New materials and coatings for implants with enhanced resistance to infections
30.05.2011
Titanium-based orthopedic and dental implants are widely used in modern clinical practice – every year hundreds of thousands of patients get a new implant for a hip, knee, or shoulder joint replacement, and more people get also various dental implants.
Implantation is always associated with a risk of infection: up to 10-15% of complications are caused by bacterial-induced infections, mainly by staphylococci, E. coli and pseudomonas forming a biofilm on the surface of and inside the porous titanium layer. Combating infections is difficult, and patients are normally treated with strong antibiotics to avoid post-operative diseases, which are becoming more and more challenging due to progressive spreading of MRSA and other resistant staphylococci.
The materials processing group led by professor Michael Gasik at Aalto University is taking part in an integrated EU project aimed at the development of the surface treatment for commercial titanium implants with reduced propensity to infections. This does not compromise the implants' biomechanical properties.
For combating infection risks and biofilm formation, several coating modification technologies have been developed. New in vitro tests have shown 65-95% reduction in biofilm formation in the treated products, thus obtaining a reduction of the infection compared with the state-of-the-art porous titanium and bare titanium disks when the surface parameters are optimized and no antibacterial substances are used.
In addition, novel alloys without aluminium and vanadium, are also required. These substances are known to be harmful for the body if dissolved. Novel bioresorbable thin coatings of hydroxyapatite, bioactive glass and drug-eluted substances have been developed for the purpose. These promising biomaterial combinations have been tested in vitro and validated in vivo.
In this project, 13 research groups from 8 countries are being taking part. Aalto University has been participating in all critical stages of the project. In Otaniemi, several researchers were involved in the studies of new metallic alloys development, in their analyses and reactions with synthetic body fluids as well as in their biomechanical and biopharmacological modeling. Implant manufacturers in 3 countries are already making experimental implants for further extensive testing.
For further information, please contact:
Professor Michael Gasik
School of Chemical Technology
Department of Materials Science and Engineering
mgasik [at] cc [dot] hut [dot] fi
p. +358-9-470 22769
