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Streekstra EJ, Keuper-Navis M, van den Heuvel JJMW, van den Broek P, Stommel MWJ, Bervoets S, O'Gorman L, Greupink R, Russel FGM, van de Steeg E, de Wildt SN. Human enteroid monolayers as a potential alternative for Ussing chamber and Caco-2 monolayers to study passive permeability and drug efflux. Eur J Pharm Sci 2024; 201:106877. [PMID: 39154715 DOI: 10.1016/j.ejps.2024.106877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 08/09/2024] [Accepted: 08/10/2024] [Indexed: 08/20/2024]
Abstract
After oral administration, the intestine is the first site of drug absorption, making it a key determinant of the bioavailability of a drug, and hence drug efficacy and safety. Existing non-clinical models of the intestinal barrier in vitro often fail to mimic the barrier and absorption of the human intestine. We explore if human enteroid monolayers are a suitable tool for intestinal absorption studies compared to primary tissue (Ussing chamber) and Caco-2 cells. Bidirectional drug transport was determined in enteroid monolayers, fresh tissue (Ussing chamber methodology) and Caco-2 cells. Apparent permeability (Papp) and efflux ratios for enalaprilat (paracellular), propranolol (transcellular), talinolol (P-glycoprotein (P-gp)) and rosuvastatin (Breast cancer resistance protein (BCRP)) were determined and compared between all three methodologies and across intestinal regions. Bulk RNA sequencing was performed to compare gene expression between enteroid monolayers and primary tissue. All three models showed functional efflux transport by P-gp and BCRP with higher basolateral to apical (B-to-A) transport compared to apical-to-basolateral (A-to-B). B-to-A Papp values were similar for talinolol and rosuvastatin in tissue and enteroids. Paracellular transport of enalaprilat was lower and transcellular transport of propranolol was higher in enteroids compared to tissue. Enteroids appeared show more region- specific gene expression compared to tissue. Fresh tissue and enteroid monolayers both show active efflux by P-gp and BCRP in jejunum and ileum. Hence, the use of enteroid monolayers represents a promising and versatile experimental platform to complement current in vitro models.
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Affiliation(s)
- Eva J Streekstra
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen (Route 137), Nijmegen, the Netherlands; Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, the Netherlands
| | - Marit Keuper-Navis
- Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, the Netherlands; Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, the Netherlands
| | - Jeroen J M W van den Heuvel
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen (Route 137), Nijmegen, the Netherlands
| | - Petra van den Broek
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen (Route 137), Nijmegen, the Netherlands
| | - Martijn W J Stommel
- Department of Surgery, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Sander Bervoets
- Radboudumc Technology Center for Bioinformatics, Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Luke O'Gorman
- Radboudumc Technology Center for Bioinformatics, Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rick Greupink
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen (Route 137), Nijmegen, the Netherlands
| | - Frans G M Russel
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen (Route 137), Nijmegen, the Netherlands
| | - Evita van de Steeg
- Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, the Netherlands
| | - Saskia N de Wildt
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen (Route 137), Nijmegen, the Netherlands; Department of Intensive Care, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Neonatal and Pediatric Intensive Care, Erasmus MC Sophia Children's Hospital, Rotterdam, the Netherlands.
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2
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Streekstra EJ, Keuper-Navis M, van den Heuvel JJWM, van den Broek P, Greupink R, Stommel MWJ, de Boode WP, Botden SMBI, Russel FGM, van de Steeg E, de Wildt SN. The potential of enteroids derived from children and adults to study age-dependent differences in intestinal CYP3A4/5 metabolism. Eur J Pharm Sci 2024; 201:106868. [PMID: 39084538 DOI: 10.1016/j.ejps.2024.106868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 07/12/2024] [Accepted: 07/27/2024] [Indexed: 08/02/2024]
Abstract
Drug metabolism in the intestinal wall affects bioavailability of orally administered drugs and is influenced by age. Hence, it is important to fully understand the drug metabolizing capacity of the gut to predict systemic exposure. The aim of this study was to investigate the potential of enteroids as a tool to study CYP3A4/5 -mediated metabolism in both children and adults. Bioconversion of midazolam, a CYP3A4/5 model substrate, was studied using enteroid monolayers as well as tissue explants in the Ussing chamber, both derived from pediatric [median (range age): 54 weeks (2 days - 13 years), n = 21] and adult (n = 5) tissue. Caco-2 cellular monolayers were employed as controls. In addition, mRNA expression of CYP3A4 was determined in enteroid monolayers (n = 11), tissue (n = 23) and Caco-2 using RT-qPCR. Midazolam metabolism was successfully detected in all enteroid monolayers, as well as in all tissue explants studied in the Ussing chamber, whereas Caco-2 showed no significant metabolite formation. The extracted fraction of midazolam was similar between enteroid monolayers and tissue. The fraction of midazolam extracted increased with age in enteroid monolayers derived from 0 to 70 week old donors. No statistically significant correlation was observed in tissue likely due to high variability observed and the smaller donor numbers included in the study. At the level of gene expression, CYP3A4 increased with age in tissues (n = 32), while this was not reflected in enteroid monolayers (n = 16). Notably, asymmetric metabolite formation was observed in enteroids and tissue, with higher metabolite formation on the luminal side of the barrier. In summary, we demonstrated that enteroids can be used to measure CYP3A4/5 midazolam metabolism, which we show is similar as observed in fresh isolated tissue. This was the case both in children and adults, indicating the potential of enteroids to predict intestinal metabolism. This study provides promising data to further develop enteroids to study drug metabolism in vitro and potentially predict oral absorption for special populations as an alternative to using fresh tissue.
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Affiliation(s)
- Eva J Streekstra
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, the Netherlands
| | - Marit Keuper-Navis
- Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, the Netherlands; Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, the Netherlands
| | - Jeroen J W M van den Heuvel
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Petra van den Broek
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rick Greupink
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Martijn W J Stommel
- Department of Surgery, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Willem P de Boode
- Department of Pediatrics, Division of Neonatology, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, the Netherlands
| | - Sanne M B I Botden
- Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans G M Russel
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Evita van de Steeg
- Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, the Netherlands
| | - Saskia N de Wildt
- Division of Pharmacology and Toxicology, Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Intensive Care, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Neonatal and Pediatric Intensive Care, Erasmus MC Sophia Children's Hospital, Rotterdam, the Netherlands.
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3
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Baas FS, Brusselaers N, Nagtegaal ID, Engstrand L, Boleij A. Navigating beyond associations: Opportunities to establish causal relationships between the gut microbiome and colorectal carcinogenesis. Cell Host Microbe 2024; 32:1235-1247. [PMID: 39146796 DOI: 10.1016/j.chom.2024.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 08/17/2024]
Abstract
The gut microbiota has been recognized as an important determinant in the initiation and progression of colorectal cancer (CRC), with recent studies shining light on the molecular mechanisms that may contribute to the interactions between microbes and the CRC microenvironment. Despite the increasing wealth of associations being established in the field, proving causality remains challenging. Obstacles include the high variability of the microbiome and its context, both across individuals and across time. Additionally, there is a lack of large and representative cohort studies with long-term follow-up and/or appropriate sampling methods for studying the mucosal microbiome. Finally, most studies focus on CRC, whereas interactions between host and bacteria in early events in carcinogenesis remain elusive, reinforced by the heterogeneity of CRC development. Here, we discuss these current most prominent obstacles, the recent developments, and research needs.
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Affiliation(s)
- Floor S Baas
- Department of Pathology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nele Brusselaers
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden; Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Iris D Nagtegaal
- Department of Pathology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lars Engstrand
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden
| | - Annemarie Boleij
- Department of Pathology, Radboud University Medical Center, Nijmegen, the Netherlands.
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Wang H, Kim R, Wang Y, Furtado KL, Sims CE, Tamayo R, Allbritton NL. In vitro co-culture of Clostridium scindens with primary human colonic epithelium protects the epithelium against Staphylococcus aureus. Front Bioeng Biotechnol 2024; 12:1382389. [PMID: 38681959 PMCID: PMC11045926 DOI: 10.3389/fbioe.2024.1382389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/28/2024] [Indexed: 05/01/2024] Open
Abstract
A complex and dynamic network of interactions exists between human gastrointestinal epithelium and intestinal microbiota. Therefore, comprehending intestinal microbe-epithelial cell interactions is critical for the understanding and treatment of intestinal diseases. Primary human colonic epithelial cells derived from a healthy human donor were co-cultured with Clostridium scindens (C. scindens), a probiotic obligate anaerobe; Staphylococcus aureus (S. aureus), a facultative anaerobe and intestinal pathogen; or both bacterial species in tandem. The co-culture hanging basket platform used for these experiments possessed walls of controlled oxygen (O2) permeability to support the formation of an O2 gradient across the intestinal epithelium using cellular O2 consumption, resulting in an anaerobic luminal and aerobic basal compartment. Both the colonic epithelial cells and C. scindens remained viable over 48 h during co-culture. In contrast, co-culture with S. aureus elicited significant damage to colonic epithelial cells within 24 h. To explore the influence of the intestinal pathogen on the epithelium in the presence of the probiotic bacteria, colonic epithelial cells were inoculated sequentially with the two bacterial species. Under these conditions, C. scindens was capable of repressing the production of S. aureus enterotoxin. Surprisingly, although C. scindens converted cholic acid to secondary bile acids in the luminal medium, the growth of S. aureus was not significantly inhibited. Nevertheless, this combination of probiotic and pathogenic bacteria was found to benefit the survival of the colonic epithelial cells compared with co-culture of the epithelial cells with S. aureus alone. This platform thus provides an easy-to-use and low-cost tool to study the interaction between intestinal bacteria and colonic cells in vitro to better understand the interplay of intestinal microbiota with human colonic epithelium.
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Affiliation(s)
- Hao Wang
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Raehyun Kim
- Department of Bioengineering, University of Washington, Seattle, WA, United States
- Department of Biological and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - Yuli Wang
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Kathleen L. Furtado
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, United States
| | - Christopher E. Sims
- Department of Bioengineering, University of Washington, Seattle, WA, United States
- Department of Medicine/Division of Rheumatology, University of Washington, Seattle, WA, United States
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, United States
| | - Nancy L. Allbritton
- Department of Bioengineering, University of Washington, Seattle, WA, United States
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5
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Sarma S, Catella CM, San Pedro ET, Xiao X, Durmusoglu D, Menegatti S, Crook N, Magness ST, Hall CK. Design of 8-mer peptides that block Clostridioides difficile toxin A in intestinal cells. Commun Biol 2023; 6:878. [PMID: 37634026 PMCID: PMC10460389 DOI: 10.1038/s42003-023-05242-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/14/2023] [Indexed: 08/28/2023] Open
Abstract
Infections by Clostridioides difficile, a bacterium that targets the large intestine (colon), impact a large number of people worldwide. Bacterial colonization is mediated by two exotoxins: toxins A and B. Short peptides that can be delivered to the gut and inhibit the biocatalytic activity of these toxins represent a promising therapeutic strategy to prevent and treat C. diff. infection. We describe an approach that combines a Peptide Binding Design (PepBD) algorithm, molecular-level simulations, a rapid screening assay to evaluate peptide:toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block Toxin A in colon epithelial cells. One peptide, SA1, is found to block TcdA toxicity in primary-derived human colon (large intestinal) epithelial cells. SA1 binds TcdA with a KD of 56.1 ± 29.8 nM as measured by surface plasmon resonance (SPR).
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Affiliation(s)
- Sudeep Sarma
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Carly M Catella
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Ellyce T San Pedro
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Xingqing Xiao
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Deniz Durmusoglu
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Stefano Menegatti
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC, 27695, USA
| | - Nathan Crook
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Scott T Magness
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Carol K Hall
- Department of Chemical Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA.
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Sarma S, Catella CM, Pedro ETS, Xiao X, Durmusoglu D, Menegatti S, Crook N, Magness ST, Hall CK. Design of 8-mer Peptides that Block Clostridioides difficile Toxin A in Intestinal Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523493. [PMID: 36711911 PMCID: PMC9882058 DOI: 10.1101/2023.01.10.523493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Clostridioides difficile ( C. diff .) is a bacterium that causes severe diarrhea and inflammation of the colon. The pathogenicity of C. diff . infection is derived from two major toxins, toxins A (TcdA) and B (TcdB). Peptide inhibitors that can be delivered to the gut to inactivate these toxins are an attractive therapeutic strategy. In this work, we present a new approach that combines a pep tide b inding d esign algorithm (PepBD), molecular-level simulations, rapid screening of candidate peptides for toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block the glucosyltransferase activity of TcdA by targeting its glucosyltransferase domain (GTD). Using PepBD and explicit-solvent molecular dynamics simulations, we identified seven candidate peptides, SA1-SA7. These peptides were selected for specific TcdA GTD binding through a custom solid-phase peptide screening system, which eliminated the weaker inhibitors SA5-SA7. The efficacies of SA1-SA4 were then tested using a trans-epithelial electrical resistance (TEER) assay on monolayers of the human gut epithelial culture model. One peptide, SA1, was found to block TcdA toxicity in primary-derived human jejunum (small intestinal) and colon (large intestinal) epithelial cells. SA1 bound TcdA with a K D of 56.1 ± 29.8 nM as measured by surface plasmon resonance (SPR). Significance Statement Infections by Clostridioides difficile , a bacterium that targets the large intestine (colon), impact a significant number of people worldwide. Bacterial colonization is mediated by two exotoxins: toxins A and B. Short peptides that can inhibit the biocatalytic activity of these toxins represent a promising strategy to prevent and treat C. diff . infection. We describe an approach that combines a Peptide B inding D esign (PepBD) algorithm, molecular-level simulations, a rapid screening assay to evaluate peptide:toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block Toxin A in small intestinal and colon epithelial cells. Importantly, our designed peptide, SA1, bound toxin A with nanomolar affinity and blocked toxicity in colon cells.
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Affiliation(s)
- Sudeep Sarma
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Carly M. Catella
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Ellyce T. San Pedro
- Department of Medicine, University of North Carolina at Chapel Hill, NC 27514, United States
| | - Xingqing Xiao
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Deniz Durmusoglu
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Stefano Menegatti
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC 27695, United States
| | - Nathan Crook
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
| | - Scott T. Magness
- Department of Medicine, University of North Carolina at Chapel Hill, NC 27514, United States
| | - Carol K. Hall
- Department of Chemical Engineering, North Carolina State University, Raleigh NC 27695-7905, USA
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Hinman SS, Massaro A, Wang Y, Sims CE, Kim R, Allbritton NL. Suspended Collagen Hydrogels to Replicate Human Colonic Epithelial Cell Interactions with Immune Cells. Adv Biol (Weinh) 2022; 6:e2200129. [PMID: 35773243 PMCID: PMC9691589 DOI: 10.1002/adbi.202200129] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Indexed: 01/28/2023]
Abstract
The human colon plays a critical role in fluid and salt absorption and harbors the largest immune compartment. There is a widespread need for in vitro models of human colon physiology with its innate immune system. A method is described to produce a cassette with a network of struts supporting a suspended, non-chemically cross-linked collagen hydrogel scaffold compatible with the co-culture of primary gastrointestinal epithelium and migratory inflammatory cells. The epithelial monolayer cultured on the suspended collagen possesses a population of polarized and differentiated cells similar to that present in vivo. This epithelial layer displays proper barrier function with a transepithelial electrical resistance (TEER) ≥ 1,500 Ω cm2 and an apparent permeability ≤10-5 cm2 s-1 . Immune cells plated on the basal face of the scaffold transmigrated over a period of 24 h to the epithelial layer in response to epithelial production of IL-8 induced by luminal stimulation of Clostridium difficile Toxin A. These studies demonstrate that this in vitro platform possesses a functional primary colonic epithelial layer with an immune cell compartment capable of recruitment in response to pro-inflammatory cues coming from the epithelium.
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Affiliation(s)
- Samuel S. Hinman
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98105, USA
| | - Angelo Massaro
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98105, USA
| | - Yuli Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98105, USA
| | - Chris E. Sims
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98105, USA
| | - Raehyun Kim
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98105, USA
| | - Nancy L. Allbritton
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98105, USA
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Cai J, Wang J, Sun C, Dai J, Zhang C. Biomaterials with Stiffness Gradient for Interface Tissue Engineering. Biomed Mater 2022; 17. [PMID: 35985317 DOI: 10.1088/1748-605x/ac8b4a] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 08/19/2022] [Indexed: 11/11/2022]
Abstract
Interface tissue engineering is a rapidly growing field that aims to develop engineered tissue alternates with the goal of promoting integration between multiple tissue types. Engineering interface tissues is a complex process, which requires a specialized biomaterials with organized material composition, stiffness, cell types, and signaling molecules. Among these, stiffness-controllable substrates have been developed to investigate the effect of stiffness on cell behavior. Especially these substrates with graded stiffness are advantageous since they allow the differentiation of multiple cell phenotypes and subsequent tissue development. In this review, we highlight the various types of manufacturing techniques that can be leveraged to fabricate scaffolds with stiffness gradient, discuss methods to characterize them, and gradient biomaterials for controlling cellular behavior including attachment, migration, proliferation, and differentiation. We also address fundamentals of interface tissue organization, and stiffness gradient biomaterials for interface tissue regeneration. Potential challenges and future directions in this emerging field are also discussed.
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Affiliation(s)
- Jialun Cai
- Hunan University, #27 Tianma Road, Changsha, Hunan, 410082, CHINA
| | - Junjuan Wang
- Hangzhou Medical College, Binwen Road, Hangzhou, Zhejiang, 310053, CHINA
| | - Chenxuan Sun
- Hunan University, 27# Tianma Road, ChangSha, Hunan, 410000, CHINA
| | - Jianwu Dai
- Institute of Genetics and Developmental Biology Chinese Academy of Sciences, No 1 West Beichen Road, Chaoyang District, Beijing, 100101, Beijing, 100101, CHINA
| | - Can Zhang
- Biomedical Engineering, Hunan University, #27 Tianma Road, Changsha, 410000, CHINA
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Cholon DM, Gentzsch M. Established and novel human translational models to advance cystic fibrosis research, drug discovery, and optimize CFTR-targeting therapeutics. Curr Opin Pharmacol 2022; 64:102210. [DOI: 10.1016/j.coph.2022.102210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/24/2022] [Accepted: 03/07/2022] [Indexed: 12/16/2022]
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Mestril S, Kim R, Hinman SS, Gomez SM, Allbritton NL. Stem/Proliferative and Differentiated Cells within Primary Murine Colonic Epithelium Display Distinct Intracellular Free Ca 2+ Signal Codes. Adv Healthc Mater 2021; 10:e2101318. [PMID: 34510822 PMCID: PMC8599644 DOI: 10.1002/adhm.202101318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/24/2021] [Indexed: 11/11/2022]
Abstract
The second messenger, intracellular free calcium (Ca2+ ), acts to transduce mitogenic and differentiation signals incoming to the colonic epithelium. A self-renewing monolayer of primary murine colonic epithelial cells is formed over a soft, transparent hydrogel matrix for the scalable analysis of intracellular Ca2+ transients. Cultures that are enriched for stem/proliferative cells exhibit repetitive, high frequency (≈25 peaks h-1 ), and short pulse width (≈25 s) Ca2+ transients. Upon cell differentiation the transient frequency declines by 50% and pulse width widens by 200%. Metabolites and growth factors that are known to modulate stem cell proliferation and differentiation through Wnt and Notch signaling pathways, including CHIR-99021, N-[(3,5-Difluorophenyl)acetyl]-L-alanyl-2-phenylglycine-1,1-dimethylethyl ester (DAPT), bone morphogenetic proteins (BMPs), and butyrate, also modulate Ca2+ oscillation patterns in a consistent manner. Increasing the stiffness of the supportive matrix from 200 Pa to 3 GPa shifts Ca2+ transient patterns toward those resembling differentiated cells. The ability to monitor Ca2+ oscillations with the spatial and temporal resolution offered by this platform, combined with its amenability to high-content screens, provides a powerful tool for investigating real-time communication within a wide range of primary tissues in addition to the colonic epithelium.
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Affiliation(s)
- Sebastian Mestril
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, and North Carolina State University, Raleigh, NC, USA
| | - Raehyun Kim
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Samuel S. Hinman
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Shawn M. Gomez
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, and North Carolina State University, Raleigh, NC, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Hirota A, AlMusawi S, Nateri AS, Ordóñez-Morán P, Imajo M. Biomaterials for intestinal organoid technology and personalized disease modeling. Acta Biomater 2021; 132:272-287. [PMID: 34023456 DOI: 10.1016/j.actbio.2021.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/08/2021] [Accepted: 05/07/2021] [Indexed: 12/20/2022]
Abstract
Recent advances in intestinal organoid technologies have paved the way for in vitro recapitulation of the homeostatic renewal of adult tissues, tissue or organ morphogenesis during development, and pathogenesis of many disorders. In vitro modelling of individual patient diseases using organoid systems have been considered key in establishing rational design of personalized treatment strategies and in improving therapeutic outcomes. In addition, the transplantation of organoids into diseased tissues represents a novel approach to treat currently incurable diseases. Emerging evidence from intensive studies suggests that organoid systems' development and functional maturation depends on the presence of an extracellular matrix with suitable biophysical properties, where advanced synthetic hydrogels open new avenues for theoretical control of organoid phenotypes and potential applications of organoids in therapeutic purposes. In this review, we discuss the status, applications, challenges and perspectives of intestinal organoid systems emphasising on hydrogels and their properties suitable for intestinal organoid culture. We provide an overview of hydrogels used for intestinal organoid culture and key factors regulating their biological activity. The comparison of different hydrogels would be a theoretical basis for establishing design principles of synthetic niches directing intestinal cell fates and functions. STATEMENT OF SIGNIFICANCE: Intestinal organoid is an in vitro recapitulation of the gut, which self-organizes from intestinal stem cells and maintains many features of the native tissue. Since the development of this technology, intestinal organoid systems have made significant contribution to rapid progress in intestinal biology. Prevailing methodology for organoid culture, however, depends on animal-derived matrices and suffers from variability and potential risk for contamination of pathogens, limiting their therapeutic application. Synthetic scaffold matrices, hydrogels, might provide solutions to these issues and deepen our understanding on how intestinal cells sense and respond to key biophysical properties of the surrounding matrices. This review provides an overview of developing intestinal models and biomaterials, thereby leading to better understanding of current intestinal organoid systems for both biologists and materials scientists.
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Affiliation(s)
- Akira Hirota
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, N15, W7, Kita-ku, Sapporo 060-8638, Japan
| | - Shaikha AlMusawi
- Cancer Genetic and Stem Cell group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom; Stem Cell biology and Cancer group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom
| | - Abdolrahman S Nateri
- Cancer Genetic and Stem Cell group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom
| | - Paloma Ordóñez-Morán
- Stem Cell biology and Cancer group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom.
| | - Masamichi Imajo
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
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12
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Dutton JS, Hinman SS, Kim R, Attayek PJ, Maurer M, Sims CS, Allbritton NL. Hyperglycemia minimally alters primary self-renewing human colonic epithelial cells while TNFα-promotes severe intestinal epithelial dysfunction. Integr Biol (Camb) 2021; 13:139-152. [PMID: 33989405 PMCID: PMC8204630 DOI: 10.1093/intbio/zyab008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/06/2021] [Accepted: 04/16/2021] [Indexed: 11/15/2022]
Abstract
Hyperglycemia is thought to increase production of inflammatory cytokines and permeability of the large intestine. Resulting intestinal inflammation is then often characterized by excess secretion of tumor necrosis factor alpha (TNFα). Thus, hyperglycemia in hospitalized patients suffering from severe trauma or disease is frequently accompanied by TNFα secretion, and the combined impact of these insults on the intestinal epithelium is poorly understood. This study utilized a simple yet elegant model of the intestinal epithelium, comprised of primary human intestinal stem cells and their differentiated progeny, to investigate the impact of hyperglycemia and inflammatory factors on the colonic epithelium. When compared to epithelium cultured under conditions of physiologic glucose, cells under hyperglycemic conditions displayed decreased mucin-2 (MUC2), as well as diminished alkaline phosphatase (ALP) activity. Conditions of 60 mM glucose potentiated secretion of the cytokine IL-8 suggesting that cytokine secretion during hyperglycemia may be a source of tissue inflammation. TNFα measurably increased secretion of IL-8 and IL-1β, which was enhanced at 60 mM glucose. Surprisingly, intestinal permeability and paracellular transport were not altered by even extreme levels of hyperglycemia. The presence of TNFα increased MUC2 presence, decreased ALP activity, and negatively impacted monolayer barrier function. When TNFα hyperglycemia and ≤30 mM glucose and were combined, MUC2 and ALP activity remained similar to that of TNFα alone, although synergistic effects were seen at 60 mM glucose. An automated image analysis pipeline was developed to assay changes in properties of the zonula occludens-1 (ZO-1)-demarcated cell boundaries. While hyperglycemia alone had little impact on cell shape and size, cell morphologic properties were extraordinarily sensitive to soluble TNFα. These results suggest that TNFα acted as the dominant modulator of the epithelium relative to glucose, and that control of inflammation rather than glucose may be key to maintaining intestinal homeostasis.
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Affiliation(s)
- Johanna S Dutton
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, NC, USA
| | - Samuel S Hinman
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Raehyun Kim
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Peter J Attayek
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, NC, USA
| | - Mallory Maurer
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, NC, USA
| | - Christopher S Sims
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Nancy L Allbritton
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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13
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Kawai T, Mihara Y, Morita M, Ohkubo M, Asami T, Watanabe TM. Quantitation of Cell Membrane Permeability of Cyclic Peptides by Single-Cell Cytoplasm Mass Spectrometry. Anal Chem 2021; 93:3370-3377. [PMID: 33550808 DOI: 10.1021/acs.analchem.0c03901] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cyclic peptides (CPs) have attracted attention as next-generation drugs because they possess both cell-permeable potential as small molecules and specific affinity similar to antibodies. As intracellular molecules are important targets of CPs, quantitation of the intracellular retention and transmembrane permeability of CPs is necessary for drug development. However, permeated CPs within cells cannot be directly assessed by conventional permeability assays using methods such as artificial membranes and cell monolayers. Here, we propose a new approach using single-cell cytoplasm mass spectrometry (SCC-MS). After cells were incubated with CPs, the cytoplasm was directly collected from a single cell using a microneedle followed by nanoelectrospray ionization mass spectrometry detection of the CPs. The height of the CP peak was plotted against time and fitted with a simple function, y = a(1 - e-bx), to calculate the apparent permeability coefficient (Papp) for both the influx and efflux directions. MCF-7 cells were selected as model cancer cells and cultured with cyclosporin A (CsA) and its demethylated analogs (dmCsA-1, -2, and -3) as model CPs. Papp values (10-6 cm/s) obtained from cells incubated with 50 μM CPs ranged from 0.017 to 0.121 for influx and 0.20 to 1.48 for efflux. The higher efflux ratio was possibly caused by efflux transporters such as P-glycoprotein, a well-known receptor of CsA. The equilibrated intracellular concentration of CPs was estimated to be as low as 4.1-6.8 μM, which showed good consistency with the high efflux ratio. SCC-MS is promising as a reliable permeability assay for next-generation CP-based pharmaceuticals.
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Affiliation(s)
- Takayuki Kawai
- RIKEN Center for Biosystems Dynamics Research, Suita, Osaka 565-0874, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yasuhiro Mihara
- Research Headquarters, Taisho Pharmaceutical Co., LTD., Saitama-shi, Saitama 331-9530, Japan
| | - Makiko Morita
- RIKEN Center for Biosystems Dynamics Research, Suita, Osaka 565-0874, Japan
| | - Masahiko Ohkubo
- Research Headquarters, Taisho Pharmaceutical Co., LTD., Saitama-shi, Saitama 331-9530, Japan
| | - Taiji Asami
- Research Headquarters, Taisho Pharmaceutical Co., LTD., Saitama-shi, Saitama 331-9530, Japan
| | - Tomonobu M Watanabe
- RIKEN Center for Biosystems Dynamics Research, Suita, Osaka 565-0874, Japan.,Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima City, Hiroshima 734-8553, Japan
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14
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Hinman SS, Wang Y, Kim R, Allbritton NL. In vitro generation of self-renewing human intestinal epithelia over planar and shaped collagen hydrogels. Nat Protoc 2021; 16:352-382. [PMID: 33299154 PMCID: PMC8420814 DOI: 10.1038/s41596-020-00419-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/23/2020] [Indexed: 12/14/2022]
Abstract
The large intestine, with its array of crypts lining the epithelium and diverse luminal contents, regulates homeostasis throughout the body. In vitro crypts formed from primary human intestinal epithelial stem cells on a 3D shaped hydrogel scaffold replicate the functional and architectural features of in vivo crypts. Collagen scaffolding assembly methods are provided, along with the microfabrication and soft lithography protocols necessary to shape these hydrogels to match the dimensions and density of in vivo crypts. In addition, stem-cell scale-up protocols are provided so that even ultrasmall primary samples can be used as starting material. Initially, these cells are seeded as a proliferative monolayer over the shaped scaffold and cultured as stem/proliferative cells to expand them and cover the scaffold surface with the crypt-shaped structures. To convert these immature crypts into fully polarized, functional units with a basal stem cell niche and luminal differentiated cell zone, stable, linear gradients of growth factors are formed across the crypts. This platform supports the formation of chemical gradients across the crypts, including those of growth and differentiation factors, inflammatory compounds, bile and food metabolites and bacterial products. All microfabrication and device assembly steps are expected to take 8 d, with the primary cells cultured for 12 d to form mature in vitro crypts.
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Affiliation(s)
- Samuel S Hinman
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Yuli Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Raehyun Kim
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Nancy L Allbritton
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
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15
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Virumbrales-Muñoz M, Ayuso JM, Gong MM, Humayun M, Livingston MK, Lugo-Cintrón KM, McMinn P, Álvarez-García YR, Beebe DJ. Microfluidic lumen-based systems for advancing tubular organ modeling. Chem Soc Rev 2020; 49:6402-6442. [PMID: 32760967 PMCID: PMC7521761 DOI: 10.1039/d0cs00705f] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Microfluidic lumen-based systems are microscale models that recapitulate the anatomy and physiology of tubular organs. These technologies can mimic human pathophysiology and predict drug response, having profound implications for drug discovery and development. Herein, we review progress in the development of microfluidic lumen-based models from the 2000s to the present. The core of the review discusses models for mimicking blood vessels, the respiratory tract, the gastrointestinal tract, renal tubules, and liver sinusoids, and their application to modeling organ-specific diseases. We also highlight emerging application areas, such as the lymphatic system, and close the review discussing potential future directions.
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Affiliation(s)
- María Virumbrales-Muñoz
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA
| | - José M Ayuso
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA and Morgridge Institute for Research, Madison, WI, USA
| | - Max M Gong
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA and Department of Biomedical Engineering, Trine University, Angola, IN, USA
| | - Mouhita Humayun
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA
| | - Megan K Livingston
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA
| | - Karina M Lugo-Cintrón
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA
| | - Patrick McMinn
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA
| | - Yasmín R Álvarez-García
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA
| | - David J Beebe
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA. and University of Wisconsin Carbone Cancer Center, Madison, WI, USA and Department of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI, USA
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16
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Toyonaga T, Steinbach EC, Keith BP, Barrow JB, Schaner MR, Wolber EA, Beasley C, Huling J, Wang Y, Allbritton NL, Chaumont N, Sadiq TS, Koruda MJ, Jain A, Long MD, Barnes EL, Herfarth HH, Isaacs KL, Hansen JJ, Shanahan MT, Rahbar R, Furey TS, Sethupathy P, Sheikh SZ. Decreased Colonic Activin Receptor-Like Kinase 1 Disrupts Epithelial Barrier Integrity in Patients With Crohn's Disease. Cell Mol Gastroenterol Hepatol 2020; 10:779-796. [PMID: 32561494 PMCID: PMC7502566 DOI: 10.1016/j.jcmgh.2020.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/09/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Intestinal epithelial cell (IEC) barrier dysfunction is critical to the development of Crohn's disease (CD). However, the mechanism is understudied. We recently reported increased microRNA-31-5p (miR-31-5p) expression in colonic IECs of CD patients, but downstream targets and functional consequences are unknown. METHODS microRNA-31-5p target genes were identified by integrative analysis of RNA- and small RNA-sequencing data from colonic mucosa and confirmed by quantitative polymerase chain reaction in colonic IECs. Functional characterization of activin receptor-like kinase 1 (ACVRL1 or ALK1) in IECs was performed ex vivo using 2-dimensional cultured human primary colonic IECs. The impact of altered colonic ALK1 signaling in CD for the risk of surgery and endoscopic relapse was evaluated by a multivariate regression analysis and a Kaplan-Meier estimator. RESULTS ALK1 was identified as a target of miR-31-5p in colonic IECs of CD patients and confirmed using a 3'-untranslated region reporter assay. Activation of ALK1 restricted the proliferation of colonic IECs in a 5-ethynyl-2-deoxyuridine proliferation assay and down-regulated the expression of stemness-related genes. Activated ALK1 signaling increased colonic IEC differentiation toward colonocytes. Down-regulated ALK1 signaling was associated with increased stemness and decreased colonocyte-specific marker expression in colonic IECs of CD patients compared with healthy controls. Activation of ALK1 enhanced epithelial barrier integrity in a transepithelial electrical resistance permeability assay. Lower colonic ALK1 expression was identified as an independent risk factor for surgery and was associated with a higher risk of endoscopic relapse in CD patients. CONCLUSIONS Decreased colonic ALK1 disrupted colonic IEC barrier integrity and was associated with poor clinical outcomes in CD patients.
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Affiliation(s)
- Takahiko Toyonaga
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Erin C. Steinbach
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina,Division of Rheumatology, Allergy and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Benjamin P. Keith
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina,Department of Genetics, Department of Biology, Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jasmine B. Barrow
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Matthew R. Schaner
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Elisabeth A. Wolber
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Caroline Beasley
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jennifer Huling
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Yuli Wang
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Nancy L. Allbritton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Nicole Chaumont
- Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Timothy S. Sadiq
- Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Mark J. Koruda
- Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Animesh Jain
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Millie D. Long
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Edward L. Barnes
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Hans H. Herfarth
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Kim L. Isaacs
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jonathan J. Hansen
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael T. Shanahan
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Reza Rahbar
- Department of Surgery, Rex Healthcare of Wakefield, North Carolina
| | - Terrence S. Furey
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina,Department of Genetics, Department of Biology, Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Shehzad Z. Sheikh
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina,Correspondence Address correspondence to: Shehzad Z. Sheikh, MD, Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, 7314 Medical Biomolecular Research Building, 111 Mason Farm Road, Chapel Hill, North Carolina 27599. fax: (919) 843-2585.
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17
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Leth Jepsen M, Willumsen A, Mazzoni C, Boisen A, Hagner Nielsen L, Dufva M. 3D Printed Stackable Titer Plate Inserts Supporting Three Interconnected Tissue Models for Drug Transport Studies. ACTA ACUST UNITED AC 2020; 4:e1900289. [DOI: 10.1002/adbi.201900289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/17/2020] [Indexed: 01/06/2023]
Affiliation(s)
- Morten Leth Jepsen
- The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN)Department of Health TechnologyTechnical University of Denmark Ørsteds Plads 345C Kgs. Lyngby 2800 Denmark
| | - Andreas Willumsen
- The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN)Department of Health TechnologyTechnical University of Denmark Ørsteds Plads 345C Kgs. Lyngby 2800 Denmark
| | - Chiara Mazzoni
- The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN)Department of Health TechnologyTechnical University of Denmark Ørsteds Plads 345C Kgs. Lyngby 2800 Denmark
| | - Anja Boisen
- The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN)Department of Health TechnologyTechnical University of Denmark Ørsteds Plads 345C Kgs. Lyngby 2800 Denmark
| | - Line Hagner Nielsen
- The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN)Department of Health TechnologyTechnical University of Denmark Ørsteds Plads 345C Kgs. Lyngby 2800 Denmark
| | - Martin Dufva
- The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN)Department of Health TechnologyTechnical University of Denmark Ørsteds Plads 345C Kgs. Lyngby 2800 Denmark
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18
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Pradhan S, Banda OA, Farino CJ, Sperduto JL, Keller KA, Taitano R, Slater JH. Biofabrication Strategies and Engineered In Vitro Systems for Vascular Mechanobiology. Adv Healthc Mater 2020; 9:e1901255. [PMID: 32100473 PMCID: PMC8579513 DOI: 10.1002/adhm.201901255] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 01/24/2020] [Indexed: 12/17/2022]
Abstract
The vascular system is integral for maintaining organ-specific functions and homeostasis. Dysregulation in vascular architecture and function can lead to various chronic or acute disorders. Investigation of the role of the vascular system in health and disease has been accelerated through the development of tissue-engineered constructs and microphysiological on-chip platforms. These in vitro systems permit studies of biochemical regulation of vascular networks and parenchymal tissue and provide mechanistic insights into the biophysical and hemodynamic forces acting in organ-specific niches. Detailed understanding of these forces and the mechanotransductory pathways involved is necessary to develop preventative and therapeutic strategies targeting the vascular system. This review describes vascular structure and function, the role of hemodynamic forces in maintaining vascular homeostasis, and measurement approaches for cell and tissue level mechanical properties influencing vascular phenomena. State-of-the-art techniques for fabricating in vitro microvascular systems, with varying degrees of biological and engineering complexity, are summarized. Finally, the role of vascular mechanobiology in organ-specific niches and pathophysiological states, and efforts to recapitulate these events using in vitro microphysiological systems, are explored. It is hoped that this review will help readers appreciate the important, but understudied, role of vascular-parenchymal mechanotransduction in health and disease toward developing mechanotherapeutics for treatment strategies.
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Affiliation(s)
- Shantanu Pradhan
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Omar A. Banda
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
| | - Cindy J. Farino
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
| | - John L. Sperduto
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
| | - Keely A. Keller
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
| | - Ryan Taitano
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
| | - John H. Slater
- Department of Biomedical Engineering, University of Delaware, 150 Academy Street, 161 Colburn Lab, Newark, DE, 19716, USA
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, DE 19716, USA
- Delaware Biotechnology Institute, 15 Innovation Way, Newark, DE 19711, USA
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19
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Snyder J, Wang CM, Zhang AQ, Li Y, Luchan J, Hosic S, Koppes R, Carrier RL, Koppes A. Materials and Microenvironments for Engineering the Intestinal Epithelium. Ann Biomed Eng 2020; 48:1916-1940. [DOI: 10.1007/s10439-020-02470-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/27/2020] [Indexed: 12/12/2022]
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20
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Wang Y, Chiang IL, Ohara TE, Fujii S, Cheng J, Muegge BD, Ver Heul A, Han ND, Lu Q, Xiong S, Chen F, Lai CW, Janova H, Wu R, Whitehurst CE, VanDussen KL, Liu TC, Gordon JI, Sibley LD, Stappenbeck TS. Long-Term Culture Captures Injury-Repair Cycles of Colonic Stem Cells. Cell 2019; 179:1144-1159.e15. [PMID: 31708126 PMCID: PMC6904908 DOI: 10.1016/j.cell.2019.10.015] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 07/15/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023]
Abstract
The colonic epithelium can undergo multiple rounds of damage and repair, often in response to excessive inflammation. The responsive stem cell that mediates this process is unclear, in part because of a lack of in vitro models that recapitulate key epithelial changes that occur in vivo during damage and repair. Here, we identify a Hopx+ colitis-associated regenerative stem cell (CARSC) population that functionally contributes to mucosal repair in mouse models of colitis. Hopx+ CARSCs, enriched for fetal-like markers, transiently arose from hypertrophic crypts known to facilitate regeneration. Importantly, we established a long-term, self-organizing two-dimensional (2D) epithelial monolayer system to model the regenerative properties and responses of Hopx+ CARSCs. This system can reenact the "homeostasis-injury-regeneration" cycles of epithelial alterations that occur in vivo. Using this system, we found that hypoxia and endoplasmic reticulum stress, insults commonly present in inflammatory bowel diseases, mediated the cyclic switch of cellular status in this process.
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Affiliation(s)
- Yi Wang
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - I-Ling Chiang
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Takahiro E Ohara
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Satoru Fujii
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Jiye Cheng
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Brian D Muegge
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Aaron Ver Heul
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Nathan D Han
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Qiuhe Lu
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Shanshan Xiong
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Feidi Chen
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Chin-Wen Lai
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Hana Janova
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Renee Wu
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Charles E Whitehurst
- Boehringer Ingelheim Pharmaceuticals, Immunology and Respiratory Disease Research, Ridgefield, CT 06877, USA
| | - Kelli L VanDussen
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Ta-Chiang Liu
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Jeffrey I Gordon
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Thaddeus S Stappenbeck
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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21
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Kim R, Attayek PJ, Wang Y, Furtado KL, Tamayo R, Sims CE, Allbritton NL. An in vitro intestinal platform with a self-sustaining oxygen gradient to study the human gut/microbiome interface. Biofabrication 2019; 12:015006. [PMID: 31519008 PMCID: PMC6933551 DOI: 10.1088/1758-5090/ab446e] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
An oxygen gradient formed along the length of colonic crypts supports stem-cell proliferation at the normoxic crypt base while supporting obligate anaerobe growth in the anoxic colonic lumen. Primary human colonic epithelial cells derived from human gastrointestinal stem cells were cultured within a device possessing materials of tailored oxygen permeability to produce an oxygen-depleted luminal (0.8% ± 0.1% O2) and oxygen-rich basal (11.1% ± 0.5% O2) compartment. This oxygen difference created a stable oxygen gradient across the colonic epithelial cells which remained viable and properly polarized. Facultative and obligate anaerobes Lactobacillus rhamnosus, Bifidobacterium adolescentis, and Clostridium difficile grew readily within the luminal compartment. When formed along the length of an in vitro crypt, the oxygen gradient facilitated cell compartmentalization within the crypt by enhancing confinement of the proliferative cells to the crypt base. This platform provides a simple system to create a physiological oxygen gradient across an intestinal mimic while simultaneously supporting anaerobe co-culture.
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Affiliation(s)
- Raehyun Kim
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, North Carolina
| | - Peter J. Attayek
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, North Carolina
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Kathleen L. Furtado
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina
| | - Christopher E. Sims
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Nancy L. Allbritton
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, North Carolina
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
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22
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Speer JE, Wang Y, Fallon JK, Smith PC, Allbritton NL. Evaluation of human primary intestinal monolayers for drug metabolizing capabilities. J Biol Eng 2019; 13:82. [PMID: 31709009 PMCID: PMC6829970 DOI: 10.1186/s13036-019-0212-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/30/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The intestinal epithelium is a major site of drug metabolism in the human body, possessing enterocytes that house brush border enzymes and phase I and II drug metabolizing enzymes (DMEs). The enterocytes are supported by a porous extracellular matrix (ECM) that enables proper cell adhesion and function of brush border enzymes, such as alkaline phosphatase (ALP) and alanyl aminopeptidase (AAP), phase I DMEs that convert a parent drug to a more polar metabolite by introducing or unmasking a functional group, and phase II DMEs that form a covalent conjugate between a functional group on the parent compound or sequential metabolism of phase I metabolite. In our effort to develop an in vitro intestinal epithelium model, we investigate the impact of two previously described simple and customizable scaffolding systems, a gradient cross-linked scaffold and a conventional scaffold, on the ability of intestinal epithelial cells to produce drug metabolizing proteins as well as to metabolize exogenously added compounds. While the scaffolding systems possess a range of differences, they are most distinguished by their stiffness with the gradient cross-linked scaffold possessing a stiffness similar to that found in the in vivo intestine, while the conventional scaffold possesses a stiffness several orders of magnitude greater than that found in vivo. RESULTS The monolayers on the gradient cross-linked scaffold expressed CYP3A4, UGTs 2B17, 1A1 and 1A10, and CES2 proteins at a level similar to that in fresh crypts/villi. The monolayers on the conventional scaffold expressed similar levels of CYP3A4 and UGTs 1A1 and 1A10 DMEs to that found in fresh crypts/villi but significantly decreased expression of UGT2B17 and CES2 proteins. The activity of CYP3A4 and UGTs 1A1 and 1A10 was inducible in cells on the gradient cross-linked scaffold when the cells were treated with known inducers, whereas the CYP3A4 and UGT activities were not inducible in cells grown on the conventional scaffold. Both monolayers demonstrate esterase activity but the activity measured in cells on the conventional scaffold could not be inhibited with a known CES2 inhibitor. Both monolayer culture systems displayed similar ALP and AAP brush border enzyme activity. When cells on the conventional scaffold were incubated with a yes-associated protein (YAP) inhibitor, CYP3A4 activity was greatly enhanced suggesting that mechano-transduction signaling can modulate drug metabolizing enzymes. CONCLUSIONS The use of a cross-linked hydrogel scaffold for expansion and differentiation of primary human intestinal stem cells dramatically impacts the induction of CYP3A4 and maintenance of UGT and CES drug metabolizing enzymes in vitro making this a superior substrate for enterocyte culture in DME studies. This work highlights the influence of mechanical properties of the culture substrate on protein expression and the activity of drug metabolizing enzymes as a critical factor in developing accurate assay protocols for pharmacokinetic studies using primary intestinal cells. GRAPHICAL ABSTRACT
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Affiliation(s)
- Jennifer E. Speer
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
| | - John K. Fallon
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA and North Carolina State University, Raleigh, NC 27607 USA
| | - Philip C. Smith
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA and North Carolina State University, Raleigh, NC 27607 USA
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, NC 27599, USA and North Carolina State University, Raleigh, NC 27607 USA
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23
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Speer JE, Gunasekara DB, Wang Y, Fallon JK, Attayek PJ, Smith PC, Sims CE, Allbritton NL. Molecular transport through primary human small intestinal monolayers by culture on a collagen scaffold with a gradient of chemical cross-linking. J Biol Eng 2019; 13:36. [PMID: 31061676 PMCID: PMC6487070 DOI: 10.1186/s13036-019-0165-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/08/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The luminal surface of the small intestine is composed of a monolayer of cells overlying a lamina propria comprised of extracellular matrix (ECM) proteins. The ECM provides a porous substrate critical for nutrient exchange and cellular adhesion. The enterocytes within the epithelial monolayer possess proteins such as transporters, carriers, pumps and channels that participate in the movement of drugs, metabolites, ions and amino acids and whose function can be regulated or altered by the properties of the ECM. Here, we characterized expression and function of proteins involved in transport across the human small intestinal epithelium grown on two different culture platforms. One strategy employs a conventional scaffolding method comprised of a thin ECM film overlaying a porous membrane while the other utilizes a thick ECM hydrogel placed on a porous membrane. The thick hydrogel possesses a gradient of chemical cross-linking along its length to provide a softer substrate than that of the ECM film-coated membrane while maintaining mechanical stability. RESULTS The monolayers on both platforms possessed goblet cells and abundant enterocytes and were impermeable to Lucifer yellow and fluorescein-dextran (70 kD) indicating high barrier integrity. Multiple transporter proteins were present in both primary-cell culture formats at levels similar to those present in freshly isolated crypts/villi; however, expression of breast cancer resistance protein (BCRP) and multidrug resistance protein 2 (MRP2) in the monolayers on the conventional scaffold was substantially less than that on the gradient cross-linked scaffold and freshly isolated crypts/villi. Monolayers on the conventional scaffold failed to transport the BCRP substrate prazosin while cells on the gradient cross-linked scaffold successfully transported this drug to better mimic the properties of in vivo small intestine. CONCLUSIONS The results of this comparison highlight the need to create in vitro intestinal transport platforms whose characteristics mimic the in vivo lamina propria in order to accurately recapitulate epithelial function. GRAPHICAL ABSTRACT
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Affiliation(s)
- Jennifer E. Speer
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Dulan B. Gunasekara
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Raleigh, NC 27599 USA
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
| | - John K. Fallon
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Peter J. Attayek
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Raleigh, NC 27599 USA
| | - Philip C. Smith
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Christopher E. Sims
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 USA
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Raleigh, NC 27599 USA
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