Bio-Ceramics for Tissue Engineering
Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon in Tissue Engineering Strategies for Organ Regeneration, 2020
Gel oxidation is a thermochemical method to produce porous but well adhered layers of titania on titanium metal. The oxidation of these layers has changed the structure and phases of the titanium surface (anatase, rutile, and residual sodium titanate). The different titania polymorphs and sodium titanate contribute to the degree of hydroxyapatite precipitation during soaking in simulated body fluid. Precipitation of hydroxyapatite increases by irradiation with UV light. Photocatalytic properties of titania enhanced the surface reaction resulting in precipitation with more hydroxyapatite on the gel-oxidised Ti. The gel-oxidised surface showed good cell attachment and penetration in the majority of the cells. The appearance of this cell growth indicated that gel-oxidised Ti can provide a superior implant owing to good ceramic-cell adhesion.
Titania Nanotubes as Silver Nanoparticle Carriers to Prevent Implant-Associated Infection
Huiliang Cao in Silver Nanoparticles for Antibacterial Devices, 2017
Owing to the large resistance of biofilms to systemic antibiotic therapy, endowing the implant surface with the ability to resist bacteria adhesion, colonisation and formation of biofilms through active release of antibacterial agents is a promising strategy. To this end, various surface modification techniques such as ion implantation, physical vapor deposition, micro-arc oxidation and anodisation have been utilised (Liu et al. 2004). In addition, construction of size-adjustable titania (TiO2) nanotubes (NTs) on Ti-based implants by anodisation has drawn tremendous attention since the first report in 1999 (Zwilling et al. 1999). TiO2 NT can not only improve osteoblast functions in vitro and osseointegration ability in vivo compared with pure Ti but also serve as drug carriers to prevent implant-associated infection (Popat et al. 2007a; von Wilmowsky et al. 2009; Yu et al. 2010). Silver (Ag) possesses excellent broad-spectrum antibacterial properties, good long-term stability, low effective concentration and satisfactory cytocompatibility for a proper dose and thus is considered an ideal bactericide (Chernousova and Epple 2013). Compared to metallic Ag, Ag nanoparticles (NPs) possess more effective antibacterial activity because of their extremely large specific surface area, which provides more contact with aqueous solutions to release more Ag+. Therefore, loading Ag NPs into TiO2 NTs and controlling the Ag+ release profiles constitute an effective strategy to prevent infection of Ti-based implants.
Inorganic Chemical Pollutants
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
nTiO2 and larger particles of titanium dioxide (TiO2) are widely used in several fields of science and technology. According to the IAREC,301 titanium dioxide accounts for 70% of the total production volume of pigments worldwide and is classified as possibly carcinogenic to humans. TiO2 is used in various applications such as joints, coatings, UV protection, photocatalysis, sensing and electrochromics, photochromics, as well as food coloring.302 Brightness and high refractive index are properties that have made TiO2 the most widely used white pigment. Other properties of TiO2 include chemical stability, low toxicity, and cheap price. Plain TiO2 nanoparticles are often altered to be better and more specifically suit their use. Alterations can be made by doping TiO2 with other elements or by modifying the surface with other semiconductor materials. TiO2 mostly occurs as rutile, anatase, or brookite crystalline polymorphs (Figure 4.10). A large portion of the chemically and electrically sensitive and chronic degenerative disease patients are sensitive to titanium. Many patients with metal implants containing this substance are sensitive to titanium and/or its alloy.
Effect of morphology and support of copper nanoparticles on basic ovarian granulosa cell functions
Published in Nanotoxicology, 2020
Alexander V. Sirotkin, Monika Radosová, Adam Tarko, Iris Martín-García, Francisco Alonso
Notwithstanding the limitation to rationalize the obtained results, it is worthwhile mentioning the distinctive behavior observed for hexagonal CuNPs: these nanoparticles are the only ones that reduce the ovarian cell viability and proliferation, inhibiting PCNA accumulation. It is known that the presence of vertices makes metal nanoparticles more reactive. Although this might be one reason of this particular behavior, the fact that the nanoparticles have been prepared in the presence of the somewhat toxic diethylene glycol must not be disregarded. As regards hormone release, the support seems to exert an outstanding role as only CuNPs/TiO2 depletes or suppresses this function. Anatasa titania is composed of chains of distorted TiO6 octahedra possessing undercoordinated atoms at the most abundant nanocrystal faces: i.e. four- or five-fold instead of six-fold-coordinated titanium atoms, as well as two-fold instead of 3-fold-coordinated oxygen atoms (Bourikas, Kordulis, and Lycourghiotis 2014); this makes titania particularly reactive. It is known that oxygen-containing molecules, such as water, can bind five-fold-coordinated titanium atoms (through the water oxygen) and two-fold-coordinated oxygen atoms (through the water hydrogens). Therefore, an interaction of titania with the oxygen atoms of the three hormones or their precursors (more enhanced in the case of testosterone and 17β-estradiol because of the presence of hydroxyl groups in their structure) cannot be ruled out and might account for the particular effect observed for CuNPs/TiO2 on hormone release.
Advancing of titanium medical implants by surface engineering: recent progress and challenges
Published in Expert Opinion on Drug Delivery, 2021
Dusan Losic
The aim of this review is to present recent progress on advancing performances of Ti implants using new surface engineering and nanotechnology modification approaches. The review will firstly present a brief overview of fundamental aspects of desirable surface properties of the Ti implants to better understand their basic performance requirements and what the surface engineering and modifications approaches are most appropriate to improve these performances. The application of several selected nanoengineering approaches and their synergetic combination will be highlighted that potentially could lead development of new generation of Ti implants with advanced osteointegration and antibacterial protection and their antibiotic resistive strains. Structural modification of Ti with nanostructured oxide layer in the form of titania nanotubes (TNTs) will be presented here in more details as one of the most promising technological developments and potential candidates for the next generation of multifunctional Ti implants. Finally, the review will conclude with a general overview and a prospective outlook on new trends, emerging fabrications using additive manufacturing (AM) and their limitations and challenges to accelerate the translation of these recent advancements toward the development of new medical implants for safe and affordable clinical applications.
Application of titanium dioxide (TiO2) nanoparticles in cancer therapies
Published in Journal of Drug Targeting, 2019
Selin Çeşmeli, Cigir Biray Avci
TiO2 is a white, odourless and non-combustible powder. There are many different names for titanium dioxide such as titanium (IV) oxide, titania, titanic acid anhydride and Ti white. Titanium dioxide has two crystal structures; these are rutile and anatase which is more chemically active. Rutile form of titanium dioxide nanoparticles are also named as titanium dioxide fine particles (FP). As the anatase crystal structure increases, production of reactive oxygen species increases, too. Therefore, it is thought that the anatase titanium dioxide is more toxic to healthy cells than the rutile titanium dioxide. The rutile titanium dioxide is considered as chemically inert but when the particles become smaller, the surface area will increase and therefore the rutile titanium dioxide particles can become harmful according to the studies. Also, the modifications that are done on the surface of nanoparticles cause changes in the activity of titanium dioxide particles [10].
Related Knowledge Centers
- Inorganic Compound
- Oxygen
- Sapphire
- Sunscreen
- Titanium
- Titanium Tetrachloride
- Food Coloring
- E Number
- Octahedral Molecular Geometry
- Chloride Process