In Vitro Degradation of Poly (DL-Lactide-ε-Caprolactone) Nerve Guides

The aim of this study was to evaluate the in vitro degradation of a poly (DL-lactide-ε-caprolactone) nerve guide with an initial molecular weight (Mw) of 1.1 x 106 kg/kmol in phosphate buffer (pH = 7.4), after different time intervals, ranging from 7-98 days. We evaluated the changes in Mw, dry and wet volume, dry and wet mass and pH of the buffer. In addition, cryo scanning electron microscopical (cryo SEM) evaluation of the degrading nerve guides was carried out to evaluate the effect of the degradation on the surface of the nerve guide. The degradation of the poly (DL-lactide-ε-caprolactone) nerve guides is characterized by a slow decrease in Mw and a change in physical properties after 10 weeks. Cryo-SEM analysis showed holes with a diameter of approximately 0.3 µm 5 weeks after degradation. After 8 weeks of degradation, cracks could also be observed. From this study, it seems likely that the temperature at which the nerve guides are stored (in this study at room temperature), has a great impact on the evaluated parameters