Improving endothelial cell adhesion and proliferation on titanium by sol-gel derived oxide coating.

In-stent restenosis becomes increasingly prevalent as a difficult-to-treat disease. An alternative therapeutic strategy is enhancing endothelialization on metallic stent surfaces. This study attempted to modify surface chemistry and topography of commercial pure titanium (cp-Ti) by different sol-gel derived oxide coatings (TiO(2), SiO(2), SiO(2)/TiO(2), and Nb(2)O(5)) to improve endothelialization.

Osteoblast responses to different oxide coatings produced by the sol-gel process on titanium substrates.

In order to improve the osseointegration of endosseous implants made from titanium, the structure and composition of the surface were modified. Mirror-polished commercially pure (cp) titanium substrates were coated by the sol-gel process with different oxides: TiO(2), SiO(2), Nb(2)O(5) and SiO(2)-TiO(2). The coatings were physically and biologically characterized.

Biomimetic implant coatings.

Biomaterials and tissue engineering technologies are becoming increasingly important in biomedical practice, particularly as the population ages. Cellular responses depend on topographical properties of the biomaterial at the nanometer scale. Structures on biomaterial surfaces are used as powerful tools to influence or even control interactions between implants and the biological system [; ].

Nanostructured niobium oxide coatings influence osteoblast adhesion.

The interaction of osteoblasts was correlated to the roughness of nanosized surface structures of Nb(2)O(5) coatings on polished CP titanium grade 2. Nb(2)O(5) sol-gel coatings were selected as a model surface to study the interaction of osteoblasts with nanosized surface structures. The surface roughness was quantified by determination of the average surface finish (Ra number) by means of atomic force microscopy.

[Corrosion behaviour, metal release and biocompatibility of implant materials coated by TiO2-sol gel chemistry].

Alloys based on titanium or cobalt have been used as implant materials for decades with good success. Because of their natural oxide layer these alloys reveal good corrosion behaviour. In contact with physiological solution metal release takes place, which can cause inflammation.

Biocompatible Nb2O5 thin films prepared by means of the sol-gel process.

Thin biocompatible oxide films with an optimised composition and structure on the surface of titanium and its alloys can improve the implant integration. The preparation of these thin oxide layers with the intended improvement of the surface properties can be realised by means of the sol-gel process. Nb2O5 is a promising coating material for this application because of its extremely high corrosion resistance and thermodynamic stability.

Biocompatibility of beta-stabilizing elements of titanium alloys.

In comparison to the presently used alpha + beta titanium alloys for biomedical applications, beta-titanium alloys have many advantageous mechanical properties, such as an improved wear resistance, a high elasticity and an excellent cold and hot formability. This will promote their future increased application as materials for orthopaedic joint replacements. Not all elements with beta-stabilizing properties in titanium alloys are suitable for biomaterial applications-corrosion and wear processes cause a release of these alloying elements to the surrounding tissue.

[High incidence of total hip arthroplasty aseptic loosening with ion-coated titanium femoral heads].

Purpose Of The Study: The purpose of this study was to determine the frequency of aseptic loosening among a series of total hip arthroplasties evaluated at 84 months and to search for the cause. Two types of acetabular cups had been implanted. It was hypothesized that the ion coating of the titanium head could be involved in the deterioration of titanium/polyethylene implants.

Growth behavior, matrix production, and gene expression of human osteoblasts in defined cylindrical titanium channels.

The purpose of the current study was to investigate the effect of different diameters of cylindrical titanium channels on human osteoblasts. Titanium samples having continuous drill channels with diameters of 300, 400, 500, 600, and 1000 microm were put into osteoblast cell cultures that were isolated from 12 adult human trauma patients. Cell migration into the drill channels was investigated by transmitted-light microscopy.

Autologous osteoblasts enhance osseointegration of porous titanium implants.

The goal of this study was to assess the osseointegration of porous titanium implants by means of coating with autologous osteoblasts. Titanium implants (8 x 5 x 4 mm) having drill channels with diameters of 400, 500, and 600 microm were coated with autologous osteoblasts obtained from spongiosa chips. The implants were inserted into the distal femora of 17 adult Chinchilla Bastard rabbits (group I).

Interactions between cells and titanium surfaces.

The interaction between cells and implant materials is determined by the surface structure and/or surface composition of the material. In the past years, titanium and titanium alloys have proved their superiority over other implant materials in many clinical applications. This predominant behaviour is caused by a dense passive oxide layer which forms within milliseconds in oxidizing media.

Cell orientation and cytoskeleton organisation on ground titanium surfaces.

A stable connection between the biomaterial surface and the surrounding tissue is one of the most important prerequisites for the long-term success of implants. Therefore, a strong adhesion of the cells on the biomaterial surface is required. Beside the surface composition the surface topography influences the properties of the adherent cells.

Electrochemical and cytocompatibility assessment of NiTiNOL memory shape alloy for orthodontic use.

Orthodontic arcs and wires are mostly realised from alloys and constitute the motor of dental shifting. Ti-base alloys rapidly replaced the formerly used stainless steel wires due to their excellent corrosion resistance, their high mechanical characteristics and their increased biocompatibility. NiTiNOL shape memory alloys add to these advantages their ability of deforming force.

Evaluation of the haemocompatibility of titanium based biomaterials.

The increased use of metallic biomaterials in contact with blood e.g. for the application as coronary stents leads to the development of new biomaterials.

Migration, matrix production and lamellar bone formation of human osteoblast-like cells in porous titanium implants.

The goal of this study was to characterize growth, mineralization and bone formation of osteoblast-like cells in titanium pore channels of defined diameter. Titanium implants with continuous drill channels of diameters of 300, 400, 500, 600 and 1,000 microm were inserted into human osteoblast-like cell cultures. The ingrowth of the cells into the drill channels was investigated by transmitted-light microscopy and scanning electron microscopy.

Preparation of TiO(2) layers on cp-Ti and Ti6Al4V by thermal and anodic oxidation and by sol-gel coating techniques and their characterization.

The excellent biocompatibility of titanium and its alloys used, for example, for medical devices, is associated with the properties of their surface oxide. For a better understanding of the tissue reaction in contact with the oxide layer, knowledge of the chemical and physical properties of this layer is of increasing interest. In this study, titania films were produced on cp-Ti and Ti6Al4V substrates by thermal oxidation, anodic oxidation, and by the sol-gel process.

[Malignant fibrous histiocytoma of bone 20 years after femoral fracture treated by plate-screw fixation: analysis of corrosion products and their role in malignancy].

We report a case of malignant fibrous histiocytoma of the bone that developed 20 years after a femoral fracture treated by plate-screw fixation. Similar cases reported over the past fifteen years in the literature suggest the possible mechanisms of sarcomatous degeneration. The possible carcinogenic effect of corrosion products is emphasized.

[The electrochemical behavior of TiTa30 and TiNb30 alloys for implantology].

The electrochemical behavior in artificial saliva of TiNb30 and TiTa30 alloys were compared with that of commercial pure titanium. The anodic potential, the current density, the passivation potential and the galvanic corrosion vs. Au were determined.

[The in vitro biological behavior of TiNb30 alloy treated with hydroxyapatite and tricalcium phosphates].

An in vitro study has been carried out in different cell systems to determine the biological response of TiNb30 alloy before and after a surface treatment with hydroxyapatite (HA) and tricalcium phosphate (TCP) by the sol-gel method. TiNb30 pure Ti induce favorable cell viability with respect to pure Ni showing a high cytotoxic effect. After surface treatment with HA or HA-TCP mixtures, no difference in cell proliferation can be observed between amorphous and cristalline forms.

Influence of the surface structure of titanium materials on the adhesion of fibroblasts.

Of utmost importance for the successful use of an implant is a good adhesion of the surrounding tissue to the biomaterial. In addition to the surface composition of the implant, the surface topography also influences the properties of the adherent cells. The aim of this investigation was thus to study the influence of the surface structure of the substrate on the formation of focal contacts and on the orientation of cultivated gingival fibroblasts by means of fluorescence microscopy.

Development of a titanium alloy suitable for an optimized coating with hydroxyapatite.

By means of the metallurgical method of alloying, the thermal expansion coefficient of commercially pure titanium was adapted to that of hydroxyapatite (HA) in order to produce a tailored composite material with a maximum adhesion strength of HA to the metallic material. The alloying element chosen was manganese, which is an important trace element in the human organism. With the alloy TiMn6 a good compromise concerning the expansion coefficient, the mechanical properties and the biocompatible behaviour was found.

Development and functionality of isoelastic dental implants of titanium alloys.

Two types of isoelastic endosseous dental implants were produced and their functionality was tested. One type consisted of a porous sintered TiTa30 alloy, the other had a special surface structure consisting of titanium wire loops. Their mechanical properties were optimized by the production parameter (sintering and diffusion bonding, respectively).

Contribution to the functional surface structure of endosseous implants.

An endosseous implant that should allow osseointegration as well as fixation by connective tissue has been developed. A special surface structure consisting of titanium wire loops on a titanium implant was produced by diffusion bonding. The mechanical properties of this implant are investigated.

Asymptomatic strut fracture in DeBakey-Surgitool aortic valves: incidence, management, and metallurgic aspects.

From August 1971 through November 1972, we implanted 62 Model 2 DeBakey-Surgitool aortic valve prostheses in 62 patients, 4 of whom later had clinically asymptomatic strut fractures. In 1 case, the patient died suddenly, and autopsy revealed detachment of the ball-cage; in each of the other 3 cases, fractures of 2 struts close to the base of the prosthesis were diagnosed fluoroscopically, and the patients underwent successful reoperation. The interval between implantation and reoperation ranged from 11 months to 16 years, 9 months.