title: Newly developed Ti-Nb-Zr-Ta-Si-Fe biomedical beta titanium alloys with increased strength and enhanced biocompatibility.
abstract: Beta titanium alloys are promising materials for load-bearing orthopaedic implants due to their excellent corrosion resistance and biocompatibility, low elastic modulus and moderate strength. Metastable beta-Ti alloys can be hardened via precipitation of the alpha phase; however, this has an adverse effect on the elastic modulus. Small amounts of Fe (0-2 wt.%) and Si (0-1 wt.%) were added to Ti-35Nb-7Zr-6Ta (TNZT) biocompatible alloy to increase its strength in beta solution treated condition. Fe and Si additions were shown to cause a significant increase in tensile strength and also in the elastic modulus (from 65 GPa to 85 GPa). However, the elastic modulus of TNZT alloy with Fe and Si additions is still much lower than that of widely used Ti-6Al-4V alloy (115 GPa), and thus closer to that of the bone (10-30 GPa). Si decreases the elongation to failure, whereas Fe increases the uniform elongation thanks to increased work hardening. Primary human osteoblasts cultivated for 21 days on TNZT with 0.5Si+2Fe (wt.%) reached a significantly higher cell population density and significantly higher collagen I production than cells cultured on the standard Ti-6Al-4V alloy. In conclusion, the Ti-35Nb-7Zr-6Ta-2Fe-0.5Si alloy proves to be the best combination of elastic modulus, strength and also biological properties, which makes it a viable candidate for use in load-bearing implants.
authors.affiliation: Department of Biomaterials and Tissue Engineering, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, , Czech Republic. Electronic address: ivana.kopova@biomed.cas.cz.
authors.forename: Ivana
authors.initials: I
authors.lastname: Kopova
authors.affiliation: Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Stráský
authors.affiliation: Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Harcuba
authors.affiliation: Institute of Thermomechanics, Academy of Sciences of the Czech Republic, Dolejskova 5, 182 00 Prague 8, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Landa
authors.affiliation: Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
authors.forename: Miloš
authors.initials: M
authors.lastname: Janeček
authors.affiliation: Department of Biomaterials and Tissue Engineering, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, , Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Bačákova
mesh_terms: D000497:Alloys; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology*; D007501:Iron / Q000737:chemistry; D009556:Niobium / Q000737:chemistry; D010012:Osteogenesis / Q000187:drug effects; D012822:Silicon Dioxide / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; C023988:beta titanium; D009556:Niobium; C031462:titanium alloy (TiAl6V4); D012822:Silicon Dioxide; D014025:Titanium; D007501:Iron
keywords: Alloy hardening; Bone implants; Cell growth; Elastic modulus; Osteogenic cell differentiation