Effect of chitosan nanogels loaded with vancomycin and gamma interferon on TNF-α gene expression in macrophage cell line activated with methicillin-resistant Staphylococcus aureus (MRSA)

Background and Objectives: Staphylococcus aureus is an opportunistic pathogen that frequently leads to asymptomatic infections. Methicillin-resistant strains (MRSA) pose a significant threat as they are resistant to most commonly used antibiotics, complicating treatment efforts. This study aimed to develop chitosan nanogels loaded with vancomycin and IFN-γ and to assess the expression of the TNF-α gene in a cell line infected with MRSA. Materials and Methods: Following the synthesis and confirmation of the chitosan nanogels, vancomycin and IFN-γ were incorporated into these nanogels. The synthesis was validated using DLS, FTIR, TEM, and SEM. Subsequently, the antibacterial efficacy of the nanogels was assessed. Finally, four groups of cell lines were designed: control, MRSA, chitosan nanogels and IFN-γ-vancomycin chitosan nanogels. After infection of the groups (except control) with MRSA, 5 μg/mL of nanogels, and nanogels (drug and IFN-γ) were added to groups 3 and 4, respectively. Then the expression of TNF-α gene in each group was analyzed by RT-PCR at 6 and 24 hours. Results: At pH 6.5 and 7.4, the MIC of 1 μg/mL was obtained for free vancomycin, whereas that of IFN-γ-vancomycin nanogels at both pHs was respectively 8 and 64 μg/mL. The IC50 of chitosan nanogels and nanogels loaded with vancomycin-IFN-γ on RAW264.7 cells were 2.37 and 4.15 μg/mL in 24 hours, respectively. In group 4 in comparison to the MRSA group, TNF-α expression decreased significantly following 24 hours. Conclusion: Loading of vancomycin and IFN-γ in the chitosan nanogel can reduce TNF-α gene expression on MRSA infected cell lines.