Commercial titanium of technical purity (c.p.) is an excellent implant material because of its high corrosion resistance and outstanding biocompatibility. It is known as not causing allergic reactions, preferred when infection is a risk. However, the applications of titanium are limited by relatively poor wear resistance and tensile strength. This stimulated interest in improving the mechanical properties of c.p. titanium, among others by hydrostatic extrusion which is a method of grain refinement by severe plastic deformation. Hydrostatic extrusion (HE) allows to obtain nanograins in bulk samples, which achieve strength similar to that of titanium alloys. This opens the new possibility for application of c.p. titanium in the biomedical devices. The present study reports the results obtained in the investigations of osteoblast culture on nanocrystalline titanium. The material examined in the study was c.p. extruded titanium with the mean grain size of 60 nm. HE titanium was examined by scanning and transmission microscopy (SEM/STEM Hitachi S 5500) and using a computer image analysis. The mechanical properties of the titanium were characterized using a HYSITRON Triboindenter. Titanium with a grain size of 20 μm and Ti6Al4V alloy were used as the reference materials. Human bone derived cells were observed in direct contact with investigated materials in vitro. Cell morphology and proliferation on nano-titanium was found to be comparable to those for micro-titanium and for Ti6Al4V alloy. This indicates, that nanocrystalline titanium obtained by hydrostatic extrusion may be taken into account as a material for bone reconstruction.

Acknowledgements

The study was support by the Ministry of Science and Higher Education.(grant 3 T08A 019 29) and by the Rector of Medical University of Warsaw (grant NZME/W2/07).