Hydrothermal synthesis of silver vanadate nanoparticles, antimicrobial and anti-inflammatory potentials, cytotoxicity and interference on the activity of antimicrobial drugs

Bacterial resistance to antimicrobial drugs represents a critical threat to global health, compromising the efficacy of standard therapies. In this study, we evaluated the antimicrobial properties of silver vanadate microrods (SVMs) against clinical isolates of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. SVMs were active against all tested isolates, with MIC values of 128 µg/mL for S. aureus and 256 µg/mL for Gram-negative species. Notably, checkerboard assays revealed synergistic interactions with azithromycin, clindamycin, and sulfamethoxazole (FICi 0.093-0.125), indicating that SVM might potentiate the activity of antimicrobial drugs. The MBC/MIC ratio classified SVM as bactericidal against Gram-negative isolates and bacteriostatic against S. aureus. Scanning electron microscopy suggested a membrane disruption mechanism by a direct nanoparticle-bacteria interaction. SVM also exhibited anti-inflammatory activity comparable to tenoxicam in vitro. SVM presented cytotoxicity to BGM cells at 3.13 µg/mL (CC50). Our findings suggest that SVM is a promising candidate for combination therapy, warranting further investigation with surface-functionalized formulations to improve its selectivity.