Nanoscale Surface Roughness Influences Candida albicans Biofilm Formation

Abstract

The microbial contamination of surfaces presents a significant challenge due to the adverse effects associated with biofilm formation, particularly on implantable devices. Here, the attachment and biofilm formation of the opportunistic human pathogen, Candida albicans ATCC 10231, were studied on surfaces with decreasing magnitudes of nanoscale roughness. The nanoscale surface roughness of nonpolished titanium, polished titanium, and glass was characterized according to average surface roughness, skewness, and kurtosis. Nonpolished titanium, polished titanium, and glass possessed average surface roughness (S a) values of 350, 20, and 2.5 nm; skewness (S skw) values of 1.0, 4.0, and 1.0; and (S kur) values of 3.5, 16, and 4, respectively. These unique characteristics of the surface nanoarchitecture were found to play a key role in limiting C. albicans attachment and modulating the functional phenotypic changes associated with biofilm formation. Our results suggest that surfaces with a specific combination of surface topographical parameters could prevent the attachment and biofilm formation of C. albicans. After 7 days, the density of attached C. albicans cells was recorded to be 230, 70, and 220 cells mm–2 on nonpolished titanium, polished titanium, and glass surfaces, respectively. Despite achieving a very low attachment density, C. albicanscells were only observed to produce hyphae associated with biofilm formation on nonpolished titanium surfaces, possessing the highest degree of surface roughness (S a = 350 nm). This study provides a more comprehensive picture of the impact of surface architectures on C. albicans attachment, which is beneficial for the design of antifungal surfaces.

Surface Architecture Influences the Rigidity of Candida albicans Cells

“…In this case, the actin cytoskeleton is required to re-polarize as a recovery response to continue the cell division process [ 46 ]. It is likely that, here, the condensed F-actin filaments and the lack of cortical actin patches of C. albicans cells on pTi may explain the significantly low cell attachment ( Figure S2 ), and the lack of morphological transformations from round shape to pseudohyphae, or elongated hyphae on pTi, as reported in elsewhere [ 27 ].…”

“…One group was directly used for experiments as npTi and the other group consisted of polished (pTi) samples. The polishing process was performed as described elsewhere [ 27 ]. The prepared Ti discs were sterilized by sequentially sonicating with MilliQ water (resistivity: 18.2 MΩ cm, 25 °C), 100% and 70% ethanol (EtOH) (Chem-Supply, Gillman, Australia) for 15 min each.…”

“…Glass slides (ProSciTech, Kirwan, Australia) were cut into 1 × 1 cm 2 pieces using a diamond pen (ProSciTech, Kirwan, Australia). The detailed cleaning steps and their purposes, using hydrochloric acid (Sigma-Aldrich Pty Ltd., Castle Hill, Australia) and a UV Ozone Cleaner (Ossila Ltd., Sheffield, UK), were described by Le et al [ 27 ]. Glass surfaces were subjected to the same sterilizing and storing procedures as Ti surfaces before being used in attachment studies.…”

Investigation of Spin Coating Cerium-Doped Hydroxyapatite Thin Films with Antifungal Properties

“…Nonetheless, due to scarce studies conducted by now, there has not been yet reached a consensus regarding the influence of the surface roughness in the development and adherence of C. albicans fungal cells. The results obtained by Le et al [79] in their study regarding "nanoscale surface roughness influences Candida albicans biofilm formation" have evidenced that that surface topography could influence the adherence of C. albicans cells and also, the results suggested that a specific surface architecture could be used to repel C. albicans attachment, therefore preventing the biofilm formation. Their study revealed that surfaces having an average surface roughness S a less than 20 nm, combined with a certain topography, was highly effective at preventing the attachment of C. albicans.…”

Enhanced Denitrification of Integrated Sewage Treatment System by Supplementing Denitrifying Carbon Source

“…During denitrification, the change trend of COD increased rapidly from 0 to 12 h, decreased gradually from 12 h to 48 h, and gradually stabilized after 48 h. This result can further explain the variation trend of NO 3 − -N removal during denitrification. Carrera [ 22 ] found, through a wastewater denitrification test, that adding a carbon source enables the C/N in water to exceed 7 and reach efficient denitrification. In this test, the average COD/N ratios of the carbon sources in water follow the order PS (10.4) > MT (7.3) > SD (4.9) > PT (3.3) > CK (0.5).…”