Fabricating Ultra-Smooth Diamond-Like Carbon Film and Investigating its Antifungal and Antibiofilm Activity

Abstract

Diamond like carbon (DLC) a carbon-based nanomaterial has been nominated as a potential solution to prevent the biofilm formation on indwelling medical devices such as dentures and heart valves.Candidaalbicansis an opportunistic fungal pathogen where biofilms are a part of its pathogenicity which primarily utilized indwelling medical devices as platform to build up the biofilm. In this work, DLC deposited on silicon substrate was prepared to accomplish the optimal characteristics for bio-coating material (roughness, purity, uniformity) and then evaluated for their ability to prevent or reduce the biofilm formation of pathogenicC.albicans(SC5314) under conditions mimicking human body. Optimized DLC was synthesized via chemical vapor deposition, and then the film was characterized by Raman spectroscopy, scan electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). The potential biofilms on DLC, silicon substrate and positive control (polyvinyl chloride-PVC) were quantified via colorimetric cell viability assay (XTT); as intact and vortexed biofilms. The characteristics of formed biofilms were carried out using confocal scanning laser microscopy (CSLM) and scan electron microscope (SEM). The result showed that DLC was successfully deposited on the silicon substrate with a root mean square (RMS) roughness of 0.183± 0.09 nm. The biofilm efficaciously grown on all samples (DLC and positive control) with thickness of 46.8 ± 6.97 μm and 42.18 ± 4.65 μm, respectively. No topological and morphological changes have been observed by SEM on biofilm-DLC compared to PVC-biofilm. Moreover, all results indicated that the hydrophobicity and roughness of DLC appeared to support the attachment and the growth ofC.albicans.In conclusion , there is no privilege of utilizing DLC over PVC in term of reduction or inhibition ofC.albicansbiofilm formation at physiological conditions. Furthermore, this study may serve as an experimental model to evaluate the potential effect of nanomaterials coating on biofilm formation at conditions mimicking human’s body.