scholarly journals Integration of Islet/Beta-Cell Transplants with Host Tissue Using Biomaterial Platforms

Endocrinology ◽  
2020 ◽  
Vol 161 (11) ◽  
Author(s):  
Daniel W Clough ◽  
Jessica L King ◽  
Feiran Li ◽  
Lonnie D Shea

Abstract Cell-based therapies are emerging for type I diabetes mellitus (T1D), an autoimmune disease characterized by the destruction of insulin-producing pancreatic β-cells, as a means to provide long-term restoration of glycemic control. Biomaterial scaffolds provide an opportunity to enhance the manufacturing and transplantation of islets or stem cell–derived β-cells. In contrast to encapsulation strategies that prevent host contact with the graft, recent approaches aim to integrate the transplant with the host to facilitate glucose sensing and insulin distribution, while also needing to modulate the immune response. Scaffolds can provide a supportive niche for cells either during the manufacturing process or following transplantation at extrahepatic sites. Scaffolds are being functionalized to deliver oxygen, angiogenic, anti-inflammatory, or trophic factors, and may facilitate cotransplantation of cells that can enhance engraftment or modulate immune responses. This local engineering of the transplant environment can complement systemic approaches for maximizing β-cell function or modulating immune responses leading to rejection. This review discusses the various scaffold platforms and design parameters that have been identified for the manufacture of human pluripotent stem cell–derived β-cells, and the transplantation of islets/β-cells to maintain normal blood glucose levels.

2021 ◽  
Vol 12 ◽  
Author(s):  
Eleonora de Klerk ◽  
Matthias Hebrok

Since its introduction more than twenty years ago, intraportal allogeneic cadaveric islet transplantation has been shown to be a promising therapy for patients with Type I Diabetes (T1D). Despite its positive outcome, the impact of islet transplantation has been limited due to a number of confounding issues, including the limited availability of cadaveric islets, the typically lifelong dependence of immunosuppressive drugs, and the lack of coverage of transplant costs by health insurance companies in some countries. Despite improvements in the immunosuppressive regimen, the number of required islets remains high, with two or more donors per patient often needed. Insulin independence is typically achieved upon islet transplantation, but on average just 25% of patients do not require exogenous insulin injections five years after. For these reasons, implementation of islet transplantation has been restricted almost exclusively to patients with brittle T1D who cannot avoid hypoglycemic events despite optimized insulin therapy. To improve C-peptide levels in patients with both T1 and T2 Diabetes, numerous clinical trials have explored the efficacy of mesenchymal stem cells (MSCs), both as supporting cells to protect existing β cells, and as source for newly generated β cells. Transplantation of MSCs is found to be effective for T2D patients, but its efficacy in T1D is controversial, as the ability of MSCs to differentiate into functional β cells in vitro is poor, and transdifferentiation in vivo does not seem to occur. Instead, to address limitations related to supply, human embryonic stem cell (hESC)-derived β cells are being explored as surrogates for cadaveric islets. Transplantation of allogeneic hESC-derived insulin-producing organoids has recently entered Phase I and Phase II clinical trials. Stem cell replacement therapies overcome the barrier of finite availability, but they still face immune rejection. Immune protective strategies, including coupling hESC-derived insulin-producing organoids with macroencapsulation devices and microencapsulation technologies, are being tested to balance the necessity of immune protection with the need for vascularization. Here, we compare the diverse human stem cell approaches and outcomes of recently completed and ongoing clinical trials, and discuss innovative strategies developed to overcome the most significant challenges remaining for transplanting stem cell-derived β cells.


2018 ◽  
Vol 96 (8) ◽  
pp. 710-718 ◽  
Author(s):  
Amir Mohamed Abdelhamid ◽  
Rania Ramadan Abdelaziz ◽  
Hatem Abdelrahman Ali Salem

Type I diabetes (TID) is generally assumed to be caused by an immune associated, if not directly immune-mediated, destruction of pancreatic β-cells. In patients with long-term diabetes, the pancreas lacks insulin-producing cells and the residual β-cells are unable to regenerate. Patients with TID are subjected to a lifelong insulin therapy which shows risks of hypoglycemia, suboptimal control and ketosis. In this study, we investigated the potential role of vildagliptin (Vilda) alone or in combination with pioglitazone (Pio), as treatment regimens for TID using streptozotocin (STZ)-induced TID model in rats. Daily oral administration of Vilda (5 mg/kg) alone or in combination with Pio (20 mg/kg) for 7 weeks significantly reduced blood glucose levels and HbA1c. It increased serum insulin levels and decreased serum glucagon. It also showed a strong antioxidant activity. Immunohistochemical analysis showed a marked improvement in β-cells in treated groups when compared with the diabetic group, which appeared in the normal cellular and architecture restoration of β-cells in the islets of Langerhans. Vilda alone or in combination with Pio has the ability to improve the overall glycemic control in type I diabetic rats and may be considered a hopeful and effective remedy for TID.


MEDISAINS ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 19
Author(s):  
Fairuz Fairuz ◽  
Hasna Dewi ◽  
Humaryanto Humaryanto

Background: Therapies for hyperglycemic treatment, including insulin and oral diabetes medications, have been confirmed to cause several side effects. Thus, finding new drugs with fewer side effects is of high importance. Salung leaf herb (Psychotria malayana Jack) reported used in traditional societies as a treatment for diabetes. However, the scientific proof of this plant for diabetes treatment is still lacking.Objective: To evaluate the antidiabetic effect of the P. malayana jack in induced type 1 diabetic rats by assessing blood glucose level and pancreatic cells in white rats.Methods: Alloxan used to induce type I diabetes. Rats randomly divided into six groups. A Group P1 received 250 mg/kg BW; group P2 received 500 mg/kg BW, group P3 received 1000 mg/kg BW. While group 4 basal received no treatment, group 5 received distilled water as a negative control, and group 6 received glibenclamide as a positive control. Medications are given for six days. Glucose levels were measured, and observation of pancreatic Langerhans cell damages.Results:  A decrease in blood glucose levels observed in all treatment groups. The most significant reduction (49.76%; 1000 mg/kg BW) occurred in the P3 group. Morphological features of pancreatic Langerhans cell damage were slightly high in the P1 group.Conclusion: P. malayana Jack can consider having an antidiabetic effect in a type 1 diabetic rat by reducing blood glucose levels.


2019 ◽  
Vol 14 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Junaid Khan ◽  
Amit Alexander ◽  
Mukta Agrawal ◽  
Ajazuddin ◽  
Sunil Kumar Dubey ◽  
...  

Diabetes and its complications are a significant health concern throughout the globe. There are physiological differences in the mechanism of type-I and type-II diabetes and the conventional drug therapy as well as insulin administration seem to be insufficient to address the problem at large successfully. Hypoglycemic swings, frequent dose adjustments and resistance to the drug are major problems associated with drug therapy. Cellular approaches through stem cell based therapeutic interventions offer a promising solution to the problem. The need for pancreatic transplants in case of Type- I diabetes can also be by-passed/reduced due to the formation of insulin producing β cells via stem cells. Embryonic Stem Cells (ESCs) and induced Pluripotent Stem Cells (iPSCs), successfully used for generating insulin producing β cells. Although many experiments have shown promising results with stem cells in vitro, their clinical testing still needs more exploration. The review attempts to bring into light the clinical studies favoring the transplantation of stem cells in diabetic patients with an objective of improving insulin secretion and improving degeneration of different tissues in response to diabetes. It also focuses on the problems associated with successful implementation of the technique and possible directions for future research.


Diabetologia ◽  
2000 ◽  
Vol 43 (8) ◽  
pp. 1000-1004 ◽  
Author(s):  
P. Pozzilli ◽  
D. Pitocco ◽  
N. Visalli ◽  
M. G. Cavallo ◽  
R. Buzzetti ◽  
...  

2018 ◽  
Vol 314 (5) ◽  
pp. E512-E521 ◽  
Author(s):  
Michael G. Spelios ◽  
Lauren A. Afinowicz ◽  
Regine C. Tipon ◽  
Eitan M. Akirav

Three-dimensional (3D) pseudoislets (PIs) can be used for the study of insulin-producing β-cells in free-floating islet-like structures similar to that of primary islets. Previously, we demonstrated the ability of islet-derived endothelial cells (iECs) to induce PIs using murine insulinomas, where PI formation enhanced insulin production and glucose responsiveness. In this report, we examined the ability of iECs to spontaneously induce the formation of free-floating 3D PIs using the EndoC-βH1 human β-cell line murine MS1 iEC. Within 14 days, the coculturing of both cell types produced fully humanized EndoC-βH1 PIs with little to no contaminating murine iECs. The size and shape of these PIs were similar to primary human islets. iEC-induced PIs demonstrated reduced dysregulated insulin release under low glucose levels and higher insulin secretion in response to high glucose and exendin-4 [a glucagon-like peptide-1 (GLP-1) analog] compared with monolayer cells cultured alone. Interestingly, iEC-PIs were also better at glucose sensing in the presence of extendin-4 compared with PIs generated on a low-adhesion surface plate in the absence of iECs and showed an overall improvement in cell viability. iEC-induced PIs exhibited increased expression of key genes involved in glucose transport, glucose sensing, β-cell differentiation, and insulin processing, with a concomitant decrease in glucagon mRNA expression. The enhanced responsiveness to exendin-4 was associated with increased protein expression of GLP-1 receptor and phosphokinase A. This rapid coculture system provides an unlimited number of human PIs with improved insulin secretion and GLP-1 responsiveness for the study of β-cell biology.


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