Microstructured ZnO-rod like coating prevents biofilm formation prompted by pathogenic Candida spp.

Abstract

Medical devices colonized by the commensal microflora or infecting pathogens can have impaired functioning while contributing for infection dissemination. The use of ZnO nanoparticles to coat medical devices is emerging as an interesting strategy considering the antimicrobial potential of these particles. For Candida albicans and C. parapsilosis, two relevant microbial colonizers of medical devices, it was reported that a reduced colonization was made at the expenses of a nanostructured ZnO coating disassembling. To overcome the usefulness of ZnO coatings for longer periods or recurrent infections, a microstructured coating was investigated. When comparing the obtained results with our published data it was clear that similar “anti-biofilm” activities were attained independently of ZnO crystal sizes, questioning the paradigm that reduction to nanoscale guarantees an improved antimicrobial efficacy. Regardless the colonization of the microstructured ZnO coating with Candida cells the observed precipitation of CaP-derived compounds on the surface can render biocompatibility advantageous even when a fungal infection occurs. Moreover, the interaction of fungi with the coating revealed that the disassembly reported for the nanosized-based coating was likewise observed for the microsized-based coating. Although ZnO-based coatings are effective against the biofilm formation of pathogenic fungi new challenges arise in the design of disassembly-resistant coatings.