Self assembled polymer layer with silver nanoparticles as an alternative coating for biomedical applications

Abstract

Healthcare-acquired infections (HAI) have a significant influence in the morbidity and mortality in hospitals. Traditionally, the prevention of the HAI involves two strategies: the use of inert materials, including stainless steel for furniture and equipment, and the disinfection of devices and facilities. In this work, we evaluate a self- assembled polymer layer with silver nanoparticles as an alternative coating on mild carbon steel for the substitution of the more expensive stainless steel and the traditional disinfection procedures. We evaluated the electrochemical response of five different compounds for the self-assembled monolayer (SAM): adipic acid (AA), cysteine (CYS), glycine (GLY), polyethylene glycol (PEG) and polyethylenimine (PEI). The electrochemical stability of the coated steel was evaluated by open circuit potential measurement (OCP), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV). For the physicochemical evaluation we used Fourier transform infrared (FTIR), Ultraviolet-visible (UV) spectroscopy and dynamic light scattering (DLS). Then, according to the results we selected the SAMs obtained with adipic acid and glycine to test their assembly with Ag nanoparticles. These coatings were evaluated by electrochemical and microbiological test. The microbiological evaluation of the silver nanoparticles inhibitory effect was performed through a modified microdilution method using Candidas spp. The results showed a relationship between the self-assembled layer synthesis procedures and the expected functions that are a low minimal inhibitory concentration (MIC) and the prevention of the corrosion of the mild carbon steel.