Production and Characterization of Graphene Oxide Surfaces against Uropathogens

Abstract

Graphene and its functionalized derivatives have been increasingly applied in the biomedical field, particularly in the production of antimicrobial and anti-adhesive surfaces. This study aimed to evaluate the performance of graphene oxide (GO)/polydimethylsiloxane (PDMS) composites against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. GO/PDMS composites containing different GO loadings (1, 3, and 5 wt.%) were synthesized and characterized regarding their morphology, roughness, and hydrophobicity, and tested for their ability to inhibit biofilm formation under conditions that mimic urinary tract environments. Biofilm formation was assessed by determining the number of total and culturable cells. Additionally, the antibacterial mechanisms of action of GO were investigated for the tested uropathogens. Results indicated that the surfaces containing GO had greater roughness and increased hydrophobicity than PDMS. Biofilm analysis showed that the 1 wt.% GO/PDMS composite was the most effective in reducing S. aureus biofilm formation. In opposition, P. aeruginosa biofilms were not inhibited by any of the synthesized composites. Furthermore, 1% (w/v) GO increased the membrane permeability, metabolic activity, and endogenous reactive oxygen species (ROS) synthesis in S. aureus. Altogether, these results suggest that GO/PDMS composites are promising materials for application in urinary catheters, although further investigation is required.

Exploring Nitrogen-Functionalized Graphene Composites for Urinary Catheter Applications

“…The surface roughness was analyzed using a non-contact white light profilometer (Proscan 2000, Scantron Industrial Products Ltd., Taunton, UK) as described by Belo et al [ 36 ]. Quadruplicate measurements for each sample were performed (n = 4).…”

Graphene-Based Composites for Biomedical Applications: Surface Modification for Enhanced Antimicrobial Activity and Biocompatibility

“…Studies have revealed that GN and its derivatives, such as GO and rGO, can inactivate both Gram-positive and Gram-negative bacteria in either planktonic or sessile states [37]. However, it has been evidenced that these graphene-based materials are more effective towards Gram-positive than Gram-negative bacteria [38,39]. While Gram-positive bacteria contain a plasmatic membrane and a thick peptidoglycan layer, Gram-negative bacteria have an outer membrane mainly composed of lipopolysaccharides, which may offer additional protection against chemical and physical stress [40].…”