A Movable Drug Carrier with High Affinity to Bacteria for Precise Antibacterial Therapy

Pathogenic bacteria infection, which is an extremely serious clinical problem, could be effectively treated by the antibiotics, but the misuse of antibiotics caused by imprecise transportation is a huge problem that causes the emergence of multidrug-resistant bacteria, which can kill millions of people. Herein, a drug-carrier is developed that can deliver antibiotics precisely to the bacteria and kill bacteria efficiently, thus avoiding the misuse of antibiotics. These drug carriers, consisting of ciprofloxacin (cip)-loaded CaCO 3 coated by asymmetrical glycol chitosan (GCS) (cip-loaded CaCO 3 @GCS carriers, abbreviated as CC@GCs), could move autonomously in the acidic environment caused by the bacteria-infection, which is based on the asymmetric pressure generated by the CO 2 concentration gradient due to the asymmetric reaction between CaCO 3 and acid. The motion of CC@GCs increases its probability to contact the bacteria, leading to the formation of effective electrostatic binding between them. The combination of movement and enhanced affinity to bacteria enable CC@GCs to precisely deliver drug to bacteria and kill them more efficiently as compared to the free drug, which shows effective treatment in bacterial infection abscess on skin with improved drug utilization. The CC@GCs based drug carriers have great potentials in treating bacterial infection with precision for efficient antibacterial therapy and alleviating the antibiotic misusage.