Hydrolytic degradation of PLLA/PCL microporous membranes prepared by freeze extraction
Hydrolytic degradation of PLLA/PCL microporous membranes prepared by freeze extraction
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DOI：
10.1016/j.polymdegradstab.2012.06.031
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发表时间：
2012-09-01
影响因子：
5.9
通讯作者：
Lebourg, M.
中科院分区：
文献类型：
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作者：
Gaona, Luis A.;Gomez Ribelles, J. L.;Lebourg, M.
采用冷冻干燥法制备了聚L-乳酸/聚己内酯（PLLA/PCL）共混多孔膜，共混比例为100/0、80/20、60/40、40/60、20/80、0/100。降解的膜在磷酸盐缓冲溶液（PBS）长达65周的研究，使用重量损失测量，高效液相色谱法（HPLC），差示扫描量热法（DSC），机械压痕，凝胶渗透色谱法（GPC），和扫描电子显微镜（SEM）。降解速率观察到的重量损失和减少的分子量和机械性能取决于共混物的组成。在大多数共混物中，降解在PLLA相中更为突出，并伴随着随后的重结晶，形成具有增加的耐水解性的结晶相。这种结晶相的发生和晶间结构域的降解导致形成几乎单分散的分子量population.Membranes与只有20%的PCL呈现出良好的行为相比，纯PLLA膜反映在较低的降解速率和有限的损失的机械性能。同时，相对于纯PCL，80/20膜的降解速率增强，并且膜在所有降解时间都比PCL膜更硬。因此，该组合物可用于骨或软骨应用的组织工程。(c)2012爱思唯尔有限公司保留所有权利。
Poly(L-lactic acid) Poly(e-caprolactone) blends (PLLA/PCL) porous membranes were prepared by freeze extraction (a modification of freeze drying) with ratios 100/0, 80/20, 60/40, 40/60, 20/80, 0/100 in weight. Degradation of the membranes in phosphate buffer solution (PBS) up to 65 weeks was studied using weight loss measurements, high performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), mechanical indentation, gel permeation chromatography (GPC), and scanning electron microscopy (SEM). Degradation rate as observed by weight loss and reduction of molecular weight and mechanical properties depended on the composition of the blends. In most blends the degradation was more prominent in the PLLA phase and was accompanied by consequent recrystallization that formed a crystalline phase with increased resistance to hydrolysis. Occurrence of such crystalline phases and degradation of intercrystalline domain led to formation of nearly monodisperse molecular weight populations.Membranes with only 20% PCL presented favorable behavior compared to pure PLLA membranes as reflected in a lower degradation rate and a limited loss of the mechanical properties. At the same time, degradation rate of 80/20 membranes was enhanced with respect to pure PCL, and membranes were stiffer than PCL membranes at all degradation times. This composition could thus be useful for use in tissue engineering for bone or cartilage applications. (c) 2012 Elsevier Ltd. All rights reserved.