[Experimental study of radiation sterilization and degradation of polylactide and copolymer membranes for maxillofacial surgery].

OBJECTIVE

The aim of the study. To evaluate the physicochemical properties and radiation stability of biodegradable membranes based on polylactic acid (PLA) and its copolymers (PLGA) for potential use in guided bone regeneration (GBR) in maxillofacial surgery.

MATERIALS AND

METHODS

Membranes made of pure PLA, PLA with hydroxyapatite (PLA/HAP), and polylactic-co-glycolic acid (PLGA) in 85:15 and 60:40 ratios were studied. Samples were sterilized using electron beam irradiation at a dose of 25 kGy. Degradation was carried out in phosphate-buffered saline at 37 °C. Molecular structure was assessed by FTIR spectroscopy, and surface morphology was evaluated using scanning electron microscopy (SEM).

RESULTS

After one month, PLGA 60:40 samples lost approximately 40% of their mass and structural integrity and were excluded from further observation. PLGA 85:15 samples maintained shape and exhibited a minor mass loss (~5%). Non-irradiated PLA/HAP composites showed variable mass loss (0-19%), while irradiated ones displayed minimal changes (up to 2%). Pure PLA samples remained the most stable throughout the 2.5-month observation period, showing only minor hydrolytic surface alterations. Radiation sterilization did not cause significant changes in the molecular structure of any tested materials.

CONCLUSION

PLA copolymers demonstrated controlled degradation rates and sufficient structural stability, making them promising candidates for the development of patient-specific resorbable membranes for GBR. Their predictable resorption profile may eliminate the need for secondary surgery to remove the membrane. The results support the feasibility of using ionizing radiation for sterilization without compromising material properties.