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Alver CG, Álvarez-Cubela S, Altilio I, Hutchison E, Warrner E, Viso ME, Vitale G, Oliver D, Pastori RL, Dominguez-Bendala J, Agarwal A. SliceChip: a benchtop fluidic platform for organotypic culture and serial assessment of human and rodent pancreatic slices. LAB ON A CHIP 2024; 24:1557-1572. [PMID: 38205530 PMCID: PMC10939771 DOI: 10.1039/d3lc00850a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Enzymatically isolated pancreatic islets are the most commonly used ex vivo testbeds for diabetes research. Recently, precision-cut living slices of human pancreas are emerging as an exciting alternative because they maintain the complex architecture of the endocrine and exocrine tissues, and do not suffer from the mechanical and chemical stress of enzymatic isolation. We report a fluidic pancreatic SliceChip platform with dynamic environmental controls that generates a warm, oxygenated, and bubble-free fluidic pathway across singular immobilized slices with continuous deliver of fresh media and the ability to perform repeat serial perfusion assessments. A degasser ensures the system remains bubble-free while systemic pressurization with compressed oxygen ensures slice medium remains adequately oxygenated. Computational modeling of perfusion and oxygen dynamics within SliceChip guide the system's physiomimetic culture conditions. Maintenance of the physiological glucose dependent insulin secretion profile across repeat perfusion assessments of individual pancreatic slices kept under physiological oxygen levels demonstrated the culture capacity of our platform. Fluorescent images acquired every 4 hours of transgenic murine pancreatic slices were reliably stable and recoverable over a 5 day period due to the inclusion of a 3D-printed bioinert metallic anchor that maintained slice position within the SliceChip. Our slice on a chip platform has the potential to expand the useability of human pancreatic slices for diabetes pathogenesis and the development of new therapeutic approaches, while also enabling organotypic culture and assessment of other tissue slices such as brain and patient tumors.
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Affiliation(s)
- Charles G Alver
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
- Medical Scientist Training Program, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Silvia Álvarez-Cubela
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Isabella Altilio
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Emily Hutchison
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
| | - Emma Warrner
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
| | - Mariana E Viso
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
| | - Giana Vitale
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
| | - David Oliver
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
| | - Ricardo L Pastori
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Juan Dominguez-Bendala
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Ashutosh Agarwal
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
- Desai Sethi Urology Institute, University of Miami Miller School of Medicine, Miami, FL, USA
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Buemi A, Mourad NI, Ambroise J, Hoton D, Devresse A, Darius T, Kanaan N, Gianello P, Mourad M. Donor- and isolation-related predictive factors of in vitro secretory function of cultured human islets. Front Endocrinol (Lausanne) 2024; 15:1345351. [PMID: 38444584 PMCID: PMC10913008 DOI: 10.3389/fendo.2024.1345351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/01/2024] [Indexed: 03/07/2024] Open
Abstract
Background and aims Human islet preparations designated for research exhibit diverse insulin-secretory profiles. This study aims to assess the impact of donor- and isolation-related factors on in vitro islet secretory function. Methods A retrospective analysis of 46 isolations from 23 pancreata discarded for clinical transplantation was conducted. In vitro islet secretory function tests were performed on Day 1 and Day 7 of culture. Linear mixed-effects models (LMMs) were employed to investigate the relationships between various predictors characterizing the patient and donor characteristics as well as the isolation effectiveness and two functional outcomes including the islet stimulation index (SI) and area under the insulin curve (AUC). Fixed effects were introduced to represent the main effects of each predictor, and backward elimination was utilized to select the most significant fixed effects for the final model. Interaction effects between the timepoint (Day 7 vs. Day 1) and the predictors were also evaluated to assess whether predictors were associated with the temporal evolution of SI and AUC. Fold-change (Fc) values associated with each predictor were obtained by exponentiating the corresponding coefficients of the models, which were built on log-transformed outcomes. Results Analysis using LMMs revealed that donor body mass index (BMI) (Fc = 0.961, 95% CI = 0.927-0.996, p = 0.05), donor gender (female vs. male, Fc = 0.702, 95% CI = 0.524-0.942, p = 0.04), and donor hypertension (Fc = 0.623, 95% CI = 0.466-0.832, p= <0.01) were significantly and independently associated with SI. Moreover, donor gender (Fc = 0.512, 95% CI = 0.302-0.864, p = 0.02), donor cause of death (cerebrovascular accident vs. cardiac arrest, Fc = 2.129, 95% CI = 0.915-4.946, p = 0.09; trauma vs. cardiac arrest, Fc = 2.129, 95% CI = 1.112-7.106, p = 0.04), pancreas weight (Fc = 1.01, 95% CI = 1.001-1.019, p = 0.03), and islet equivalent (IEQ)/mg (Fc = 1.277, 95% CI = 1.088-1.510, p ≤ 0.01) were significantly and independently associated with AUC. There was no predictor significantly associated with the temporal evolution between Day 1 and Day 7 for both SI and AUC outcomes. Conclusion This study identified donor- and isolation-related factors influencing in vitro islet secretory function. Further investigations are essential to validate the applicability of these results in clinical practice.
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Affiliation(s)
- Antoine Buemi
- Department of Surgery, Surgery and Abdominal Transplantation Division, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Nizar I. Mourad
- IREC, Pôle de Chirurgie Expérimentale et Transplantation, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Jérôme Ambroise
- Institute of Experimental and Clinical Research (IREC), Centre de Technologies Moléculaires Appliquées, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Delphine Hoton
- Department of Anatomical Pathology, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Arnaud Devresse
- Department of Surgery, Surgery and Abdominal Transplantation Division, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Tom Darius
- Department of Surgery, Surgery and Abdominal Transplantation Division, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Nada Kanaan
- Department of Internal Medicine, Nephrology Division, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Pierre Gianello
- IREC, Pôle de Chirurgie Expérimentale et Transplantation, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Michel Mourad
- Department of Surgery, Surgery and Abdominal Transplantation Division, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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Omori K, Qi M, Salgado M, Gonzalez N, Hui LT, Chen KT, Rawson J, Miao L, Komatsu H, Isenberg JS, Al-Abdullah IH, Mullen Y, Kandeel F. A scalable human islet 3D-culture platform maintains cell mass and function long-term for transplantation. Am J Transplant 2024; 24:177-189. [PMID: 37813189 DOI: 10.1016/j.ajt.2023.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 09/19/2023] [Accepted: 10/03/2023] [Indexed: 10/11/2023]
Abstract
Present-day islet culture methods provide short-term maintenance of cell viability and function, limiting access to islet transplantation. Attempts to lengthen culture intervals remain unsuccessful. A new method was developed to permit the long-term culture of islets. Human islets were embedded in polysaccharide 3D-hydrogel in cell culture inserts or gas-permeable chambers with serum-free CMRL 1066 supplemented media for up to 8 weeks. The long-term cultured islets maintained better morphology, cell mass, and viability at 4 weeks than islets in conventional suspension culture. In fact, islets cultured in the 3D-hydrogel retained β cell mass and function on par with freshly isolated islets in vitro and, when transplanted into diabetic mice, restored glucose balance similar to fresh islets. Using gas-permeable chambers, the 3D-hydrogel culture method was scaled up over 10-fold and maintained islet viability and function, although the cell mass recovery rate was 50%. Additional optimization of scale-up methods continues. If successful, this technology could afford flexibility and expand access to islet transplantation, especially single-donor islet-after-kidney transplantation.
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Affiliation(s)
- Keiko Omori
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA.
| | - Meirigeng Qi
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Mayra Salgado
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Nelson Gonzalez
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Lauren T Hui
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Kuan-Tsen Chen
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Jeffrey Rawson
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Lynn Miao
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Hirotake Komatsu
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Jeffrey S Isenberg
- Department of Diabetes Complications & Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Ismail H Al-Abdullah
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Yoko Mullen
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Fouad Kandeel
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
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4
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Wang LH, Marfil-Garza BA, Ernst AU, Pawlick RL, Pepper AR, Okada K, Epel B, Viswakarma N, Kotecha M, Flanders JA, Datta AK, Gao HJ, You YZ, Ma M, Shapiro AMJ. Inflammation-induced subcutaneous neovascularization for the long-term survival of encapsulated islets without immunosuppression. Nat Biomed Eng 2023:10.1038/s41551-023-01145-8. [PMID: 38052996 DOI: 10.1038/s41551-023-01145-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/25/2023] [Indexed: 12/07/2023]
Abstract
Cellular therapies for type-1 diabetes can leverage cell encapsulation to dispense with immunosuppression. However, encapsulated islet cells do not survive long, particularly when implanted in poorly vascularized subcutaneous sites. Here we show that the induction of neovascularization via temporary controlled inflammation through the implantation of a nylon catheter can be used to create a subcutaneous cavity that supports the transplantation and optimal function of a geometrically matching islet-encapsulation device consisting of a twisted nylon surgical thread coated with an islet-seeded alginate hydrogel. The neovascularized cavity led to the sustained reversal of diabetes, as we show in immunocompetent syngeneic, allogeneic and xenogeneic mouse models of diabetes, owing to increased oxygenation, physiological glucose responsiveness and islet survival, as indicated by a computational model of mass transport. The cavity also allowed for the in situ replacement of impaired devices, with prompt return to normoglycemia. Controlled inflammation-induced neovascularization is a scalable approach, as we show with a minipig model, and may facilitate the clinical translation of immunosuppression-free subcutaneous islet transplantation.
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Affiliation(s)
- Long-Hai Wang
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Braulio A Marfil-Garza
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
- National Institute of Medical Sciences and Nutrition Salvador Zubiran, Mexico City, Mexico
- Tecnologico de Monterrey, School of Medicine and Health Sciences, Monterrey, Mexico
| | - Alexander U Ernst
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Rena L Pawlick
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Pepper
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Kento Okada
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
- O2M Technologies, LLC, Chicago, IL, USA
| | | | | | | | - Ashim K Datta
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Hong-Jie Gao
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Ye-Zi You
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Minglin Ma
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
| | - A M James Shapiro
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
- Clinical Islet Transplant Program, University of Alberta, Edmonton, Alberta, Canada.
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5
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Le Tran P, Pham TT, Lee HS, Hahn S, Choi JU, Kim JH, Jiang HL, Yook S, Jeong JH. Magnetic resonance imaging of pancreatic islets using tissue-adhesive particles containing iron oxide nanoparticles. J Control Release 2023; 364:37-45. [PMID: 37813125 DOI: 10.1016/j.jconrel.2023.10.008] [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: 05/20/2023] [Revised: 09/13/2023] [Accepted: 10/04/2023] [Indexed: 10/11/2023]
Abstract
Post-transplantation tracking of pancreatic islets is a prerequisite for advancing cell therapy to treat type 1 diabetes. Magnetic resonance imaging (MRI) has emerged as a safe and non-invasive technique for visualizing cells in clinical applications. In this study, we proposed a novel MRI contrast agent formulation by encapsulating iron oxide nanoparticles (IONPs) in poly(lactic-co-glycolic acid) (PLGA) particles functionalized with a tissue adhesive polydopamine (PD) layer (IONP-PLGA-PD MS). Intriguingly, our particles facilitated efficient and robust labeling through a one-step process, allowing for the incorporation of a substantial amount of IONPs without detrimental impacts on the viability and functionality of pancreatic islets. The MRI signals emanating from islets labeled using our particles were found to be stable over 30 days in vitro and 60 days when transplanted under kidney capsules of diabetic mice. These results suggest that our approach provides a potential platform for monitoring the fate of pancreatic islets after transplantation.
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Affiliation(s)
- Phuong Le Tran
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Tung Thanh Pham
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Han Sin Lee
- R&D Center, Cellstormer, Suwon, Gyeonggi 16677, Republic of Korea
| | - Soojung Hahn
- Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 06355, Republic of Korea
| | - Jeong Uk Choi
- College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Jae Hyeon Kim
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Department of Clinical Research Design and Evaluation, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Hu-Lin Jiang
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China; Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, Nanjing 210009, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China; Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, China Pharmaceutical University, Nanjing 210009, China
| | - Simmyung Yook
- College of Pharmacy, Keimyung University, Daegu 42601, Republic of Korea; School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi 16419, Republic of Korea; Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, Gyeonggi 16419, Republic of Korea.
| | - Jee-Heon Jeong
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea; Department of Precision Medicine, School of Medicine, Sungkyunkwan University, Suwon, Gyeonggi 16419, Republic of Korea.
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6
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Paris F, Marrazzo P, Pizzuti V, Marchionni C, Rossi M, Michelotti M, Petrovic B, Ciani E, Simonazzi G, Pession A, Bonsi L, Alviano F. Characterization of Perinatal Stem Cell Spheroids for the Development of Cell Therapy Strategy. Bioengineering (Basel) 2023; 10:bioengineering10020189. [PMID: 36829683 PMCID: PMC9952228 DOI: 10.3390/bioengineering10020189] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Type 1 diabetes mellitus (T1DM) is a complex metabolic disease characterized by a massive loss of insulin-producing cells due to an autoimmune reaction. Currently, daily subcutaneous administration of exogenous insulin is the only effective treatment. Therefore, in recent years considerable interest has been given to stem cell therapy and in particular to the use of three-dimensional (3D) cell cultures to better reproduce in vivo conditions. The goal of this study is to provide a reliable cellular model that could be investigated for regenerative medicine applications for the replacement of insulin-producing cells in T1DM. To pursue this aim we create a co-culture spheroid of amniotic epithelial cells (AECs) and Wharton's jelly mesenchymal stromal cells (WJ-MSCs) in a one-to-one ratio. The resulting co-culture spheroids were analyzed for viability, extracellular matrix production, and hypoxic state in both early- and long-term cultures. Our results suggest that co-culture spheroids are stable in long-term culture and are still viable with a consistent extracellular matrix production evaluated with immunofluorescence staining. These findings suggest that this co-culture may potentially be differentiated into endo-pancreatic cells for regenerative medicine applications in T1DM.
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Affiliation(s)
- Francesca Paris
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
| | - Pasquale Marrazzo
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
- Correspondence: (P.M.); (L.B.)
| | - Valeria Pizzuti
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
| | - Cosetta Marchionni
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
| | - Maura Rossi
- Department of Medical and Surgical Sciences, University of Bologna, 40138 Bologna, Italy
| | - Martina Michelotti
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
| | - Biljana Petrovic
- Department of Medical and Surgical Sciences, University of Bologna, 40138 Bologna, Italy
- Center for Applied Biomedical Research (CRBA), University of Bologna, 40138 Bologna, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Science, University of Bologna, 40126 Bologna, Italy
| | - Giuliana Simonazzi
- Department of Medical and Surgical Sciences, University of Bologna, 40138 Bologna, Italy
- Obstetrics Unit, Department of Obstetrics and Gynecology, IRCCS Azienda Ospedaliero-Universitaria Sant’Orsola, 40138 Bologna, Italy
| | - Andrea Pession
- Pediatric Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy
| | - Laura Bonsi
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
- Correspondence: (P.M.); (L.B.)
| | - Francesco Alviano
- Unit of Histology, Embryology and Applied Biology, Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
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7
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Ernst AU, Wang LH, Worland SC, Marfil-Garza BA, Wang X, Liu W, Chiu A, Kin T, O'Gorman D, Steinschneider S, Datta AK, Papas KK, James Shapiro AM, Ma M. A predictive computational platform for optimizing the design of bioartificial pancreas devices. Nat Commun 2022; 13:6031. [PMID: 36229614 PMCID: PMC9561707 DOI: 10.1038/s41467-022-33760-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 09/30/2022] [Indexed: 11/09/2022] Open
Abstract
The delivery of encapsulated islets or stem cell-derived insulin-producing cells (i.e., bioartificial pancreas devices) may achieve a functional cure for type 1 diabetes, but their efficacy is limited by mass transport constraints. Modeling such constraints is thus desirable, but previous efforts invoke simplifications which limit the utility of their insights. Herein, we present a computational platform for investigating the therapeutic capacity of generic and user-programmable bioartificial pancreas devices, which accounts for highly influential stochastic properties including the size distribution and random localization of the cells. We first apply the platform in a study which finds that endogenous islet size distribution variance significantly influences device potency. Then we pursue optimizations, determining ideal device structures and estimates of the curative cell dose. Finally, we propose a new, device-specific islet equivalence conversion table, and develop a surrogate machine learning model, hosted on a web application, to rapidly produce these coefficients for user-defined devices.
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Affiliation(s)
- Alexander U Ernst
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Long-Hai Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA. .,Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China.
| | - Scott C Worland
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | | | - Xi Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Wanjun Liu
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Alan Chiu
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Tatsuya Kin
- Department of Surgery, University of Alberta, Edmonton, AB, Canada.,Clinical Islet Transplant Program, University of Alberta, Edmonton, AB, Canada
| | - Doug O'Gorman
- Department of Surgery, University of Alberta, Edmonton, AB, Canada.,Clinical Islet Transplant Program, University of Alberta, Edmonton, AB, Canada
| | | | - Ashim K Datta
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | | | - A M James Shapiro
- Department of Surgery, University of Alberta, Edmonton, AB, Canada.,Clinical Islet Transplant Program, University of Alberta, Edmonton, AB, Canada
| | - Minglin Ma
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
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8
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PEGDA microencapsulated allogeneic islets reverse canine diabetes without immunosuppression. PLoS One 2022; 17:e0267814. [PMID: 35613086 PMCID: PMC9132281 DOI: 10.1371/journal.pone.0267814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 04/17/2022] [Indexed: 11/21/2022] Open
Abstract
Background Protection of islets without systemic immunosuppression has been a long-sought goal in the islet transplant field. We conducted a pilot biocompatibility/safety study in healthy dogs followed by a dose-finding efficacy study in diabetic dogs using polyethylene glycol diacrylate (PEGDA) microencapsulated allogeneic canine islets. Methods Prior to the transplants, characterization of the canine islets included the calculations determining the average cell number/islet equivalent. Following measurements of purity, insulin secretion, and insulin, DNA and ATP content, the islets were encapsulated and transplanted interperitoneally into dogs via a catheter, which predominantly attached to the omentum. In the healthy dogs, half of the microspheres injected contained canine islets, the other half of the omentum received empty PEGDA microspheres. Results In the biocompatibility study, healthy dogs received increasing doses of cells up to 1.7 M cells/kg body weight, yet no hypoglycemic events were recorded and the dogs presented with no adverse events. At necropsy the microspheres were identified and described as clear with attachment to the omentum. Several of the blood chemistry values that were abnormal prior to the transplants normalized after the transplant. The same observation was made for the diabetic dogs that received higher doses of canine islets. In all diabetic dogs, the insulin required to attempt to control blood glucose was cut by 50–100% after the transplant, down to no required insulin for the course of the 60-day study. The dogs had no adverse events and behavioral monitoring suggested normal activity after recovery from the transplant. Conclusions and implications The study provides evidence that PEGDA microencapsulated canine islets reversed the signs of diabetes without immunosuppression and led to states of insulin-independence or significantly lowered insulin requirements in the recipients.
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9
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De Toni T, Stock AA, Devaux F, Gonzalez GC, Nunez K, Rubanich JC, Safley SA, Weber CJ, Ziebarth NM, Buchwald P, Tomei AA. Parallel Evaluation of Polyethylene Glycol Conformal Coating and Alginate Microencapsulation as Immunoisolation Strategies for Pancreatic Islet Transplantation. Front Bioeng Biotechnol 2022; 10:886483. [PMID: 35651551 PMCID: PMC9149081 DOI: 10.3389/fbioe.2022.886483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/12/2022] [Indexed: 01/21/2023] Open
Abstract
Pancreatic islet transplantation improves metabolic control and prevents complications in patients with brittle type 1 diabetes (T1D). However, chronic immunosuppression is required to prevent allograft rejection and recurrence of autoimmunity. Islet encapsulation may eliminate the need for immunosuppression. Here, we analyzed in parallel two microencapsulation platforms that provided long-term diabetes reversal in preclinical T1D models, alginate single and double capsules versus polyethylene glycol conformal coating, to identify benefits and weaknesses that could inform the design of future clinical trials with microencapsulated islets. We performed in vitro and in vivo functionality assays with human islets and analyzed the explanted grafts by immunofluorescence. We quantified the size of islets and capsules, measured capsule permeability, and used these data for in silico simulations of islet functionality in COMSOL Multiphysics. We demonstrated that insulin response to glucose stimulation is dependent on capsule size, and the presence of permselective materials augments delays in insulin secretion. Non-coated and conformally coated islets could be transplanted into the fat pad of diabetic mice, resulting in comparable functionality and metabolic control. Mac-2+ cells were found in conformally coated grafts, indicating possible host reactivity. Due to their larger volume, alginate capsules were transplanted in the peritoneal cavity. Despite achieving diabetes reversal, changes in islet composition were found in retrieved capsules, and recipient mice experienced hypoglycemia indicative of hyperinsulinemia induced by glucose retention in large capsules as the in silico model predicted. We concluded that minimal capsule size is critical for physiological insulin secretion, and anti-inflammatory modulation may be beneficial for small conformal capsules.
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Affiliation(s)
- Teresa De Toni
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Aaron A. Stock
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Floriane Devaux
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Grisell C. Gonzalez
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Kailyn Nunez
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Jessica C. Rubanich
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Susan A. Safley
- Department of Surgery, Emory University, Atlanta, GA, United States
| | - Collin J. Weber
- Department of Surgery, Emory University, Atlanta, GA, United States
| | - Noel M. Ziebarth
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Peter Buchwald
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Alice A. Tomei
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
- *Correspondence: Alice A. Tomei,
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10
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Patel SN, Mathews CE, Chandler R, Stabler CL. The Foundation for Engineering a Pancreatic Islet Niche. Front Endocrinol (Lausanne) 2022; 13:881525. [PMID: 35600597 PMCID: PMC9114707 DOI: 10.3389/fendo.2022.881525] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 03/30/2022] [Indexed: 12/01/2022] Open
Abstract
Progress in diabetes research is hindered, in part, by deficiencies in current experimental systems to accurately model human pathophysiology and/or predict clinical outcomes. Engineering human-centric platforms that more closely mimic in vivo physiology, however, requires thoughtful and informed design. Summarizing our contemporary understanding of the unique and critical features of the pancreatic islet can inform engineering design criteria. Furthermore, a broad understanding of conventional experimental practices and their current advantages and limitations ensures that new models address key gaps. Improving beyond traditional cell culture, emerging platforms are combining diabetes-relevant cells within three-dimensional niches containing dynamic matrices and controlled fluidic flow. While highly promising, islet-on-a-chip prototypes must evolve their utility, adaptability, and adoptability to ensure broad and reproducible use. Here we propose a roadmap for engineers to craft biorelevant and accessible diabetes models. Concurrently, we seek to inspire biologists to leverage such tools to ask complex and nuanced questions. The progenies of such diabetes models should ultimately enable investigators to translate ambitious research expeditions from benchtop to the clinic.
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Affiliation(s)
- Smit N. Patel
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Clayton E. Mathews
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, United States
- Diabetes Institute, University of Florida, Gainesville, FL, United States
| | - Rachel Chandler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Cherie L. Stabler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
- Diabetes Institute, University of Florida, Gainesville, FL, United States
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11
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Marfil-Garza BA, Pawlick RL, Szeto J, Kroger C, Tahiliani V, Hefler J, Dadheech N, Seavey MM, Wolf J, Jasuja RR, James Shapiro AM. Tumor necrosis factor receptor superfamily member 25 (TNFRSF25) agonists in islet transplantation: Endogenous in vivo regulatory T cell expansion promotes prolonged allograft survival. Am J Transplant 2022; 22:1101-1114. [PMID: 34965021 DOI: 10.1111/ajt.16940] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 11/30/2021] [Accepted: 12/22/2021] [Indexed: 01/25/2023]
Abstract
Regulatory T cells (Tregs) modulate alloimmune responses and may facilitate minimization or withdrawal of immunosuppression posttransplant. Current approaches, however, rely on complex ex vivo Treg expansion protocols. Herein, we explore endogenous in vivo Treg expansion through antibody-mediated agonistic stimulation of the tumor necrosis factor receptor superfamily member 25 (TNFRSF25) pathway and its potential to prolong graft survival in a mouse model of islet allotransplantation. C57BL/6 male mice were treated with a single dose of TNFRSF25 agonistic antibodies (4C12 or mPTX-35) or IgG control. Diabetes was induced using streptozotocin. Four days later, flow cytometry was completed to corroborate Treg expansion, and 500 islets (CBA/J male mice) were transplanted. Glycemia was assessed thrice weekly until rejection/endpoint. Early intra-graft Treg infiltration was assessed 36 h posttransplant. TNFRSF25 antibodies enabled pronounced Treg expansion and treated mice had significantly prolonged graft survival compared with controls (p < .001). Additionally, the degree of Treg expansion significantly correlated with graft survival (p < .001). Immunohistochemistry demonstrated marked Treg infiltration in long-term surviving grafts; intra-graft Treg infiltration occurred early posttransplant. In conclusion, a single dose of TNFRSF25 antibodies enabled in vivo Treg expansion, which promotes prolonged graft survival. TNFRSF25-mediated in vivo Treg expansion could contribute to achieving lasting immunological tolerance in organ transplantation.
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Affiliation(s)
- Braulio A Marfil-Garza
- Department of Surgery, University of Alberta, Edmonton, Canada.,National Institute of Medical Sciences and Nutrition Salvador Zubiran, Mexico City, Mexico.,CHRISTUS-LatAm Hub - Excellence and Innovation Center, Monterrey, Mexico
| | - Rena L Pawlick
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Jake Szeto
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Charles Kroger
- Heat Biologics, Inc./Pelican Therapeutics, Inc., Morrisville, North Carolina
| | - Vikas Tahiliani
- Heat Biologics, Inc./Pelican Therapeutics, Inc., Morrisville, North Carolina
| | - Joshua Hefler
- Department of Surgery, University of Alberta, Edmonton, Canada
| | | | - Mathew M Seavey
- Heat Biologics, Inc./Pelican Therapeutics, Inc., Morrisville, North Carolina
| | - Jeffrey Wolf
- Heat Biologics, Inc./Pelican Therapeutics, Inc., Morrisville, North Carolina
| | - Rahul R Jasuja
- Heat Biologics, Inc./Pelican Therapeutics, Inc., Morrisville, North Carolina
| | - A M James Shapiro
- Department of Surgery, University of Alberta, Edmonton, Canada.,Clinical Islet Transplant Program, University of Alberta, Edmonton, Canada
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12
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Wang LH, Ernst AU, An D, Datta AK, Epel B, Kotecha M, Ma M. A bioinspired scaffold for rapid oxygenation of cell encapsulation systems. Nat Commun 2021; 12:5846. [PMID: 34615868 PMCID: PMC8494927 DOI: 10.1038/s41467-021-26126-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 09/18/2021] [Indexed: 01/13/2023] Open
Abstract
Inadequate oxygenation is a major challenge in cell encapsulation, a therapy which holds potential to treat many diseases including type I diabetes. In such systems, cellular oxygen (O2) delivery is limited to slow passive diffusion from transplantation sites through the poorly O2-soluble encapsulating matrix, usually a hydrogel. This constrains the maximum permitted distance between the encapsulated cells and host site to within a few hundred micrometers to ensure cellular function. Inspired by the natural gas-phase tracheal O2 delivery system of insects, we present herein the design of a biomimetic scaffold featuring internal continuous air channels endowed with 10,000-fold higher O2 diffusivity than hydrogels. We incorporate the scaffold into a bulk hydrogel containing cells, which facilitates rapid O2 transport through the whole system to cells several millimeters away from the device-host boundary. A computational model, validated by in vitro analysis, predicts that cells and islets maintain high viability even in a thick (6.6 mm) device. Finally, the therapeutic potential of the device is demonstrated through the correction of diabetes in immunocompetent mice using rat islets for over 6 months.
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Affiliation(s)
- Long-Hai Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | | | - Duo An
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Ashim Kumar Datta
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
| | | | - Minglin Ma
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
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13
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Yu X, Zhang P, He Y, Lin E, Ai H, Ramasubramanian MK, Wang Y, Xing Y, Oberholzer J. A Smartphone-Fluidic Digital Imaging Analysis System for Pancreatic Islet Mass Quantification. Front Bioeng Biotechnol 2021; 9:692686. [PMID: 34350161 PMCID: PMC8326521 DOI: 10.3389/fbioe.2021.692686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/06/2021] [Indexed: 11/20/2022] Open
Abstract
Islet beta-cell viability, function, and mass are three decisive attributes that determine the efficacy of human islet transplantation for type 1 diabetes mellitus (T1DM) patients. Islet mass is commonly assessed manually, which often leads to error and bias. Digital imaging analysis (DIA) system has shown its potential as an alternative, but it has some associated limitations. In this study, a Smartphone-Fluidic Digital Imaging Analysis (SFDIA) System, which incorporates microfluidic techniques and Python-based video processing software, was developed for islet mass assessment. We quantified islets by tracking multiple moving islets in a microfluidic channel using the SFDIA system, and we achieved a relatively consistent result. The counts from the SFDIA and manual counting showed an average difference of 2.91 ± 1.50%. Furthermore, our software can analyze and extract key human islet mass parameters, including quantity, size, volume, IEq, morphology, and purity, which are not fully obtainable from traditional manual counting methods. Using SFDIA on a representative islet sample, we measured an average diameter of 99.88 ± 53.91 µm, an average circularity of 0.591 ± 0.133, and an average solidity of 0.853 ± 0.107. Via analysis of dithizone-stained islets using SFDIA, we found that a higher islet tissue percentage is associated with top-layer islets as opposed to middle-layer islets (0.735 ± 0.213 and 0.576 ± 0.223, respectively). Our results indicate that the SFDIA system can potentially be used as a multi-parameter islet mass assay that is superior in accuracy and consistency, when compared to conventional manual techniques.
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Affiliation(s)
- Xiaoyu Yu
- Department of Surgery, University of Virginia, Charlottesville, VA, United States
| | - Pu Zhang
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, United States
| | - Yi He
- Department of Surgery, University of Virginia, Charlottesville, VA, United States
| | - Emily Lin
- Department of Surgery, University of Virginia, Charlottesville, VA, United States
| | - Huiwang Ai
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
| | - Melur K Ramasubramanian
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, United States
| | - Yong Wang
- Department of Surgery, University of Virginia, Charlottesville, VA, United States
| | - Yuan Xing
- Department of Surgery, University of Virginia, Charlottesville, VA, United States
| | - José Oberholzer
- Department of Surgery, University of Virginia, Charlottesville, VA, United States
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14
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Wang LH, Ernst AU, Flanders JA, Liu W, Wang X, Datta AK, Epel B, Kotecha M, Papas KK, Ma M. An inverse-breathing encapsulation system for cell delivery. SCIENCE ADVANCES 2021; 7:eabd5835. [PMID: 33990318 PMCID: PMC8121434 DOI: 10.1126/sciadv.abd5835] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 03/25/2021] [Indexed: 05/04/2023]
Abstract
Cell encapsulation represents a promising therapeutic strategy for many hormone-deficient diseases such as type 1 diabetes (T1D). However, adequate oxygenation of the encapsulated cells remains a challenge, especially in the poorly oxygenated subcutaneous site. Here, we present an encapsulation system that generates oxygen (O2) for the cells from their own waste product, carbon dioxide (CO2), in a self-regulated (i.e., "inverse breathing") way. We leveraged a gas-solid (CO2-lithium peroxide) reaction that was completely separated from the aqueous cellular environment by a gas permeable membrane. O2 measurements and imaging validated CO2-responsive O2 release, which improved cell survival in hypoxic conditions. Simulation-guided optimization yielded a device that restored normoglycemia of immunocompetent diabetic mice for over 3 months. Furthermore, functional islets were observed in scaled-up device implants in minipigs retrieved after 2 months. This inverse breathing device provides a potential system to support long-term cell function in the clinically attractive subcutaneous site.
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Affiliation(s)
- Long-Hai Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | | | | | - Wanjun Liu
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Xi Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Ashim K Datta
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL 60637, USA
| | | | | | - Minglin Ma
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
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15
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Tse HM, Gardner G, Dominguez-Bendala J, Fraker CA. The Importance of Proper Oxygenation in 3D Culture. Front Bioeng Biotechnol 2021; 9:634403. [PMID: 33859979 PMCID: PMC8042214 DOI: 10.3389/fbioe.2021.634403] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/09/2021] [Indexed: 12/15/2022] Open
Abstract
Cell culture typically employs inexpensive, disposable plasticware, and standard humidified CO2/room air incubators (5% CO2, ∼20% oxygen). These methods have historically proven adequate for the maintenance of viability, function, and proliferation of many cell types, but with broad variation in culture practices. With technological advances it is becoming increasingly clear that cell culture is not a “one size fits all” procedure. Recently, there is a shift toward comprehension of the individual physiological niches of cultured cells. As scale-up production of single cell and 3D aggregates for therapeutic applications has expanded, researchers have focused on understanding the role of many environmental metabolites/forces on cell function and viability. Oxygen, due to its role in cell processes and the requirement for adequate supply to maintain critical energy generation, is one such metabolite gaining increased focus. With the advent of improved sensing technologies and computational predictive modeling, it is becoming evident that parameters such as cell seeding density, culture media height, cellular oxygen consumption rate, and aggregate dimensions should be considered for experimental reproducibility. In this review, we will examine the role of oxygen in 3D cell culture with particular emphasis on primary islets of Langerhans and stem cell-derived insulin-producing SC-β cells, both known for their high metabolic demands. We will implement finite element modeling (FEM) to simulate historical and current culture methods in referenced manuscripts and innovations focusing on oxygen distribution. Our group and others have shown that oxygen plays a key role in proliferation, differentiation, and function of these 3D aggregates. Their culture in plastic consistently results in core regions of hypoxia/anoxia exacerbated by increased media height, aggregate dimensions, and oxygen consumption rates. Static gas permeable systems ameliorate this problem. The use of rotational culture and other dynamic culture systems also have advantages in terms of oxygen supply but come with the caveat that these endocrine aggregates are also exquisitely sensitive to mechanical perturbation. As recent work demonstrates, there is a strong rationale for the use of alternate in vitro systems to maintain physio-normal environments for cell growth and function for better phenotypic approximation of in vivo counterparts.
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Affiliation(s)
- Hubert M Tse
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Graeme Gardner
- Department of Surgery, Diabetes Research Institute, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States
| | - Juan Dominguez-Bendala
- Department of Surgery, Diabetes Research Institute, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States.,Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Christopher A Fraker
- Department of Surgery, Diabetes Research Institute, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States
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16
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Alcazar O, Alvarez A, Ricordi C, Linetsky E, Buchwald P. The Effect of Recovery Warm-up Time Following Cold Storage on the Dynamic Glucose-stimulated Insulin Secretion of Isolated Human Islets. Cell Transplant 2021; 29:963689720908278. [PMID: 32223315 PMCID: PMC7444215 DOI: 10.1177/0963689720908278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Standardized islet characterization assays that can provide results in a timely manner are essential for successful islet cell transplantation. A critical component of islet cell quality is β-cell function, and perifusion-based assessments of dynamic glucose-stimulated insulin secretion (GSIS) are the most informative method to assess this, as they provide the most complex in vitro evaluation of GSIS. However, protocols used vary considerably among centers and investigators as they often use different low- and high-glucose concentrations, exposure-times, flow-rates, oxygen concentrations, islet numbers, analytical methods, measurement units, and instruments, which result in different readouts and make comparisons across platforms difficult. Additionally, the conditions of islet storage and shipment prior to assessment may also affect islet function. Establishing improved standardized protocols for perifusion GSIS assays should be an integral part of the ongoing effort to increase the rigor of human islet studies. Here, we performed detailed evaluation of GSIS of human islets using a fully automated multichannel perifusion instrument following various warm-up recovery times after cold storage that corresponds to current shipping conditions (8°C). We found that recovery times shorter than 18 h (overnight) resulted in impaired insulin secretion. While the effects were relatively moderate on second-phase insulin secretion, first-phase peaks were restored only following 18-h incubation. Hence, the biphasic profile of dynamic GSIS was considerably affected when islets were not allowed to recover for a sufficient time after being maintained in cold. Accordingly, while cold storage might improve islet cell survival during shipment and prolong the length of culture, functional assessments should be performed only after allowing for at least overnight recovery at physiological temperatures.
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Affiliation(s)
- Oscar Alcazar
- Diabetes Research Institute, Miller School of Medicine, University of Miami, FL, USA
| | - Alejandro Alvarez
- Diabetes Research Institute, Miller School of Medicine, University of Miami, FL, USA
| | - Camillo Ricordi
- Diabetes Research Institute, Miller School of Medicine, University of Miami, FL, USA.,Department of Surgery, Division of Cellular Transplantation, cGMP Advanced Cell and Biologic Manufacturing Facility, Miller School of Medicine, University of Miami, FL, USA
| | - Elina Linetsky
- Diabetes Research Institute, Miller School of Medicine, University of Miami, FL, USA.,Department of Surgery, Division of Cellular Transplantation, cGMP Advanced Cell and Biologic Manufacturing Facility, Miller School of Medicine, University of Miami, FL, USA
| | - Peter Buchwald
- Diabetes Research Institute, Miller School of Medicine, University of Miami, FL, USA.,Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, FL, USA
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17
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Patel SN, Ishahak M, Chaimov D, Velraj A, LaShoto D, Hagan DW, Buchwald P, Phelps EA, Agarwal A, Stabler CL. Organoid microphysiological system preserves pancreatic islet function within 3D matrix. SCIENCE ADVANCES 2021; 7:7/7/eaba5515. [PMID: 33579705 PMCID: PMC7880596 DOI: 10.1126/sciadv.aba5515] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 12/23/2020] [Indexed: 05/14/2023]
Abstract
Three-dimensional (3D) multicellular organoids recapitulate the native complexities of human tissue better than traditional cellular monolayers. As organoids are insufficiently supported using standard static culture, microphysiological systems (MPSs) provide a key enabling technology to maintain organoid physiology in vitro. Here, a polydimethylsiloxane-free MPS that enables continuous dynamic culture and serial in situ multiparametric assessments was leveraged to culture organoids, specifically human and rodent pancreatic islets, within a 3D alginate hydrogel. Computational modeling predicted reduced hypoxic stress and improved insulin secretion compared to static culture. Experimental validation via serial, high-content, and noninvasive assessments quantitatively confirmed that the MPS platform retained organoid viability and functionality for at least 10 days, in stark contrast to the acute decline observed overnight under static conditions. Our findings demonstrate the importance of a dynamic in vitro microenvironment for the preservation of primary organoid function and the utility of this MPS for in situ multiparametric assessment.
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Affiliation(s)
- S N Patel
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - M Ishahak
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA
| | - D Chaimov
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - A Velraj
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - D LaShoto
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - D W Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - P Buchwald
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - E A Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - A Agarwal
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA.
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - C L Stabler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
- University of Florida Diabetes Institute, Gainesville, FL 32610, USA
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18
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Harrington S, Ott L, Karanu F, Ramachandran K, Stehno-Bittel L. A Versatile Microencapsulation Platform for Hyaluronic Acid and Polyethylene Glycol. Tissue Eng Part A 2021; 27:153-164. [PMID: 32103710 PMCID: PMC7891217 DOI: 10.1089/ten.tea.2019.0286] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/14/2020] [Indexed: 12/16/2022] Open
Abstract
Cell microencapsulation is a rapidly expanding field with broad potential for stem cell therapies and tissue engineering research. Traditional alginate microspheres suffer from poor biocompatibility, and microencapsulation of more advanced hydrogels is challenging due to their slower gelation rates. We have developed a novel, noncytotoxic, nonemulsion-based method to produce hydrogel microspheres compatible with a wide variety of materials, called core-shell spherification (CSS). Fabrication of microspheres by CSS derived from two slow-hardening hydrogels, hyaluronic acid (HA) and polyethylene glycol diacrylate (PEGDA), was characterized. HA microspheres were manufactured with two different crosslinking methods: thiolation and methacrylation. Microspheres of methacrylated HA (MeHA) had the greatest swelling ratio, the largest average diameter, and the lowest diffusion barrier. In contrast, PEGDA microspheres had the smallest diameters, the lowest swelling ratio, and the highest diffusion barrier, while microspheres of thiolated HA had characteristics that were in between the other two groups. To test the ability of the hydrogels to protect cells, while promoting function, diabetic NOD mice received intraperitoneal injections of PEGDA or MeHA microencapsulated canine islets. PEGDA microspheres reversed diabetes for the length of the study (up to 16 weeks). In contrast, islets encapsulated in MeHA microspheres at the same dose restored normoglycemia, but only transiently (3-4 weeks). Nonencapsulated canine islet transplanted at the same dose did not restore normoglycemia for any length of time. In conclusion, CSS provides a nontoxic microencapsulation procedure compatible with various hydrogel types.
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Affiliation(s)
- Stephen Harrington
- Likarda LLC, Kansas City, Missouri, USA
- Department of Rehabilitation Science, University of Kansas Medical Center, Kansas City, Kansas, USA
| | | | | | | | - Lisa Stehno-Bittel
- Likarda LLC, Kansas City, Missouri, USA
- Department of Rehabilitation Science, University of Kansas Medical Center, Kansas City, Kansas, USA
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19
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Han EX, Wang J, Kural M, Jiang B, Leiby KL, Chowdhury N, Tellides G, Kibbey RG, Lawson JH, Niklason LE. Development of a Bioartificial Vascular Pancreas. J Tissue Eng 2021; 12:20417314211027714. [PMID: 34262686 PMCID: PMC8243137 DOI: 10.1177/20417314211027714] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 06/08/2021] [Indexed: 12/16/2022] Open
Abstract
Transplantation of pancreatic islets has been shown to be effective, in some patients, for the long-term treatment of type 1 diabetes. However, transplantation of islets into either the portal vein or the subcutaneous space can be limited by insufficient oxygen transfer, leading to islet loss. Furthermore, oxygen diffusion limitations can be magnified when islet numbers are increased dramatically, as in translating from rodent studies to human-scale treatments. To address these limitations, an islet transplantation approach using an acellular vascular graft as a vascular scaffold has been developed, termed the BioVascular Pancreas (BVP). To create the BVP, islets are seeded as an outer coating on the surface of an acellular vascular graft, using fibrin as a hydrogel carrier. The BVP can then be anastomosed as an arterial (or arteriovenous) graft, which allows fully oxygenated arterial blood with a pO2 of roughly 100 mmHg to flow through the graft lumen and thereby supply oxygen to the islets. In silico simulations and in vitro bioreactor experiments show that the BVP design provides adequate survivability for islets and helps avoid islet hypoxia. When implanted as end-to-end abdominal aorta grafts in nude rats, BVPs were able to restore near-normoglycemia durably for 90 days and developed robust microvascular infiltration from the host. Furthermore, pilot implantations in pigs were performed, which demonstrated the scalability of the technology. Given the potential benefits provided by the BVP, this tissue design may eventually serve as a solution for transplantation of pancreatic islets to treat or cure type 1 diabetes.
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Affiliation(s)
- Edward X Han
- Department of Biomedical Engineering,
Yale School of Engineering and Applied Science, New Haven, CT, USA
| | - Juan Wang
- Vascular Biology and Therapeutics
Program, Yale School of Medicine, New Haven, CT, USA
- Department of Anesthesiology, Yale
School of Medicine, New Haven, CT, USA
| | - Mehmet Kural
- Vascular Biology and Therapeutics
Program, Yale School of Medicine, New Haven, CT, USA
- Department of Anesthesiology, Yale
School of Medicine, New Haven, CT, USA
| | - Bo Jiang
- Department of Surgery, Yale School of
Medicine, New Haven, CT, USA
- Department of Vascular Surgery, The
First Hospital of China Medical University, Shenyang, China
| | - Katherine L Leiby
- Department of Biomedical Engineering,
Yale School of Engineering and Applied Science, New Haven, CT, USA
| | - Nazar Chowdhury
- Molecular, Cellular, and Developmental
Biology, Yale University, New Haven, CT, USA
| | - George Tellides
- Vascular Biology and Therapeutics
Program, Yale School of Medicine, New Haven, CT, USA
- Department of Surgery, Yale School of
Medicine, New Haven, CT, USA
- Veterans Affairs Connecticut Healthcare
System, West Haven, CT, USA
| | - Richard G Kibbey
- Department of Internal Medicine
(Endocrinology), Yale University, New Haven, CT, USA
- Department of Cellular & Molecular
Physiology, Yale School of Medicine, New Haven, CT, USA
| | - Jeffrey H Lawson
- Department of Surgery, Duke
University, Durham, NC, USA
- Humacyte Inc., Durham, NC, USA
| | - Laura E Niklason
- Department of Biomedical Engineering,
Yale School of Engineering and Applied Science, New Haven, CT, USA
- Vascular Biology and Therapeutics
Program, Yale School of Medicine, New Haven, CT, USA
- Department of Anesthesiology, Yale
School of Medicine, New Haven, CT, USA
- Humacyte Inc., Durham, NC, USA
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20
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Laporte C, Tubbs E, Pierron M, Gallego A, Moisan A, Lamarche F, Lozano T, Hernandez A, Cottet-Rousselle C, Gauchez AS, Persoons V, Bottausci F, Fontelaye C, Boizot F, Lablanche S, Rivera F. Improved human islets’ viability and functionality with mesenchymal stem cells and arg-gly-asp tripeptides supplementation of alginate micro-encapsulated islets in vitro. Biochem Biophys Res Commun 2020; 528:650-657. [DOI: 10.1016/j.bbrc.2020.05.107] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 05/15/2020] [Indexed: 12/19/2022]
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21
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Misun PM, Yesildag B, Forschler F, Neelakandhan A, Rousset N, Biernath A, Hierlemann A, Frey O. In Vitro Platform for Studying Human Insulin Release Dynamics of Single Pancreatic Islet Microtissues at High Resolution. ADVANCED BIOSYSTEMS 2020; 4:e1900291. [PMID: 32293140 PMCID: PMC7610574 DOI: 10.1002/adbi.201900291] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Indexed: 01/18/2023]
Abstract
Insulin is released from pancreatic islets in a biphasic and pulsatile manner in response to elevated glucose levels. This highly dynamic insulin release can be studied in vitro with islet perifusion assays. Herein, a novel platform to perform glucose-stimulated insulin secretion (GSIS) assays with single islets is presented for studying the dynamics of insulin release at high temporal resolution. A standardized human islet model is developed and a microfluidic hanging-drop-based perifusion system is engineered, which facilitates rapid glucose switching, minimal sample dilution, low analyte dispersion, and short sampling intervals. Human islet microtissues feature robust and long-term glucose responsiveness and demonstrate reproducible dynamic GSIS with a prominent first phase and a sustained, pulsatile second phase. Perifusion of single islet microtissues produces a higher peak secretion rate, higher secretion during the first and second phases of insulin release, as well as more defined pulsations during the second phase in comparison to perifusion of pooled islets. The developed platform enables to study compound effects on both phases of insulin secretion as shown with two classes of insulin secretagogs. It provides a new tool for studying physiologically relevant dynamic insulin secretion at comparably low sample-to-sample variation and high temporal resolution.
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Affiliation(s)
- Patrick M. Misun
- Bio Engineering Laboratory Department of Biosystems Science and Engineering ETH Zürich Mattenstrasse 26, 4058 Basel, Switzerland
| | | | - Felix Forschler
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | | | - Nassim Rousset
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | | | - Andreas Hierlemann
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Olivier Frey
- InSphero AG Wagistrasse 27, 8952 Schlieren, Switzerland
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22
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Sibilla S, Manenti S, Cazzato T, Colombo F, Tomei AA, Redaelli A, Manzoli V, Consolo F. Smoothed Particle Hydrodynamics multiphase modelling of an experimental microfluidic device for conformal coating of pancreatic islets. Med Eng Phys 2020; 77:19-30. [PMID: 32008936 DOI: 10.1016/j.medengphy.2020.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 12/13/2019] [Accepted: 01/05/2020] [Indexed: 11/29/2022]
Abstract
The paper discusses a Smoothed Particle Hydrodynamics (SPH) model for the analysis of the multiphase flow occurring in an experimental microfluidic device for conformal coating of pancreatic islets with a biocompatible and permeable polymer. The proposed numerical model, based on a weakly-compressible SPH approach, accurately mimics the encapsulation process while assuring phase conservation, thus overcoming potential limitations of grid-based models. The proposed SPH model is a triphasic multi-phase model that allows one: (i) to reproduce the physics of islet conformal coating, including the effects of surface tension at the interface of the involved fluids and of the islet diameter; and (ii) to evaluate how modulation of process parameters influences the fluid dynamics within the microfluidic device and the resulting coating characteristics. This model can represent a valuable, time- and cost-effective tool for the definition of optimized encapsulation conditions through in silico screening of novel combinations of conformal coating parameters, including polymeric coating blends, size range of insulin-secreting cell clusters, utilized chemical reagents, device geometry and scale.
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Affiliation(s)
- Stefano Sibilla
- Dipartimento di Ingegneria Civile e Architettura, Università di Pavia, via Ferrata 3, 27100 Pavia, Italy.
| | - Sauro Manenti
- Dipartimento di Ingegneria Civile e Architettura, Università di Pavia, via Ferrata 3, 27100 Pavia, Italy
| | - Tommaso Cazzato
- Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano, via Ponzio 34/5, 20133 Milano, Italy
| | - Federica Colombo
- Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano, via Ponzio 34/5, 20133 Milano, Italy
| | - Alice A Tomei
- Diabetes Research Institute, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL 33136-1011, USA; Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive, McArthur Engineering Building, Coral Gables, FL 33146, USA
| | - Alberto Redaelli
- Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano, via Ponzio 34/5, 20133 Milano, Italy
| | - Vita Manzoli
- Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano, via Ponzio 34/5, 20133 Milano, Italy; Diabetes Research Institute, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL 33136-1011, USA
| | - Filippo Consolo
- Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano, via Ponzio 34/5, 20133 Milano, Italy; Università Vita Salute San Raffaele, Via Olgettina 58, 20132 Milano, Italy
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23
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Skrzypek K, Curcio E, Stamatialis D. Modelling of mass transport and insulin secretion of a membrane-based encapsulation device of pancreatic islets. Chem Eng Res Des 2020. [DOI: 10.1016/j.cherd.2019.11.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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24
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Alcazar O, Buchwald P. Concentration-Dependency and Time Profile of Insulin Secretion: Dynamic Perifusion Studies With Human and Murine Islets. Front Endocrinol (Lausanne) 2019; 10:680. [PMID: 31632354 PMCID: PMC6783504 DOI: 10.3389/fendo.2019.00680] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/19/2019] [Indexed: 12/16/2022] Open
Abstract
The detailed characterization and quantification of the kinetics of glucose-stimulated insulin secretion (GSIS) by normal pancreatic islets is of considerable interest for characterizing β-cell dysfunction, assessing the quality of isolated islets, and improving the design of artificial pancreas devices. Here, we performed dynamic evaluation of GSIS by human and mouse islets at high temporal resolution (every minute) in response to different glucose steps using an automated multichannel perifusion instrument. In both species, insulin responses were biphasic (a transient first-phase peak followed by a sustained second-phase), and the amount of insulin released showed a sigmoid-type dependence on glucose concentration. However, compared to murine islets, human islets have (1) a less pronounced first-phase response, (2) a flat secretion rate during second-phase response, (3) a left-shifted concentration response (reaching half-maximal response at 7.9 ± 0.4 vs. 13.7 ± 0.6 mM), and (4) an ~3-fold lower maximal secretion rate (8.3 ± 2.3 vs. 23.9 ± 5.1 pg/min/islet at 30 mM glucose). These results can be used to establish a more informative protocol for the calculation of the stimulation index, which is widely used for islet assessment in both research and clinical applications, but without an accepted standard or clear evidence as to what low- to high-glucose steps can provide better characterization of islet function. Data obtained here suggest that human islet functionality might be best characterized with a dynamic stimulation index obtained with a glucose step from a low of 4-5 to a high of 14-17 mM (e.g., G4 → G16).
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Affiliation(s)
- Oscar Alcazar
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Peter Buchwald
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, Miami, FL, United States
- *Correspondence: Peter Buchwald
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25
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Development of the human pancreas and its vasculature — An integrated review covering anatomical, embryological, histological, and molecular aspects. Ann Anat 2019; 221:115-124. [DOI: 10.1016/j.aanat.2018.09.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 09/12/2018] [Accepted: 09/25/2018] [Indexed: 01/18/2023]
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26
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Huang HH, Harrington S, Stehno-Bittel L. The Flaws and Future of Islet Volume Measurements. Cell Transplant 2018; 27:1017-1026. [PMID: 29954219 PMCID: PMC6158542 DOI: 10.1177/0963689718779898] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/09/2018] [Accepted: 04/01/2018] [Indexed: 11/17/2022] Open
Abstract
When working with isolated islet preparations, measuring the volume of tissue is not a trivial matter. Islets come in a large range of sizes and are often contaminated with exocrine tissue. Many factors complicate the procedure, and yet knowledge of the islet volume is essential for predicting the success of an islet transplant or comparing experimental groups in the laboratory. In 1990, Ricordi presented the islet equivalency (IEQ), defined as one IEQ equaling a single spherical islet of 150 μm in diameter. The method for estimating IEQ was developed by visualizing islets in a microscope, estimating their diameter in 50 μm categories and calculating a total volume for the preparation. Shortly after its introduction, the IEQ was adopted as the standard method for islet volume measurements. It has helped to advance research in the field by providing a useful tool improving the reproducibility of islet research and eventually the success of clinical islet transplants. However, the accuracy of the IEQ method has been questioned for years and many alternatives have been proposed, but none have been able to replace the widespread use of the IEQ. This article reviews the history of the IEQ, and discusses the benefits and failings of the measurement. A thorough evaluation of alternatives for estimating islet volume is provided along with the steps needed to uniformly move to an improved method of islet volume estimation. The lessons learned from islet researchers may serve as a guide for other fields of regenerative medicine as cell clusters become a more attractive therapeutic option.
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Affiliation(s)
- Han-Hung Huang
- Angelo State University, Texas Tech University System, San Angelo, TX, USA
| | | | - Lisa Stehno-Bittel
- Likarda, LLC, Kansas City, MO, USA
- University of Kansas Medical Center, Kansas City, KS, USA
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27
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Buchwald P, Bernal A, Echeverri F, Tamayo-Garcia A, Linetsky E, Ricordi C. Fully Automated Islet Cell Counter (ICC) for the Assessment of Islet Mass, Purity, and Size Distribution by Digital Image Analysis. Cell Transplant 2018; 25:1747-1761. [PMID: 27196960 DOI: 10.3727/096368916x691655] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
For isolated pancreatic islet cell preparations, it is important to be able to reliably assess their mass and quality, and for clinical applications, it is part of the regulatory requirement. Accurate assessment, however, is difficult because islets are spheroid-like cell aggregates of different sizes (<50 to 500 μm) resulting in possible thousandfold differences between the mass contribution of individual particles. The current standard manual counting method that uses size-based group classification is known to be error prone and operator dependent. Digital image analysis (DIA)-based methods can provide less subjective, more reproducible, and better-documented islet cell mass (IEQ) estimates; however, so far, none has become widely accepted or used. Here we present results obtained using a compact, self-contained islet cell counter (ICC3) that includes both the hardware and software needed for automated islet counting and requires minimal operator training and input; hence, it can be easily adapted at any center and could provide a convenient standardized cGMP-compliant IEQ assessment. Using cross-validated sample counting, we found that for most human islet cell preparations, ICC3 provides islet mass (IEQ) estimates that correlate well with those obtained by trained operators using the current manual SOP method ( r2 = 0.78, slope = 1.02). Variability and reproducibility are also improved compared to the manual method, and most of the remaining variability (CV = 8.9%) results from the rearrangement of the islet particles due to movement of the sample between counts. Characterization of the size distribution is also important, and the present digitally collected data allow more detailed analysis and coverage of a wider size range. We found again that for human islet cell preparations, a Weibull distribution function provides good description of the particle size.
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Affiliation(s)
- Peter Buchwald
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA.,Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | | | | | | | - Elina Linetsky
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Camillo Ricordi
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
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28
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Buchwald P, Tamayo-Garcia A, Manzoli V, Tomei AA, Stabler CL. Glucose-stimulated insulin release: Parallel perifusion studies of free and hydrogel encapsulated human pancreatic islets. Biotechnol Bioeng 2018; 115:232-245. [PMID: 28865118 PMCID: PMC5699962 DOI: 10.1002/bit.26442] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/14/2017] [Accepted: 08/30/2017] [Indexed: 12/29/2022]
Abstract
To explore the effects immune-isolating encapsulation has on the insulin secretion of pancreatic islets and to improve our ability to quantitatively describe the glucose-stimulated insulin release (GSIR) of pancreatic islets, we conducted dynamic perifusion experiments with isolated human islets. Free (unencapsulated) and hydrogel encapsulated islets were perifused, in parallel, using an automated multi-channel system that allows sample collection with high temporal resolution. Results indicated that free human islets secrete less insulin per unit mass or islet equivalent (IEQ) than murine islets and with a less pronounced first-phase peak. While small microcapsules (d = 700 µm) caused only a slightly delayed and blunted first-phase insulin response compared to unencapsulated islets, larger capsules (d = 1,800 µm) completely blunted the first-phase peak and decreased the total amount of insulin released. Experimentally obtained insulin time-profiles were fitted with our complex insulin secretion computational model. This allowed further fine-tuning of the hormone-release parameters of this model, which was implemented in COMSOL Multiphysics to couple hormone secretion and nutrient consumption kinetics with diffusive and convective transport. The results of these GSIR experiments, which were also supported by computational modeling, indicate that larger capsules unavoidably lead to dampening of the first-phase insulin response and to a sustained-release type insulin secretion that can only slowly respond to changes in glucose concentration. Bioartificial pancreas type devices can provide long-term and physiologically desirable solutions only if immunoisolation and biocompatibility considerations are integrated with optimized nutrient diffusion and insulin release characteristics by design.
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Affiliation(s)
- Peter Buchwald
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, FL
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL
| | | | - Vita Manzoli
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, FL
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Italy
| | - Alice A. Tomei
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, FL
- Biomedical Engineering, University of Miami, Miller School of Medicine, Miami, FL
| | - Cherie L. Stabler
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
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29
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Harrington S, Williams SJ, Otte V, Barchman S, Jones C, Ramachandran K, Stehno-Bittel L. Improved yield of canine islet isolation from deceased donors. BMC Vet Res 2017; 13:264. [PMID: 28830425 PMCID: PMC5567429 DOI: 10.1186/s12917-017-1177-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 08/10/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Canine diabetes is a strikingly prevalent and growing disease, and yet the standard treatment of a twice-daily insulin injection is both cumbersome to pet owners and only moderately effective. Islet transplantation has been performed with repeated success in canine research models, but has unfortunately not been made available to companion animals. Standard protocols for islet isolation, developed primarily for human islet transplantation, include beating-heart organ donation, vascular perfusion of preservation solutions, specialized equipment. Unfortunately, these processes are prohibitively complex and expensive for veterinary use. The aim of the study was to develop a simplified approach for isolating canine islets that is compatible with the financial and logistical restrictions inherent to veterinary medicine for the purpose of translating islet transplantation to a clinical treatment for canine diabetes. RESULTS Here, we describe simplified strategies for isolating quality islets from deceased canine donors without vascular preservation and with up to 90 min of cold ischemia time. An average of more than 1500 islet equivalents per kg of donor bodyweight was obtained with a purity of 70% (N = 6 animals). Islets were 95% viable and responsive to glucose stimulation for a week. We found that processing only the body and tail of the pancreas increased isolation efficiency without sacrificing islet total yield. Islet yield per gram of tissue increased from 773 to 1868 islet equivalents when the head of the pancreas was discarded (N = 3/group). CONCLUSIONS In summary, this study resulted in the development of an efficient and readily accessible method for obtaining viable and functional canine islets from deceased donors. These strategies provide an ethical means for obtaining donor islets.
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Affiliation(s)
| | - S Janette Williams
- University of Kansas Medical Center, MS 2002, Kansas City, KS, 66160, USA.,Likarda, LLC, 2002 W 39th Avenue, Kansas City, KS, 66103, USA
| | - Vern Otte
- State Line Animal Hospital, 2009 W 104th Street, Leawood, KS, 66206, USA
| | - Sally Barchman
- State Line Animal Hospital, 2009 W 104th Street, Leawood, KS, 66206, USA
| | - Cheryl Jones
- State Line Animal Hospital, 2009 W 104th Street, Leawood, KS, 66206, USA
| | | | - Lisa Stehno-Bittel
- University of Kansas Medical Center, MS 2002, Kansas City, KS, 66160, USA. .,Likarda, LLC, 2002 W 39th Avenue, Kansas City, KS, 66103, USA.
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30
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Micro-fabricated scaffolds lead to efficient remission of diabetes in mice. Biomaterials 2017; 135:10-22. [DOI: 10.1016/j.biomaterials.2017.03.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 03/19/2017] [Accepted: 03/21/2017] [Indexed: 01/12/2023]
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31
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Garcia-Contreras M, Tamayo-Garcia A, Pappan KL, Michelotti GA, Stabler CL, Ricordi C, Buchwald P. Metabolomics Study of the Effects of Inflammation, Hypoxia, and High Glucose on Isolated Human Pancreatic Islets. J Proteome Res 2017; 16:2294-2306. [PMID: 28452488 PMCID: PMC5557342 DOI: 10.1021/acs.jproteome.7b00160] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The transplantation of human pancreatic islets is a therapeutic possibility for a subset of type 1 diabetic patients who experience severe hypoglycemia. Pre- and post-transplantation loss in islet viability and function, however, is a major efficacy-limiting impediment. To investigate the effects of inflammation and hypoxia, the main obstacles hampering the survival and function of isolated, cultured, and transplanted islets, we conducted a comprehensive metabolomics evaluation of human islets in parallel with dynamic glucose-stimulated insulin release (GSIR) perifusion studies for functional evaluation. Metabolomics profiling of media and cell samples identified a total of 241 and 361 biochemicals, respectively. Metabolites that were altered in highly significant manner in both included, for example, kynurenine, kynurenate, citrulline, and mannitol/sorbitol under inflammation (all elevated) plus lactate (elevated) and N-formylmethionine (depressed) for hypoxia. Dynamic GSIR experiments, which capture both first- and second-phase insulin release, found severely depressed insulin-secretion under hypoxia, whereas elevated baseline and stimulated insulin-secretion was measured for islet exposed to the inflammatory cytokine cocktail (IL-1β, IFN-γ, and TNF-α). Because of the uniquely large changes observed in kynurenine and kynurenate, they might serve as potential biomarkers of islet inflammation, and indoleamine-2,3-dioxygenase on the corresponding pathway could be a worthwhile therapeutic target to dampen inflammatory effects.
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Affiliation(s)
- Marta Garcia-Contreras
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
- Ri.Med, Palermo, Italy
- Catholyc University of Valencia, Valencia, Spain
| | | | | | | | - Cherie L. Stabler
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Camillo Ricordi
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
- Ri.Med, Palermo, Italy
| | - Peter Buchwald
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
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32
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Lenguito G, Chaimov D, Weitz JR, Rodriguez-Diaz R, Rawal SAK, Tamayo-Garcia A, Caicedo A, Stabler CL, Buchwald P, Agarwal A. Resealable, optically accessible, PDMS-free fluidic platform for ex vivo interrogation of pancreatic islets. LAB ON A CHIP 2017; 17:772-781. [PMID: 28157238 PMCID: PMC5330806 DOI: 10.1039/c6lc01504b] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We report the design and fabrication of a robust fluidic platform built out of inert plastic materials and micromachined features that promote optimized convective fluid transport. The platform is tested for perfusion interrogation of rodent and human pancreatic islets, dynamic secretion of hormones, concomitant live-cell imaging, and optogenetic stimulation of genetically engineered islets. A coupled quantitative fluid dynamics computational model of glucose stimulated insulin secretion and fluid dynamics was first utilized to design device geometries that are optimal for complete perfusion of three-dimensional islets, effective collection of secreted insulin, and minimization of system volumes and associated delays. Fluidic devices were then fabricated through rapid prototyping techniques, such as micromilling and laser engraving, as two interlocking parts from materials that are non-absorbent and inert. Finally, the assembly was tested for performance using both rodent and human islets with multiple assays conducted in parallel, such as dynamic perfusion, staining and optogenetics on standard microscopes, as well as for integration with commercial perfusion machines. The optimized design of convective fluid flows, use of bio-inert and non-absorbent materials, reversible assembly, manual access for loading and unloading of islets, and straightforward integration with commercial imaging and fluid handling systems proved to be critical for perfusion assay, and particularly suited for time-resolved optogenetics studies.
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Affiliation(s)
- Giovanni Lenguito
- Department of Biomedical Engineering, Department of Pathology & Laboratory Medicine, University of Miami, Miami, FL 33136, USA.
| | - Deborah Chaimov
- Department of Biomedical Engineering, University of Florida, USA
| | | | | | - Siddarth A K Rawal
- Department of Biomedical Engineering, Department of Pathology & Laboratory Medicine, University of Miami, Miami, FL 33136, USA.
| | | | | | - Cherie L Stabler
- Department of Biomedical Engineering, University of Florida, USA
| | - Peter Buchwald
- Diabetes Research Institute, University of Miami, USA and Department of Molecular and Cellular Pharmacology, University of Miami, USA
| | - Ashutosh Agarwal
- Department of Biomedical Engineering, Department of Pathology & Laboratory Medicine, University of Miami, Miami, FL 33136, USA. and Diabetes Research Institute, University of Miami, USA
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33
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Sabek OM, Farina M, Fraga DW, Afshar S, Ballerini A, Filgueira CS, Thekkedath UR, Grattoni A, Gaber AO. Three-dimensional printed polymeric system to encapsulate human mesenchymal stem cells differentiated into islet-like insulin-producing aggregates for diabetes treatment. J Tissue Eng 2016; 7:2041731416638198. [PMID: 27152147 PMCID: PMC4843232 DOI: 10.1177/2041731416638198] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 02/18/2016] [Indexed: 01/19/2023] Open
Abstract
Diabetes is one of the most prevalent, costly, and debilitating diseases in the world. Pancreas and islet transplants have shown success in re-establishing glucose control and reversing diabetic complications. However, both are limited by donor availability, need for continuous immunosuppression, loss of transplanted tissue due to dispersion, and lack of vascularization. To overcome the limitations of poor islet availability, here, we investigate the potential of bone marrow–derived mesenchymal stem cells differentiated into islet-like insulin-producing aggregates. Islet-like insulin-producing aggregates, characterized by gene expression, are shown to be similar to pancreatic islets and display positive immunostaining for insulin and glucagon. To address the limits of current encapsulation systems, we developed a novel three-dimensional printed, scalable, and potentially refillable polymeric construct (nanogland) to support islet-like insulin-producing aggregates’ survival and function in the host body. In vitro studies showed that encapsulated islet-like insulin-producing aggregates maintained viability and function, producing steady levels of insulin for at least 4 weeks. Nanogland—islet-like insulin-producing aggregate technology here investigated as a proof of concept holds potential as an effective and innovative approach for diabetes cell therapy.
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Affiliation(s)
- Omaima M Sabek
- Department of Surgery, Houston Methodist Hospital, Houston, TX, USA
| | - Marco Farina
- Department of Nanomedicine, Institute for Academic Medicine, Houston Methodist Research Institute, Houston, TX, USA; Department of Electronics and Telecommunications, Politecnico di Torino, Torino, Italy
| | - Daniel W Fraga
- Department of Surgery, Houston Methodist Hospital, Houston, TX, USA
| | - Solmaz Afshar
- Department of Surgery, Houston Methodist Hospital, Houston, TX, USA
| | - Andrea Ballerini
- Department of Nanomedicine, Institute for Academic Medicine, Houston Methodist Research Institute, Houston, TX, USA; Department of Biotechnology and Translational Medicine, The University of Milan, Milan, Italy
| | - Carly S Filgueira
- Department of Nanomedicine, Institute for Academic Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Usha R Thekkedath
- Department of Nanomedicine, Institute for Academic Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Alessandro Grattoni
- Department of Nanomedicine, Institute for Academic Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - A Osama Gaber
- Department of Surgery, Houston Methodist Hospital, Houston, TX, USA
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34
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Hawthorne WJ, Williams L, Chew YV. Clinical Islet Isolation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 938:89-122. [PMID: 27586424 DOI: 10.1007/978-3-319-39824-2_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The overarching success of islet transplantation relies on the success in the laboratory to isolate the islets. This chapter focuses on the processes of human islet cell isolation and the ways to optimally provide islet cells for transplantation. The major improvements in regards to the choice of enzyme type, way the digested pancreas tissue is handled to best separate islets from the acinar and surrounding tissues, the various methods of purification of the islets, their subsequent culture and quality assurance to improve outcomes to culminate in safe and effective islet transplantation will be discussed. After decades of improvements, islet cell isolation and transplantation now clearly offer a safe, effective and feasible therapeutic treatment option for an increasing number of patients suffering from type 1 diabetes specifically for those with severe hypoglycaemic unawareness.
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Affiliation(s)
- Wayne J Hawthorne
- National Pancreas and Islet Transplant Laboratories, The Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia. .,Department of Surgery, Westmead Clinical School, Westmead Hospital, University of Sydney, Westmead, NSW, 2145, Australia.
| | - Lindy Williams
- National Pancreas and Islet Transplant Laboratories, The Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia
| | - Yi Vee Chew
- National Pancreas and Islet Transplant Laboratories, The Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia
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Wang LJ, Kaufman DB. Digital Image Analysis to Assess Quantity and Morphological Quality of Isolated Pancreatic Islets. Cell Transplant 2015; 25:1219-25. [PMID: 26610269 DOI: 10.3727/096368915x689947] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Quantity and quality assessment of human pancreatic islets are essential processes to define a safe and potent quality product used for clinical transplantation. The conventional method of manual assessment has been used in the field for longer than two decades. The high degree of variability in product quantity and lack of archival imaging records of the product for verification are two major disadvantages of using the manual method for quantity and quality assessment of human pancreatic islets. Investigators have developed promising new methods for technical improvement. In this study, we briefly review the published methods and highlight the advantages of digital imaging analysis (DIA) when compared to the manual method. The application of DIA reduces measurement variability and increases the precision of islet equivalent (IEQ) determination for batch analysis. It produces images that can be archived for retrospective analysis and validation, and the data can be transmitted electronically for off-site analysis. These features are important for quality pancreatic islet assessment and are consistent with FDA requirements of current good manufacturing practice for clinical islet transplantation.
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Affiliation(s)
- Ling-Jia Wang
- Department of Surgery, University of Illinois at Chicago, Chicago, IL, USA
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Weaver JD, Song Y, Yang EY, Ricordi C, Pileggi A, Buchwald P, Stabler CL. Controlled Release of Dexamethasone from Organosilicone Constructs for Local Modulation of Inflammation in Islet Transplantation. Tissue Eng Part A 2015; 21:2250-61. [DOI: 10.1089/ten.tea.2014.0487] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Jessica D. Weaver
- Department of Biomedical Engineering, University of Miami, Miami, Florida
- Diabetes Research Institute, University of Miami, Miami, Florida
| | - Yun Song
- Diabetes Research Institute, University of Miami, Miami, Florida
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, Florida
| | - Ethan Y. Yang
- Diabetes Research Institute, University of Miami, Miami, Florida
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, Florida
| | - Camillo Ricordi
- Department of Biomedical Engineering, University of Miami, Miami, Florida
- Diabetes Research Institute, University of Miami, Miami, Florida
- Department of Surgery, University of Miami, Miami, Florida
- Department of Microbiology and Immunology, University of Miami, Miami, Florida
- Department of Medicine, University of Miami, Miami, Florida
| | - Antonello Pileggi
- Department of Biomedical Engineering, University of Miami, Miami, Florida
- Diabetes Research Institute, University of Miami, Miami, Florida
- Department of Surgery, University of Miami, Miami, Florida
- Department of Microbiology and Immunology, University of Miami, Miami, Florida
- Department of Medicine, University of Miami, Miami, Florida
| | - Peter Buchwald
- Diabetes Research Institute, University of Miami, Miami, Florida
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, Florida
| | - Cherie L. Stabler
- Department of Biomedical Engineering, University of Miami, Miami, Florida
- Diabetes Research Institute, University of Miami, Miami, Florida
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, Florida
- Department of Surgery, University of Miami, Miami, Florida
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Nano R, Melzi R, Mercalli A, Balzano G, Scavini M, Bonadonna R, Piemonti L. Islet Volume and Indexes of β-Cell Function in Humans. Cell Transplant 2015; 25:491-501. [PMID: 26102316 DOI: 10.3727/096368915x688498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Islet volume and endocrine pancreas architecture (islet size distribution) may be independent determinants of β-cell function. Furthermore, the accuracy of homeostatic model assessment (HOMA) indexes in predicting β-cell mass has never been assessed. Here we investigated the relationships between islet volume, islet density, and islet size distribution, estimated after pancreatic tissue digestion, with established indexes of β-cell function in humans. We included in this study 42 patients who were candidates for islet autotransplantation and had well-characterized glucose metabolism. Indexes of insulin secretion were calculated and compared with the islet volume, as a surrogate of β-cell mass, obtained after digestion of pancreas. Islet counting analysis showed considerable interindividual variation in islet density and size. Islet volume, but not density nor size, was the only independent determinant of β-cell function assessed by insulin HOMA β-cell. Islet volume was significantly reduced in the patients with overt hyperglycemia, but not in patients with impaired fasting glucose. Insulin HOMA β-cell predicted islet volume better than other measures of fasting insulin secretion. In conclusion, the present study documented a close direct relationship between indexes of β-cell function and islet volume in humans. The insulin HOMA β-cell provides a more reliable estimate of pancreatic islet volume than fasting glucose before islet isolation.
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Affiliation(s)
- Rita Nano
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
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Bloch K, Gil-Ad I, Tarasenko I, Vanichkin A, Taler M, Hornfeld SH, Vardi P, Weizman A. Intracranial pancreatic islet transplantation increases islet hormone expression in the rat brain and attenuates behavioral dysfunctions induced by MK-801 (dizocilpine). Horm Behav 2015; 72:1-11. [PMID: 25943974 DOI: 10.1016/j.yhbeh.2015.04.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 04/19/2015] [Accepted: 04/20/2015] [Indexed: 01/15/2023]
Abstract
The treatment of rodents with non-competitive antagonist of the N-Methyl-D-aspartate (NMDA) receptor, MK-801 (dizocilpine), induces symptoms of psychosis, deficits in spatial memory and impairment of synaptic plasticity. Recent studies have suggested that insulin administration might attenuate the cognitive dysfunctions through the modulatory effect on the expression of NMDA receptors and on the brain insulin signaling. Intrahepatic pancreatic islet transplantation is known as an efficient tool for correcting impaired insulin signaling. We examined the capacity of syngeneic islets grafted into the cranial subarachnoid cavity to attenuate behavioral dysfunctions in rats exposed to MK-801. Animals were examined in the open field (OF) and the Morris Water Maze (MWM) tests following acute or subchronic administration of MK-801. We found well-vascularized grafted islets expressing insulin, glucagon and somatostatin onto the olfactory bulb and prefrontal cortex. Significantly higher levels of insulin were detected in the hippocampus and prefrontal cortex of transplanted animals compared to the non-transplanted rats. All animals expressed normal peripheral glucose homeostasis for two months after transplantation. OF tests revealed that rats exposed to MK-801 treatment, showed hyper-responsiveness in motility parameters and augmented center field exploration compared to intact controls and these effects were attenuated by the grafted islets. Moreover, in the MWM, the rats treated with MK-801 showed impairment of spatial memory that were partially corrected by the grafted islets. In conclusion, intracranial islet transplantation leads to the expression of islet hormones in the brain and attenuates behavioral and cognitive dysfunctions in rats exposed to MK-801 administration without altering the peripheral glucose homeostasis.
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Affiliation(s)
- Konstantin Bloch
- Laboratory of Diabetes and Obesity Research, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel.
| | - Irit Gil-Ad
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Igor Tarasenko
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Alexey Vanichkin
- Laboratory of Transplantation, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Michal Taler
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Shay Henry Hornfeld
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Pnina Vardi
- Laboratory of Diabetes and Obesity Research, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Abraham Weizman
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, Petah Tikva, Israel; Research Unit, Geha Mental Health Center, Petah Tikva, Israel
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Buchwald P, Cechin SR, Weaver JD, Stabler CL. Experimental evaluation and computational modeling of the effects of encapsulation on the time-profile of glucose-stimulated insulin release of pancreatic islets. Biomed Eng Online 2015; 14:28. [PMID: 25889474 PMCID: PMC4403786 DOI: 10.1186/s12938-015-0021-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 03/03/2015] [Indexed: 01/11/2023] Open
Abstract
Background In type 1 diabetic patients, who have lost their ability to produce insulin, transplantation of pancreatic islet cells can normalize metabolic control in a manner that is not achievable with exogenous insulin. To be successful, this procedure has to address the problems caused by the immune and autoimmune responses to the graft. Islet encapsulation using various techniques and materials has been and is being extensively explored as a possible approach. Within this framework, it is of considerable interest to characterize the effect encapsulation has on the insulin response of pancreatic islets. Methods To improve our ability to quantitatively describe the glucose-stimulated insulin release (GSIR) of pancreatic islets in general and of micro-encapsulated islets in particular, we performed dynamic perifusion experiments with frequent sampling. We used unencapsulated and microencapsulated murine islets in parallel and fitted the results with a complex local concentration-based finite element method (FEM) computational model. Results The high-resolution dynamic perifusion experiments allowed good characterization of the first-phase and second-phase insulin secretion, and we observed a slightly delayed and blunted first-phase insulin response for microencapsulated islets when compared to free islets. Insulin secretion profiles of both free and encapsulated islets could be fitted well by a COMSOL Multiphysics model that couples hormone secretion and nutrient consumption kinetics with diffusive and convective transport. This model, which was further validated and calibrated here, can be used for arbitrary geometries and glucose stimulation sequences and is well suited for the quantitative characterization of the insulin response of cultured, perifused, transplanted, or encapsulated islets. Conclusions The present high-resolution GSIR experiments allowed for direct characterization of the effect microencapsulation has on the time-profile of insulin secretion. The multiphysics model, further validated here with the help of these experimental results, can be used to increase our understanding of the challenges that have to be faced in the design of bioartificial pancreas-type devices and to advance their further optimization. Electronic supplementary material The online version of this article (doi:10.1186/s12938-015-0021-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Peter Buchwald
- Diabetes Research Institute, University of Miami, DRI, 1450 NW 10th Ave (R-134), Miami, FL, 33136, USA. .,Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, USA.
| | - Sirlene R Cechin
- Diabetes Research Institute, University of Miami, DRI, 1450 NW 10th Ave (R-134), Miami, FL, 33136, USA.
| | - Jessica D Weaver
- Diabetes Research Institute, University of Miami, DRI, 1450 NW 10th Ave (R-134), Miami, FL, 33136, USA. .,Biomedical Engineering, University of Miami, Miller School of Medicine, Miami, FL, USA.
| | - Cherie L Stabler
- Diabetes Research Institute, University of Miami, DRI, 1450 NW 10th Ave (R-134), Miami, FL, 33136, USA. .,Biomedical Engineering, University of Miami, Miller School of Medicine, Miami, FL, USA. .,DeWitt-Daughtry Department of Surgery, University of Miami, Miller School of Medicine, Miami, FL, USA.
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Ramachandran K, Huang HH, Stehno-Bittel L. A Simple Method to Replace Islet Equivalents for Volume Quantification of Human Islets. Cell Transplant 2014; 24:1183-94. [PMID: 24835624 DOI: 10.3727/096368914x681928] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Human islets come in a variety of sizes and shapes, and the total volume of islets used for research or clinical transplants must be estimated in a manner that is simple and valid. Islet equivalent (IEQ) measurements are the standard estimate of islet volume. We published a new method (the Kansas method) for estimating rat islet volume using cell numbers that was reliable and valid. Here we modified the method for human islets. We measured the dimensions of isolated human islets showing that they are not spherical and became less so in larger islets, with an average smallest/largest diameter ratio of 0.73 in large islets and 0.85 in small islets. Human islets were individually loaded into 96-well plates, dissociated into single cells, and the total cell number per islet determined with computer-assisted cytometry. Based on the counted cell number per islet, a regression model was created to convert islet diameter to cell number with a high R(2) value (0.99). Separate regression equations for male and female donors or young and old donors were not significantly different than the pooled data and did not improve the regression values. There was an inverse correlation between the cell number per IEQ and islet size. The Kansas method was validated with ATP/cell and cell viability data. Compared to the actual cell count, conventional IEQ measurements overestimated tissue volume of large islets by nearly double. Examples of differences in results obtained from the same data sets normalized to IEQ or the Kansas method included viability and insulin secretion concentrations. The implications of the error associated with the current IEQ method of volume estimation are discussed.
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Wang LJ, Kissler HJ, Wang X, Cochet O, Krzystyniak A, Misawa R, Golab K, Tibudan M, Grzanka J, Savari O, Kaufman DB, Millis M, Witkowski P. Application of Digital Image Analysis to Determine Pancreatic Islet Mass and Purity in Clinical Islet Isolation and Transplantation. Cell Transplant 2014; 24:1195-204. [PMID: 24806436 PMCID: PMC4436081 DOI: 10.3727/096368914x681612] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pancreatic islet mass, represented by islet equivalent (IEQ), is the most important parameter in decision making for clinical islet transplantation. To obtain IEQ, the sample of islets is routinely counted under a microscope and discarded thereafter. Islet purity, another parameter in islet processing, is routinely assessed by estimation only. In this study, we validated our digital image analysis (DIA) system by using the software of Image Pro Plus and a custom-designed Excel template to assess islet mass and purity to better comply with current good manufacturing practice (cGMP) standards. Human islet samples (60 collected from a single isolation and 24 collected from 12 isolations) were captured as calibrated digital images for the permanent record. Seven trained technicians participated in determination of IEQ and purity by the manual counting method (manual image counting, Manual I) and DIA. IEQ count showed statistically significant correlations between the Manual I and DIA in all sample comparisons (r > 0.819 and p < 0.0001). A statistically significant difference in IEQ between Manual I and DIA was not found in all sample groups (p > 0.05). In terms of purity determination, statistically significant differences between assessment and DIA measurement were found in high-purity 100-µl samples (p < 0.005) and low-purity 100-µl samples (p < 0.001) of the single isolation. In addition, islet particle number (IPN) and the IEQ/IPN ratio did not differ statistically between Manual I and DIA. In conclusion, the DIA used in this study is a reliable technique to determine IEQ and purity. Islet sample preserved as a digital image and results produced by DIA can be permanently stored for verification, technical training, and information exchange among islet centers. Therefore, DIA complies better with cGMP requirements than the manual counting method. We propose DIA as a quality control tool to supplement the established standard manual method for islet counting and purity estimation.
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Affiliation(s)
- Ling-Jia Wang
- Department of Surgery, Division of Transplantation, University of Chicago, Chicago, IL, USA
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Abstract
Islet equivalent (IE), the standard estimate of isolated islet volume, is an essential measure to determine the amount of transplanted islet tissue in the clinic and is used in research laboratories to normalize results, yet it is based on the false assumption that all islets are spherical. Here, we developed and tested a new easy-to-use method to quantify islet volume with greater accuracy. Isolated rat islets were dissociated into single cells, and the total cell number per islet was determined by using computer-assisted cytometry. Based on the cell number per islet, we created a regression model to convert islet diameter to cell number with a high R2 value (0.8) and good validity and reliability with the same model applicable to young and old rats and males or females. Conventional IE measurements overestimated the tissue volume of islets. To compare results obtained using IE or our new method, we compared Glut2 protein levels determined by Western Blot and proinsulin content via ELISA between small (diameter≤100 μm) and large (diameter≥200 μm) islets. When normalized by IE, large islets showed significantly lower Glut2 level and proinsulin content. However, when normalized by cell number, large and small islets had no difference in Glut2 levels, but large islets contained more proinsulin. In conclusion, normalizing islet volume by IE overestimated the tissue volume, which may lead to erroneous results. Normalizing by cell number is a more accurate method to quantify tissue amounts used in islet transplantation and research.
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Affiliation(s)
- Han-Hung Huang
- Department of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, MS 2002, 3901 Rainbow Blvd., Kansas City, KS 66160 USA
| | - Karthik Ramachandran
- Bioengineering Graduate Program, University of Kansas, School of Engineering, Lawrence, KS 66045 USA
| | - Lisa Stehno-Bittel
- Department of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, MS 2002, 3901 Rainbow Blvd., Kansas City, KS 66160 USA
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Ohira M, Nishida S, Tryphonopoulos P, Tekin A, Selvaggi G, Moon J, Levi D, Ricordi C, Ishiyama K, Tanaka Y, Ohdan H, Tzakis AG. Clinical-scale isolation of interleukin-2-stimulated liver natural killer cells for treatment of liver transplantation with hepatocellular carcinoma. Cell Transplant 2013; 21:1397-406. [PMID: 22469170 DOI: 10.3727/096368911x627589] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Tumor recurrence is the main limitation of liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) and can be promoted by immunosuppressants. However, there is no prevention or treatment for HCC recurrence after LT. Here we describe a clinical-scale method for an adoptive immunotherapy approach that uses natural killer (NK) cells derived from deceased donor liver graft perfusate to prevent tumor recurrence after LT. Liver mononuclear cells (LMNCs) that were extracted from deceased donor liver graft perfusate contained a high percentage of NK cells (45.0 ± 4.0%) compared with peripheral blood mononuclear cells (PBMCs) (21.8 ± 5.2%) from the same donor. The CD69 activation marker and the natural cytotoxicity receptors, NKp44 and NKp46, were expressed at high levels in freshly isolated liver NK cells. Furthermore, interleukin-2 (IL-2)-stimulated NK cells showed greater upregulation of activation markers and the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is critical for NK cell-mediated antitumor cell death and increased production of interferon. Moreover, IL-2 stimulation induced LMNCs to exhibit a strong cytotoxicity against NK-susceptible K562 target cells compared with PBMCs (p < 0.01). Finally, we also showed that the final product contained a very low T-cell contamination (0.02 ± 10(6) cells/kg(-1)), which reduces the risk of graft-versus-host disease (GVHD). Collectively, our results suggest that the adoptive transfer of IL-2-stimulated NK cells from deceased donor liver graft perfusate could be a promising treatment for LT patients with HCC.
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Affiliation(s)
- Masahiro Ohira
- Department of Surgery, Division of Liver and Gastrointestinal Transplantation, University of Miami Miller School of Medicine, 1801 NW 9th Avenue, Miami, FL 33136, USA
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Islet Transplantation in a Subarachnoid Cavity Surrounding Olfactory Bulb of Diabetic Rats. Transplantation 2013; 95:e54-7. [DOI: 10.1097/tp.0b013e3182875ddc] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Wang Y, Danielson KK, Ropski A, Harvat T, Barbaro B, Paushter D, Qi M, Oberholzer J. Systematic analysis of donor and isolation factor's impact on human islet yield and size distribution. Cell Transplant 2013; 22:2323-33. [PMID: 23363652 DOI: 10.3727/096368912x662417] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Islet transplantation is a promising therapy for T1DM. Key factors influencing islet yield have been identified with conflicting results. In this study, we analyzed 276 isolations to identify variables for islet yield and, additionally, islet size and size distribution. Pearson correlation analyses demonstrated that BMI had a positive correlation with pancreas size, actual islet count (AIC), and islet equivalent (IEQ)/g (all p ≤ 0.009), while CIT had a negative correlation with AIC and IEQ/g (all p ≤ 0.003). In mixed linear regression, BMI also had a positive correlation with islet size but only for shorter digestion times (≤15 min); there was no association between BMI and islet size for longer digestion times (>15 min). CIT was not associated with islet size. Donor age, sex, and preservation solutions were shown to have no correlation with islet yields or size distribution. Pancreas size had a positive correlation with AIC and a negative association with IEQ/g; it also had positive association with islet size but only for females, not males. Overdigestion was positively associated with islet counts; however, there was also a greater proportion of smaller islets when digestion rate was >74% (p = 0.005). Of the three collagenases analyzed, Sigma V had the lowest digestion rate (mean = 65%), approximately 5% or 10% lower than Roche Liberase HI (p = 0.04) and Serva NB1 (p = 0.0003), respectively; however, the Sigma V group showed better islet size preservation. Yet, the enzymes resulted in similar IEQ/g digested tissue. Of the isolated islets, 70.2% were smaller than 150 µm and contributed only 20.4% to the total IEQ, while 7.4% of the islets were larger than 250 µm but contributed 42.4% to the total IEQ. In summary, BMI, pancreas size, and CIT are useful variables for predicting islet yield, but selection of enzyme and balancing digestion time and rate are also important.
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Affiliation(s)
- Y Wang
- Department of Transplant/Surgery, University of Illinois at Chicago, Chicago, IL, USA
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Buchwald P, Cechin SR. Glucose-stimulated insulin secretion in isolated pancreatic islets: Multiphysics FEM model calculations compared to results of perifusion experiments with human islets. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/jbise.2013.65a006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Fraker CA, Cechin S, Álvarez-Cubela S, Echeverri F, Bernal A, Poo R, Ricordi C, Inverardi L, Domínguez-Bendala J. A physiological pattern of oxygenation using perfluorocarbon-based culture devices maximizes pancreatic islet viability and enhances β-cell function. Cell Transplant 2012; 22:1723-33. [PMID: 23068091 DOI: 10.3727/096368912x657873] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Conventional culture vessels are not designed for physiological oxygen (O2) delivery. Both hyperoxia and hypoxia-commonly observed when culturing cells in regular plasticware-have been linked to reduced cellular function and death. Pancreatic islets, used for the clinical treatment of diabetes, are especially sensitive to sub- and supraphysiological O2 concentrations. A result of current culture standards is that a high percentage of islet preparations are never transplanted because of cell death and loss of function in the 24-48 h postisolation. Here, we describe a new culture system designed to provide quasiphysiological oxygenation to islets in culture. The use of dishes where islets rest atop a perfluorocarbon (PFC)-based membrane, coupled with a careful adjustment of environmental O2 concentration to target the islet physiological pO2 range, resulted in dramatic gains in viability and function. These observations underline the importance of approximating culture conditions as closely as possible to those of the native microenvironment, and fill a widely acknowledged gap in our ability to preserve islet functionality in vitro. As stem cell-derived insulin-producing cells are likely to suffer from the same limitations as those observed in real islets, our findings are especially timely in the context of current efforts to define renewable sources for transplantation.
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Affiliation(s)
- Chris A Fraker
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
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Pedraza E, Brady AC, Fraker CA, Molano RD, Sukert S, Berman DM, Kenyon NS, Pileggi A, Ricordi C, Stabler CL. Macroporous three-dimensional PDMS scaffolds for extrahepatic islet transplantation. Cell Transplant 2012; 22:1123-35. [PMID: 23031502 DOI: 10.3727/096368912x657440] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Clinical islet transplantation has demonstrated success in treating type 1 diabetes. A current limitation is the intrahepatic portal vein transplant site, which is prone to mechanical stress and inflammation. Transplantation of pancreatic islets into alternative sites is preferable, but challenging, as it may require a three-dimensional vehicle to confer mechanical protection and to confine islets to a well-defined, retrievable space where islet neovascularization can occur. We have fabricated biostable, macroporous scaffolds from poly(dimethylsiloxane) (PDMS) and investigated islet retention and distribution, metabolic function, and glucose-dependent insulin secretion within these scaffolds. Islets from multiple sources, including rodents, nonhuman primates, and humans, were tested in vitro. We observed high islet retention and distribution within PDMS scaffolds, with retention of small islets (< 100 µm) improved through the postloading addition of fibrin gel. Islets loaded within PDMS scaffolds exhibited viability and function comparable to standard culture conditions when incubated under normal oxygen tensions, but displayed improved viability compared to standard two-dimensional culture controls under low oxygen tensions. In vivo efficacy of scaffolds to support islet grafts was evaluated after transplantation in the omental pouch of chemically induced diabetic syngeneic rats, which promptly achieved normoglycemia. Collectively, these results are promising in that they indicate the potential for transplanting islets into a clinically relevant, extrahepatic site that provides spatial distribution of islets as well as intradevice vascularization.
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Affiliation(s)
- Eileen Pedraza
- Diabetes Research Institute, University of Miami, Miami, FL 33136, USA
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Ho JH, Tseng TC, Ma WH, Ong WK, Chen YF, Chen MH, Lin MW, Hong CY, Lee OK. Multiple intravenous transplantations of mesenchymal stem cells effectively restore long-term blood glucose homeostasis by hepatic engraftment and β-cell differentiation in streptozocin-induced diabetic mice. Cell Transplant 2011; 21:997-1009. [PMID: 22004871 DOI: 10.3727/096368911x603611] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Depletion of pancreatic β-cells results in insulin insufficiency and diabetes mellitus (DM). Single transplantation of mesenchymal stem cells exhibits short-term effects in some preclinical studies. Here, we further investigated the long-term therapeutic effects of multiple intravenous MSC transplantations. In this study, multiple human MSC transplantations (4.2 × 10(7) cells/kg each time) were performed intravenously at 2-week intervals into streptozocin (STZ)-induced diabetic mice for 6 months. Blood sugar, insulin, renal function, cholesterol, and triglyceride levels were monitored. We demonstrated that compared to single intravenous transplantation, which only transiently decreased hyperglycemia, multiple MSC transplantations effectively restored blood glucose homeostasis. Systemic oxidative stress levels were reduced from the seventh week of treatment. From the 11th week, production of human insulin was markedly increased. When MSC transplantation was skipped after blood sugar level returned to normal at the end of 15th week, a sharp rebound of blood sugar occurred, and was then controlled by subsequent transplantations. At the end of 6 months, histopathology examination revealed MSCs specifically engrafted into liver tissues of the recipients. Fifty-one percent of human cells in the recipient liver coexpressed human insulin, especially those surrounding the central veins. Taken together, intravenous MSC delivery was safe and effective for blood glucose stabilization in this preclinical DM model. Multiple transplantations were essential to restore and maintain glucose homeostasis through decreasing systemic oxidative stress in the early stage and insulin production in the late stage. Liver engraftment and differentiation into insulin-producing cells account for the long-term therapeutic effects of MSCs.
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Affiliation(s)
- Jennifer H Ho
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
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