Sustained release of N-acetylcysteine by sandwich structured polycaprolactone/collagen scaffolds for wound healing

Sustained release of N-acetylcysteine by sandwich structured polycaprolactone/collagen scaffolds for wound healing

PCL (poly-caprolactone) nanofibers have good biocompatibility and high porosity, which are usually utilized for application in wound dressings. However, wound healing could be hindered by the overproduction of reactive oxygen species (ROS) and different factors. Pure nanofibers cannot satisfy these requirements of wound healing. N-acetylcysteine (NAC), as an antioxidant, meets the requirements for wound healing by resisting the overproduction of ROS and by promoting angiogenesis and maturation of the epidermis. In this study, we prepared a sandwich structured PCL-Col/NAC scaffold using the molding method, which consisted of PCL nanofibers at the core and NAC-loaded collagen on both sides. The hydroscopicity and tensile modulus of PCL-Col/NAC scaffolds showed best performance of these properties among groups. Meanwhile, the drug release profiles of PCL-Col/NAC scaffolds were investigated using the HPLC method and the results suggested a sustained drug release of NAC for PCL-Col/NAC scaffolds. In addition, PCL-Col/NAC scaffolds presented better properties than the control groups in cell migration and proliferation. The in vivo wound healing therapy effect was studied using an oval (2 x 1 cm) full-thickness skin defect wound model for SD rats. After 21 days, gross view and histological analysis showed a favorable beneficial therapeutic effect as well as better epidermal maturation compared with the control groups. CD31 immunohistology results revealed relatively more new vessels in the PCL-Col/NAC group than the control groups. This study developed novel PCL-Col/NAC scaffolds with an excellent hydroscopicity, tensile modulus and the ability to promote epidermal maturation and angiogenesis, demonstrating its promising potential in wound healing treatment. (c) 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

聚己内酯（PCL）纳米纤维具有良好的生物相容性和高孔隙率，通常用于伤口敷料。然而，伤口愈合可能会因活性氧物质（ROS）的过量产生和不同因素而受阻。纯纳米纤维无法满足伤口愈合的这些要求。N - 乙酰半胱氨酸（NAC）作为一种抗氧化剂，通过抵抗ROS的过量产生以及促进血管生成和表皮成熟，满足伤口愈合的要求。在本研究中，我们采用成型方法制备了一种三明治结构的PCL - Col/NAC支架，其核心为PCL纳米纤维，两侧为负载NAC的胶原蛋白。PCL - Col/NAC支架的吸水性和拉伸模量在各组中表现出最佳性能。同时，采用高效液相色谱法（HPLC）研究了PCL - Col/NAC支架的药物释放曲线，结果表明PCL - Col/NAC支架中的NAC具有持续释放的特性。此外，PCL - Col/NAC支架在细胞迁移和增殖方面比对照组表现出更好的性能。采用SD大鼠椭圆形（2×1 cm）全层皮肤缺损伤口模型研究了体内伤口愈合治疗效果。21天后，大体观察和组织学分析显示，与对照组相比，具有良好的治疗效果以及更好的表皮成熟度。CD31免疫组织学结果显示，PCL - Col/NAC组的新生血管比对照组相对更多。本研究开发了新型的PCL - Col/NAC支架，具有优异的吸水性、拉伸模量以及促进表皮成熟和血管生成的能力，展示了其在伤口愈合治疗中的良好潜力。（c）2019威利期刊公司。《生物医学材料研究A部分》，2019年。