Antibiotic-loaded reactive oxygen species-responsive nanomedicine for effective management of chronic bacterial prostatitis

Chronic bacterial prostatitis (CBP) occurs frequently in the male population and significantly influences quality of life. Antibiotics are the main strategy for managing chronic bacterial prostatitis; however, most antibiotics have low efficacy due to their poor penetration of prostate tissues. To overcome this challenge, we fabricated cefpodoxime proxetil (CPD)-loaded reactive oxygen species (ROS)-responsive nanoparticles (NPs) for targeted treatment of CBP. These NPs were modified with folic acid (FA) and could be effectively internalized by bacteria-infected macrophages and prostatic epithelial cells because of the high expression of folate receptors (FRs) in these cells. In vitro cellular assays demonstrated that the CPD-loaded nanomedicine can obviously reduce proinflammatory cytokine expression in cells since the nanomedicine can efficiently eradicate cellular bacteria. In vivo imaging results verified that FA-modified nanomedicines can penetrate the prostatic epithelium and accumulate in the glandular lumen because FRs overexpression was also observed in the prostate tissues of CBP mice. Animal experiments demonstrated that FA-modified nanomedicine can remarkably relieve pelvic pain in CBP mice and dramatically decrease proinflammatory cytokine expression in prostate tissues via eradication of bacteria and scavenging of ROS. Our results provide a new strategy to deliver antibiotics for targeted therapy of CBP. STATEMENT OF SIGNIFICANCE: To overcome poor penetration of antibiotics in prostatic tissues, we developed an antibiotics-loaded ROS-responsive NPs for targeted treatment of CBP. We demonstrated that both bacteria-infected macrophages and prostatic epithelial cells have FRs overexpression, thus FA-modified NPs can be efficiently internalized by these cells. FA-modified NPs can penetrate the prostatic epithelium and accumulate in the glandular lumen via FRs-mediated endocytosis, and the accumulated NPs can smartly release their payload under high ROS microenvironment. A distinguished therapy outcome was obtained in murine CBP model since CPD-loaded NPs can efficiently eradicate the resident bacteria in prostate tissues and downregulate proinflammatory cytokine expression. Our work provides a practicable strategy to expand the application of antibiotics for management of CBP.