes using culture inserts to measure apical-to-basolateral transport in intestinal cells, and Results §3.2 calculates permeability using the membrane surface area. The paper does not show a cellular uptake assay or an endothelial-cell barrier experiment, so those examples extend beyond what it demonstrates. Page numbers are unavailable in our copy. (LLM, conf=0.84)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Premisecitation

    These microfluidic devices can apply only one flow rate for the introduced tissues although the gut and liver require different flow rates to realize their proper functions.

    “for example, we can apply only one flow rate for the introduced tissues although the gut and liver require different flow rates to realize their proper functions.17,18”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [17] 2019, IScience source

      The Results section ('Computer Simulation Predicts Transepithelial Morphogen Gradient'; page unavailable) shows that intestinal epithelial morphogenesis varies with flow rate, supporting the point that flow conditions matter for gut tissue. The paper does not establish that gut and liver require different flow rates, or that a device containing both tissues can apply only one flow rate. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [18] 2017, Lab Chip source

  • May combine two claims.

    Findingreasoning

    Valve 2 is slower than valves 1 and 3, which leads to a peristaltic valve motion to generate output flow in one direction during actuation.

    “Thus, valve 2 is slower than that of valves 1 and 3, which leads to a peristaltic valve motion to generate output flow in one-direction during actuation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    The presented MPS requires only 1.5 × 10^4 cells for each cell culture chamber, which is considerably smaller than 24-well cell culture inserts (3 × 10^5 cells).

    “The presented MPS requires only 1.5 × 10 4 cells for each cell culture chamber, which is considerably smaller than those of the 24-well cell culture inserts (3 × 10 5 cells).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    After culture, Caco-2 and HepG2 cells showed 95% and 92% cell viability, respectively.

    “After the culture, Caco-2 and HepG2 cells showed 95% and 92% cell viability, respectively (Figure 5b).”
    Quote in the paperSubstantial claim

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

    Findingnone given

    Caco-2 intestinal epithelial and HepG2 hepatocyte-like cells are applied to their own physiologically relevant FSSs for enhancing their functions, respectively.

    “The Caco-2 intestinal epithelial and HepG2 hepatocyte-like cells are applied to their own physiologically relevant FSSs for enhancing their functions, respectively.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    The porous membrane separates the cell-culture chamber and circulation channel to perform two different flows; soluble factors are transported via holes.

    “This membrane separates the cell-culture chamber and circulation channel to perform two different flows; soluble factors are transported via holes.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    At a 1-Hz working frequency and working pressure of 50 to 150 kPa, the circulation flow rates were 22 to 61 nL min−1.

    “this gave flow rates from 22 to 61 nL min -1 for circulation at a 1-Hz working frequency.”
    Quote in the paperNot a substantial claim

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

    Findingnone given

    Low-temperature bonding causes less deformation on the PDMS block, which prevents shrinkage and bending, and leads to flat surfaces for multilayer bonding.

    “Low-temperature bonding causes less deformations on the PDMS block, which prevents shrinkage and bending, and leads to flat surfaces for multilayer bonding.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Disruption of GLA functions leads to liver disease progression and gastrointestinal disorders.

    “The disruption of GLA functions leads to liver disease progression and gastrointestinal disorders.4”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] source

  • May combine two claims.

    Premisecitation

    GLA regulates the absorption/prevention of exogenous agents at the gut barrier and metabolic processes in the liver.

    “that regulates the absorption/prevention of exogenous agents at the gut barrier and metabolic processes in the liver.2,3”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [2] 2020, Lab Chip source
    • cites [3] source

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

    Premisecitation

    A number of MPSs as an in vitro GLA model (GLA-MPS) have been reported, such as GLA for metabolism and inflammation axes.

    “Thus far, a number of MPSs as an in vitro GLA model (GLA-MPS) have been reported, such as GLA for metabolism and inflammation axess.3,7- 11”
    Quote in the paperNot a substantial claim0 of 6 sources checked
    • cites [3] source
    • cites [7] 2020, Cell Syst source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [8] source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [9] 2020, Lab Chip source
    • cites [10] source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [11] 2021, Micromachines source

      Checked before — its earlier verdict is held back until a new check runs.

  • Classified as probably not a substantial claim.

    Premisecitation

    The gut-liver-axis (GLA) is a bidirectional interaction between the gut and liver mediated by dietary, genetic, and environmental factors.

    “The gut-liver-axis (GLA) is a bidirectional interaction between the gut and liver mediated by dietary, genetic, and environmental factors, 1”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [1] source

  • May combine two claims.

    Premisecitation

    MPS features are critical to investigate the absorption, distribution, metabolism, excretion, and toxicity (ADME-T) of drug candidates and for disease modeling.

    “These features are critical to investigate the absorption, distribution, metabolism, excretion, and toxicity (ADME-T) of the drug candidate and for disease modeling as well.6”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [6] 2015, Adv. Healthc. Mater source

  • May combine two claims.

    Interpretationreasoning

    Our MPS is not limited to recapitulating only GLA but is also applicable to other organs and the microbiome.

    “Thus, our MPS is not limited to recapitulate only GLA, but it is also applicable to other organs and the microbiome.”
    Quote in the paperNot a substantial claim

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

    Premisecitation

    Gut-on-a-chips integrated with TEER measurements have been reported.

    “Until now, gut-on-a-chips integrated with a TEER measurements have been reported.39,40”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [39] 2021, Electron. Commun. Japan source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [40] source

      Checked before — its earlier verdict is held back until a new check runs.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationnone given

    Flow perfusion conditions should be investigated for each organ's cells.

    “The flow perfusion conditions should be investigated for each organ cells.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    FSS was one of the most important physical factors affecting cell function and morphology.

    “The FSS was one of the most important physical factors affecting the cell function and morphology, 26,18”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [26] source
    • cites [18] 2017, Lab Chip source

  • May combine two claims.

    Interpretationreasoning

    The GLA-MPS allows treating one tissue to induce disease phenotypes and investigating its effects on other tissues.

    “We can treat one of the tissues to induce disease phenotypes and investigate its effects on other tissues.”
    Quote in the paperSubstantial claim

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

    Interpretationreasoning

    An advanced in vitro GLA model requires (i) application of appropriate perfusion flow for the gut and liver, (ii) study of molecular transports across the gut barrier, and (iii) interconnection of the gut and liver to study their interactions within a single microfluidic device.

    “Thus, there is an urgent need to fulfill these requirements for establishing an advanced in vitro GLA model that (i) enables the application of appropriate perfusion flow for the gut and liver, (ii) studies molecular transports across the gut barrier, and (iii) interconnects the gut and liver to study their interactions within a single microfluidic device.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Gut and liver cells have cellular polarity, which should be functionalized in molecular transportation.
    • Rests on an assumption: Circulation flow needs to connect two organs for inter-tissue interactions.

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

    Study design and conductnone given

    The widely used cell lines Caco-2 and HepG2 can provide the standard performance of the presented GLA-MPS.

    “In the present study, we used widely used cell lines (Caco-2 and HepG2) that can provide the standard performance of the presented GLA-MPS.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The circulation flow could be coupled with gut perfusion flow to improve cell function and induce organ-to-organ interaction for cell culture experiments.

    “Therefore, we could couple the circulation flow with gut perfusion flow to improve the cell function and induce the organ to organ interaction for cell culture experiments.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The GLA-MPS device's four-layered planar microfluidic structure allows integration of electrical read-out sensors in cell-culture chambers and circulation channel, enabling real-time and non-invasive monitoring of cell conditions and behaviors during culture and treatments.

    “Owing to this feature, its another advantage is the capability to integrate electrical read-out sensors in cell-culture chambers and circulation channel, which allows monitoring cell conditions and behaviors during cell culture and treatments in a real-time and non-invasive fashion.38”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [38] 2019, iScience source

      Checked before — its earlier verdict is held back until a new check runs.

  • May combine two claims.

    Interpretationown data

    HepG2 cells facilitated hepatic functions such as ALB production by FSS and molecular transport in the circulation channel.

    “These results suggest that HepG2 cells facilitated hepatic functions such as ALB production by FSS, and as a molecular transport in the circulation channel.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisenone given

    Previous GLA-MPSs faced challenges in the control of FSS.

    “but the previous GLA-MPSs faced challenges in the control.”
    Quote in the paperSubstantial claim

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

    Interpretationnone given

    The device is suitable for demonstrating individual accessibility to investigate GLA interaction mediated by IBD and NAFLD.

    “It is also suitable for demonstrating the individual accessibility to investigate the GLA interaction, mediated by IBD and NAFLD.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Effective drugs or treatments for IBD and NAFLD are not available because of the lack of mechanistic insights.

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

    Interpretationnone given

    The device is a more distinctive platform than the current GLA-MPS, resembling the physiological flow perfusion and circulation of in vivo GLA.

    “The device is a more distinctive platform than the current GLA-MPS, resembling the physiological flow perfusion and circulation of in vivo GLA.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The medium contained both autocrine and paracrine factors and facilitated interactions of Caco-2 and HepG2 cells by the circulation flow.

    “Thus, the medium contained both autocrine and paracrine factors and facilitated the interactions of Caco-2 and HepG2 cells by the circulation flow.”
    Quote in the paperSubstantial claim

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

    Interpretationreasoning

    The MPS device allows introduction of other tissue cells such as neurons and investigation of their interactions with the gut microbiome.

    “Instead of liver cells; our MPS device allows the introduction of other tissue cells such as neurons, and we can investigate the interactions with the gut microbiome.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Use of a microfluidic device allows control of perfusion flow in planar compartmentalized chambers and interconnection of two or more tissue cells via a microfluidic channel with an on-chip micropump.

    “In contrast, the use of a microfluidic device allows the control of perfusion flow in the planar compartmentalized chambers and the interconnection of two or more tissue cells via a microfluidic channel with an on-chip micropump.12,13,16”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [12] source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [13] source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [16] 2020, Sensors Actuators A Phys source

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

    Premisenone given

    In cell-culture insert systems, under the porous membrane, a circulation channel could be used to connect two organs as well as apply flow perfusion.

    “under porous membrane, a circulation channel could be used to connect two organs as well as apply flow perfusion;”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisereasoning

    There remain several concerns of flow perfusion control, organ functions, and inter-tissue interaction that need to be addressed for GLA-MPS.

    “However, there remain several concerns of flow perfusion control, organ functions, and inter-tissue interaction that need to be addressed for GLA-MPS.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Because patient-derived primary cells could have large patient-to-patient variations, it is beneficial to obtain standard datasets using commonly used cell lines.

    “Since patient-derived primary cells could have large patient-to-patient variations, it would be beneficial to obtain such standard datasets with the use of commonly used cell lines.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Patient-derived primary cells could have large patient-to-patient variations.

  • May combine two claims.

    Interpretationown data

    Conventional MPSs could not provide these results because of their drawbacks, whereas our MPS showed advantages over conventional MPSs.

    “The conventional MPSs could not provide these results because of the aforementioned drawbacks of MPSs; our MPS showed advantages over the conventional MPSs.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Conventional cell-culture methods have an unsolved challenge to activate in vitro cultured hepatocytes to express their in vivo physiological hepatic functions.

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

    Premisenone given

    Gut and liver cells have different physiologically relevant flow perfusion to be realized via precise flow control in the chip.

    “First, gut and liver cells have different physiologically relevant flow perfusion to be realized via a precise flow control in the chip.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Our approach based on GLA-MPS has the potential for applications in understanding GLA mechanisms associated with individual physiological flow perfusion and multi-organ interactions for disease modeling.

    “Finally, our approach based on GLA-MPS has the potential for applications in understanding the GLA mechanisms associated with individual physiological flow perfusion and multi-organ interactions for disease modeling.”
    Quote in the paperNot a substantial claim

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

    Study design and conductnone given

    In this study, the fluorescent dye used to investigate gut barrier function might also influence cellular functions.

    “In this study, we used a fluorescent dye to investigate gut barrier function; however, the dye might also influence cellular functions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    The mean FSS range for intestinal cells was in the physiologically relevant range and could promote gut cell barrier formation and differentiation.

    “which was in the physiologically relevant range 26,27 and could promote gut cell barrier formation and differentiation process.28,29”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [26] source
    • cites [27] source
    • cites [28] source
    • cites [29] 2019, Biomaterials source
39 of 39

  • The paper relies on this without support.

    Experimental animal models do not yield clear information about GLA because they have a whole set of organs that show complicated interactions in addition to GLA.

    “However, using experimental animal models does not yield clear information about GLA because they have a whole set of organs that show complicated interactions in addition to GLA.”

  • The paper relies on this without support.

    Gut and liver cells have cellular polarity, which should be functionalized in molecular transportation.

    “Second, gut and liver cells have the cellular polarity, which should be functionalized in molecular transportation.”

  • The paper relies on this without support.

    Circulation flow needs to connect two organs for inter-tissue interactions.

    “Third, circulation flow needs to connect two organs for inter-tissue interactions.”

  • The paper relies on this without support.

    MPSs recapitulate pathophysiological conditions in vitro by utilizing micro/nanotechnology approaches for applications in drug discovery.

    “Microphysiological systems (MPSs) or organs-on-chips (OoCs) recapitulate pathophysiological conditions in vitro by utilizing micro/nanotechnology approaches for applications in drug discovery.”

  • The authors state this as an assumption.

    The cell-culture medium is an incompressible and homogeneous Newtonian fluid with conditions similar to water at 37 °C.

    “The cell-culture medium was considered an incompressible and homogeneous Newtonian fluid with conditions similar to water at 37 °C (density: 997 kg m -3 , viscosity: 6.9 × 10 -4 Pa s -1 ).”

  • The authors state this as an assumption.

    A 10-µm-thick layer covering the upper side of the porous membrane with no direct flow across via the interior wall setting models the cell layer.

    “A 10-µmthick layer covered the upper side of the porous membrane with no direct flow across via the interior wall setting to model the cell layer.”

  • The paper relies on this without support.

    The center cross-section along the gut chamber perfusion direction is representative for the CFD calculation.

    “The center cross-section along the gut chamber perfusion direction was used in the calculation;”

  • The paper relies on this without support.

    There are seldom reports of GLA-MPSs used to investigate flow perfusion for cells on the apical side or flow on the basal side.

    “However, so far, there are seldom reports of GLA-MPSs used to investigate the flow perfusion for cells on the apical side or flow on the basal side.”

  • The paper relies on this without support.

    Conventional cell-culture methods have an unsolved challenge to activate in vitro cultured hepatocytes to express their in vivo physiological hepatic functions.

    “The conventional cell-culture methods continue to have an important but unsolved challenge to activate in vitro cultured hepatocytes to express their in vivo physiological hepatic functions.”

  • The paper relies on this without support.

    Effective drugs or treatments for IBD and NAFLD are not available because of the lack of mechanistic insights.

    “Although it is well known that IBD 7 and NAFLD 35 are strongly associated with the gut microbiome, effective drugs or treatments are not available in the market because of the lack of mechanistic insights.”

  • The paper relies on this without support.

    Patient-derived primary cells are limited in their ability to recapitulate patients' pathological conditions in vitro.

    “These cells are limited in their ability to recapitulate the patients' pathological conditions in vitro.”

  • The paper relies on this without support.

    Patient-derived primary cells could have large patient-to-patient variations.

    “Since patient-derived primary cells could have large patient-to-patient variations, it would be beneficial to obtain such standard datasets with the use of commonly used cell lines.”
12 of 12

Cites

Flagged first, then by citations

Research works printed but not linked: 2

  1. 2006, J. Micromechanics Microengineering, 17, 199
  2. 2019, Adv. Biosyst, 3, 1

Cited by

Sorted by citations

Related

Authors
Yang, J., Hirai, Y., Imamura, S., Tsuchiya, T., Tabata, O., & Kamei, K.-I.
Affiliations
  • Kyoto University (JP)
  • Institute for Integrated Cell-Material Sciences, Kyoto University (JP)
  • Shenyang Pharmaceutical University (CN)
ORCID
Venue
Biomicrofluidics
Publisher
openRxiv
Published
2022-02-02
Volume
16
Issue
4
Pages
044113-044113
ISSN
1932-1058 (ISSN-L)
DOI
10.1101/2022.01.31.478467
PMC
PMC9420048
OpenAlex
W4293124489
Semantic Scholar
6fc5556f02f328927dff7663c25580985a77e95b
Cited by
21
References
47
Citations by year
2026: 8 · 2025: 5 · 2024: 6 · 2023: 2
FWCI
0.93
Type
journal article
Language
en
Open access
Locations
  • Biomicrofluidics (publishedVersion)
  • bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Japan Agency for Medical Research and Development (17937667)
  • Ebara Hatakeyama Memorial Foundation
  • Ministry of Education, Culture, Sports, Science and Technology
  • Liaoning Revitalization Talents Program (XLYC1902061)
  • Japan Society for the Promotion of Science (18KK0306, 17H02083, and 21H01728, 19H02572, 21H01728)
Topics
  • Physical Sciences › Engineering › Biomedical Engineering › 3D Printing in Biomedical Research
  • Physical Sciences › Engineering › Biomedical Engineering › Microfluidic and Capillary Electrophoresis Applications
  • Health Sciences › Medicine › Surgery › Tissue Engineering and Regenerative Medicine
Keywords
gut-liver axis, microphysiological systems, fluid shear stress, Caco-2 cells, HepG2 cells, perfusion flow, zonula occludens-1, albumin expression, inflammatory bowel disease, lipopolysaccharide, inducible nitric oxide synthase, in vitro disease model, organ-on-a-chip

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 2026-11-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-11-06.

Cited sources are checked by gpt-6-sol.

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 ›

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