Zhou Wenhao, Lu Ling, Chen Dafu, Wang Zhengao, Zhai Jinxia, Wang Renxian, Tan Guoxing, Mao Jianping, Yu Peng, Ning Chengyun
School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China.
J Mater Chem B. 2018 May 21;6(19):3128-3135. doi: 10.1039/c7tb03085a. Epub 2018 Apr 30.
Conductive polymers (CPs) are frequently used as neural and osteogenic implants for signal recording and electrical stimulation due to their electroactive and good biocompatibility. However, these implants often fail due to bacterial infection. In this research, a novel nano-functionalized polypyrrole (PPy) with high surface potential was electrochemically developed to improve the antibacterial properties of CPs. Sulfosalicylic acid (SSA)-a biomolecule with abundant negatively charged functional groups-was introduced to not only successfully assist in the electrical assembly of Py micelles into a bacterial extracellular matrix mimetic nanostructure, but also to modulate the surface electrical properties of PPy. Scanning Kelvin probe microscopy (SKPM) results confirm the increased positive charges on SSA-assisted PPy (PPy/SSA nanorod and irregular PPy/SSA film) relative to the irregular PPy/Cl film. Plate colony-counting experiments confirm that SSA-assisted PPy has excellent antibacterial properties relative to the irregular PPy/Cl film. The higher antibacterial rate for PPy/SSA nanorods suggests a synergistic effect via the nanorod structure and the high surface potential induced by dopants. Cytotoxicity testing demonstrates that PPy/SSA samples were nontoxic to the cells. Our work provides an effective way to develop antibacterial CPs.
导电聚合物（CPs）因其具有电活性和良好的生物相容性，常被用作神经和骨生成植入物用于信号记录和电刺激。然而，这些植入物常常因细菌感染而失效。在本研究中，通过电化学方法制备了一种具有高表面电位的新型纳米功能化聚吡咯（PPy），以提高CPs的抗菌性能。引入了磺基水杨酸（SSA）——一种具有大量带负电荷官能团的生物分子——不仅成功地协助将Py胶束电组装成模拟细菌细胞外基质的纳米结构，而且还调节了PPy的表面电学性质。扫描开尔文探针显微镜（SKPM）结果证实，相对于不规则的PPy/Cl膜，SSA辅助的PPy（PPy/SSA纳米棒和不规则PPy/SSA膜）上的正电荷增加。平板菌落计数实验证实，相对于不规则的PPy/Cl膜，SSA辅助的PPy具有优异的抗菌性能。PPy/SSA纳米棒更高的抗菌率表明，通过纳米棒结构和掺杂剂诱导的高表面电位产生了协同效应。细胞毒性测试表明，PPy/SSA样品对细胞无毒。我们的工作为开发抗菌CPs提供了一种有效的方法。
