Objective To investigate the therapeutic effects of copper-doped barium titanate(BaCuTiO4)piezoelectric materials combined with low-intensity pulsed ultrasound(LIPUS)to activate their piezoelectric-catalytic synergistic effect for treating implant-associated infections.Methods BaCuTiO4 coatings were synthesized on the surface of Ti-6Al-4V substrates using a hydrothermal method,and their surface morphology was characterized by scanning electron microscopy.The piezoelectric characteristics of the coatings were analyzed using a piezoresponse force microscope.An in vitro biofilm model of methicillin-resistant staphylococcus aureus(MRSA)was used,with barium titanate(BaTiO3)coatings serving as the control group.Under LIPUS intervention(1.0 W/cm2,1 MHz,10 min),the bacterial viability was assessed using colony counting to evaluate the antibacterial performance of the BaCuTiO4 coatings.Confocal microscopy was used to observe biofilm viability in different groups,assessing the biofilm removal capability of the coatings.Reactive oxygen species(ROS)generation in each group was detected using Rhodamine b as a probe to evaluate the catalytic efficiency of the coatings in generating ROS.Results Copper doping significantly reduced the piezoelectric coefficient of the coating(from 17.7 pm/V to 7.8 pm/V),bringing its piezoelectric performance closer to the requirements of natural bone tissues.Under LIPUS activation,the BaCuTiO4 coatings increased the generation efficiency of reactive oxygen species by 67.5％and effectively disrupted and removed biofilms formed by MRSA,achieving an antibacterial rate of 90.5％.Conclusions The BaCuTiO4 coatings achieve efficient antibacterial and biofilm-clearing functions through a piezoelectric-catalytic synergistic mechanism.Their piezoelectric properties are well-matched with natural bone tissues,promoting implant osseointegration.

Objective To investigate the therapeutic effects of copper-doped barium titanate(BaCuTiO4)piezoelectric materials combined with low-intensity pulsed ultrasound(LIPUS)to activate their piezoelectric-catalytic synergistic effect for treating implant-associated infections.Methods BaCuTiO4 coatings were synthesized on the surface of Ti-6Al-4V substrates using a hydrothermal method,and their surface morphology was characterized by scanning electron microscopy.The piezoelectric characteristics of the coatings were analyzed using a piezoresponse force microscope.An in vitro biofilm model of methicillin-resistant staphylococcus aureus(MRSA)was used,with barium titanate(BaTiO3)coatings serving as the control group.Under LIPUS intervention(1.0 W/cm2,1 MHz,10 min),the bacterial viability was assessed using colony counting to evaluate the antibacterial performance of the BaCuTiO4 coatings.Confocal microscopy was used to observe biofilm viability in different groups,assessing the biofilm removal capability of the coatings.Reactive oxygen species(ROS)generation in each group was detected using Rhodamine b as a probe to evaluate the catalytic efficiency of the coatings in generating ROS.Results Copper doping significantly reduced the piezoelectric coefficient of the coating(from 17.7 pm/V to 7.8 pm/V),bringing its piezoelectric performance closer to the requirements of natural bone tissues.Under LIPUS activation,the BaCuTiO4 coatings increased the generation efficiency of reactive oxygen species by 67.5％and effectively disrupted and removed biofilms formed by MRSA,achieving an antibacterial rate of 90.5％.Conclusions The BaCuTiO4 coatings achieve efficient antibacterial and biofilm-clearing functions through a piezoelectric-catalytic synergistic mechanism.Their piezoelectric properties are well-matched with natural bone tissues,promoting implant osseointegration.

Objective To evaluate the effects of low-intensity pulsed ultrasound (LIPUS) treatment on the proliferation and differentiation of osteoblasts cultured on barium titanate/titanium alloy (BaTiO3) and zinc oxide/titanium alloy (ZnO) piezoelectric ceramic composite scaffolds.Methods The BaTiO3 and ZnO porous composite scaffolds were randomly divided into ultrasound (UBaTiO3 and UZnO) and control (CBaTiO3 and CZnO)groups,and MC3T3-E1 cells were cultured on the surface of the materials in each group.Cells in the ultrasound groups were subjected to a 20-min treatment LIPUS session daily,and the control group was sham-treated without the power source.The proliferation and differentiation rates of osteoblasts were evaluated using methyl thiazolyl tetrazolium (MTT),alkaline phosphatase (ALP),and osteocalcin (OCN) assays.Results Significant differences in the MTF values were observed between the UBaTiO3 and CBaTiO3 groups at day 4 (P ＜ 0.05) and between the UBaTiO3 and UZnO groups at days 1,4,and 7 (P ＜ 0.05).Compared with the CBaTiO3 group,the UBaTiO3 group showed significantly higher ALP activity and OCN levels at days 4 and 7 (P ＜ 0.05).Further,a significant difference in the ALP and OCN values between the UBaTiO3 and UZnO groups (P ＜ 0.05) was observed.Conclusion LIPUS promotes the proliferation and differentiation of osteoblasts on BaTiO3 and ZnO scaffolds.BaTiO3 scaffolds enable better promotion of osteogenesis under LIPUS treatment than ZnO scaffolds do.