Gellan film as an implant for insulin delivery.

Gellan gum is an anionic polysaccharide produced by the aerobic fermentation of Pseudomonas elodea in batch culture. Gellan undergoes calcium-induced cross-linking to form a three-dimensional network, and this property makes it particularly attractive for the incorporation of biological moieties such as proteins. In this study, a procedure for the preparation of gellan films was developed and optimized, and the characteristics of these films were investigated. In addition, the effects of the concentration of each ingredient in gellan films and in vitro release behavior of fluorescein isothiocyanate dextran from these films was examined. This film device was implanted for insulin delivery in diabetic rats. The blood glucose levels of the diabetic rats implanted with insulin-loaded films were about half of those implanted with blank films, and this therapeutic effect of insulin could last for one week. Both in vitro and in vivo studies indicated that the gellan film could be an ideal candidate in the development of protein delivery systems.