Laboratory of Equine Exercise Physiology and Pharmacology (LAFEQ), Department of Animal Morphology and Physiology, School of Agricultural and Veterinarian Sciences, São Paulo State University (Unesp), Jaboticabal, SP, Brazil.
Department of Materials Engineering, São Carlos School of Engineering, University of São Paulo (USP), São Carlos, SP, Brazil.
Biomed Phys Eng Express. 2021 Mar 15;7(3). doi: 10.1088/2057-1976/abeb5a.
Poly(lactic acid) (PLA) and poly(-caprolactone) (PCL) are two important aliphatic esters known for their biodegradability and bioresorbability properties; the former is stiffer and brittle while the smaller modulus of the latter allows a suitable elongation. The new biomaterials being developed from the blend of these two polymers (PLA and PCL) is opportune due to the reducing interfacial tension between their immiscible phases. In a previous study, PLA/PCL immiscible blend when compatibilized with poly(-caprolactone--tetrahydrofuran) resulted in enhanced ductility and toughness no cytotoxic effect intests. There is little published data on the effect of poly(-caprolactone--tetrahydrofuran) on PLA and PCL biocompatibility and biodegradabilitytests. This study focuses on evaluating the behavioral response and polymer-tissue interaction of compatibilized PLA/PCL blend compared to neat PLA implanted via intraperitoneal (IP) and subcutaneous (SC) in male Wistar rats, distributed in four experimental groups: neat PLA, PLA/PCL blend, sham, and control at 2-, 8- and 24-weeks post-implantation (WPI). An open-field test was performed to appraise emotionality and spontaneous locomotor activity. Histopathological investigation using hematoxylin-eosin (H&E) and picrosirius-hematoxylin (PSH) was used to assess polymer-tissue interaction. Modifications in PLA and the PLA/PCL blend's surface morphology were determined by scanning electron microscopy (SEM). PLA group defecated more often than PLA/PCL rats 2 and 8 WPI. Conjunctive capsule development around implants, cell adhesion, angiogenesis, and giant cells of a foreign body to the biomaterial was observed in light microscopy. Both groups displayed a fibrous reaction along with collagen deposition around the biomaterials. In the SEM, the images showed a higher degradation rate for the PLA/PCL blend in both implantation routes. The polymers implanted via IP exhibited a higher degradation rate compared to SC. These findings emphasize the biocompatibility of the PLA/PCL blend compatibilized with poly(-caprolactone--tetrahydrofuran), making this biopolymer an acceptable alternative in a variety of biomedical applications.
聚乳酸（PLA）和聚（-己内酯）（PCL）是两种重要的脂肪族酯类，以其可生物降解性和生物可吸收性而闻名；前者刚性较大且易碎，而后者较小的模量允许适当的伸长率。由于两种聚合物（PLA 和 PCL）的混合界面张力降低，由这些新生物材料开发的混合物是合适的。在以前的研究中，当 PLA/PCL 不混溶的混合物与聚（-己内酯-四氢呋喃）相容化时，会导致延展性和韧性增强，并且对测试无细胞毒性。关于聚（-己内酯-四氢呋喃）对 PLA 和 PCL 生物相容性和生物降解性测试的影响，发表的数据很少。本研究重点评估了相容化 PLA/PCL 混合物与通过腹腔内（IP）和皮下（SC）植入的纯 PLA 相比的行为反应和聚合物-组织相互作用，雄性 Wistar 大鼠分为四个实验组：纯 PLA、PLA/PCL 混合物、假手术和对照，在植入后 2、8 和 24 周（WPI）。进行开放式测试以评估情绪和自发运动活动。使用苏木精-伊红（H&E）和苦味酸-苏木精（PSH）进行组织病理学研究，以评估聚合物-组织相互作用。通过扫描电子显微镜（SEM）确定 PLA 和 PLA/PCL 混合物表面形貌的变化。PLA 组在植入后 2 和 8 周时比 PLA/PCL 组更频繁地排便。在光镜下观察到围绕植入物的结合囊的发育、细胞黏附、血管生成和异物对生物材料的巨细胞。两组都显示出在生物材料周围沿胶原沉积的纤维反应。在 SEM 中，图像显示 PLA/PCL 混合物在两种植入途径中的降解速率更高。通过 IP 植入的聚合物比 SC 具有更高的降解速率。这些发现强调了相容化聚（-己内酯-四氢呋喃）的 PLA/PCL 混合物的生物相容性，使这种生物聚合物成为各种生物医学应用中可接受的替代品。
