Studies on Gelatin-Keratin-Chitosan Functionalized Silver Nanoparticles Based Bionanocomposite Films With Improved Antimicrobial and UV-Blocking Properties

This study investigates the properties of a biocomposite film made from gelatin and sustainably sourced keratin incorporating chitosan-functionalized silver nanoparticles. Varied concentrations of chitosan solution (i.e., 0.4%, 0.6%, 0.8%, and 1% w/v) were used in the synthesis of silver nanoparticles, and their particle size, distribution, and antibacterial and antifungal activities were evaluated against foodborne pathogens (Escherichia coli, Staphylococcus aureus, Rhizopus stolonifer, and Aspergillus niger). The addition of keratin enhanced the film's tensile strength to 16.64 MPa, a 403% increase compared to the gelatin film. However, incorporating 2% chitosan functionalized silver nanoparticles reduced the tensile strength to 9.07 MPa compared to the Gelatin-Keratin film. The distribution of nanoparticles and the interaction between the polymer chains were analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. The composite films also exhibited significant UV blocking efficiency, achieving 99% blockage of ultraviolet A and 100% blockage of ultraviolet B. The biocompatibility of the films was tested with MG63 cell lines, showing that silver nanoparticle concentrations (0.3%–2%) improved cell viability to 87% after 96 h of incubation. These findings reveal that the bionanocomposite films exhibit strong antibacterial and antifungal properties, along with excellent biocompatibility, making them ideal materials for wound healing and tissue engineering applications.