Department of Chemistry, Ardabil Branch, Islamic Azad University, Ardabil, Iran.
Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Canada.
J Biomater Sci Polym Ed. 2020 Feb;31(2):169-187. doi: 10.1080/09205063.2019.1680928. Epub 2019 Oct 30.
Materials and scaffolds with antimicrobial properties are of great importance in wound dressing and other tissue engineering applications. The objective of the present work was to fabricate scaffolds made from nanocomposites of polycaprolactone (PCL) and quaternary ammonium salt-modified montmorillonite (MMT) by the electrospinning technique, and then characterize their antimicrobial and other properties for wound dressing applications. The effect of MMT on the structure, morphology, and thermal behavior of the electrospun wound dressings was assessed by means of X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM); the swelling capacity, antibacterial activity, and cytotoxicity were also evaluated. The results of XRD and SEM analyses showed MMT was successfully incorporated into the PCL polymeric matrix and its inclusion reduced the size and thickness of the electrospun fibers compared to pure PCL fibers. The TGA results illustrated an increase in the thermal stability of nanocomposites upon incorporation of nanoclay into the PCL matrix. The swelling capacity of the wound dressings was reduced by increasing the amount of MMT in the PCL matrix due to the increased hydrophobicity of the original MMT resulting from its modification with quaternary ammonium salt. The curcumin (Cur) release profile revealed an initial burst release followed by a sustained release, with the burst release level reduced by the introduction of MMT into the polymeric matrix. Increasing the nanoclay content further reduced the curcumin release, with the PCL/20% MMT/Cur dressings having the lowest curcumin release of all those tested. The beneficial effect of MMT on the antibacterial behavior of electrospun wound dressings based on PCL/MMT nanocomposites was confirmed, with the introduction of both MMT and curcumin into the PCL matrix resulting in lower bacterial viability. PCL/10% MMT/Cur demonstrated higher antimicrobial activity and the greatest bacterial colony reduction compared to both pure PCL and PCL/10% MMT. The cytotoxicity evaluation indicated low toxicity and confirmed the potential of PCL/MMT nanocomposite scaffolds for wound dressing applications.
具有抗菌性能的材料和支架在伤口敷料和其他组织工程应用中非常重要。本工作的目的是通过静电纺丝技术制备由聚己内酯（PCL）和季铵盐改性蒙脱石（MMT）纳米复合材料制成的支架，并对其用于伤口敷料的抗菌和其他性能进行表征。通过 X 射线衍射（XRD）、热重分析（TGA）和扫描电子显微镜（SEM）评估 MMT 对静电纺伤口敷料的结构、形态和热行为的影响；还评估了溶胀能力、抗菌活性和细胞毒性。XRD 和 SEM 分析结果表明，MMT 成功地掺入到 PCL 聚合物基质中，与纯 PCL 纤维相比，其掺入降低了电纺纤维的尺寸和厚度。TGA 结果表明，纳米粘土的加入提高了纳米复合材料的热稳定性。由于原始 MMT 经季铵盐改性后疏水性增加，因此 PCL 基质中 MMT 含量的增加会降低伤口敷料的溶胀能力。姜黄素（Cur）释放曲线表明，初始突释后释放持续，由于将 MMT 引入聚合物基质，突释水平降低。进一步增加纳米粘土的含量会进一步降低姜黄素的释放，与所有测试的敷料相比，PCL/20%MMT/Cur 敷料的姜黄素释放最低。证实了 MMT 对基于 PCL/MMT 纳米复合材料的静电纺伤口敷料的抗菌行为的有益影响，同时引入 MMT 和姜黄素到 PCL 基质中导致细菌活力降低。与纯 PCL 和 PCL/10%MMT 相比，PCL/10%MMT/Cur 表现出更高的抗菌活性和最大的细菌菌落减少。细胞毒性评估表明毒性低，并证实了 PCL/MMT 纳米复合材料支架在伤口敷料应用中的潜力。
