The use of vitamin E as an anti-adhesive coating for cells and bacteria for temporary bone implants

In recent years, vitamin E (or more specifically alpha tocopherol) has been widely discussed in the literature due to its strong anti-oxidant, -inflammatory, -cancer, and -bacterial properties and successfully applied in hip and knee arthroplasty to confer oxidation resistance to irradiated ultra-high molecular weight polyethylene (UHMWPE). In this study, vitamin E has been used, characterized, and in vitro tested as a coating on a chemically treated titanium alloy. The target final application is in temporary trauma fixation devices. The results of the physico-chemical characterization from FTIR-ATR and reflectance spectroscopy, z-potential titration curves, contact angle measurements, and tape test revealed a continuous coating, with hydrophobic behaviour, low surface energy (39 mN/m), and high adhesion to the substrate. Interestingly, the biological characterization revealed a strong anti-adhesion ability of the vitamin E coating as >90 % of the human mesenchymal stem cells (hMSC) seeded directly onto specimens' surface failed to attach, resulting nevertheless viable as demonstrated by the live/dead assay. Similarly, when vitamin E coated specimens were infected by the pathogens Staphylococcus aureus and Escherichia coli, a strong antifouling effect was observed as the colony forming units (CFU) count showed that >95 % bacteria were viable, but unable to adhere and colonize the Ti specimens (>2 logs reduction in comparison to controls). This work highlights a novel promising application of this biomolecule as a coating preventing unintended osseointegration on removable temporary devices, as well as preventing the adhesion of bacterial pathogens thus reducing the risk of implant-associated infections.