MIRA Institute for Biomedical Technology and Technical Medicine and Department of Biomaterials Science and Technology, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands.
Biomaterials. 2011 Aug;32(22):4994-5002. doi: 10.1016/j.biomaterials.2011.03.062. Epub 2011 Apr 20.
The intraocular degradation behavior of poly(trimethylene carbonate) (PTMC) networks and poly(D,L-lactic acid) (PDLLA) networks and of linear high molecular weight PTMC and PDLLA was evaluated. PTMC is known to degrade by enzymatic surface erosion in vivo, whereas PDLLA degrades by hydrolytic bulk degradation. Rod shaped specimens were implanted in the vitreous of New Zealand white rabbits for 6 or 13 wk. All materials were well tolerated in the rabbit vitreous. The degradation of linear high molecular weight PTMC and PTMC networks was very slow and no significant mass loss was observed within 13 wk. Only some minor signs of macrophage mediated erosion were found. The fact that no significant enzymatic surface erosion occurs can be related to the avascularity of the vitreous and the limited number of cells it contains. PDLLA samples showed more evident signs of degradation. For linear PDLLA significant swelling and a large decrease in molecular weight in time was observed and PDLLA network implants started to lose mass within 13 wk. Of the tested materials, PDLLA networks seem to be most promising for long term degradation controlled intravitreal drug delivery since this material degrades without significant swelling. Furthermore the preparation method of these networks allows easy and efficient incorporation of drugs.
研究了聚三亚甲基碳酸酯（PTMC）网络、聚（D，L-乳酸）（PDLLA）网络以及线性高分子量的 PTMC 和 PDLLA 的眼内降解行为。已知 PTMC 在体内通过酶促表面侵蚀降解，而 PDLLA 通过水解整体降解。棒状样品被植入新西兰白兔的玻璃体中 6 或 13 周。所有材料在兔玻璃体中均耐受良好。线性高分子量的 PTMC 和 PTMC 网络的降解非常缓慢，在 13 周内没有观察到明显的质量损失。仅发现一些巨噬细胞介导的侵蚀的轻微迹象。没有发生明显的酶促表面侵蚀的事实可以归因于玻璃体的无血管性及其所含的细胞数量有限。PDLLA 样品显示出更明显的降解迹象。对于线性 PDLLA，观察到明显的溶胀和分子量随时间的大量下降，并且 PDLLA 网络植入物在 13 周内开始失去质量。在所测试的材料中，PDLLA 网络似乎是最有前途的用于长期降解控制的眼内药物输送的材料，因为这种材料在降解时没有明显的肿胀。此外，这些网络的制备方法允许药物的简便和高效掺入。
