Microgels of Starch Phosphates for the Controlled Release of Biomacromolecules

Abstract

Hydrogels on the basis of starch phosphates containing 2.1-3.8 mmol/g of phosphoric acid groups have been prepared by etherification of starch in an orthophosphoric acid-urea system. In in vitro experiments, the rate of starch phosphates degradation in a phosphate buffer in the absence and presence of а-amylase in the reaction mixture was studied. It was shown that phosphate starch is available for enzymatic hydrolysis; however, the rate of biodegradation was gradually reduced with increasing amounts of phosphate groups. The possibility of using microgels with average sizes 7.8-60.1 μm to create systems with interferon alpha-2b controlled release was demonstrated.