Daily sonic toothbrush triggered biocompatible BaTiO3/chitosan multiporous coating with enhanced piezocatalysis for intraoral antibacterial activity

Pure titanium and its alloys are widely used in dental implants because of their excellent physical chemistry and biocompatibility properties, but their negligible antibacterial activity may lead to bacterial infection and implants failure. Inspired by the piezoelectricity and porous structure of living bone, a multiporous piezo-coating with barium titanate (BaTiO3, BTO) nanoparticles embedded in chitosan film is modified on acid-etched pure titanium. The surface of coating shows antibacterial effects and can be further improved under daily sonic toothbrush stimulation with an antibacterial rate of 90.41%. Interestingly, the planktonic bacteria around this coating also have low proliferation. The antibacterial mechanism may be BTO-mediated intracellular and extracellular reactive oxygen species (ROS). On the one hand, the contact potential difference (CPD) caused by the spontaneous polarization of BTO nanoparticles may destroy the intracellular electron transfer and lead to ROS burst. On the other hand, BTO could transfer mechanical energy to electrical energy under the stimulation of sonic toothbrushing (ST), then driving piezocatalytic effect to generate extracellular ROS. In addition, the piezo-coating also exhibits excellent biocompatibility to MC3T3-E1 cells, and promotes more hydroxyapatite deposition and plasma albumin adhesion. In summary, during the stimulation of daily sonic toothbrush, the bioinspired piezo-coating can effectively inhibit the formation of bacterial biofilm, which is a promising strategy to prevent dental implants infection in daily life.