Pyrogallic acid-PLGA conjugate as new biodegradable material suitable for final sterilization by irradiation

This paper reports the feasibility to prepare a biodegradable material stable to gamma-irradiation by grafting of poly(lactide-co-glycolide) with pyrogallic acid (PLGA-g-PA) and ferulic acid (PLGA-g-FA) in mild condition. Only the grafting procedure with PA did not modify molecular weight (Mw) of the starting polymer and PLGA-g-PA showed antioxidant properties. The polymer degradation in pH 7.4 phosphate buffer saline (PBS) was mainly governed by a random chain scission mechanism according to a first-order reaction. The irradiation at the dose of 25 kGy caused only a very slight decrease of Mw and the degradation patterns of the non-irradiated and irradiated material were superimposable. PLGA-g-PA resulted a promising material to develop biodegradable drug delivery systems which would be sterilizable in the final container.