scholarly journals Bioengineering a pre-vascularized pouch for subsequent islet transplantation using VEGF-loaded polylactide capsules

2020 ◽  
Vol 8 (2) ◽  
pp. 631-647 ◽  
Author(s):  
Naresh Kasoju ◽  
Alžběta Pátíková ◽  
Edyta Wawrzynska ◽  
Alžběta Vojtíšková ◽  
Tomáš Sedlačík ◽  
...  
Keyword(s):  
Cell Transplantation ◽  
Islet Transplantation ◽  
Transplantation Site

The effectiveness of cell transplantation can be improved by optimization of the transplantation site.

scholarly journals Inflammatory Response in Islet Transplantation

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Mazhar A. Kanak ◽  
Morihito Takita ◽  
Faisal Kunnathodi ◽  
Michael C. Lawrence ◽  
Marlon F. Levy ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Cell Transplantation ◽  
Islet Transplantation ◽  
Islet Cell ◽  
Molecular Mechanisms ◽  
Graft Loss ◽  
Islet Cell Transplantation ◽  
Beta Cell Replacement ◽  
Insulin Dependent ◽  
Islet Inflammation

Islet cell transplantation is a promising beta cell replacement therapy for patients with brittle type 1 diabetes as well as refractory chronic pancreatitis. Despite the vast advancements made in this field, challenges still remain in achieving high frequency and long-term successful transplant outcomes. Here we review recent advances in understanding the role of inflammation in islet transplantation and development of strategies to prevent damage to islets from inflammation. The inflammatory response associated with islets has been recognized as the primary cause of early damage to islets and graft loss after transplantation. Details on cell signaling pathways in islets triggered by cytokines and harmful inflammatory events during pancreas procurement, pancreas preservation, islet isolation, and islet infusion are presented. Robust control of pre- and peritransplant islet inflammation could improve posttransplant islet survival and in turn enhance the benefits of islet cell transplantation for patients who are insulin dependent. We discuss several potent anti-inflammatory strategies that show promise for improving islet engraftment. Further understanding of molecular mechanisms involved in the inflammatory response will provide the basis for developing potent therapeutic strategies for enhancing the quality and success of islet transplantation.

Obstacles in the Application of Microencapsulation in Islet Transplantation

1993 ◽  
Vol 16 (4) ◽  
pp. 205-212 ◽  
Author(s):  
P. De Vos ◽  
G.H.J. Wolters ◽  
W.M. Fritschy ◽  
R. Van Schilfgaarde
Keyword(s):  
Islet Transplantation ◽  
Insulin Response ◽  
Limiting Factors ◽  
Survival Times ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Functional Aspects ◽  
Second Category ◽  
Transplantation Site ◽  
Insight Into

Several factors stand in the way of successful clinical transplantation of alginate-polylysine-alginate microencapsulated pancreatic islets. These obstacles can be classified into three categories. The first regards the technical aspects of the production process. Limiting factors are the insufficient ability to produce small capsules with an adequate production rate, and insufficient insight into the factors determining the optimal chemical and mechanical properties of the capsules. The second category regards the functional aspects of the microencapsulated islets, such as the limitations of the transplantation site and the absence of a physiologic insulin response of the encapsulated islets to elevated blood glucose levels. The third category regards the fact that survival times of encapsulated islet grafts are still limited to several weeks or months, which is mainly explained by a pericapsular fibrotic overgrowth reaction as a consequence of the bioincom-patibility of the capsule membrane. This study describes these obstacles, and thereby summarizes the requirements needed for successful clinical application of encapsulated islet transplantation.

scholarly journals Preferences of Type 1 Diabetic Patients on Devices for Islet Transplantation

2020 ◽  
Vol 29 ◽  
pp. 096368972095234
Author(s):  
M. Rezaa Mohammadi ◽  
Farideh Dehkordi-Vakil ◽  
Joni Ricks-Oddie ◽  
Robert Mansfield ◽  
Himala Kashimiri ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Type 1 Diabetes ◽  
Islet Transplantation ◽  
Credit Card ◽  
Implantable Devices ◽  
Diabetic Patients ◽  
Type 1 Diabetic Patients ◽  
To Receive ◽  
Transplantation Site

Transplantation of pancreatic islets within a biomaterial device is currently under investigation in clinical trials for the treatment of patients with type 1 diabetes (T1D). Patients’ preferences on such implants could guide the designs of next-generation implantable devices; however, such information is not currently available. We surveyed the preferences of 482 patients with T1D on the size, shape, visibility, and transplantation site of islet containing implants. More than 83% of participants were willing to receive autologous stem cells, and there was no significant association between implant fabricated by one’s own stem cell with gender ( χ 2 (1, n = 468) = 0.28; P = 0.6) or with age ( χ 2 (4, n = 468) = 2.92; P = 0.6). Preferred location for islet transplantation within devices was under the skin (52.7%). 48.3% preferred microscopic disks, and 32.3% preferred a thin device (like a credit card). Moreover, 58.4% preferred the implant to be as small as possible, 25.4% did not care about visibility, and 16.2% preferred their implants not to be visible. Among female participants, 81% cared about the implant visibility, whereas this number was 64% for male respondents ( χ 2 test (1, n = 468) = 16.34; P < 0.0001). 22% of those younger than 50 years of age and 30% of those older than 50 did not care about the visibility of implant ( χ 2 test (4, n = 468) = 23.69; P < 0.0001). These results suggest that subcutaneous sites and micron-sized devices are preferred choices among patients with T1D who participated in our survey.

scholarly journals Spleen, as an Optimal Site for Islet Transplantation

2018 ◽  
Author(s):  
Naoaki Sakata ◽  
Gumpei Yoshimatsu ◽  
Shohta Kodama
Keyword(s):  
Islet Transplantation ◽  
Islet Cells ◽  
Clinical Success ◽  
Splenic Infarction ◽  
Severe Diabetes ◽  
Clinical Islet Transplantation ◽  
Long Time ◽  
Transplantation Site ◽  
Optimal Site ◽  
Selection Of

Islet transplantation is a cellular replacement therapy to treat severe diabetes mellitus, but its clinical outcome is unsatisfactory at present. One factor in clinical success of this therapy is selection of the most appropriate transplantation site. In this review, we review evidence showing the advantages of the spleen as a transplantation site for islets. The spleen has been studied for a long time as a candidate site for islet transplantation. Its advantages include physiological insulin drainage and regulation of immunity. Recently it has also been shown that the spleen contributes to the regeneration of transplanted islets and that splenic stem cells have the potential to differentiate into islet cells. The spleen also has some disadvantages associated with the transplantation procedure itself (bleeding, thrombosis and splenic infarction). The efficacy of transplantation is not as high as that obtained with intraportal transplantation, which is the current representative method of clinical islet transplantation. Safer and more effective methods of islet transplantation need to be established before the spleen can be effectively used in the clinic to support the engraftment of multiple transplanted islets.

Experimental Islet Cell Transplantation in Rats: Optimization of the Transplantation Site

1998 ◽  
Vol 30 (2) ◽  
pp. 400-403 ◽  
Author(s):  
A. Refaie ◽  
M. Gabr ◽  
I. Mahmoud ◽  
M.A. Bakr ◽  
M. El-Baz ◽  
...  
Keyword(s):  
Cell Transplantation ◽  
Islet Cell ◽  
Islet Cell Transplantation ◽  
Transplantation Site

scholarly journals A New Islet Transplantation Method Combining Mesenchymal Stem Cells with Recombinant Peptide Pieces, Microencapsulated Islets, and Mesh Bags

Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 299
Author(s):  
Ryo Kogawa ◽  
Kentaro Nakamura ◽  
Yusuke Mochizuki
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Blood Glucose ◽  
Islet Transplantation ◽  
The Other ◽  
Recombinant Peptide ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Transplantation Site ◽  
Mesh Bag

Microencapsulated islet transplantation was widely studied as a promising treatment for type 1 diabetes mellitus. However, micro-encapsulated islet transplantation has the following problems—early dysfunction of the islets due to the inflammatory reaction at the transplantation site, and hyponutrition and hypoxia due to a lack of blood vessels around the transplantation site, and difficulty in removal of the islets. On the other hand, we proposed a cell transplantation technique called CellSaic, which was reported to enhance the vascular induction effect of mesenchymal stem cells (MSCs) in CellSaic form, and to enhance the effect of islet transplantation through co-transplantation. Therefore, we performed islet transplantation in diabetic mice by combining three components—microencapsulated islets, MSC-CellSaic, and a mesh bag that encapsulates them and enables their removal. Mesh pockets were implanted in the peritoneal cavity of Balb/c mice as implantation sites. After 4 weeks of implantation, a pocket was opened and transplanted with (1) pancreatic islets, (2) microencapsulated islets, and (3) microencapsulated islets + MSC-CellSaic. Four weeks of observation of blood glucose levels showed that the MSC-CellSaic co-transplant group showed a marked decrease in blood glucose levels, compared to the other groups. A three-component configuration of microcapsules, MSC-CellSaic, and mesh bag was shown to enhance the efficacy of islet transplantation.

630: A Novel Model System for the Treatment of Renal Cancer by Nonmyeloablative Allogeneic Hemopoietic Cell Transplantation Using Cyclophosphamide in Mice

2005 ◽  
Vol 173 (4S) ◽  
pp. 172-172
Author(s):  
Masatoshi Eto ◽  
Masahiko Harano ◽  
Katsunori Tatsugami ◽  
Hirofumi Koga ◽  
Seiji Naito
Keyword(s):  
Cell Transplantation ◽  
Renal Cancer ◽  
Model System ◽  
Hemopoietic Cell ◽  
Novel Model
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