Proliferative and Antimicrobial Evaluation of the Benzalkonium Chloride Loaded Walnut Shell-Rich Chitosan Gels

Tissue engineering studies combine cells, biomaterials, and biomolecules to mimic native tissue. The selection of appropriate materials for tissue engineering applications encourages best practices from the lab to clinical trials, and natural biomaterials have the potential to offer desired features for these applications. Material abundance, ease of the process, and biocompatibility are the first milestones to choosing a suitable material. Lignocellulose is one of the most promising biomaterials for its biocompatible, antioxidant, and biodegradable features and is the most abundant material in nature. A walnut shell-added chitosan gel was developed in this study by exploiting chitosan's desired properties, such as biocompatibility, biodegradability, and mechanical capabilities, which boosted cell proliferation. Furthermore, the gel system was reinforced with benzalkonium chloride (BAC), a well-known eye drop sterilizing agent. The hydrogels were subjected to Fourier-transform infrared spectroscopy (FTIR) analyses, and BAC-related signals were observed. The results of BAC-loaded hydrogels revealed that the viability of the primary fibroblasts was enhanced on the BAC-loaded gels compared to tissue culture polystyrene, but the difference was not found statistically significant. Yet, antibacterial activity results demonstrated that only BAC-loaded gel systems have solid antibacterial activity. Additionally, the fibroblasts had the strongest proliferation profile on the walnut shell-added chitosan hydrogels compared to other test groups, but the films' bactericidal activity of the hydrogels was not apparent. After revising the BAC and walnut shell concentrations in the hydrogels, the findings demonstrated that the injectable gel system could be used for cell transplantation in vitro and in vivo.