Extracellular hemoglobin combined with an O2‐generating material overcomes O2 limitation in the bioartificial pancreas.

Autor: Mouré, Anne, Bacou, Elodie, Bosch, Steffi, Jegou, Dominique, Salama, Apolline, Riochet, David, Gauthier, Olivier, Blancho, Gilles, Soulillou, Jean‐Paul, Poncelet, Denis, Olmos, Eric, Bach, Jean‐Marie, Mosser, Mathilde
Zdroj: Biotechnology & Bioengineering; May2019, Vol. 116 Issue 5, p1176-1189, 14p
Abstrakt: The bioartificial pancreas encapsulating pancreatic islets in immunoprotective hydrogel is a promising therapy for Type 1 diabetes. As pancreatic islets are highly metabolically active and exquisitely sensitive to hypoxia, maintaining O2 supply after transplantation remains a major challenge. In this study, we address the O2 limitation by combining silicone‐encapsulated CaO2 (silicone‐CaO2) to generate O2 with an extracellular hemoglobin O2‐carrier coencapsulated with islets. We showed that the hemoglobin improved by 37% the O2‐diffusivity through an alginate hydrogel and displayed antioxidant properties neutralizing deleterious reactive O2 species produced by silicone‐CaO2. While the hemoglobin alone failed to maintain alginate macroencapsulated neonate pig islets under hypoxia, silicone‐CaO2 alone or combined to the hemoglobin restored islet viability and insulin secretion and prevented proinflammatory metabolism (PTGS2 expression). Interestingly, the combination took the advantages of the two individual strategies, improved neonate pig islet viability and insulin secretion in normoxia, and VEGF secretion and PDK1 normalization in hypoxia. Moreover, we confirmed the specific benefits of the combination compared to silicone‐CaO2 alone on murine pseudo‐islet viability in normoxia and hypoxia. For the first time, our results show the interest of combining an O2 provider with hemoglobin as an effective strategy to overcome O2 limitations in tissue engineering. Mouré et al. adress the O2 limitation in a bioartificial pancreas, composed of neonate pig islets encapsulated in an alginate hydrogel, by combining an O2 generator (silicone‐CaO2) with an extracellular hemoglobin O2‐carrier. By increasing the O2 diffusivity in the alginate hydrogel and neutralising reactive O2 species produced by the silicone‐CaO2, the hemoglobin aims to improve the integration of the O2 generator into the device and the adaptation of the bioartificial pancreas to the varying O2 tensions encountered after transplantation. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index