Development of nanoclay-based nanocomposite surfaces with antibacterial properties for potential biomedical applications

Abstract

Biofilm formation on biomedical implant surfaces requires bacterial adhesion, which increases the risk of infection and chronic inflammation. Since intercalation of quaternary ammonium salts (QAS) into montmorillonite (MMT) clay, known as organoclays, has been reported to increase surface broad-spectrum antibacterial properties, we aimed to develop an antibacterial surface composed of thermoplastic polyurethane (TPU) embedded with bentonite and MMT clay containing QAS to prevent initial bacterial attachment. We evaluated its potential application in reducing bacterial adhesion and enhancing bacteria-killing properties using Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Our results demonstrated that the nanoclay-embedded TPU surfaces with QAS significantly reduced the adhesion of E. coli and S. aureus by 68.82% and 65.18%, respectively, compared to the plain TPU surfaces. Additionally, a higher nanoclay concentration coating on the surface could enhance its effectiveness, as shown by 85.34% and 82.74% reduction in E. coli and S. aureus adhesion and killing efficiency. Furthermore, we observed that nanoclay-embedded TPU surfaces had no detrimental effects on the viability of human dermal fibroblasts. Taken together, these techniques could provide novel strategies for inhibiting bacterial adhesion and supporting bacteria killing on biomedical implant surfaces, as the investigated surfaces are simple to synthesize, efficient, and cost-effective.