Hydrophilic amylose-based graft copolymers for controlled protein release

Graft copolymerization of 2-hydroxyethylmethacrylate (HEMA) onto high-amylose starch using ceric ammonium nitrate (CAN) as an initiator was carried out in an aqueous solution. Our attention has been focused on efficient and well controlled grafted copolymerization methods in order to obtain a biocompatible copolymer for controlled-release of drugs and proteins. Here, we report on the synthesis and physico-chemical characterization as well as other experiments to test the enzymatic resistance and the capacity of fermentation by colonic bacteria of this product. It can be observed that this copolymer gives a good controlled-release of drugs (Theophylline and Procaine hydrochloride), as well as proteins (BSA). The in vitro experiments let us know that quantities lower than 10% of BSA are released at pH 1.5 (stomach), keeping the protein in the matrix to be released at higher pHs (intestine), where the matrix suffers anaerobic degradation.