Pyroelectric Janus BaTiO₃ Nanoparticles With Antibiotics Loaded For Antibacterial Treamtent

Pyroelectric dynamic method(PEDT)refers to a new therapy in which the dipole of the pyroelectric material is oscillated due to the temperature rise of the material caused.The voltage and the reactive oxygen species(ROS)were generated on its surface through electric stimulation(ES)to treat bacteria and tumors.PEDT has the advantages of high controllability,less invasiveness,low toxicity and no drug resistance,but it requires a large temperature change to generate enough ROS.The normal tissues and cells would be damaged by higher temperatures and excessive ROS.Antibiotics are the most effective means to treat bacterial infections.Electrical stimulation can trigger the release of drugs,promote the entry of drugs into bacteria and effectively reduce the dosage of antibiotics,cytotoxicity and drug resistance to bacteria,which are of great significance and broad prospects in clinical medicine.The tetragonal barium titanate was polarized by electric field,and silver nanoparticles were deposited on the surface after mixing with silver nitrate and methanol to obtain barium titanate(tBT)nanoparticles.Polydopamine(PDA),as a photothermal agent and drug carrier,was half-coating on the surface of tBT by phase separation technology to prapres tBT@PDA nanoparticles.Ciprofloxacin hydrochloride(CIP)was loaded on the surface of tBT@PDA(tBT@PDA-Cip)through the ?-? stacking,hydrogen bonding and electrostatic interaction between PDA and Cip.Under near-infrared(NIR)excitating,tBT@PDA-Cip nanoparticles with half-coating of PDA not only have high motion velocity(2.05 ?m/s),photothermal effect and pyroelectric output.In addition,the partial coating of PDA could reduce the effect of quinone groups from PDA on the ROS generation ability of PEDT.The COMSOL simulation of tBT@PDA-Cip nanoparticles shows that the pyroelectric voltage could reach 1.68 V,and the methylene blue(MB)degradationtests indicate the degradation rate as high as 79.0%,which proves the ability of ROS generation.The increased temperature and pyroelectric voltage under NIR illumination ptomoted the drug release from tBT@PDA-Cip nanoparticles.In vitro antibacterial experiment shows that tBT@PDA-Cip nanoparticles show high detructruction capabilities to both S.aureus and P.aeruginosa,the addition of ROS generation after tBT@PDA-Cip/NIR treatment killed almost all of the bacterial(98%).The tBT@PDA-Cip/NIR treatment indicated a wound recovery of over 95.3%,resulted from both the PEDT and antibiotic therapy.The cytotoxicity experiment and histological analysis show that tBT@PDA-Cip/NIR have excellent antibacterial ability and outstanding biosafety in vivo.In summary,PEDT and antibiotic therapy were combined to reduce the amount of antibiotics while ensuring efficient sterilization,provides a prerequisite for new antibacterial treatments in the future.