Department of Biomedical Engineering, Tampere University of Technology, Hermiankatu 12, PO Box 692, FI-33101 Tampere, Finland.
J Mech Behav Biomed Mater. 2011 Oct;4(7):1283-90. doi: 10.1016/j.jmbbm.2011.04.015. Epub 2011 Apr 29.
The hydrolytic degradation of oriented poly(L-lactide-co-glycolide) 85 L/15 G (PLGA 85/15) sample materials with various amounts of lactide monomer was monitored in vitro at 37 °C. The materials were manufactured from medical grade PLGA 85/15 by a two-step melt extrusion-die drawing process. Results showed that the hydrolytic degradation rate depended highly on the lactide monomer content, which in turn influenced the retention of mechanical properties, mass loss, crystallinity, and dimensional stability. Even small quantities of lactide monomer (0.05-0.20 wt%) affected especially the retention of mechanical properties, which started to decline rapidly upon the inherent viscosity reaching 0.6-0.8 dl/g due to hydrolytic degradation. Based on our hydrolytic degradation data, we constructed a simplified mathematical model of degradation-related strength retention and recommend it as a functional quality control tool for melt-processed biodegradable medical devices manufactured from poly(L-lactide-co-glycolide) 85 L/15 G.
在 37°C 下，体外监测了不同乳酸单体含量的定向聚（L-丙交酯-co-乙交酯）85 L/15 G（PLGA 85/15）样品材料的水解降解情况。这些材料是由医用级 PLGA 85/15 通过两步熔融挤出-模头拉伸工艺制造的。结果表明，水解降解速率高度依赖于乳酸单体含量，进而影响力学性能、质量损失、结晶度和尺寸稳定性的保留。即使少量的乳酸单体（0.05-0.20wt%）也会特别影响力学性能的保留，由于水解降解，当固有粘度达到 0.6-0.8dl/g 时，力学性能开始迅速下降。根据我们的水解降解数据，我们构建了一个简化的降解相关强度保留的数学模型，并推荐其作为用于制造自聚（L-丙交酯-co-乙交酯）85 L/15 G 的可熔融加工的生物降解医疗器械的功能质量控制工具。
