102
Views
13
CrossRef citations to date
0
Altmetric
Original Research

Biological response of chemically treated surface of the ultrafine-grained Ti–6Al–7Nb alloy for biomedical applications

, , , , , , & show all
Pages 1725-1736 | Published online: 06 Mar 2019
 

Abstract

Background

Nanophase surface properties of titanium alloys must be obtained for a suitable biological performance, particularly to facilitate cell adhesion and bone tissue formation. Obtaining a bulk nanostructured material using severe plastic deformation is an ideal processing route to improve the mechanical performance of titanium alloys. By decreasing the grain size of a metallic material, a superior strength improvement can be obtained, while surface modification of a nanostructured surface can produce an attractive topography able to induce biological responses in osteoblastic cells.

Methods

Aiming to achieve such an excellent synergetic performance, a processing route, which included equal channel angular pressing (ECAP), hot and cold extrusion, and heat treatments, was used to produce a nanometric and ultrafine-grained (UFG) microstructure in the Ti-6Al-7Nb alloy (around of 200 nm). Additionally, UFG samples were surface-modified with acid etching (UFG-A) to produce a uniform micron and submicron porosity on the surface. Subsequently, alkaline treatment (UFG-AA) produced a sponge-like nanotopographic substrate able to modulate cellular interactions.

Results

After several kinds of biological tests for both treatment conditions (UFG-A and UFG-AA), the main results have shown that there was no cytotoxicity, expressed alkaline phosphatase activity and total protein amounts without statistical differences compared to control. However, the UFG-AA samples presented an attractive effect on the cell membranes, and cell adhesions were preferentially induced as compared with UFG-A. Both conditions demonstrated cell projections, but for UFG-AA, cells were more widely dispersed, and more quantities of filopodia formation could be observed.

Conclusion

Herein, the reasons for such behaviors are discussed, and further results are presented in addition to those mentioned above.

Acknowledgments

AOL and FRM would like to thank the National Council for Scientific and Technological Development (CNPq grant numbers: AOL – 303752/2017-3 and FRM – 304133/2017-5). EP and RZV acknowledge financial support from Saint Petersburg State University, Event 3 project (id 26130576). DPO would like to thank FAPESP for financial support (2013/06258-0).

Disclosure

The authors report no conflicts of interest in this work.