Jagdish Singh
North Dakota State University, USA
Title: Molecularly modified insulin for controlled delivery from triblock copolymers
Biography
Biography: Jagdish Singh
Abstract
The objective of the present work was to develop a delivery system for controlled release of insulin at basal level based on chitosan-zinc-insulin complex incorporated into poly (lactic acid)-poly (ethylene glycol)-poly (lactic acid) (PLA-PEG-PLA, 4500 Da) thermosensitive polymer. In vitro release profile of insulin from the delivery system was studied in phosphate buffered saline, pH 7.4 (PBS). A significant decrease (p<0.05) in the initial burst was observed from the formulation containing chitosan-zinc-insulin complex compared to zinc-insulin, chitosan-insulin and insulin alone. Additionally, the release of insulin was complete with minimal secondary burst. The polymeric formulations containing chitosan-zinc-insulin complex showed a long-term controlled release (~84 days) of insulin. The in vivo absorption and bioactivity of insulin released from the delivery systems were studied in the streptozotocin-induced diabetic rat model. Chitosan-zinc-insulin complex significantly (P<0.05) reduced the initial burst release of insulin from the polymeric delivery system in comparison to zinc-insulin or insulin alone in vivo in rat. The delivery system released insulin for ~3 months in biologically active form with corresponding reduction in blood glucose levels in diabetic rats. The delivery systems were biocompatible both in vitro and in vivo and were non-immunogenic. The results indicate that the chitosan-zinc-insulin complex incorporated in the thermosensitive polymeric delivery system can be used as an alternative to the conventional daily basal insulin therapy