1Center for Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
J Biomater Appl. 2014 Jan;28(5):779-89. doi: 10.1177/0885328213480979. Epub 2013 Mar 20.
Cellulose acetate phthalate and Pluronic F-127 combined together (70:30 wt:wt) create a rigid, surface-eroding association polymer. To impart flexibility into the polymer system and allow for a drug delivery film that can contour to varying wound shapes, plasticizers were added. Triethyl citrate or tributyl citrate was combined with cellulose acetate phthalate and Pluronic F-127 at 0, 10, or 20 wt%. Mechanical analysis was performed on the films as they were prepared and following a 2-h incubation in phosphate-buffered saline. Tensile tests showed that higher plasticizer content increased the % elongation but decreased the elastic modulus and ultimate tensile strength. The effect triethyl citrate had on the % elongation was twice as much than that of tributyl citrate. After incubation, % elongation, elastic modulus, and ultimate tensile strength all increased because plasticizer leached out of the films. Microcomputed tomography and scanning electron microscopy were performed on the samples both before and after incubation to determine how erosion and leaching of plasticizer affected the interior and exterior structure of the films. Porosity increased as plasticizer content increased; however, plasticizer content did not have a significant effect on the rate of erosion. The mechanical properties of cellulose acetate phthalate-Pluronic films can be adjusted by the type and amount of plasticizer added to the system and therefore can be tailored for different drug delivery applications.
醋酸纤维素邻苯二甲酸酯和泊洛沙姆 F-127 按 70:30（质量比）结合在一起，形成一种刚性、表面侵蚀性的缔合聚合物。为了使聚合物体系具有柔韧性，并使药物输送膜能够适应不同的伤口形状，添加了增塑剂。柠檬酸三乙酯或柠檬酸三丁酯与醋酸纤维素邻苯二甲酸酯和泊洛沙姆 F-127 以 0、10 或 20wt%的比例混合。在制备过程中和在磷酸盐缓冲盐水孵育 2 小时后，对薄膜进行机械分析。拉伸试验表明，较高的增塑剂含量会增加伸长率，但会降低弹性模量和极限拉伸强度。柠檬酸三乙酯对伸长率的影响是柠檬酸三丁酯的两倍。孵育后，伸长率、弹性模量和极限拉伸强度都增加了，因为增塑剂从薄膜中渗出。在孵育前后对样品进行了微计算机断层扫描和扫描电子显微镜检查，以确定增塑剂的侵蚀和渗出如何影响薄膜的内外结构。随着增塑剂含量的增加，孔隙率增加；然而，增塑剂含量对侵蚀速率没有显著影响。通过向系统中添加不同类型和数量的增塑剂，可以调整醋酸纤维素邻苯二甲酸酯-泊洛沙姆薄膜的机械性能，从而可以针对不同的药物输送应用进行定制。
