Comparative properties of composite poly(lactic-co-glycolic acid)/poly(acrylic acid) implants synthesized using ultraviolet and gamma irradiation

Abstract

Composite implants comprising a biodegradable hydrophobic polymer matrix and crosslinked hydrogel with fixed ion exchange groups are promising materials for the construction of controlled drug delivery systems. Poly(lactic-co-glycolic acid)/poly(acrylic acid) (PLGA/PAA) composite implants in our study were synthesized using the sequential application of irradiation and immersion precipitation. Precursor solutions with all functional components were dispensed into a disc-shaped non-stick mold and cured either by ultraviolet (UV) or gamma irradiation. Cured disks were subsequently immersed in the phosphate buffer saline bath to finalize phase separation and solidification of the implants. The synthesized implants were characterized by FTIR-ATR and DSC, and their basic properties such as ion exchange capacity, swelling degree, and swelling kinetics were examined. Synthesis using gamma irradiation resulted in implants with similar ion exchange capacity, but the greater swelling degree and faster swelling kinetics compared to the implants prepared with UV irradiation. Gamma irradiation also resulted in altered and less homogeneous chemical composition compared to the implants synthesized with UV irradiation. Further investigations are required to determine the differences in drug release kinetics and degradation behavior of the synthesized implants.