James Nirmala R, Jayakrishnan A
Polymer Chemistry Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Satelmond Palace Campus, Trivandrum 695 012, India.
Biomaterials. 2003 Jun;24(13):2205-12. doi: 10.1016/s0142-9612(03)00022-x.
Thiocyanates, especially bis-alkylthiocyanates are highly effective in killing a number of bacterial strains and are reported to be potent biocides at ppm concentrations. In order to examine whether a covalently bound and immobilized thiocyanate group on a biomaterial surface is still effective as a bactericide, plasticized poly(vinyl chloride) (PVC) was thiocyanated using sodium thiocyanate in the presence of a phase transfer catalyst in aqueous media leading to the nucleophilic substitution of chlorine by thiocyanate on the PVC surface. Thiocyanation imparted hydrophilicity to the surface in comparison with bare PVC. Control and thiocyanated PVC surfaces were exposed to two strains of bacteria commonly implicated in device-associated infections, such as Staphylococcus aureus and Staphylococcus epidermidis. Bacterial adhesion and colonization was quantitated by counting the viable organisms on the adhered surface as well as by optical and scanning electron microscopy. Significantly reduced retention of S. epidermidis and S. aureus was seen on the thiocyanated PVC surface. Immobilized thiocyanate was non-cytotoxic in a preliminary cell culture assay. The study thus showed that even though an immobilized thiocyanate moiety on the polymer surface was not as effective as a bactericide unlike soluble thiocyanates, it prevented the retention and colonization of the bacteria to a considerable extent.
硫氰酸盐，尤其是双烷基硫氰酸盐，在杀死多种细菌菌株方面非常有效，据报道在百万分之一浓度下就是强效杀菌剂。为了研究生物材料表面共价结合并固定的硫氰酸基团作为杀菌剂是否仍然有效，在水介质中，在相转移催化剂存在的情况下，使用硫氰酸钠对增塑聚氯乙烯（PVC）进行硫氰化处理，导致PVC表面的氯被硫氰酸根亲核取代。与未处理的PVC相比，硫氰化处理使表面具有亲水性。将未处理的和硫氰化处理的PVC表面暴露于两种通常与器械相关感染有关的细菌菌株，如金黄色葡萄球菌和表皮葡萄球菌。通过对粘附表面上的活菌进行计数以及通过光学和扫描电子显微镜对细菌粘附和定植进行定量。在硫氰化处理的PVC表面上，表皮葡萄球菌和金黄色葡萄球菌的留存率显著降低。在初步的细胞培养试验中，固定化硫氰酸盐无细胞毒性。该研究因此表明，尽管聚合物表面固定化的硫氰酸部分不像可溶性硫氰酸盐那样作为杀菌剂有效，但它在很大程度上阻止了细菌的留存和定植。
