Department of Biomedical Engineering, Tampere University of Technology, Tampere, Finland.
J Endourol. 2012 Jun;26(6):701-5. doi: 10.1089/end.2011.0199. Epub 2012 Jan 16.
To investigate in vitro whether pH ranging between 6 and 9 has an effect on the degradation of stent fibers made of poly(l-lactide-co-glycolide) (PLGA) 80/20.
The fibers were divided into three groups and immersed in sodium phosphate-buffered saline (Na-PBS) solution with three different pH values: 6, 7.4, and 9. The mechanical and thermal properties were studied, and scanning electron microscopy (SEM) images were taken at specific time points of hydrolysis.
The tensile testing showed that the strength of the fibers decreased through hydrolysis and was lost at 8 weeks in all groups. The T(m) and T(g) of the PLGA fibers did not indicate any significant differences between the different groups. In SEM images taken at 4 weeks, there were no significant differences between the fibers immersed in Na-PBS solutions of different pH values. However, at 8 weeks the surface of the fiber immersed in saline with a pH of 6 seemed coarser than that of those immersed in neutral (pH 7.4) or alkaline (pH 9) Na-PBS.
The studied pH values did not influence the degradation behavior of the PLGA 80/20 fibers. Therefore, rabbits can be used as model animals for human biodegradable urological devices even though the pH of their urine is different.
研究 pH 值在 6 至 9 范围内对聚（L-丙交酯-共-乙交酯）（PLGA）80/20 支架纤维降解的体外影响。
将纤维分为三组，分别浸泡在三种不同 pH 值的磷酸缓冲盐溶液（Na-PBS）中：6、7.4 和 9。研究了力学和热学性能，并在水解的特定时间点拍摄扫描电子显微镜（SEM）图像。
拉伸试验表明，纤维的强度随水解而降低，所有组在 8 周时均丧失强度。PLGA 纤维的 T(m)和 T(g)在不同组之间没有显示出任何显著差异。在 4 周时拍摄的 SEM 图像中，浸泡在不同 pH 值的 Na-PBS 溶液中的纤维之间没有明显差异。然而，在 8 周时，浸泡在 pH 值为 6 的盐水中的纤维表面似乎比浸泡在中性（pH 值为 7.4）或碱性（pH 值为 9）Na-PBS 溶液中的纤维表面更粗糙。
研究的 pH 值并未影响 PLGA 80/20 纤维的降解行为。因此，即使兔子尿液的 pH 值不同，也可以将其用作人类可生物降解泌尿科器械的模型动物。
