Enhancing the Antimicrobial Effect of Ciprofloxacin by Loading with Silica Nanoparticles Derived From Rice Straw: Spectral, Morphological, and Drug Release Studies

Abstract

Antimicrobial resistance is a significant threat to both human and animal health, such as salmonellosis, brucellosis, and resistant E. coli and S. aureus infections. The growing resistance of these pathogens complicates treatment and raises healthcare costs, highlighting the urgent need for alternative therapeutic strategies. Therefore, this study aimed to prepare silica nanoparticles (SiO₂-NPs) from rice straw through acid leaching method, then ciprofloxacin, one of the most abundant broad-spectrum antibiotics used worldwide, was loaded to SiO2-NPs. Comprehensive characterization of TEM, SEM, EDX, and FTIR confirmed successful SiO2-NPs synthesis and effective drug incorporation. TEM analysis for unmodified SiO₂-NPs showed spherical particles with a size of 130–170 nm, while ciprofloxacin-loaded SiO₂-NPs (CIP@SiO₂-NPs) expanded to 340–640 nm, indicating successful encapsulation and surface modification. These nanoparticles' antibacterial efficacy was tested against Gram-positive and Gram-negative bacteria frequently involved with zoonotic illnesses. The finding revealed that the ciprofloxacin-loaded SiO₂-NPs exhibited superior antibacterial activity to free ciprofloxacin especially for Gram (+ve) bacterial strains. Furthermore, the study proves the efficacy of rice straw-derived SiO₂-NPs as an eco-friendly nanocarrier approach for improving antibiotic delivery that enhances the management of bacterial infections in veterinary medicine, minimizing the risk of zoonotic disease transmission to humans.