Project: Researching & developing a process of electrodepositing Thin Antimicrobial Coating (TAC) on orthopaedic implants

Titanium and its alloys are amply used for the manufacturing of orthopaedic prostheses due to excellent mechanical properties and biocompatibility. In order to improve osseointegration, those titanium implants are coated with a bioactive ceramic layer: calcium phosphate layer._x000D_Such coatings have been applied on titanium implants by using plasma spray and are successfully used in clinical practice for improving the initial healing and long term stability of orthopaedic hip prostheses. _x000D__x000D_Recently appeared on the market a new range of surface implants which improve the primary fixation of the implant in the body: porous surface and complex geometries surfaces implants. As the plasma spray method is a 'line-of-sight' process, it is unsuitable for porous surfaces and complex implant geometries: only the external surfaces directly facing the spray gun are coated. Furthermore, the plasma spray method takes place at extremely high temperatures possibly affecting the structure and mechanical properties of titanium and the homogeneity of the hydroxyapatite coating. Finally, thick plasma-sprayed coatings are suspected of loosening, causing some infections case. _x000D__x000D_Electrodeposition of calcium phosphate coatings on conductive substrate is an alternative process that shows many advantages: _x000D_- uses of aqueous solutions at low temperatures and which cannot affect the properties and structure of the implant_x000D_- this is a multidirectional process, _x000D_- suitable for implants the surface of which has a complex geometry, _x000D_- the thickness of the coating can be controlled by adjusting physical parameters, in a wide range (very thin coatings can be obtained )_x000D_- antibacterial agent can be added in the coating solution, leading to implants which can prevent infections (nosocomial diseases). _x000D_Electrodeposition process produces a coating featuring different properties than plasma-sprayed coating: thin coatings which can suit for complex geometries whereas plasma sprayed process will suit for thicker coatings and whis no complex surfaces geometry. Those products are complementary ones._x000D__x000D_MedicalGroup owns great experience in plasma spray coating. As a leader in coating industry, MedicalGroup is naturally interested by new technologies which can solve medical and technical issues and allow to offer bigger variety of products to its customers. Furthermore its R&D department has already experienced antibacterial agent, and is know leading a project for incorporating silver ions in synthetic bone substitutes. The advantages of silver ions compared to antibioprophylaxis by antibiotics is that silver ions don't generate antibiotic resistant bacterial strains._x000D_For its part the TUD-MBC is very experienced in developing techniques for surface engineering of biomaterials surfaces. Substancial work has been performed in the area of using electrochemical approaches for immobilization of compounds of biological/biomedical interest such as electrochemically assisted deposition of calcium phosphate phases either alone or as compound coatings together with organic components like collagen, chlorhexidine or chitosan. TUD-MBC has already run several national and international Pships in both basic and applied research._x000D__x000D_This project is meant to be run in collaboration between the MedicalGroup company (MG) and the Technische Universität Dresden-Max Bergman Center (TUD-MBC) with an exchange of know-how, background and means. The research part of the project will be lead by the TUD-MBC, whereas the industrialization part will be performed by MedicalGroup under the TUD-MBC assistance._x000D_MedicalGroup and the TUDresden will mutualize their know-how, background and characterization means to search and develop a coating process, to fit with the complex and porous implant surfaces and featuring a biofunctionnality._x000D_Thanks to this process many kinds of implants could be coated, and many orthopaedic prostheses markets targetted: hip, knee, shoulder, spine._x000D_The first implant the Ps aim to coat is hip prosthesis (stem and acetabulum).

Acronym	TAC (Reference Number: 5520)
Duration	01/12/2009 - 30/11/2012
Project Topic	The objective is to coat ortopaedic implants with a thin homogeneous and antimicrobial film of calcium phosphate phases. The coating covers internal surface of a porous coating already present upon the implant. The final coating aims to prevent nosocomial infections and to improve osteointegration.
Project Results (after finalisation)	The project lead to the implementation of a process of depositing a coating upon medical devices._x000D_As a result of this project, the expertise of the company in bioactive coating for orthopaedic implants increased.
Network	Eurostars
Call	Eurostars Cut-Off 4

Project partner

Number	Name	Role	Country
2	MedicalGroup	Coordinator	France
2	Technische Universität Dresden	Partner	Germany