“一步法”构建基于Zn^(2+)的抗菌表面

‘One-step’Construction of Zn^(2+)-based Antibacterial Surface

不依赖于抗生素的抗菌表面是生物材料及器械设计领域的重要研究内容,可以避免耐药性细菌问题。现有材料表面抗菌策略仍然存在步骤较为繁琐、反应条件过于苛刻等不足,因此,本研究以多巴胺和硫酸锌(ZnSO_(4))为原料,在常温、水相条件下采用“一步法”构建广谱性含锌聚多巴胺抗菌涂层(PDA@Zn)。水接触角、涂层厚度和X光电子能谱等结果证实PDA@Zn涂层成功构建。涂层中的锌以Zn^(2+)的形式与PDA中邻苯二酚官能团配位结合;涂层的表面Zn^(2+)密度可以通过改变ZnSO_(4)投料的浓度来调控。抗菌实验的结果表明ZnSO_(4)投料浓度为1 mg/m L时所构建的PDA@Zn涂层(PDA@Zn/1)具有优异的杀菌效果,对大肠杆菌和表皮葡萄球菌的抗菌率分别为99.7%和99.3%。体外细胞培养试验结果表明,PDA@Zn/1涂层上L929的24 h和72 h相对增殖率分别为63.63%及48.32%,具有一定的细胞毒性。该方法提供了一种高效、简单的表面抗菌策略,但该策略的生物相容性还有待进一步提升。

Antibiotic-independent antibacterial surfaces are important research to avoid the problem of antimicrobial-resistant bacteria in the field of bioma-terial and device design.Unfortunately,existing surface antibacterial strategies still have shortcomings,such as cumbersome steps and harsh reaction conditions.Therefore,in this study,a broad-spectrum antibacterial coating containing zinc polydopamine(PDA@Zn)was con-structed in a‘one-step’process using dopamine and zinc sulfate(ZnSO_(4))as raw materials under normal temperature and aqueous phase condi-tions.The results of water contact angle,thickness of coating and XPS confirmed the successful construction of the PDA@Zn coating.The Zn in the coating is ligand-bound to the catechol functional group in PDA in the form of Zn^(2+);the surface Zn^(2+)density can be controlled by adjusting the feeding concentration of ZnSO4.The results of antibacterial experiments showed that the PDA@Zn/1 constructed at a ZnSO4 feeding concentra-tion of 1 mg/mL had excellent bactericidal effect,with 99.7%and 99.3%antibacterial rates against E.coli and S.epidermidi,respectively.The results of in vitro cell culture assay showed that the RGR of L929 on PDA@Zn/1 coating at 24 h and 72 h were 63.63%and 48.32%,respectively,with some cytotoxicity.This method provides an efficient and simple surface antibacterial strategy,but its biocompatibility needs to be further improved.