Titanium nanostructures for biomedical applications

Abstract

Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

The Role of Titanium Surface Nanostructuring on Preosteoblast Morphology, Adhesion, and Migration

“…To date, titanium and its alloys find wide application in regenerative medicine, representing clinically relevant implant materials which need further improvement for enhancement of healing and tissue regeneration. [5][6][7] Particularly, the speed and effectiveness with which these alloys become populated by progenitor cells, may be crucial for their efficacy in promoting repair. Besides their chemical properties, others have already proposed that the material surface topography is fundamental for this process.…”

Cytotoxic and Bacteriostatic Activity of Nanostructured TiO2 Coatings

“…Due to its high refractive index small amounts of TiO 2 can be used to achieve an opaque coating with a great resistance to discolor under UV light (Mikkelsen et al, 2011). In the last decade great interest arose from the field of synthesis and applications of nanostructured TiO 2 materials (Kulkarni et al, 2015). In this regard examples of applications are, for instance, dyesensitized solar cells, sensors, rechargeable batteries, electrocatalysis, self-cleaning and antibacterial surfaces, photocatalytic cancer treatment and dental implants surface modification to prevent infections (Petrini et al, 2006;Seo et al, 2007;Roy et al, 2011;Cai et al, 2013;Lee et al, 2014;Behzadnia et al, 2014).…”

Characterization of TiO2 films obtained by a wet chemical process

“…Despite its probable biological toxicity (not fully proved) in animals and humans TiO 2 NPs have a considerable potential in biomedicines, and a variety of works have been conducted to develop new antibacterial and drug delivery systems based on this nanoparticle due to its photocatalytic properties, which explain its ability to destroy bacteria, viruses, and even cancer cells [7].…”