molecular weight effect of methoxypoly (ethylene glycol) activated with Succinimidyl Carbonate on camouflaging pancreatic islets

Surface modification of Langerhans islets by grafting activated polyethylene glycol on their capsules in order to prevent immune system stimulation is a novel method in diabetes cell therapy. In this study methoxypoly (ethylene glycol) with two molecular weight of 5 and 10 kDa was activated with Succinimidyl Carbonate and applied via grafted reaction to coat surface of pancreatic islets at polymer concentration of 22 mg/mL. Effect of two molecular weight of activated mPEG on viability, functional activity and immunological response of PEG grafted pancreatic islets; compared to free islets were studied. It has been seen that PEGylated islets are viable and active. However, the PEGylated islet with mPEG-SC in molecular weight of 10 kDa, because of lower amount of IL-2 secretion from lymphocyte co-cultured with them (112.1167±23.09pg /mL), compared to mPEG-SC grafted islets with molecular weight of 5 kDa (127.7518±27.94pg /mL), and is more suitable for camouflaging islets from immune system.

Keywords:

methoxypoly (ethylene glycol) , pancreatic islets , PEGylation , mPEG-SC , lymphocyte