The project ANR TECSAN “ACTISURF” has for main objective to propose a new generation of joint prosthesis (hip, knee, shoulder) made of TAl6V titanium alloy capable of limiting and even preventing the joint infections. A chemical modification of titanium surfaces has been set up to confer desirable functional and required properties to the joint prostheses. In order to prevent bacteria adhesion and to improve the long-term osteointegration, bioactive polymers bearing ionic groups were covalently grafted onto titanium surfaces by a grafting “from” technique. The bioactive polymer grafted surfaces named “bioactive TAl6V surfaces” (cylinder, prostheses, discs) were extensively characterized in vitro and in vivo to assess the bacteria and cell responses. The chemical treatment was industrialized by Ceraver Society, which is now able to produce the bioactive prosthesis at the industrial level. At the same time, a method to follow and/or to detect inflammation and infection in patient sera has been developed. Results showed that: (1) grafting of ionic polymers was successful by using radicals from titanium peroxides able to initiate the radical polymerization of ionic monomers; (2) anionic polymers successfully prevent bacterial adhesion and favor osteoblast cell adhesion and differentiation in vitro. In vivo results are still in process and will be delivered at the end of the year.