Titanium biological properties

Legostaeva, E.V., Kulyashova, K.S., Komarova, E.G., Epple, M., Sharkeev, Y.P., and Khlusov, I.A. (2013) Physical, chemical and biological properties of micro-arc deposited calcium phosphate coatings on titanium and zirconium-niobium alloy. Materialwiss. Werkstofftech., 44 (2-3), 188-197. 

Ha, Y., Kuh, S.-U., 2010. The electron beam deposition of titanium on polyetheretherketone (PEEK) and the resulting enhanced biological properties. Biomaterials 31, 3465—3470. 

The absorption of ZnO from intact skin after topical application is non-detectable. The data on TiOg are controversial. Earlier studies suggested that a very small amount of titanium dioxide may penetrate the skin, but it is unlikely that this would have any biological significance (237). However, a recent in viuo human study, in which skin punch biopsies were collected after application of titanium dioxide, (256) showed that this sunscreen is solely deposited on the outermost surface of the stratum corneum and does not penetrate into the deeper stratum corneum layers, the epidermis or the dermis regardless of the surface properties of the particles (256). 

As nanomaterials are transported through the environment or the human body, they may undergo transformations that could influence their properties. Oxidation-reduction (redox) reactions are known to cause environmentally and biologically relevant transformations for certain nanomaterials. Titanium dioxide (TiOa), for example, can oxidize orgaiuc compounds in the environment and inactivate microorganisms (26,27). This oxidative property of Ti02 has led to applications such as skin care and water treatment, where antimicrobial properties are desirable, but it may be detrimental to microorganisms that are beneficial to the natural environment. Solar... 

Guidewires, mechanical heart-valve housings and struts, biologic heart-valve stents, vascular stents, vena cava umbrellas, artificial heart housings, pacemaker leads, leads for implantable electrical stimulators, surgical staples, supereleastic properties of some nickel-titanium formulations, shape memory properties of some Ni titanium formulation, radiopaque markers... 

A popular titanium alloy, originally developed for aerospace applications, has the composition Ti-6A1-4V. It contains two phases, the a-phase which has a (he) structure and the P-phase having a (cc) structure. Compared to pure titanium, Ti-6A1-4V exhibits much better mechanical properties, whereas its corrosion resistance in chloride media is almost as good as that of pure titanium. Titanium and its alloys are the materials of choice for biomedical implants that require mechanical strength and good corrosion resistance in chloride media. In addition, titanium and its alloys exhibit good compatibility with biological tissue. 

PARK are frequently used without surface modification. There are a significant number of papers and patents which describe PEEK modified with fillers such as hydroxyapatite (HA) or calcium phosphates, titanimn coatings or even biomimetic protein and peptide sequences. Some of these are described in reference [2]. However, in HA-filled PARK there is a trade-off between mechanical properties and modified biocompatibility. Various attempts have been made to overcome this limitation - for example by using HA coatings or HA whiskers [3, 4]. Biological modifications would be subject to extremely complex regulatory approval. In fact unmodified PEEK has been shown to be comparable in vitro with the bone forming capacity of titanium [5]. 

Titanium dioxide (Ti02) is an n-type SC with a wide Eg of 3.0-3.5eV, it is well-known for its potential applications in the field of photocatalysis and photoelectrochemistry because of its excellent optical transmittance and high refractive index (2.5-3.87) (Table 1) [11]. Ti02 is of outstanding importance as a white pigment because of its scattering properties, chemical stability, biological inertness, and lack of toxicity. Applications are found in paints, papers, fibers, cosmetics, sunscreen products, toothpaste etc. 

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