Fabrication of silver nanoparticles-embedded antibacterial polymer surface through thermal annealing and soft molding technique

Abstract

The major challenge faced in biomedical field is the formation of biofilm on polymer devices like catheters. It is important to functionalize the biomedical devices with a bactericidal agent through an easy and safe process in order to protect them from bacterial attack. In this article, the new method of impregnation of silver nanoparticles (AgNPs) into polymer film was proposed and tested against bacterial cells. The different sizes of silver nanoparticles were embedded in polystyrene film using thermal annealing and soft molding technique. Silver films having different thickness were deposited on the highly polished machinable glass ceramic (MACOR) substrate using direct current (DC) sputtering and subjected to at 750 °C for 15 min. After the heat treatment, AgNPs were formed on MACOR sample. It was then characterized using field emission scanning electron microscope (FE-SEM). Image-J software was used to analysed shape, size and distribution of AgNPs. The spin coating method was adopted to coat polystyrene film on to MACOR substrate supported AgNPs and allow it to cure for 24 h. After curing, the polystyrene film was peeled off and finally, AgNPs got transferred to polystyrene film. The AgNPs embedded polystyrene film was analyzed using FE-SEM and atomic force microscopy (AFM). Spread plate (plate counting) method was used to evaluate the bacterial killing potential of modified polystyrene film against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. The modified polystyrene film shows effective antibacterial ability against both the types of bacteria compared to the plain polystyrene surface.