Gold nanocluster & indocyanine green based triple-effective therapy for MRSA infected central nervous system

For the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections occur in the central nervous system, the commonly used vancomycin (Van) is highly nephrotoxic, hard to cross the blood-brain barrier (BBB), and prone to induce bacterial resistance during long-term usage. Herein, QAI, the quaternary ammonium salt modified gold nanocluster (QA) combined with indocyanine green (ICG), was synthesized. With the help of the near-infrared laser, QAI could effectively cross the BBB and treat intracranial MRSA infection at low doses through a triple-combination synergistic therapy of direct-killing (DK), photothermal therapy (PTT), and photodynamic therapy (PDT). Another attractive feature of QAI was the difficulty to produce drug resistance, which was attributed to its physical antibacterial mechanism. Compared with traditional Van therapy, QAI therapy was significantly less toxic to the liver and kidney and thus would be a healthier strategy for intracranial MRSA-infection therapy.