Biocompatible, Injectable Anionic Hydrogels Based on Poly(Oligo Ethylene Glycol Monoacrylate-co-Acrylic Acid) for Protein Delivery

Development of biocompatible hydrogels for sustained delivery of biological therapeutic agents is important for many regenerative medicine applications. In this study, a facile method is developed to synthesize injectable, anionic hydrogels based on poly(oligo ethylene glycol monoacrylate-co-acrylic acid) for protein controlled release. The synthesis of the copolymers is robust involving a single step of an aqueous free radical polymerization. These copolymers are then allowed to swell into the microporous injectable hydrogels. The covalent incorporation of the anionic group, acrylic acid, into the hydrogels increases the thermal stability and the viscosity of hydrogels due to the stronger intermolecular interactions in the copolymer network. These anionic groups also significantly enhance electrostatic interactions between the hydrogels and positively charged proteins, thus, rendering the hydrogels suitable for sustained release of the proteins under physiological conditions. An animal study shows these injectable hydrogels do not adversely affect wound healing. These findings warrant further investigation of these injectable hydrogels for their use in protein delivery for wound healing applications.