Synthesis and evaluation of smart nanoparticles for real-time diagnosis and treatment of surgical site infections

Surgical site infections (SSIs) represent a significant challenge in global healthcare, severely impacting patients' quality of life and imposing substantial economic burdens on medical systems. In the current era of escalating antibiotic resistance, the development of novel and efficacious materials for SSI management has emerged as a critical focus in the realms of materials science and biomedical engineering. This study presents the design and evaluation of multifunctional intelligent nanoparticles that integrate both diagnostic and therapeutic capabilities, using a pH-responsive Rhodamine B fluorescent probe as the signal sensing molecule. Under normal conditions, Rhodamine B is quenched due to the closed spirolactam structure. During bacterial infection, the local acidic environment opens the spirolactam ring, forming a positively charged open-ring structure, and the probe emits a fluorescent signal to warn of bacterial infection. Meanwhile, the vancomycin endows the intelligent nanoparticles with antibacterial functionality. Through a comprehensive series of in vitro assays and in vivo animal experiments, the developed intelligent nanoparticles have demonstrated sensitive responses to bacterial infections, providing timely infection warnings and exhibiting autonomous antibacterial action. MSN@V@R demonstrates strong diagnostic and therapeutic potential for bacterial infections. In the SSI model, the fluorescence intensity at the wound site in bacteria-infected mice treated with MSN@V@R was 6.12 fold higher than that of the control group, indicating effective infection detection. Furthermore, MSN@V@R treatment significantly accelerated wound healing, with the healing rate being 19.33% faster than that observed in the untreated group. This innovative approach overcomes the limitations of traditional medical diagnosis and treatment of surgical site infections, offering a promising strategy for early detection and targeted therapy of SSIs.