The Antibacterial And Osteogenic Activity Of Titanium By Codoping Of Mg And Ag

To simultaneously enhance the osteogenic and antibacterial properties of titanium,we introduced magnesium(Mg),silver(Ag),or both by using the plasma immersion ion implantation(PIII)technique,producing three PIII sample groups,namely,Mg-doped titanium(Mg-PIII),Ag-doped titanium(Ag-PIII),and Mg and Ag codoped titanium(Mg/Ag-PIII).The in vitro antibacterial efficacy of Mg/Ag-PIII group was about 7-10% higher than that of Ag-PIII.In vitro and in vivo results demonstrated that osteogenic property of Mg/Ag PIII group was better than that of Ag-PIII or Mg-PIII.In addition,we assessed the osteogenic performance of titanium implants contaminated by the residual bacterial debris and lipopolysaccharide(LPS).In vitro results demonstrated that osteogenic property of Mg/Ag-PIII and Mg-PIII with the presence of LPS or bacterial debris was better than that of Ag-PIII or Ti.Meanwhile,in vivo study evidenced that magnesium can improve the osteogenesis no matter of occurence of infection or not,and it may inhibit inflammatory reaction caused by the residual bacterial debris in vivo.It was believed that the galvanic effects between Mg and Ag NPs played a key role in facilitating the release of Mg but reducing the release of silver,answering for the selective performances of the Mg/Ag-PIII group over bacterial and mammalian cells.Therefore,Ag combined withMg is highly complementary against implant associated infection.This study demonstrated that the integration of multiple functional elements could be realized by the dual-source PIII technique,and in this case,the antibacterial properties and osteogenic property of titanium could be balanced.