Migliaresi C, Fambri L, Cohn D
Dipartimento di Ingegneria dei Materiali, Università di Trento, Italy.
J Biomater Sci Polym Ed. 1994;5(6):591-606. doi: 10.1163/156856294x00220.
The in vitro degradation of samples of L- and D,L-lactic acid polymers, P(L)LA and P(DL)LA respectively, having different molecular weights, morphology and/or geometry, has been studied through the determination of viscometric molecular weight, mass and mechanical properties as function of the immersion time in Ringer solution at 37 degrees C. In particular have been compared the degradation kinetics of P(L)LA, amorphous and crystalline, and of P(L)LA and P(DL)LA having different molecular weight and sample geometry. From the molecular weight versus the degradation time data, a degradation rate has been defined, as the derivative of the function best fitting the data, normalized to the molecular weight of the polymer at each time. The behavior of the degradation rate curves, plotted against the degradation time, has been interpreted and compared with relation to the initial physical and geometrical characteristics of the PLA samples.
通过测定粘均分子量、质量和机械性能作为在37℃林格溶液中浸泡时间的函数，研究了具有不同分子量、形态和/或几何形状的L-和D,L-乳酸聚合物样品（分别为聚L-乳酸（P(L)LA）和聚D,L-乳酸（P(DL)LA））的体外降解。特别比较了无定形和结晶态的P(L)LA以及具有不同分子量和样品几何形状的P(L)LA和P(DL)LA的降解动力学。根据分子量与降解时间的数据，定义了降解速率，即最适合数据的函数的导数，并在每次测量时对聚合物的分子量进行归一化。绘制了降解速率曲线与降解时间的关系图，并根据聚乳酸样品的初始物理和几何特征对其行为进行了解释和比较。
