Cytotoxic Effect on Osteosarcoma MG-63 Cells by Degradation of Magnesium

Biocompatible and biodegradable magnesium （Mg） based metals have attracted great interest for use in orthopedic implants and devices. Based on our previous study that Mg with and without micro-arc oxidation （MAO） coating showed obvious cytotoxic effect on tumor cells due to the increase of pH value during the degradation of Mg, this study further evaluated the cytotoxic effect of Mg and MAO coated Mg on osteosarcoma （MG-63） cells by analyzing the cell adhesion, morphology and number through observation of scanning electron microscope, as well as live/dead staining, lactate dehydrogenase （LDH） activity and 4, 6- diamidino-2-phenylindole （DAPI） assay. The results indicated that, compared to titanium, Mg could strongly inhibit the cell adherence, morphology and number of MG-63 on the surface of the naked Mg, whereas the MAO coated Mg showed relative weak cytotoxic effect on MG-63 cells, expecting that magnesium based metals with suitable coating can be designed to be applied as tumor prosthesis in the clinical practice.

Promoting Bone Mesenchymal Stem Cells and Inhibiting Bacterial Adhesion of Acid-Etched Nanostructured Titanium by Ultraviolet Functionalization

Titanium(Ti) and its alloys are used extensively in orthopedic implants because of their excellent biocompatibility,mechanical properties and corrosion resistance. However,titanium-based implant materials face many severe complications,such as implant loosening due to poor osseointegration and bacterial infections,which may lead to implant failure. Hence,preparing a biomaterial surface,which enhances the interactions with host cells and inhibits bacterial adhesion,may be an optimal strategy to reduce the incidence of implant failure. This study aims to improve osseointegration and confer antibacterial properties on Ti through a combination of two surface modifications including nanostructuring generated by acid etching and ultraviolet(UV) light treatment.Our results showed that without UV treatment,the acid etching treatment of Ti surface was effective at both improving the adhesion of bone mesenchymal stem cells(BMSCs) and increasing bacterial adhesion. A further UV treatment of the acid-etched surface however,not only significantly improved the cell adhesion but also inhibited bacterial adhesion. The acid-etched nanostructured titanium with UV treatment also showed a significant enhancement on cell proliferation,alkaline phosphatase(ALP) activity and mineralization. These results suggest that such nanostructured materials with UV treatment can be expected to have a good potential in orthopedic applications.