CuO/Ag hybrid nanomaterial coated hydrophilic natural rubber film with minimal bacterial adhesion and contact killing efficiency

Abstract

The formation of biofilms and bacterial infections associated with biomedical equipment continues to be a severe clinical problem. To provide a high-efficiency bactericidal coating, CuO/Ag hybrid nanomaterial was introduced onto the surface of natural rubber polymer by a simple immersion strategy. The hybrid nanomaterial was synthesised using Carboxymethyl chitosan as the stabilising agent. The effective conjugation of CuO/Ag on rubber film was assured by inductively coupled plasma mass spectrometry (ICP-MS) and hydrophilicity of the coated and uncoated rubber films were tested by water contact angle measurements. The antimicrobial drop test results authenticate the eradication of the attached bacterial strains. The live/dead bacterial assay further confirmed the destruction of 83% of E. coli and 92% of S. aureus on the rubber film with minimal bacterial adhesion. In fact, clinical infections caused by biofilms are more challenging in the healthcare sector rather than those caused by planktonic cells. The colorimetric (crystal violet) assay depicts that there is biofilm reduction of 53.82% E. coli, 54.87% S. aureus and 49.71% P. aeruginosa on rubber film by modification with CuO/Ag. The results of qualitative and quantitative antibacterial assessments show good bacterial resistance for the coated rubber film. The modified hydrophilic surface can be selectively used in rubber-based medical devices, especially to avoid nosocomial infections.

Keywords

• Natural rubber film
• Hydrophilicity
• Antibacterial
• Contact killing
• Hybrid nanomaterial