Composite coatings of Mg-MOF74 and Sr-substituted hydroxyapatite on titanium substrates for local antibacterial, anti-osteosarcoma and pro-osteogenesis applications

Abstract It has been noticed that residual osteosarcoma cells or infective bacteria would greatly hinder the osseointegration between implants and natural bone at the early stage of implant surgeries. Thus, in this work, composite coatings of magnesium-mediated metal-organic frameworks (Mg-MOF74) and strontium-substituted hydroxyapatite (Sr-HA) were constructed on titanium surfaces for improving the local injury treatment even with complications (osteosarcoma or bacterial infection). It was proved that the superficial Mg-MOF74 could rapidly degrade (especially under bacteria- or osteosarcoma-induced acid microenvironment) and effectively kill surrounding Staphylococcus aureus, Escherichia coli and Saos-2 cells, and then the exposed Sr-HA coating had great potential to promote the proliferation and osteogenic differentiation of osteoblasts.