Preparation of highly effective antibacterial coating with polydopamine/chitosan/silver nanoparticles via simple immersion

In this study, we report a simple and facile method to fabricate an antibacterial composite coating by combining polydopamine (PDA), chitosan (CS) and silver nanoparticles (AgNPs) on urinary catheter and titanium (Ti) surfaces. The preparation consists of a co-deposition of PDA and CS in acid solution and subsequently immersion into silver nitrate (AgNO₃) solution. This approach allows the antibacterial PDA/CS/AgNPs coating to be prepared for several hours by the simple immersion process under friendly conditions, and the surface morphology for coated catheters illustrated that CS plays a key role in improvement of the coating smoothness. The antibacterial tests against S. aureus were performed on the measurements of the inhibition halo and adhered bacterial numbers. The results showed that the PDA/CS/AgNPs-coated catheter has long-lasting stability for more than 30 days and antibacterial activity against S. aureus, and the antiadhesion rates of PDA/CS/AgNPs-coated Ti surface are 91% and 85% for live and dead bacteria, respectively. The PDA/CS/AgNPs coating based on the simple immersion has great potential in practical application for antibacterial urinary catheters and other biomedical devices.