Construction and Biological Performance of Surface Treated Porous Titanium Scaffold Using Nanotube Arrays of Anatase

TiO2 nanotube in diameter of ~ 100 nm array films were prepared on a porous titanium scaffold with a porosity of 70% via anodic oxidation. The morphology and phases of the films were characterized, and the thermal stability of the films were also studied. In-vitro, the bioactivity of the modified scaffolds was evaluated by simulated body fluid immersion test. In vivo, the scaffolds were implanted into the back muscles of the dog for 6 months. Results show that the anatase nanotubues give better bioactivity than the amorphous. The scaffold after anodic oxidation and annealing at 500 °C for 5 hours not only can induce the formation of hydroxyapatite, but also can induce blood vessel formation and promote the expressions of bone morphogenetic protein BMP-2. The BMP-2 concentrations is 5.57±0.20 μ/L for the scaffold been anodically oxidated and heat-preserved, the value is much higher than that of untreated scaffold(2.78±0.16 μg/L)or only been anodically oxidated(2.86±0.17 μg/L). It shows that the anatase TiO2 nanotubes can contribute to the potential osteoinductivity. This study will promote the development of novel functional porous supports.

PCL-ZnO/TiO2/HAp Electrospun Composite Fibers with Applications in Tissue Engineering

The main objective of the tissue engineering field is to regenerate the damaged parts of the body by developing biological substitutes that maintain, restore, or improve original tissue function. In this context, by using the electrospinning technique, composite scaffolds based on polycaprolactone (PCL) and inorganic powders were successfully obtained, namely: zinc oxide (ZnO), titanium dioxide (TiO2) and hydroxyapatite (HAp). The novelty of this approach consists in the production of fibrous membranes based on a biodegradable polymer and loaded with different types of mineral powders, each of them having a particular function in the resulting composite. Subsequently, the precursor powders and the resulting composite materials were characterized by the structural and morphological point of view in order to determine their applicability in the field of bone regeneration. The biological assays demonstrated that the obtained scaffolds represent support that is accepted by the cell cultures. Through simulated body fluid immersion, the biodegradability of the composites was highlighted, with fiber fragmentation and surface degradation within the testing period.

Evaluation of Protein Adsorption Capacity of TiO2-Supported Spherical Porous Hydroxyapatite

In this study, a novel titania-supported spherical porous hydroxyapatite (sHAp + TiO2) was prepared by compounding minute, uniquely shaped spherical porous hydroxyapatites (sHAp) with TiO2. Adsorption of the representative protein bovine serum albumin (BSA) was evaluated and simulated body fluid immersion experiments were carried out. Minimal adsorption of BSA to TiO2 was observed, and 33% and 25% adsorption to sHAp + TiO2 and sHAp were observed, respectively. The reduction in BSA concentration observed in the sHAp and sHAp + TiO2 solutions is presumably due to adsorption to HAp. It is highly likely that adsorption of the acidic protein BSA occurred at the sHAp Ca2+ site. In the simulated body fluid immersion experiments, there was greater expression of hydroxyapatite (HAp) on the surface of sHAp than there was on the surface of sHAp + TiO2. In the case of TiO2 alone, no HAp was produced, even after immersion for 3 days. These results suggest a relationship between BSA adsorption and the osteoconductivity of materials.

Laser Cladding of Fluoridated Hydroxyapatite Coatings on Titanium Alloy: Preparation and Characterization

In this research, Fluoridated hydroxyapatite bio-ceramic coatings were produced by laser cladding on the titanium alloy with hydroxyapatite and CaF2 as raw materials. The microstructures and phase constitutions of coatings were characterized by OM, SEM, EDS and XRD, the mechanical properties was investigated by micro-hardness and simulated body fluid immersion test. The results indicated that Fluoridated hydroxyapatite bio-ceramic coatings with anticipated structure and properties were achieved successfully by laser cladding on the titanium alloy. Compared with CO2 laser, the FHA coatings prepared by fiber laser had better deposition of biological activity phase.

Characteristics of As-Cast and Forged Biodegradable Mg-Ca Binary Alloy Immersed in Kokubo Simulated Body Fluid

Biodegradable implant is an alternative to metallic implant and has the advantage of not being necessary to remove once the fracture has healed. Magnesium is particularly desirable since it is biocompatible and has a modulus of elasticity closer to bone. In addition, it shows ability to biodegrade in situ, when used as an implant material. In this research, different percentages of calcium were added to magnesium during melting of the alloy. A selected alloy was forged at different parameters. Both as cast and forged alloys were subjected to polarization test performed in Kokubo simulated body fluid. Immersion test in the fluid was conducted for 96 hours to investigate the formation, growth and morphology of the hydroxyapatite on the surface of the alloys. The results showed that similar electrochemical behaviour took place in the alloys regardless of the calcium content. However, an increase in corrosion rate was observed with increasing calcium content. It was also observed that forging process decreased the corrosion resistance of the alloy. Furthermore, increasing calcium content accelerated the growth of bone-like apatite in the alloy.

High Cellular Biocompatibility of Calcium Carbonate / Poly (Lactic Acid) Composites Doped with Silicon

Silicon-doped calcium carbonate / poly (lactic acid) composites (Si-CCPC) were estimated in cellular biocompatibility with culture tests using osteoblast-like cells (MC3T3-E1) and mesenchymal stem cells (MSC). The cellular biocompatibility of Si-CCPC was enhanced by coating with bone-like hydroxycarbonate apatite (b-HA) formed by simulated body fluid immersion. The b-HA was formed on Si-CCPC after 3-days of immersion and closely bonded with Si-CCPC. Numerous MC3T3-E1 and MSC showed good adhesion on the b-HA with extending their lamellipodia. The number of adhering MC3T3-E1 on Si-CCPC coated with the b-HA was higher than that on Si-CCPC. The b-HA has excellent biocompatibility and silicon is regarded to stimulate osteoblast and bone formation in vivo and vitro. The b-HA containing silicon on Si-CCPCis expected to enhance the cellular adheresion, proliferation and differentiation.