Duration of the project:
1. 2. 2010 – 31. 1. 2013
Monica Mihaela Popa, PhD, Senior Researcher, rank II, Institute of Physical Chenistry “Ilie Murgulescu”, Romanian Academy
Institute of Physical Chemistry (ICF), Romania (coordinator)
SC R&D Consulting and Services SRL (R&D), Romania (partner 2)
SC Tehnomed Impex CO S.A. (TMI), Romania (partner 3)
Josef Stefan Institute (JSI), Slovenia (partner 4)
University of Primorska (UP), College of Health Care Izola (CHCI), Slovenia (partner 5)
State of the art. A biomaterial must have suited mechanical properties and interfacial biocompatibility in order to cause the appropriate and desirable biological response of the human body. Preliminary interactions between implanted materials and biological fluids are governed by surface properties. Therefore, the implant surface plays a decisive role in the response of the tissue to artificial medical devices. Recent studies have shown that changes in the surface topography at the nanoscale level improve the implant bioactivity, but those studies are in an early stage of research.
Market needs. The surface treatments by mechanical techniques and plasma deposition used in actual orthopaedic titanium implants present important drawbacks such as poor stability of the bonding between the metal and the oxide layer, inability to cover porous implants and for the incorporation of active biological agents, the release of delaminated particulates and uncontrolled surface structure and composition at the nanoscale level; these issues translate into a limited, low average lifetime after the implant surgical insertion. The need of bioactive implants with rapid osseointegration and extended lifetime calls for the development of new implants with increased stimulation of cellular activity, high bioactivity and mechanical properties close to those of human bone.
Overall objectives. The long-term objective of this project is the improvement of the life quality of the patients which will utilise the new advanced alloy, by better health conditions through the substitution of risky materials with non-toxic bioalloys. A durable development will be realised using high vacuum and green chemistry technologies. The new alloy will have a very long life time (more than 20 years) and so will realise an efficient use of material resources. The first objective is the synthesis (using environmentally friendly method) of new advanced and innovative bioalloy (original composition) for orthopaedic implants, based on non toxic elements, with high added value due to the increased corrosion resistance, biocompatibility and improved mechanical properties, close to those of the human bone. The second objective is the surface functionalisation by controlled application of surface treatments (original scientific contributions) using non-polluting and non-toxic chemical solution and electrochemical methods for the obtaining of nanoporous structures, with increased osseointegration ability and development of bone cells. Another objective is the complete and complex evaluation of the structural and functional characteristics (scientific novelties) correlated with the increase of the bioactivity. Multi and interdisciplinary original research will be oriented towards the knowledge of the phenomena and mechanisms, which permit the control of the processes at the biomaterial/tissue interface for the stimulation of the cell growth. Finally, verifying parameters for implant execution, a test lot, technology transfer, industrial implementation program to generate a new, competitive European product in a rapidly growing world market.
Targeted innovation. Elaboration of a new alloy based on non-toxic elements Ti, Nb, Zr, which will ensure a very good biocompatibility and corrosion resistance. The surface structuring of this alloy will follow the hierarchy: (1) bioalloy with good corrosion resistance, mechanical, tribological properties; (2) micrometric oxide layer with strong adherence, controlled composition, morphology and micro-topography, realised by electrochemical routes; (3) nanoscale surface layer, with added functionality and optimized surface structure obtained by chemical treatments, leading to increased bioactivity.
Expected results: demonstration of the biochemical and biomechanical compatibility of the new advanced bioalloy; determination of the osseointegration ability; rapid methods for obtaining predictable information about the behaviour of new surface functionalised alloy; original data bank for the users of the alloy with bioactive surface; test lot using advanced bioalloy with functionalised surface; design specifications for implant execution; industrial implementation planning; the formation of a trained European nucleus that covers the whole process from materials generation to physical, chemical and biological testing; 2 patents; 6 scientific papers; 7 conference presentations. Producing companies will use project results and will develop bioactive surfaces. New innovative and RD projects for implementation of the alloy fabrication into industrial units will be initiated.