To endow Ti-based orthopedic implants with strong bactericidal activity,a ZnO nanorods-patterned coating(namely ZNR)was fabricated on Ti utilizing a catalyst-and template-free method of micro-arc oxidation(MAO)and hyd...To endow Ti-based orthopedic implants with strong bactericidal activity,a ZnO nanorods-patterned coating(namely ZNR)was fabricated on Ti utilizing a catalyst-and template-free method of micro-arc oxidation(MAO)and hydrothermal treatment(HT).The coating comprises an outer layer of ZnO nanorods and a partially crystallized inner layer with nanocrystalline TiO_(2) and Zn_(2)TiO_(4) embedded amorphous matrix containing Ti,O and Zn.During HT,Zn^(2+)ions contained in amorphous matrix of the as-MAOed layer migrate to surface and react with OHin hydrothermal solution to form ZnO nuclei growing in length at expense of the migrated Zn^(2+).ZNR exhibits intense bactericidal activity against the adhered and planktonic S.aureus in vitro and in vivo.The crucial contributors to kill the adhered bacteria are ZnO nanorods derived mechano-penetration and released reactive oxygen species(ROS).Within 30 min of S.aureus incubation,ROS is the predominant bactericidal contributor with quantitative contribution value of ~20%,which transforms into mechano-penetration with prolonging time to reach quantitative contribution value of ~96% at 24 h.In addition,the bactericidal contributor against the planktonic bacteria of ZNR is relied on the released Zn^(2+).This work discloses an in-depth bactericidal mechanism of ZnO nanorods.展开更多
基金the National Natural Science Foundation of China(Grant number 51631007,51971171 and 31700860)for financially supporting this work.
文摘To endow Ti-based orthopedic implants with strong bactericidal activity,a ZnO nanorods-patterned coating(namely ZNR)was fabricated on Ti utilizing a catalyst-and template-free method of micro-arc oxidation(MAO)and hydrothermal treatment(HT).The coating comprises an outer layer of ZnO nanorods and a partially crystallized inner layer with nanocrystalline TiO_(2) and Zn_(2)TiO_(4) embedded amorphous matrix containing Ti,O and Zn.During HT,Zn^(2+)ions contained in amorphous matrix of the as-MAOed layer migrate to surface and react with OHin hydrothermal solution to form ZnO nuclei growing in length at expense of the migrated Zn^(2+).ZNR exhibits intense bactericidal activity against the adhered and planktonic S.aureus in vitro and in vivo.The crucial contributors to kill the adhered bacteria are ZnO nanorods derived mechano-penetration and released reactive oxygen species(ROS).Within 30 min of S.aureus incubation,ROS is the predominant bactericidal contributor with quantitative contribution value of ~20%,which transforms into mechano-penetration with prolonging time to reach quantitative contribution value of ~96% at 24 h.In addition,the bactericidal contributor against the planktonic bacteria of ZNR is relied on the released Zn^(2+).This work discloses an in-depth bactericidal mechanism of ZnO nanorods.
