Effects of surface morphology variation on the degradation rate of poly(_L-lactic acid) membranes and the behavior of attached cells

To study the effect of membrane morphology variation on biodegradation and the behavior of adhering cells, three types of poly(_L-lactic acid) (PLLA) membranes with different morphologies-particulate, porous, and dense-were prepared. Degradation of the PLLA membranes was performed at 37°C in hydrogen peroxide solution to accelerate degradation. In addition, these degradation curves were compared with degradation in PBS solution. The estimations of degradation in the two solutions were analyzed by gel permeation chromatography, scanning electron microscopy, and differential scanning calorimetry for 12 and 24 weeks. In addition, cell behavior on the three types of PLLA membrane was also investigated. The results showed that the molecular weight of PLLA membranes dropped gradually during the in vitro degradation period in both hydrogen peroxide and PBS solutions. The surface morphologies of the three types of membrane were observed to differ in the accelerated degradation system, suggesting that morphology affected the crystallinity and resulted in different degradation rates. Adhering cell behavior was also affected by surface morphology, with cells on the particulate membrane displaying the best viability. As the degradation rate of the particulate membrane was the slowest and its biocompatibility was the best, the particulate PLLA membrane may be most suitable for long-term orthopedic implants.