Characterisation of a duplex TiO2/CaP coating on Ti6Al4V for hard tissue replacement

Effect of Surface Modification with TiO2 Coating on Improving Filtration Efficiency of Whisker-Hydroxyapatite (HAp) Membrane

Whisker-like hydroxyapatite (HAp) particles were prepared by controlling particle growth via hydrothermal synthesis. The surface modification for the hydrothermally synthesized HAp whiskers was accomplished by TiO2 coating. After the TiO2 modification, the zeta potential of the HAp whiskers was significantly improved from +8.6 to +21 mV at pH = 8.5. A free-standing membrane (diameter of ~4.5 cm and thickness of ~0.2 mm) was fabricated by using the TiO2-coated HAp whiskers and was used to separate the Au nanoparticles (size = 5 nm and zeta potential = −38.6 mV at pH = 8.5) at a significantly high filtration efficiency of ~100%. The achieved high filtration efficiency was considered to be the result of effectively utilizing the electrostatic interaction between the positively-charged TiO2-coated HAp whiskers and negatively-charged Au nanoparticles. The excellently biocompatible and highly effective TiO2-coated HAp membrane would be potentially applied as biological and artificial separators in biotechnology processes for the biomedicine field.

A superparamagnetic Fe3O4–TiO2 composite coating on titanium by micro-arc oxidation for percutaneous implants

The micro-magnetic field induced by the Fe₃O₄ nanoparticles in TiO₂ can efficiently enhance the fibroblast response, reduce bacterial reproduction in vitro, and improve skin integration in vivo.

Conformal coating containing Ca, P, Si and Na with double-level porous surface structure on titanium formed by a three-step microarc oxidation

Development of conformal MAO coating on a Ti plate with a double-level porous surface, followed by characterization and evaluation in SBF.

An efficient biomimetic coating methodology for a prosthetic alloy

The combination of the load-bearing metallic implants with the bioactive materials in the design of synthetic implants is an important aspect in the biomaterials research. Biomimetic coating of bioinert alloys with calcium phosphate phases provides a good alternative to the prerequisite for the continual replacement of implants because of the failure of bone-implant integration. We attempted to accelerate the biomimetic coating process of stainless steel alloy (316L) with biomimetic apatite. In addition, we investigated the incorporation of functioning minerals such as strontianite and smithsonite into the deposited layer. In order to develop a highly mature apatite coating, our method requires soaking of the pre-treated alloy in highly concentrated synthetic body fluid for only few hours. Surface characterizations were performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Also, the deposited apatitic layers were analysed by powder diffraction X-ray analysis (XRD). 316L surface showed the growth of highly crystalline, low carbonated hydroxyapatite, after only 6h of the whole soaking process.

Dental implant systems

Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities.

Development and bio-electrochemical characterization of a novel TiO(2)-SiO (2) mixed oxide coating for titanium implants

Titanium and its alloys, the most commonly used materials for dental and orthopaedic implants are generally coated with bioactive materials such as sol-gel derived titania, silica and calcium phosphate in order to render these materials bioactive. In the present work a coating containing nanosized titania particles having anatase structure was developed on titanium substrate by thermal decomposition of titanium tetrachloride in isopropanol. A modified titania-silica mixed oxide coating was developed by incorporating the required amount of silica in the coating system. The presence of silica at small weight percentage caused improvement of adhesion and corrosion resistance of the coating. In vitro bioactivity tests were performed in 1.5 Kokubo's simulated body fluid after alkaline treatment of the titania/titania-silica coatings and the performance was compared with that of the titania coating developed by simple thermal oxidation. TF-XRD, FTIR and SEM-EDAX were used to investigate the microstructural morphology and crystallinity of the coatings. Elemental analysis of simulated body fluid was carried out using ICP-AES and spectrophotometry. Enhanced biogrowth was facilitated on the titania coating incorporated with low silica content.

Cell Growth on TiAlNb Alloy as a Function of Bioactivation Method

This paper it supposed to demonstrate how to obtain the hydroxylapatite on the surface of TiAlNb biomaterial used as dental implant. The bone-forming bioactivity of TiAlNb is associated with its chemical and structural properties, including composition, porosity, specific surface area and particle size. After different bioactivation surface treatments as chemical and electrochemical treatments, it was observed a better stability for the TiAlNb alloy that was treated electrochemically.

Selfprotective smart orthopedic implants

In this review, we discuss current advances leading to an exciting change in implant design for orthopedic surgery. The initial biomaterial approaches in implant design are being replaced by cellular-molecular interactions and nanoscale chemistry. New designs address implant complications, particularly loosening and infection. For infection, local delivery systems are an important first step in the process. Selfprotective 'smart' devices are an example of the next generation of orthopedic implants. If proven to be effective, antibiotics or other active molecules that are tethered to the implant surface through a permanent covalent bond and tethering of antibiotics or other biofactors are likely to transform the practice of orthopedic surgery and other medical specialties. This new technology has the potential to eliminate periprosthetic infection, a major and growing problem in orthopedic practice.

Influence of TiO2 and Ag2O addition on tricalcium phosphate ceramics

Degradation of implanted ceramics allows for bone in-growth and eventual replacement with natural tissue. Calcium phosphate-based materials have gained the most significant attention because of their excellent biocompatibility and compositional similarities to natural bone. Adding various dopants to these ceramics significantly influences critical properties. In this study, tricalcium phosphate (TCP) compacts were fabricated via uniaxial compression with four compositions: (i) pure TCP, (ii) TCP with 1.0 wt % TiO(2), (iii) TCP with 0.5 wt % Ag(2)O, and (iv) ternary of TCP and 1.0 wt % TiO(2), and 0.5 wt % Ag(2)O. These compacts were sintered at 1250 degrees C for 4 h to obtain dense ceramic structures. Phase analyses were carried out using an X-ray diffractometer. The presence of TiO(2) in TCP improved densification and increased compression strength from 70 (+/-25) to 145 (+/-40) MPa. The ternary composition had the highest density and compression strength of 180 (+/-15) MPa. Human osteoblast cell growth behavior was studied using an osteoprecursor cell line (OPC 1) to assure that the biocompatibility of these ceramics was not altered due to the dopants. For long-term biodegradation studies, density, weight change, surface microstructure, and uniaxial compression strength were measured as a function of time in a simulated body fluid (SBF). Weight gain in SBF correlated strongly with precipitation viewed in the inter-connected pores of the samples. After 3 months in SBF, a 35% drop in compression strength was noticed for pure TCP, but for doped compositions, no strength loss was noticed.

Corrosion behavior of titanium in the presence of calcium phosphate and serum proteins

The effect of calcium phosphate surface deposit and the surface adsorption of the serum proteins, bovine serum albumin (BSA) and fibrinogen, on the corrosion resistance and electrochemical behavior of (cp)titanium in phosphate buffer saline solution (pH 7.4) was investigated at physiological temperature, 37 degrees C, using electrochemical impedance spectroscopy and dc electrochemical polarization techniques. The formation of calcium phosphate deposit on the Ti surface decreased both the corrosion rate at the open circuit potential (OCP) and the anodic reaction current in the high anodic potential range (>2.6 V). Addition of BSA significantly moved the OCP towards a more negative (cathodic) potential and inhibited the cathodic corrosion reaction, but did not significantly change the corrosion resistance at the OCP. Addition of fibrinogen showed a similar, but less pronounced effect than BSA. The possible mechanisms leading to these observed effects are discussed.