Antibacterial effect of cerium oxide nanoparticle against Pseudomonas aeruginosa

Background Antibiotics have been widely used for the treatment of bacterial infections for decades. However, the rapid emergence of antibiotic-resistant bacteria has created many problems with a heavy burden for the medical community. Therefore, the use of nanoparticles as an alternative for antibacterial activity has been explored. In this context, metal nanoparticles have demonstrated broad-spectrum antimicrobial activity. This study investigated the antimicrobial activity of naked cerium oxide nanoparticles dispersed in aqueous solution (CNPs) and surface-stabilized using Pseudomonas aeruginosa as a bacterial model. Methods Gelatin-polycaprolactone nanofibers containing CNPs (Scaffold@CNPs) were synthesized, and their effect on P. aeruginosa was investigated. The minimum inhibitory and bactericidal concentrations of the nanoparticls were determined in an ATCC reference strain and a clinical isolate strain. To determine whether the exposure to the nanocomposites might change the expression of antibiotic resistance, the expression of the genes shv, kpc, and imp was also investigated. Moreover, the cytotoxicity of the CNPs was assessed on fibroblast using flow cytometry. Results Minimum bactericidal concentrations for the ATCC and the clinical isolate of 50 mu g/mL and 200 mu g/mL were measured, respectively, when the CNPs were used. In the case of the Scaffold@CNPs, the bactericidal effect was 50 mu g/mL and 100 mu g/mL for the ATCC and clinical isolate, respectively. Interestingly, the exposure to the Scaffold@CNPs significantly decreased the expression of the genes shv, kpc, and imp. Conclusions A concentration of CNPs and scaffold@CNPs higher than 50 mu g/mL can be used to inhibit the growth of P. aeruginosa. The fact that the scaffold@CNPs significantly reduced the expression of resistance genes, it has the potential to be used for medical applications such as wound dressings.

Automated summary

This study demonstrated the antimicrobial activity of cerium oxide nanoparticles and gelatin-polycaprolactone nanofibers containing these nanoparticles against Pseudomonas aeruginosa, showing potential for medical applications in wound dressings. The nanoparticles were effective in inhibiting bacterial growth and reducing the expression of resistance genes, indicating their promising role as alternative antibacterial agents.