TEXTIR (Texturing & Functionalization of titanium for the design of osseointegration and antimicrobial surfaces)
The quality of implantation of prostheses is directly realted to the surface properties of the materials, which determines the quality of anchoring of the prosthesis (osseointegration) in the bone tissue. The development of new “intelligent” prostheses with an improved biological response is a major challenge in reconstructive surgery. The development of new so-called “intelligent” prostheses with an improved biological response is a major challenge in reconstructive medicine. It is now accepted that the integration of inert material in bone tissue requires adequate surface functionality. The topography and chemical composition of an implant define its intrinsic properties (roughness, anisotropy, wettability, free surface energy, etc.), which play an essential role in controlling interactions between the implant and the host tissue.
In recent years, several physical, chemical and mechanical methods have been developed to modify the surface properties of titanium alloys. Although some of these methods (plasma-spraying, grit-blasting, acid-etching and anodizing) were commercial success, many of them tend to pollute the surface, to change fundamentally the structure and properties of the material, to influence the aging of the implant and to enhance bacterial colonization. Moreover, these methods do not make it possible to produce the desired textures in a reproducible manner.
The TEXTIR project ambitions to use the approaches of surface functionalization and regenerative medicine to offer reconstructive surgery or even dentistry new generation prostheses that will allow bone regeneration while preventing the risk of infection, especially against microorganisms that are difficult to fight, such as Gram-positive bacteria (e.g. aerobic S. aureus and anaerobic C. acnes).
The innovative aspect of the TEXTIR project relates to the design of a multifunctional textured titanium alloy surface by an innovative texturing technique, namely the projection of fine particles by nitrogen jet, thus promoting bone regeneration and inhibiting bacterial adhesion via surface functionalization processes. The originality is threefold since the project aims at developing a bioactive surface that (i) will have an osteoconductive / osteoinductive activity, (ii) will have an antibacterial activity; and (iii) block the internalization process of bacteria in stem cells responsible, among other, for the regeneration of bone tissue.
Besides the biological characterization of surfaces, the project is largely based on a physico-chemical and biophysical approach of cell / bacteria, cells / materials and bacteria / materials interactions under flow conditions (microfluidic system). These approaches are based on methodologies combining vibrational spectroscopies (infrared and Raman), atomic force microscopy (AFM) and epifluorescence microscopy in order to follow the structural modifications of cell walls and thus identify virulence biomarkers.
