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Mitchelson F, Safley SA, Gordon K, Weber CJ, Sambanis A. Peritoneal dissolved oxygen and function of encapsulated adult porcine islets transplanted in streptozotocin diabetic mice. Xenotransplantation 2021; 28:e12673. [PMID: 33522023 DOI: 10.1111/xen.12673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/06/2020] [Accepted: 12/24/2020] [Indexed: 01/02/2023]
Abstract
BACKGROUND Alginate-encapsulated islet xenografts have restored normoglycemia in diabetic animals for various periods of time. Plausible mechanisms of graft failure in vivo include immune rejection and hypoxia. We sought to understand the effects of encapsulated adult porcine islet (API) dosage on the peritoneal dissolved oxygen (DO) level in correlation to the achieved glycemic regulation in diabetic mice. METHODS Adult porcine islets encapsulated in barium alginate were transplanted intraperitoneally in streptozotocin diabetic BALB/c mice at 6000 and 4000 islet equivalents (IEQ) and in normal mice at 500 IEQ; APIs encapsulated in calcium alginate were transplanted at 6000 IEQ in diabetic mice. In all cases, cell-free barium alginate capsules containing a perfluorocarbon emulsion were co-implanted for DO measurements using 19 F NMR spectroscopy. Blood glucose levels and peritoneal DO were measured over 60 days or until graft failure. Explanted capsules were evaluated microscopically and histologically. RESULTS Both barium and calcium alginate-encapsulated APIs at 6000 IEQ reversed diabetes until day 60; barium alginate-encapsulated APIs at 4000 IEQ also reversed diabetes but with a higher failure rate. Transplanted APIs significantly reduced the peritoneal DO, approximately in a dose-dependent manner. The number of viable islets and the insulin content per capsule decreased over time. Capsules retrieved from normoglycemic mice exhibited minimal host cell adherence. CONCLUSIONS Transplantation of encapsulated APIs can reduce peritoneal DO to severely hypoxic levels. Although normoglycemia could be maintained within the study period, the DO levels suggest that hypoxia is a factor contributing to loss of islet viability and insulin secretion with time in mice.
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Affiliation(s)
- Fernie Mitchelson
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Susan A Safley
- Department of General Surgery, Emory University, Atlanta, GA, USA
| | - Kereen Gordon
- Department of General Surgery, Emory University, Atlanta, GA, USA
| | - Collin J Weber
- Department of General Surgery, Emory University, Atlanta, GA, USA
| | - Athanassios Sambanis
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, USA.,W.M. Keck Foundation, Los Angeles, CA, USA
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Chan KH, Krishnan R, Alexander M, Lakey JRT. Developing a Rapid Algorithm to Enable Rapid Characterization of Alginate Microcapsules. Cell Transplant 2017; 26:765-772. [PMID: 27729095 DOI: 10.3727/096368916x693446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The islets of Langerhans are endocrine tissue clusters that secrete hormones that regulate the body's glucose, carbohydrate, and fat metabolism, the most important of which is insulin, a hormone secreted by β-cells within the islets. In certain instances, a person's own immune system attacks and destroys them, leading to the development of type 1 diabetes (T1D), a life-long condition that needs daily insulin administration to maintain health and prolong survival. Islet transplantation is a surgical procedure that has demonstrated the ability to normalize blood sugar levels for up to a few years, but the need for chronic immunosuppression relegates it to a last resort that is often only used sparingly and in seriously ill patients. Islet microencapsulation is a biomedical innovation designed to protect islets from the immune system by coating them with a biocompatible polymer, and this new technology has demonstrated various degrees of success in small- and large-animal studies. This success is significantly impacted by microcapsule morphology and encapsulation efficiency. Since hundreds of thousands of microcapsules are generated during the process, characterization of encapsulated islets without the help of some degree of automation would be difficult, time-consuming, and error prone due to inherent observer bias. We have developed an image analysis algorithm that can analyze hundreds of microencapsulated islets and characterize their size, shape, circularity, and distortion with minimal observer bias. This algorithm can be easily adapted to similar nano- or microencapsulation technologies to implement stricter quality control and improve biomaterial device design and success.
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Sandrof MA, Emerich DF, Thanos CG. Primary Choroid Plexus Tissue for Use in Cellular Therapy. Methods Mol Biol 2017; 1479:237-249. [PMID: 27738941 DOI: 10.1007/978-1-4939-6364-5_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The choroid plexus (CP) has been explored as a cellular therapeutic due to its broad-ranging secretome and demonstrated longevity in a variety of encapsulation modalities. While the CP organ is normally involved in disease repair processes in the brain, the range of indications that could potentially be ameliorated with exogenous CP therapy is widespread, including diseases of the central nervous system, hearing loss, chronic wounds, and others. The CP can be isolated from animal sources and digested into a highly purified epithelial culture that can withstand encapsulation and transplantation. Its epithelium can adapt to different microenvironments, and depending on culture conditions, can be manipulated into various three-dimensional configurations with distinct gene expression profiles. The cocktail of proteins secreted by the CP can be harvested in culture, and purified forms of these extracts have been evaluated in topical applications to treat poorly healing wounds. When encapsulated, the epithelial clusters can be maintained for extended durations in vitro with minimal impact on potency. A treatment for Parkinson's disease utilizing encapsulated porcine CP has been developed and is currently being evaluated in a Phase I clinical trial. The current chapter serves to summarize recent experience with CP factor delivery, and provides a description of the relevant materials and methods employed in these studies.
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Affiliation(s)
- M A Sandrof
- Cytosolv, Inc., 117 Chapman Street, Suite 107, Providence, RI, 02905, USA
| | | | - Chris G Thanos
- Cytosolv, Inc., 117 Chapman Street, Suite 107, Providence, RI, 02905, USA.
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Cooper DK, Matsumoto S, Abalovich A, Itoh T, Mourad NI, Gianello PR, Wolf E, Cozzi E. Progress in Clinical Encapsulated Islet Xenotransplantation. Transplantation 2016; 100:2301-2308. [PMID: 27482959 PMCID: PMC5077652 DOI: 10.1097/tp.0000000000001371] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
At the 2015 combined congress of the Cell Transplant Society, International Pancreas and Islet Transplant Association, and International Xenotransplantation Association, a symposium was held to discuss recent progress in pig islet xenotransplantation. The presentations focused on 5 major topics - (1) the results of 2 recent clinical trials of encapsulated pig islet transplantation, (2) the inflammatory response to encapsulated pig islets, (3) methods to improve the secretion of insulin by pig islets, (4) genetic modifications to the islet-source pigs aimed to protect the islets from the primate immune and/or inflammatory responses, and (5) regulatory aspects of clinical pig islet xenotransplantation. Trials of microencapsulated porcine islet transplantation to treat unstable type 1 diabetic patients have been associated with encouraging preliminary results. Further advances to improve efficacy may include (1) transplantation into a site other than the peritoneal cavity, which might result in better access to blood, oxygen, and nutrients; (2) the development of a more biocompatible capsule and/or the minimization of a foreign body reaction; (3) pig genetic modification to induce a greater secretion of insulin by the islets, and/or to reduce the immune response to islets released from damaged capsules; and (4) reduction of the inflammatory response to the capsules/islets by improvements in the structure of the capsules and/or in genetic engineering of the pigs and/or in some form of drug therapy. Ethical and regulatory frameworks for islet xenotransplantation are already available in several countries, and there is now a wider international perception of the importance of developing an internationally harmonized ethical and regulatory framework.
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Affiliation(s)
- David K.C. Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shinichi Matsumoto
- Otsuka Pharmaceutical Factory, Tateiwa, Muya-cho, Naruto Tokushima, Japan
| | | | - Takeshi Itoh
- Department of Regenerative Medicine and Transplantation, Faculty of Medicine, Fukuoka University, Fukuoka City, Fukuoka, Japan
| | - Nizar I. Mourad
- Laboratory of Surgery and Transplantation, Catholic University of Louvain, Brussels, Belgium
| | - Pierre R Gianello
- Laboratory of Surgery and Transplantation, Catholic University of Louvain, Brussels, Belgium
| | - Eckhard Wolf
- Gene Center, LMU Munich and German Center for Diabetes Research (DZD), Munich, Germany
| | - Emanuele Cozzi
- Transplantation Immunology Unit, Padua University Hospital, and the Consortium for Research in Organ Transplantation (CORIT), Padua, Italy
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Itoh T, Hata Y, Nishinakamura H, Kumano K, Takahashi H, Kodama S. Islet-derived damage-associated molecular pattern molecule contributes to immune responses following microencapsulated neonatal porcine islet xenotransplantation in mice. Xenotransplantation 2016; 23:393-404. [DOI: 10.1111/xen.12253] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 06/29/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Takeshi Itoh
- Department of Regenerative Medicine & Transplantation; Faculty of Medicine; Fukuoka University; Fukuoka Japan
- Center for Regenerative Medicine; Fukuoka University Hospital; Fukuoka Japan
| | - Yuko Hata
- Department of Regenerative Medicine & Transplantation; Faculty of Medicine; Fukuoka University; Fukuoka Japan
| | - Hitomi Nishinakamura
- Department of Regenerative Medicine & Transplantation; Faculty of Medicine; Fukuoka University; Fukuoka Japan
- Department of Pharmacology; Faculty of Medicine; Fukuoka University; Fukuoka Japan
| | - Kenjiro Kumano
- Department of Regenerative Medicine & Transplantation; Faculty of Medicine; Fukuoka University; Fukuoka Japan
- Department of Gastroenterological Surgery; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan
| | - Hiroyuki Takahashi
- Department of Regenerative Medicine & Transplantation; Faculty of Medicine; Fukuoka University; Fukuoka Japan
- Center for Regenerative Medicine; Fukuoka University Hospital; Fukuoka Japan
- Department of Gastroenterological Surgery; Faculty of Medicine; Fukuoka University; Fukuoka Japan
| | - Shohta Kodama
- Department of Regenerative Medicine & Transplantation; Faculty of Medicine; Fukuoka University; Fukuoka Japan
- Center for Regenerative Medicine; Fukuoka University Hospital; Fukuoka Japan
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Zhu H, Yu L, He Y, Lyu Y, Wang B. Microencapsulated Pig Islet Xenotransplantation as an Alternative Treatment of Diabetes. TISSUE ENGINEERING PART B-REVIEWS 2015; 21:474-89. [PMID: 26028249 DOI: 10.1089/ten.teb.2014.0499] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Haitao Zhu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
- Heart Center, Northwest Women's and Children's Hospital, Xi'an, China
| | - Liang Yu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
| | - Yayi He
- Department of Endocrinology, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
| | - Yi Lyu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
- Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Bo Wang
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
- Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University, Xi'an, China
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Buzhor E, Leshansky L, Blumenthal J, Barash H, Warshawsky D, Mazor Y, Shtrichman R. Cell-based therapy approaches: the hope for incurable diseases. Regen Med 2015; 9:649-72. [PMID: 25372080 DOI: 10.2217/rme.14.35] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cell therapies aim to repair the mechanisms underlying disease initiation and progression, achieved through trophic effect or by cell replacement. Multiple cell types can be utilized in such therapies, including stem, progenitor or primary cells. This review covers the current state of cell therapies designed for the prominent disorders, including cardiovascular, neurological (Parkinson's disease, amyotrophic lateral sclerosis, stroke, spinal cord injury), autoimmune (Type 1 diabetes, multiple sclerosis, Crohn's disease), ophthalmologic, renal, liver and skeletal (osteoarthritis) diseases. Various cell therapies have reached advanced clinical trial phases with potential marketing approvals in the near future, many of which are based on mesenchymal stem cells. Advances in pluripotent stem cell research hold great promise for regenerative medicine. The information presented in this review is based on the analysis of the cell therapy collection detailed in LifeMap Discovery(®) (LifeMap Sciences Inc., USA) the database of embryonic development, stem cell research and regenerative medicine.
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Weidling J, Sameni S, Lakey JRT, Botvinick E. Method measuring oxygen tension and transport within subcutaneous devices. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:087006. [PMID: 25162910 PMCID: PMC4407670 DOI: 10.1117/1.jbo.19.8.087006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/27/2014] [Accepted: 07/28/2014] [Indexed: 06/03/2023]
Abstract
Cellular therapies hold promise to replace the implantation of whole organs in the treatment of disease. For most cell types, in vivo viability depends on oxygen delivery to avoid the toxic effects of hypoxia. A promising approach is the in situ vascularization of implantable devices which can mediate hypoxia and improve both the lifetime and utility of implanted cells and tissues. Although mathematical models and bulk measurements of oxygenation in surrounding tissue have been used to estimate oxygenation within devices, such estimates are insufficient in determining if supplied oxygen is sufficient for the entire thickness of the implanted cells and tissues. We have developed a technique in which oxygen-sensitive microparticles (OSMs) are incorporated into the volume of subcutaneously implantable devices. Oxygen partial pressure within these devices can be measured directly in vivo by an optical probe placed on the skin surface. As validation, OSMs have been incorporated into alginate beads, commonly used as immunoisolation devices to encapsulate pancreatic islet cells. Alginate beads were implanted into the subcutaneous space of Sprague–Dawley rats. Oxygen transport through beads was characterized from dynamic OSM signals in response to changes in inhaled oxygen. Changes in oxygen dynamics over days demonstrate the utility of our technology.
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Affiliation(s)
- John Weidling
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California 92617, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California 92617, United States
| | - Sara Sameni
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California 92617, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California 92617, United States
| | - Jonathan R. T. Lakey
- University of California Irvine, Department of Biomedical Engineering, Irvine, California 92617, United States
- University of California Irvine, Department of Surgery, Orange, California 92868, United States
| | - Elliot Botvinick
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California 92617, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California 92617, United States
- University of California Irvine, Department of Surgery, Orange, California 92868, United States
- University of California Irvine, Edwards Lifesciences Center for Advanced Cardiovascular Technology, 1002 Health Sciences Road, Irvine, California 92617, United States
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9
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Robles L, Storrs R, Lamb M, Alexander M, Lakey JRT. Current status of islet encapsulation. Cell Transplant 2013; 23:1321-48. [PMID: 23880554 DOI: 10.3727/096368913x670949] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell encapsulation is a method of encasing cells in a semipermeable matrix that provides a permeable gradient for the passage of oxygen and nutrients, but effectively blocks immune-regulating cells from reaching the graft, preventing rejection. This concept has been described as early as the 1930s, but it has exhibited substantial achievements over the last decade. Several advances in encapsulation engineering, chemical purification, applications, and cell viability promise to make this a revolutionary technology. Several obstacles still need to be overcome before this process becomes a reality, including developing a reliable source of islets or insulin-producing cells, determining the ideal biomaterial to promote graft function, reducing the host response to the encapsulation device, and ultimately a streamlined, scaled-up process for industry to be able to efficiently and safely produce encapsulated cells for clinical use. This article provides a comprehensive review of cell encapsulation of islets for the treatment of type 1 diabetes, including a historical perspective, current research findings, and future studies.
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Affiliation(s)
- Lourdes Robles
- Department of Surgery, University of California Irvine, Irvine, CA, USA
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10
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Immunoisolation. Biomater Sci 2013. [DOI: 10.1016/b978-0-08-087780-8.00123-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Mendelsohn AD, Nyitray C, Sena M, Desai TA. Size-controlled insulin-secreting cell clusters. Acta Biomater 2012; 8:4278-84. [PMID: 22902301 PMCID: PMC4030672 DOI: 10.1016/j.actbio.2012.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 08/03/2012] [Accepted: 08/08/2012] [Indexed: 10/28/2022]
Abstract
The search for an effective cure for type I diabetes from the transplantation of encapsulated pancreatic β-cell clusters has so far produced sub-optimal clinical outcomes. Previous efforts have not controlled the size of transplanted clusters, a parameter implicated in affecting long-term viability and the secretion of therapeutically sufficient insulin. Here we demonstrate a method based on covalent attachment of patterned laminin for fabricating uniformly size-controlled insulin-secreting cell clusters. We show that cluster size within the range 40-120μm in diameter affects a variety of therapeutically relevant cellular responses including insulin expression, content and secretion. Our studies elucidate two size-dependent phenomena: (1) as the cluster size increases from 40μm to 60μm, glucose stimulation results in a greater amount of insulin produced per cell; and (2) as the cluster size increases beyond 60μm, sustained glucose stimulation results in a greater amount of insulin secreted per cell. Our study describes a method for producing uniformly sized insulin-secreting cell clusters, and since larger cluster sizes risk nutrient availability limitations, our data suggest that 100-120μm clusters may provide optimal viability and efficacy for encapsulated β-cell transplants as a treatment for type I diabetes and that further in vivo evaluation is warranted.
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Affiliation(s)
- Adam D. Mendelsohn
- UC Berkeley – UCSF Graduate Program in Bioengineering, University of California at San Francisco and University of California at Berkeley, San Francisco, California, 94158
| | - Crystal Nyitray
- Department of Chemistry and Chemical Biology, University of California at San Francisco, San Francisco, California, 94158
| | - Mark Sena
- UC Berkeley – UCSF Graduate Program in Bioengineering, University of California at San Francisco and University of California at Berkeley, San Francisco, California, 94158
| | - Tejal A. Desai
- UC Berkeley – UCSF Graduate Program in Bioengineering, University of California at San Francisco and University of California at Berkeley, San Francisco, California, 94158
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, California, 94158
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Hillberg AL, Kathirgamanathan K, Lam JBB, Law LY, Garkavenko O, Elliott RB. Improving alginate-poly-L-ornithine-alginate capsule biocompatibility through genipin crosslinking. J Biomed Mater Res B Appl Biomater 2012; 101:258-68. [DOI: 10.1002/jbm.b.32835] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 09/11/2012] [Indexed: 12/11/2022]
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A three-dimensional microfluidic approach to scaling up microencapsulation of cells. Biomed Microdevices 2012; 14:461-9. [PMID: 22245953 DOI: 10.1007/s10544-011-9623-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Current applications of the microencapsulation technique include the use of encapsulated islet cells to treat Type 1 diabetes, and encapsulated hepatocytes for providing temporary but adequate metabolic support to allow spontaneous liver regeneration, or as a bridge to liver transplantation for patients with chronic liver disease. Also, microcapsules can be used for controlled delivery of therapeutic drugs. The two most widely used devices for microencapsulation are the air-syringe pump droplet generator and the electrostatic bead generator, each of which is fitted with a single needle through which droplets of cells suspended in alginate solution are produced and cross-linked into microbeads. A major drawback in the design of these instruments is that they are incapable of producing sufficient numbers of microcapsules in a short-time period to permit mass production of encapsulated and viable cells for transplantation in large animals and humans. We present in this paper a microfluidic approach to scaling up cell and protein encapsulations. The microfluidic chip consists of a 3D air supply and multi-nozzle outlet for microcapsule generation. It has one alginate inlet and one compressed air intlet. The outlet has 8 nozzles, each having 380 micrometers inner diameter, which produce hydrogel microspheres ranging from 500 to 700 μm in diameter. These nozzles are concentrically surrounded by air nozzles with 2 mm inner diameter. There are two tubes connected at the top to allow the air to escape as the alginate solution fills up the chamber. A variable flow pump 115 V is used to pump alginate solution and Tygon® tubing is used to connect in-house air supply to the air channel and peristaltic/syringe pump to the alginate chamber. A pressure regulator is used to control the flow rate of air. We have encapsulated islets and proteins with this high throughput device, which is expected to improve product quality control in microencapsulation of cells, and hence the outcome of their transplantation.
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Jeong JH, Yook S, Jung Y, Im BH, Lee M, Ahn CH, Lee DY, Byun Y. Functional enhancement of beta cells in transplanted pancreatic islets by secretion signal peptide-linked exendin-4 gene transduction. J Control Release 2012; 159:368-75. [DOI: 10.1016/j.jconrel.2012.01.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 12/29/2011] [Accepted: 01/22/2012] [Indexed: 10/14/2022]
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Park K. Functional enhancement of transplanted islets by Extendin-4. J Control Release 2012; 159:311. [DOI: 10.1016/j.jconrel.2012.04.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Accepted: 06/04/2011] [Indexed: 10/28/2022]
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Induction of protective genes leads to islet survival and function. J Transplant 2011; 2011:141898. [PMID: 22220267 PMCID: PMC3246756 DOI: 10.1155/2011/141898] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 09/01/2011] [Indexed: 12/16/2022] Open
Abstract
Islet transplantation is the most valid approach to the treatment of type 1 diabetes. However, the function of transplanted islets is often compromised since a large number of β cells undergo apoptosis induced by stress and the immune rejection response elicited by the recipient after transplantation. Conventional treatment for islet transplantation is to administer immunosuppressive drugs to the recipient to suppress the immune rejection response mounted against transplanted islets. Induction of protective genes in the recipient (e.g., heme oxygenase-1 (HO-1), A20/tumor necrosis factor alpha inducible protein3 (tnfaip3), biliverdin reductase (BVR), Bcl2, and others) or administration of one or more of the products of HO-1 to the donor, the islets themselves, and/or the recipient offers an alternative or synergistic approach to improve islet graft survival and function. In this perspective, we summarize studies describing the protective effects of these genes on islet survival and function in rodent allogeneic and xenogeneic transplantation models and the prevention of onset of diabetes, with emphasis on HO-1, A20, and BVR. Such approaches are also appealing to islet autotransplantation in patients with chronic pancreatitis after total pancreatectomy, a procedure that currently only leads to 1/3 of transplanted patients being diabetes-free.
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Abstract
PURPOSE OF REVIEW Porcine islet xenotransplantation into humans faces two major hurdles - safety issues related to xenosis and xenorejection of the transplants. The former has been overcome mainly by selection of a suitable disease-free source herd. RECENT FINDINGS Four strategies have been employed to date to overcome the rejection, all of which have shown some efficacy in animal models. SUMMARY Immune suppression, Sertoli cell co-transplantation and microencapsulation have been tried in type 1 diabetic humans with some clinical benefit derived reported from the latter two. Unaware hypoglycemia in particular seems amenable to the microencapsulation approach.
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Hall KK, Gattás-Asfura KM, Stabler CL. Microencapsulation of islets within alginate/poly(ethylene glycol) gels cross-linked via Staudinger ligation. Acta Biomater 2011; 7:614-24. [PMID: 20654745 DOI: 10.1016/j.actbio.2010.07.016] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 07/09/2010] [Accepted: 07/14/2010] [Indexed: 11/18/2022]
Abstract
Functionalized alginate and poly(ethylene glycol) (PEG) polymers were used to generate covalently linked alginate-PEG (XAlgPEG) microbeads of high stability. The cell-compatible Staudinger ligation scheme was used to cross-link phosphine-terminated PEG chemoselectively to azide-functionalized alginate, resulting in XAlgPEG hydrogels. XAlgPEG microbeads were formed by co-incubation of the two polymers, followed by ionic cross-linking of the alginate using barium ions. The enhanced stability and gel properties of the resulting XAlgPEG microbeads, as well as the compatibility of these polymers for the encapsulation of islets and beta cells lines, were investigated. The data show that XAlgPEG microbeads exhibit superior resistance to osmotic swelling compared with traditional barium cross-linked alginate (Ba-Alg) beads, with a five-fold reduction in observed swelling, as well as resistance to dissolution via chelation solution. Diffusion and porosity studies found XAlgPEG beads to exhibit properties comparable with standard Ba-Alg. XAlgPEG microbeads were found to be highly cell compatible with insulinoma cell lines, as well as rat and human pancreatic islets, where the viability and functional assessment of cells within XAlgPEG are comparable with Ba-Alg controls. The remarkable improved stability, as well as demonstrated cellular compatibility, of XAlgPEG hydrogels makes them an appealing option for a wide variety of tissue engineering applications.
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Affiliation(s)
- K K Hall
- Department of Biomedical Engineering, College of Engineering, University of Miami, 1450 NW 10th Avenue, Miami, FL 33136, USA
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Tan PLJ. Company profile: Tissue regeneration for diabetes and neurological diseases at Living Cell Technologies. Regen Med 2010; 5:181-7. [PMID: 20210578 DOI: 10.2217/rme.10.4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Living Cell Technologies’ (LCT’s) cell-based therapeutic for Type 1 diabetes, DIABECELL®, comprises encapsulated porcine insulin-producing cells. DIABECELL is presently in a Phase II clinical trial in New Zealand following positive early results. The cells are implanted into the abdomen to replace the patient’s pancreatic β-islet cells that have been lost as a result of autoimmune disease. LCT is also developing brain choroid plexus cells for the treatment of neurologic diseases. The aim is to enhance the brain’s natural repair mechanism by implanting cells releasing neurotrophins. Choroid plexus cell implants alleviate disease in animal models of Parkinson’s disease, Huntington’s disease and stroke. LCT encapsulates all cells in alginate, permitting implantation without using immunosuppressive drugs.
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Schmoeckel M. Xenotransplantation: die ewige Zukunft der Herztransplantation? ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2010. [DOI: 10.1007/s00398-009-0765-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Current world literature. Curr Opin Organ Transplant 2010; 15:254-61. [PMID: 20351662 DOI: 10.1097/mot.0b013e328337a8db] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Freimark D, Pino-Grace P, Pohl S, Weber C, Wallrapp C, Geigle P, Pörtner R, Czermak P. Use of Encapsulated Stem Cells to Overcome the Bottleneck of Cell Availability for Cell Therapy Approaches. ACTA ACUST UNITED AC 2010; 37:66-73. [PMID: 20737048 DOI: 10.1159/000285777] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 12/29/2009] [Indexed: 11/19/2022]
Abstract
Nowadays cell-based therapy is rarely in clinical practice because of the limited availability of appropriate cells. To apply cells therapeutically, they must not cause any immune response wherefore mainly autologous cells have been used up to now. The amount of vital cells in patients is limited, and under certain circumstances in highly degenerated tissues no vital cells are left. Moreover, the extraction of these cells is connected with additional surgery; also the expansion in vitro is difficult. Other approaches avoid these problems by using allo-or even xenogenic cells. These cells are more stable concerning their therapeutic behavior and can be produced in stock. To prevent an immune response caused by these cells, cell encapsulation (e.g. with alginate) can be performed. Certain studies showed that encapsulated allo- and xenogenic cells achieve promising results in treatment of several diseases. For such cell therapy approaches, stem cells, particularly mesenchymal stem cells, are an interesting cell source. This review deals on the one hand with the use of encapsulated cells, especially stem cells, in cell therapy and on the other hand with bioreactor systems for the expansion and differentiation of mesenchymal stem cells in reproducible and sufficient amounts for potential clinical use.
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Affiliation(s)
- D Freimark
- Institute of Biopharmaceutical Technology, University of Applied Sciences, Giessen, Hamburg, Germany
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Schneider MKJ, Seebach JD. Xenotransplantation literature update January-February, 2009. Xenotransplantation 2009; 16:115-7. [PMID: 19392726 DOI: 10.1111/j.1399-3089.2009.00516.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mårten K J Schneider
- Laboratory for Transplantation Immunology, Department of Internal Medicine, University Hospital Zurich, Raemistrasse 100, Zurich, Switzerland.
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