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Ladeira B, Custodio C, Mano J. Core-Shell Microcapsules: Biofabrication and Potential Applications in Tissue Engineering and Regenerative Medicine. Biomater Sci 2022; 10:2122-2153. [DOI: 10.1039/d1bm01974k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The construction of biomaterial scaffolds that accurately recreate the architecture of living tissues in vitro is a major challenge in the field of tissue engineering and regenerative medicine. Core-shell microcapsules...
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2
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Ramirez M, Courtoy G, Kharrat O, de Beukelaer M, Mourad N, Guiot Y, Bouzin C, Gianello P. Semi-automated digital quantification of cellular infiltrates for in vivo evaluation of transplanted islets of Langerhans encapsulated with bioactive materials. Xenotransplantation 2021; 28:e12704. [PMID: 34218466 DOI: 10.1111/xen.12704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/29/2021] [Accepted: 06/24/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND In the field of xenotransplantation, digital image analysis (DIA) is an asset to quantify heterogeneous cell infiltrates around transplanted encapsulated islets. MATERIALS AND METHODS RGD-alginate was used to produce empty capsules or to encapsulate neonatal porcine islets (NPI) with different combinations of human pancreatic extracellular matrix (hpECM), porcine mesenchymal stem cells (pMSC) and a chitosan anti-fouling coating. Capsules were transplanted subcutaneously in rats for one month and then processed for immunohistochemistry. Immunostainings for macrophages (CD68) and lymphocytes (CD3) were quantified by DIA in two concentric regions of interest (ROI) around the capsules. DIA replicability and reproducibility were assessed by two blind operators. Repeatability was evaluated by processing the same biopsies at different time points. DIA was also compared with quantification by point counting (PC). RESULTS Methodology validation: different sizes of ROIs were highly correlated. Intraclass correlation coefficients confirmed replicability and reproducibility. Repeatability showed a very strong correlation with CD3 stains and moderate/strong for CD68 stains. Group comparisons for CD68 IHC at each time point proved internal consistency. Point counting and DIA were strongly correlated with both CD3 and CD68. Capsule biocompatibility: Macrophage infiltration was higher around capsules containing biomaterials than around empty and RGD-alginate-NPI capsules. Lymphocytic infiltration was comparable among groups containing cells and higher than in empty capsules. CONCLUSION We validated a semi-automated quantification methodology to assess cellular infiltrates and successfully applied it to investigate graft biocompatibility, showing that neonatal porcine islets encapsulated in alginate alone triggered less infiltration than capsules containing islets and bioactive materials.
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Affiliation(s)
- Matias Ramirez
- Laboratory of Experimental Surgery and Transplantation, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
| | - Guillaume Courtoy
- IREC Imaging Platform, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Oumaima Kharrat
- Laboratory of Experimental Surgery and Transplantation, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
| | - Michele de Beukelaer
- IREC Imaging Platform, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Nizar Mourad
- Laboratory of Experimental Surgery and Transplantation, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
| | - Yves Guiot
- Department of Pathology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Caroline Bouzin
- IREC Imaging Platform, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Pierre Gianello
- Laboratory of Experimental Surgery and Transplantation, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
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3
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Leon Plata P, Zaroudi M, Lee CY, Foster C, Nitsche LC, Rios PD, Wang Y, Oberholzer J, Liu Y. Heterogeneous toroidal spiral particles for islet encapsulation. Biomater Sci 2021; 9:3954-3967. [PMID: 33620354 DOI: 10.1039/d0bm02082f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Transplantable cell encapsulation systems present a promising approach to deliver a therapeutic solution from hormone-producing cells for the treatment of endocrine diseases like type 1 diabetes. However, the development of a broadly effective and safe transplantation system has been challenging. While some current micro-sized capsules have been optimized for adequate nutrient and metabolic transport, they lack the robustness and retrievability for the clinical safety translation that macro-devices may offer. An existing challenge to be addressed in the current macro-devices is their configuration which may lead to unsatisfactory mass transfer. Here, we design and characterize a millimeter-size particle system of poly-ethylene glycol (PEG) featuring internal toroidal spiral channels, called toroidal spiral particles (TSPs). The characteristic internal structure of the TSPs allows for large encapsulation capacity and large surface area available to all the encapsulated cell mass for effective molecular diffusion. The polymeric matrix renders the particle flexible yet robust for safe transplantation and retrieval. We demonstrate the feasibility of fabricating these particles with various polymer compositions, while optimizing their mechanical properties as well as glucose and insulin permeability. Encapsulation of islets of Langerhans is achieved with high loading capacity (∼160 IEQ per TSP) and excellent cell viability. TSP-encapsulated islets showed similar glucose-stimulated insulin secretion to the naked islets. Preliminary biocompatibility of the TSPs on naïve C57BL/6 mice shows minimal inflammatory response after 4-week transplantation into the intraperitoneal (IP) space. Long-term therapeutic efficacy of encapsulated islets needs to be confirmed in diabetic rodent models in the future, while determining minimal mass required to reverse diabetes. However, we believe from the in vitro favorable results and the TSPs' unique design that TSPs may provide a safe, effective method to transplant and retrieve therapeutic cells for type 1 diabetes treatment and may also be applicable for other cell therapies.
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Affiliation(s)
- Paola Leon Plata
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL, USA.
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4
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Enck K, Tamburrini R, Deborah C, Gazia C, Jost A, Khalil F, Alwan A, Orlando G, Opara EC. Effect of alginate matrix engineered to mimic the pancreatic microenvironment on encapsulated islet function. Biotechnol Bioeng 2020; 118:1177-1185. [PMID: 33270214 DOI: 10.1002/bit.27641] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/15/2020] [Accepted: 11/21/2020] [Indexed: 12/13/2022]
Abstract
Islet transplantation is emerging as a therapeutic option for type 1 diabetes, albeit, only a small number of patients meeting very stringent criteria are eligible for the treatment because of the side effects of the necessary immunosuppressive therapy and the relatively short time frame of normoglycemia that most patients achieve. The challenge of the immune-suppressive regimen can be overcome through microencapsulation of the islets in a perm-selective coating of alginate microbeads with poly-l-lysine or poly- l-ornithine. In addition to other issues including the nutrient supply challenge of encapsulated islets a critical requirement for these cells has emerged as the need to engineer the microenvironment of the encapsulation matrix to mimic that of the native pancreatic scaffold that houses islet cells. That microenvironment includes biological and mechanical cues that support the viability and function of the cells. In this study, the alginate hydrogel was modified to mimic the pancreatic microenvironment by incorporation of extracellular matrix (ECM). Mechanical and biological changes in the encapsulating alginate matrix were made through stiffness modulation and incorporation of decellularized ECM, respectively. Islets were then encapsulated in this new biomimetic hydrogel and their insulin production was measured after 7 days in vitro. We found that manipulation of the alginate hydrogel matrix to simulate both physical and biological cues for the encapsulated islets enhances the mechanical strength of the encapsulated islet constructs as well as their function. Our data suggest that these modifications have the potential to improve the success rate of encapsulated islet transplantation.
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Affiliation(s)
- Kevin Enck
- Wake Forest School of Medicine, Virginia Tech School of Biomedical Engineering & Sciences (SBES), Wake Forest University, Winston-Salem, North Carolina.,Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina
| | - Riccardo Tamburrini
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina.,Department of Surgery, Wake Forest University, Winston-Salem, North Carolina
| | - Chaimov Deborah
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina.,Department of Surgery, Wake Forest University, Winston-Salem, North Carolina
| | - Carlo Gazia
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina.,Department of Surgery, Wake Forest University, Winston-Salem, North Carolina
| | - Alec Jost
- Wake Forest School of Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - Fatma Khalil
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina
| | - Abdelrahman Alwan
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina
| | - Giuseppe Orlando
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina.,Department of Surgery, Wake Forest University, Winston-Salem, North Carolina
| | - Emmanuel C Opara
- Wake Forest School of Medicine, Virginia Tech School of Biomedical Engineering & Sciences (SBES), Wake Forest University, Winston-Salem, North Carolina.,Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine (WFIRM), Winston-Salem, North Carolina
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5
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Liu Y, Yang M, Cui Y, Yao Y, Liao M, Yuan H, Gong G, Deng S, Zhao G. A novel prevascularized tissue-engineered chamber as a site for allogeneic and xenogeneic islet transplantation to establish a bioartificial pancreas. PLoS One 2020; 15:e0234670. [PMID: 33270650 PMCID: PMC7714105 DOI: 10.1371/journal.pone.0234670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/18/2020] [Indexed: 12/16/2022] Open
Abstract
Although sites for clinical or experimental islet transplantation are well established, pancreatic islet survival and function in these locations remain unsatisfactory. A possible factor that might account for this outcome is local hypoxia caused by the limited blood supply. Here, we modified a prevascularized tissue-engineered chamber (TEC) that facilitated the viability and function of the seeded islets in vivo by providing a microvascular network prior to transplantation. TECs were created, filled with Growth Factor-Matrigel™ (Matrigel™) and then implanted into the groins of mice with streptozotocin-induced diabetes. The degree of microvascularization in each TECs was analyzed by histology, real-time PCR, and Western blotting. Three hundred syngeneic islets were seeded into each chamber on days 0, 14, and 28 post-chamber implantation, and 300, 200, or 100 syngeneic islets were seeded into additional chambers on day 28 post-implantation, respectively. Furthermore, allogeneic or xenogeneic islet transplantation is a potential solution for organ shortage. The feasibility of TECs as transplantation sites for islet allografts or xenografts and treatment with anti-CD45RB and/or anti-CD40L (MR-1) was therefore explored. A highly developed microvascularized network was established in each TEC on day 28 post-implantation. Normalization of blood glucose levels in diabetic mice was negatively correlated with the duration of prevascularization and the number of seeded syngeneic islets. Combined treatment with anti-CD45RB and MR-1 resulted in long-term survival of the grafts following allotransplantation (5/5, 100%) and xenotransplantation (16/20, 80%). Flow cytometry demonstrated that the frequency of CD4+Foxp3-Treg and CD4+IL-4+-Th2 cells increased significantly after tolerogenic xenograft transplantation, while the number of CD4+IFN-γ-Th1 cells decreased. These findings demonstrate that highly developed microvascularized constructs can facilitate the survival of transplanted islets in a TECs, implying its potential application as artificial pancreas in the future.
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Affiliation(s)
- Yanzhuo Liu
- Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Maozhu Yang
- Organ Transplantation Translational Medicine Key Laboratory of Sichuan Province, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, Chengdu, Sichuan Province, China
| | - Yuanyuan Cui
- Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Yuanyuan Yao
- Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Minxue Liao
- Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Hao Yuan
- Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Guojin Gong
- Department of Gastrointestinal Surgery, Xi Chang People’s Hospital, Xi Chang, Sichuan Province, China
| | - Shaoping Deng
- Organ Transplantation Translational Medicine Key Laboratory of Sichuan Province, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, Chengdu, Sichuan Province, China
| | - Gaoping Zhao
- Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
- Organ Transplantation Translational Medicine Key Laboratory of Sichuan Province, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, Chengdu, Sichuan Province, China
- * E-mail:
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6
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Somo SI, Brown JM, Brey EM. Dual Crosslinking of Alginate Outer Layer Increases Stability of Encapsulation System. Front Chem 2020; 8:575278. [PMID: 33282827 PMCID: PMC7688585 DOI: 10.3389/fchem.2020.575278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/21/2020] [Indexed: 01/17/2023] Open
Abstract
The current standard treatment for Type 1 diabetes is the administration of exogenous insulin to manage blood glucose levels. Cellular therapies are in development to address this dependency and allow patients to produce their own insulin. Studies have shown that viable, functional allogenic islets can be encapsulated inside alginate-based materials as a potential treatment for Type 1 diabetes. The capability of these grafts is limited by several factors, among which is the stability and longevity of the encapsulating material in vivo. Previous studies have shown that multilayer Alginate-Poly-L-Ornithine-Alginate (A-PLO-A) microbeads are effective in maintaining cellular function in vivo. This study expands upon the existing encapsulation material by investigating whether covalent crosslinking of the outer alginate layer increases stability. The alginate comprising the outer layer was methacrylated, allowing it to be covalently crosslinked. Microbeads with a crosslinked outer layer exhibited a consistent outer layer thickness and increased stability when exposed to chelating agents in vitro. The outer layer was maintained in vivo even in the presence of a robust inflammatory response. The results demonstrate a technique for generating A-PLO-A with a covalently crosslinked outer layer.
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Affiliation(s)
- Sami I. Somo
- Biomedical Engineering Department, Illinois Institute of Technology, Chicago, IL, United States
| | - Jacob M. Brown
- Biomedical Engineering Department, University of Texas at San Antonio, San Antonio, TX, United States
| | - Eric M. Brey
- Biomedical Engineering Department, University of Texas at San Antonio, San Antonio, TX, United States
- *Correspondence: Eric M. Brey
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White Adipose Tissue as a Site for Islet Transplantation. TRANSPLANTOLOGY 2020. [DOI: 10.3390/transplantology1010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Although islet transplantation is recognized as a useful cellular replacement therapy for severe diabetes, surgeons face difficulties in islet engraftment. The transplant site is a pivotal factor that influences the engraftment. Although the liver is the current representative site for clinical islet transplantation, it is not the best site because of limitations in immunity, inflammation, and hypoxia. White adipose tissue, including omentum, is recognized as a useful candidate site for islet transplantation. Its effectiveness has been evaluated in not only various basic and translational studies using small and large animals but also in some recent clinical trials. In this review, we attempt to shed light on the characteristics and usefulness of white adipose tissue as a transplant site for islets.
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8
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White Adipose Tissue as a Site for Islet Transplantation. TRANSPLANTOLOGY 2020. [DOI: 10.3390/transplantology1020006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Although islet transplantation is recognized as a useful cellular replacement therapy for severe diabetes, surgeons face difficulties in islet engraftment. The transplant site is a pivotal factor that influences the engraftment. Although the liver is the current representative site for clinical islet transplantation, it is not the best site because of limitations in immunity, inflammation, and hypoxia. White adipose tissue, including omentum, is recognized as a useful candidate site for islet transplantation. Its effectiveness has been evaluated in not only various basic and translational studies using small and large animals but also in some recent clinical trials. In this review, we attempt to shed light on the characteristics and usefulness of white adipose tissue as a transplant site for islets.
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9
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Xu Y, Xia M, Chen T, Yang Y, Fu G, Ji P, Wu Q. Inferior alveolar nerve transection disturbs innate immune responses and bone healing after tooth extraction. Ann N Y Acad Sci 2019; 1448:52-64. [PMID: 31095746 DOI: 10.1111/nyas.14120] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/14/2019] [Accepted: 04/24/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Yamei Xu
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
| | - Mengnan Xia
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
| | - Tao Chen
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
| | - Yao Yang
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
| | - Gang Fu
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
| | - Ping Ji
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
| | - Qingqing Wu
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical SciencesChongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China
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Salg GA, Giese NA, Schenk M, Hüttner FJ, Felix K, Probst P, Diener MK, Hackert T, Kenngott HG. The emerging field of pancreatic tissue engineering: A systematic review and evidence map of scaffold materials and scaffolding techniques for insulin-secreting cells. J Tissue Eng 2019; 10:2041731419884708. [PMID: 31700597 PMCID: PMC6823987 DOI: 10.1177/2041731419884708] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/04/2019] [Indexed: 12/18/2022] Open
Abstract
A bioartificial endocrine pancreas is proposed as a future alternative to current treatment options. Patients with insulin-secretion deficiency might benefit. This is the first systematic review that provides an overview of scaffold materials and techniques for insulin-secreting cells or cells to be differentiated into insulin-secreting cells. An electronic literature survey was conducted in PubMed/MEDLINE and Web of Science, limited to the past 10 years. A total of 197 articles investigating 60 different materials met the inclusion criteria. The extracted data on materials, cell types, study design, and transplantation sites were plotted into two evidence gap maps. Integral parts of the tissue engineering network such as fabrication technique, extracellular matrix, vascularization, immunoprotection, suitable transplantation sites, and the use of stem cells are highlighted. This systematic review provides an evidence-based structure for future studies. Accumulating evidence shows that scaffold-based tissue engineering can enhance the viability and function or differentiation of insulin-secreting cells both in vitro and in vivo.
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Affiliation(s)
- Gabriel Alexander Salg
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Nathalia A Giese
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Miriam Schenk
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Felix J Hüttner
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Klaus Felix
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Pascal Probst
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus K Diener
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Thilo Hackert
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Hannes Götz Kenngott
- Department of General, Abdominal and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany
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Zhu H, Li W, Liu Z, Li W, Chen N, Lu L, Zhang W, Wang Z, Wang B, Pan K, Zhang X, Chen G. Selection of Implantation Sites for Transplantation of Encapsulated Pancreatic Islets. TISSUE ENGINEERING PART B-REVIEWS 2018; 24:191-214. [PMID: 29048258 DOI: 10.1089/ten.teb.2017.0311] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pancreatic islet transplantation has been validated as a valuable therapy for type 1 diabetes mellitus patients with exhausted insulin treatment. However, this therapy remains limited by the shortage of donor and the requirement of lifelong immunosuppression. Islet encapsulation, as an available bioartificial pancreas (BAP), represents a promising approach to enable protecting islet grafts without or with minimal immunosuppression and possibly expanding the donor pool. To develop a clinically implantable BAP, some key aspects need to be taken into account: encapsulation material, capsule design, and implant site. Among them, the implant site exerts an important influence on the engraftment, stability, and biocompatibility of implanted BAP. Currently, an optimal site for encapsulated islet transplantation may include sufficient capacity to host large graft volumes, portal drainage, ease of access using safe and reproducible procedure, adequate blood/oxygen supply, minimal immune/inflammatory reaction, pliable for noninvasive imaging and biopsy, and potential of local microenvironment manipulation or bioengineering. Varying degrees of success have been confirmed with the utilization of liver or extrahepatic sites in an experimental or preclinical setting. However, the ideal implant site remains to be further engineered or selected for the widespread application of encapsulated islet transplantation.
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Affiliation(s)
- Haitao Zhu
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China .,2 Department of Hepatobiliary Surgery, the First Affiliated Hospital, Medical School of Xi'an Jiaotong University , Xi'an, China
| | - Wenjing Li
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Zhongwei Liu
- 3 Department of Cardiology, Shaanxi Provincial People's Hospital , Xi'an, China
| | - Wenliang Li
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Niuniu Chen
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Linlin Lu
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Wei Zhang
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Zhen Wang
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Bo Wang
- 2 Department of Hepatobiliary Surgery, the First Affiliated Hospital, Medical School of Xi'an Jiaotong University , Xi'an, China .,4 Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University , Xi'an, China
| | - Kaili Pan
- 5 Department of Pediatrics (No. 2 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Xiaoge Zhang
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
| | - Guoqiang Chen
- 1 Department of Pediatrics (No. 3 Ward), Northwest Women's and Children's Hospital , Xi'an, China
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Gonzalez-Pujana A, Orive G, Pedraz JL, Santos-Vizcaino E, Hernandez RM. Alginate Microcapsules for Drug Delivery. SPRINGER SERIES IN BIOMATERIALS SCIENCE AND ENGINEERING 2018. [DOI: 10.1007/978-981-10-6910-9_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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13
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Somo SI, Langert K, Yang CY, Vaicik MK, Ibarra V, Appel AA, Akar B, Cheng MH, Brey EM. Synthesis and evaluation of dual crosslinked alginate microbeads. Acta Biomater 2018; 65:53-65. [PMID: 29101016 PMCID: PMC5902406 DOI: 10.1016/j.actbio.2017.10.046] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 10/28/2017] [Accepted: 10/30/2017] [Indexed: 12/17/2022]
Abstract
Alginate hydrogels have been investigated for a broad variety of medical applications. The ability to assemble hydrogels at neutral pH and mild temperatures makes alginate a popular choice for the encapsulation and delivery of cells and proteins. Alginate has been studied extensively for the delivery of islets as a treatment for type 1 diabetes. However, poor stability of the encapsulation systems after implantation remains a challenge. In this paper, alginate was modified with 2-aminoethyl methacrylate hydrochloride (AEMA) to introduce groups that can be photoactivated to generate covalent bonds. This enabled formation of dual crosslinked structure upon exposure to ultraviolet light following initial ionic crosslinking into bead structures. The degree of methacrylation was varied and in vitro stability, long term swelling, and cell viability examined. At low levels of the methacrylation, the beads could be formed by first ionic crosslinks followed by exposure to ultraviolet light to generate covalent bonds. The methacrylated alginate resulted in more stable beads and cells were viable following encapsulation. Alginate microbeads, ionic (unmodified) and dual crosslinked, were implanted into a rat omentum pouch model. Implantation was performed with a local injection of 100 µl of 50 µg/ml of Lipopolysaccharide (LPS) to stimulate a robust inflammatory challenge in vivo. Implants were retrieved at 1 and 3 weeks for analysis. The unmodified alginate microbeads had all failed by week 1, whereas the dual-crosslinked alginate microbeads remained stable up through 3 weeks. The modified alginate microbeads may provide a more stable alternative to current alginate-based systems for cell encapsulation. STATEMENT OF SIGNIFICANCE Alginate, a naturally occurring polysaccharide, has been used for cell encapsulation to prevent graft rejection of cell transplants for people with type I diabetes. Although some success has been observed in clinical trials, the lack of reproducibility and failure to reach insulin dependence for longer periods of time indicates the need for improvements in the procedure. A major requirement for the long-term function of alginate encapsulated cells is the mechanical stability of microcapsules. Insufficient mechanical integrity of the capsules can lead to immunological reactions in the recipients. In this work, alginate was modified to allow photoactivatable groups in order to allow formation of covalent crosslinks in addition to ionic crosslinking. The dual crosslinking design prevents capsule breakdown following implantation in vivo.
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Affiliation(s)
- Sami I Somo
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; Research Service, Edward Hines, Jr. VA. Hospital, Hines, IL, USA
| | - Kelly Langert
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; Research Service, Edward Hines, Jr. VA. Hospital, Hines, IL, USA
| | - Chin-Yu Yang
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Marcella K Vaicik
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; Research Service, Edward Hines, Jr. VA. Hospital, Hines, IL, USA
| | - Veronica Ibarra
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Alyssa A Appel
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Banu Akar
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; Research Service, Edward Hines, Jr. VA. Hospital, Hines, IL, USA
| | - Ming-Huei Cheng
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
| | - Eric M Brey
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; Research Service, Audie L. Murphy Memorial VA Hospital, San Antonio, TX, USA; Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA
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14
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Gonzalez-Pujana A, Santos E, Orive G, Pedraz JL, Hernandez RM. Cell microencapsulation technology: Current vision of its therapeutic potential through the administration routes. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2017.03.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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15
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Appel AA, Ibarra V, Somo SI, Larson JC, Garson AB, Guan H, McQuilling JP, Zhong Z, Anastasio MA, Opara EC, Brey EM. Imaging of Hydrogel Microsphere Structure and Foreign Body Response Based on Endogenous X-Ray Phase Contrast. Tissue Eng Part C Methods 2016; 22:1038-1048. [PMID: 27796159 PMCID: PMC5116683 DOI: 10.1089/ten.tec.2016.0253] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/28/2016] [Indexed: 12/22/2022] Open
Abstract
Transplantation of functional islets encapsulated in stable biomaterials has the potential to cure Type I diabetes. However, the success of these materials requires the ability to quantitatively evaluate their stability. Imaging techniques that enable monitoring of biomaterial performance are critical to further development in the field. X-ray phase-contrast (XPC) imaging is an emerging class of X-ray techniques that have shown significant promise for imaging biomaterial and soft tissue structures. In this study, XPC imaging techniques are shown to enable three dimensional (3D) imaging and evaluation of islet volume, alginate hydrogel structure, and local soft tissue features ex vivo. Rat islets were encapsulated in sterile ultrapurified alginate systems produced using a high-throughput microfluidic system. The encapsulated islets were implanted in omentum pouches created in a rodent model of type 1 diabetes. Microbeads were imaged with XPC imaging before implantation and as whole tissue samples after explantation from the animals. XPC microcomputed tomography (μCT) was performed with systems using tube-based and synchrotron X-ray sources. Islets could be identified within alginate beads and the islet volume was quantified in the synchrotron-based μCT volumes. Omental adipose tissue could be distinguished from inflammatory regions resulting from implanted beads in harvested samples with both XPC imaging techniques. Individual beads and the local encapsulation response were observed and quantified using quantitative measurements, which showed good agreement with histology. The 3D structure of the microbeads could be characterized with XPC imaging and failed beads could also be identified. These results point to the substantial potential of XPC imaging as a tool for imaging biomaterials in small animal models and deliver a critical step toward in vivo imaging.
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Affiliation(s)
- Alyssa A. Appel
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Services, Edward Hines Jr. VA Hospital, Chicago, Illinois
| | - Veronica Ibarra
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Sami I. Somo
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Jeffery C. Larson
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Services, Edward Hines Jr. VA Hospital, Chicago, Illinois
| | - Alfred B. Garson
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Huifeng Guan
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | | | - Zhong Zhong
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York
| | - Mark A. Anastasio
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Emmanuel C. Opara
- Wake Forest Institute of Regenerative Medicine, Winston-Salem, North Carolina
| | - Eric M. Brey
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Services, Edward Hines Jr. VA Hospital, Chicago, Illinois
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