Amorphous Magnesium\nCoating for Achieving Functional\nChanges from Antibacterial to Osteogenic Activities

Medical devices composed of titanium (Ti) should exhibit\nantibacterial\nand osteogenic activities to achieve both infection prevention and\nrapid bone reconstruction. Here, a Ti surface was modified by performing\nmagnetron sputtering (MS) using pure Mg or Mg–30Ca alloy targets\nfor surface functionalization. MC0, prepared with a pure Mg target,\nhad a crystalline metallic-Mg coating layer, whereas MC30, prepared\nwith an Mg–30Ca alloy target, had an amorphous coating composed\nof Mg and Ca. Both samples rapidly dissolved when immersed in a cell\nculture medium and exhibited antibacterial activities against methicillin-resistant Staphylococcus aureus and cytotoxicity against MC3T3-E1\ncells. Furthermore, MC30 promoted the proliferation and calcification\nof MC3T3-E1 cells because of the subsequent deposition of calcite\non the surface after rapid dissolution. Our findings are the first\nto reveal that MS performed by using an Mg–30Ca alloy target\nendowed Ti surfaces with functional changes from antibacterial to\nosteogenic activities over time. Our results provide fundamental insights\ninto the surface design of Ti-based medical devices for enhanced bone\nreconstruction and infection prevention and offer possibilities for\nbiomedical applications of Mg-based coatings.