Injectable photoreactive azidophenyl hyaluronic acid hydrogels for tissue augmentation

Abstract

A photoreactive azidophenyl hyaluronic acid (Az-HA) derivative for tissue augmentation was prepared by direct amide bond formation between the carboxyl groups of HA and the amine groups of 4-azidoaniline. 4-Azidoaniline was introduced to the carboxyl group of hyaluronic acid that was activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). The prepared Az-HA derivative was characterized by 1H NMR to measure the degree of modification. The Az-HA derivative was photo-cross-linked with varying UV irradiation times. Az-HA-20 hydrogels were formulated into injectable gels for soft tissue augmentation. The morphology, equilibrium swelling, rheological property, and in vitro degradation of hydrogels were examined. The cell cytotoxicity test of the Az-HA derivative was also examined. Az-HA-20 formed stronger hydrogels with higher storage modulus (Pa’) as UV irradiation time increased. Also, the in vitro degradation rate was lower as UV irradiation time increased. This study demonstrates that Az-HA-20 hydrogels have potential for use as injectable, biodegradable, and biocompatible hydrogels for tissue augmentation. Open image in new window