Synergic antibacterial coatings combining Ti nanocolumns and Te nanorods

Abstract

The glancing angle deposition technique by magnetron sputtering is a scalable technique that allows the production of nanostructured coatings in large areas [1]. In recent works, we have shown that nanocolumnar coatings made of Ti were successfully prepared with this method [2] and how they exhibited selective behavior towards osteoblast and Staphylococcus aureus (S. a.) proliferation [3]: the biocompatibility towards human cells was preserved, whilst the adherence and proliferation of S. a. were dramatically reduced, not only with commercial strains but also with clinical ones coming from infected patients.

In this new work, not only Gram-positive bacteria but also Gram-negative ones (E. Coli) have been used to test the response of different coatings fabricated in two set-ups, one of them being a semi-industrial equipment, in order to check the robustness of this approach. Moreover, Te nanorods were synthesized on top of the nanocolumns (see Fig.) using a hydrothermal and environmentally-friendly approach. It will be shown that the antibacterial behavior is enhanced when this synergic route combining Ti nanocolumns and Te nanorods is used, especially in the case of long nanocolumns. Furthermore, all the coatings remain biocompatible for human cells and allow for their proliferation.