Improving Natural Biopolymeric Membranes Based on Chitosan and Collagen for Biomedical Applications Introducing Silver

The aim of this study was to obtain new films based on collagen-chitosan with and without silver for biomedical applications. Membranes with a thin transparent elastic structure were obtained and after immersion in silver nitrate new membranes with silver have been elaborated and their physicochemical properties were assessed using infrared spectroscopy as well as contact angle determinations, and sorption properties. The water absorption has permitted the evaluation of the diffusion coefficient for modified collagen membranes and the values were comparable with diffusion coefficient specific for human cornea. Adsorption and desorption studies of silver ions were investigated based on the concentration of the silver solution. This concentration was determined by an inductively coupled plasma spectrometer. Antimicrobial investigations performed on Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria and hemolytic properties assays have been evaluated measuring optical density. The enhancement of antibacterial activity of membranes with silver content was emphasized.