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Titanium and its alloys have good strength, toughness, hardness, biocompatibility and corrosion-resistant ability is widely used in orthopedic and dental replacement material. Bone by cells and calcification of the stromal cells, stromal cells main component is incompletely calcium deficiency of moisture, the matrix and crystalline hydroxyapatite. And the main component of the matrix is ??collagen, as well as a small amount of non-collagenous protein. Vitro experiments show that the composite material of calcium phosphate and collagen embodied in many physiological environment good biological activity, as well as biodegradable, i.e. the composite material of calcium phosphate and collagen can effectively promote the growth of bone tissue, the reason for the collagen type of biological material through the promote cell cling manner, enriched in the bone tissue to form the desired cells and growth factors. Such as it is a environment conducive to the formation of bone tissue given metal implant surface that will surely make it the ability to integrate with the bone and the quality is greatly improved, but also to accelerate the speed of integration, and reduce the cure time. On the basis of previous work by electrochemical deposition techniques, carried out the research work of preparation of calcium phosphate / collagen composite coating on titanium substrate. First, in the preparation of calcium phosphate coating of titanium substrate surface, adjust the experimental parameters in order to optimize the composition of the product, and microstructure; optimization of experimental parameters, the preparation of calcium phosphate composite coating of collagen and microscopic morphology, composition, mechanical and biological performance aspects of the analysis, research; Finally, on the basis of the test results, summarized the mechanism to give the electrochemical deposition method. Lay the theoretical foundation for the subsequent electrochemical deposition research. In the surface of titanium metal is deposited by an electrochemical method of preparation calcium phosphate coating process, with the continuous extension of the deposition time from 30min to 60min, the deposition of calcium phosphate salts, calcium phosphate particles can be formed on the substrate surface, and the collagen deposition densification trend; the initial pH value of the electrolyte is decided collagen suggest an important factor in a mesh form is deposited on the substrate surface, collagen deposition of the substrate, the electrolyte pH value can not be higher than the electrolyte initial pH value below 4.5 5.5 collagen directly precipitated in solution and can not be a subsequent deposition; voltage provides the driving force for the electrochemical deposition process, the voltage is lower than 2.8V, the thermodynamic conditions that can not satisfy the deposition, the voltage is higher than 3.5V, calcium phosphate and collagen are disorderly heaps gathered in the surface of the substrate; study using two drying methods: were freeze-dried and air Zhongping home dry, dry on the surface morphology of the product greater impact, fluffy and porous surface of the freeze-drying collagen filamentous structures, and placed in the air dried, due to surface tension effects in the process of evaporation of water, a higher collagen density. Found that by optimizing the deposition parameters when the voltage reaches 3V, the deposition time of 60min, prior to deposition under the conditions of the pH value of 5.0 to 5.3, freeze-drying method can produce the porous composite coating, while the air the Zhongping set drying method to obtain a dense coating. layer. This study finally uniform deposition surface collagen mineralization product, 5-10 microns in thickness, the coating is close to the substrate at a dense calcium phosphate coating, outer layer of a porous fibrous layer of the mineralized collagen composition uniformity within each layer . Mechanical, biological characterization of product, as well as the morphology, composition, structure analysis, the establishment of a more comprehensive theoretical model of the electrochemical deposition of calcium phosphate / collagen composite coating. The model is mainly divided into the following four parts: the initial stage of the electrochemical, calcium phosphate in the rapid deposition of the cathode, At the same time, collagen move to the cathode, and in the vicinity of the isoelectric point to achieve self-assembly; the isoelectric point of the collagen and other self-assembled in the process, the calcium phosphate collagen sentinel nucleation growth, collagen mineralization; with the thickening of the cathode layer of calcium phosphate deposition, the cathodic reaction is slowed, the solution pH gradient slows collagen in inorganic ions and isoelectric point, move to the cathode; collagen surface mineralization ongoing growth of calcium phosphate on the titanium substrate ongoing collagen to the substrate close to a reasonable distance, calcium phosphate growth coincide, and to achieve adhesion of the collagen with the substrate calcium phosphate. Under the guidance of this model, we get the good mechanical properties, in vitro tests prove the biological toxicity of a calcium phosphate / collagen composite coatings. The material is porous, highly mineralized collagen fibers, SEM, XRD, FTIR and performance testing, characterization of the materials have the basic characteristics of the carrier as biological factors.
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