Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384, China.
Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384, China.
J Colloid Interface Sci. 2017 Dec 1;507:344-352. doi: 10.1016/j.jcis.2017.08.013. Epub 2017 Aug 5.
Poly(l-lactic acid) (PLLA) is a biocompatible polyester derived from renewable sources. It is desirable to reduce its brittleness and introduce antibacterial activity for biomedical applications by using graphene oxide (GO) as a structural and antibacterial agent. However, commonly used polymer/GO composite synthesis methods, such as physical mixing and covalent functionalization, either cause phase segregation or compromise the intrinsic properties of GO. Here, a novel approach is demonstrated to synthesize PLLA/GO films. First, perylene bisimides-containing PLLA (PBI-PLLA) was synthesized via ring-opening polymerization of l-lactide using a hydroxyl-derivate of perylene bisimides (PBI-OH) as the initiator. Next, PBI-PLLA was conjugated with GO via π-π stacking to form PLLA-conjugated GO (PLLA-c-GO). Last, PLLA/GO films were fabricated by simple solution casting of commercial PLLA and PLLA-c-GO dissolved in chloroform. Detailed characterization shows that GO retains its morphology and functional groups in PLLA-c-GO, which enables unique properties in the PLLA/GO films. The starting thermal degradation temperature of PLLA/GO films in N increases to 313°C comparing to commercial PLLA films at 293°C. Their surface is more hydrophilic with the water contact angle of 53°. Their elongation at break improves significantly from 3% to 30% compared to commercial PLLA films, demonstrating much better flexibility. Most importantly, the PLLA/GO films show good antibacterial activity towards Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Bacillus subtiliscells (B. subtilis) cells with the bacterial colony number reduction by 80%. At the same time, they show low toxicity towards mammalian cells, such asL929 and macrophage cells. Overall, the novel PLLA/GO films demonstrate various beneficial characteristics for potential biomedical applications.
聚（L-乳酸）（PLLA）是一种源自可再生资源的生物相容性聚酯。为了使其具有韧性并引入抗菌活性，以用于生物医学应用，通常使用氧化石墨烯（GO）作为结构和抗菌剂。然而，常用的聚合物/GO 复合材料合成方法，如物理混合和共价功能化，要么导致相分离，要么损害 GO 的固有性质。这里，展示了一种合成 PLLA/GO 薄膜的新方法。首先，通过使用羟基取代的苝二酰亚胺（PBI-OH）作为引发剂，通过开环聚合 L-丙交酯合成了含苝二酰亚胺的 PLLA（PBI-PLLA）。接下来，通过π-π堆积将 PBI-PLLA 与 GO 进行共轭，形成 PLLA 共轭 GO（PLLA-c-GO）。最后，通过将商业 PLLA 和 PLLA-c-GO 溶解在氯仿中进行简单的溶液浇铸来制备 PLLA/GO 薄膜。详细的表征表明，GO 在 PLLA-c-GO 中保留了其形态和官能团，这使 PLLA/GO 薄膜具有独特的性能。与商业 PLLA 薄膜相比，PLLA/GO 薄膜在氮气中的起始热降解温度从 293°C 提高到 313°C。其表面的亲水性提高，水接触角从 53°变为 33°。与商业 PLLA 薄膜相比，其断裂伸长率从 3%显著提高至 30%，柔韧性明显提高。最重要的是，PLLA/GO 薄膜对大肠杆菌（E. coli）、金黄色葡萄球菌（S. aureus）和枯草芽孢杆菌（B. subtilis）细胞表现出良好的抗菌活性，细菌菌落数减少了 80%。同时，它们对哺乳动物细胞（如 L929 和巨噬细胞）的毒性较低。总体而言，新型 PLLA/GO 薄膜具有多种有益特性，具有潜在的生物医学应用前景。
