| The material for repairing bone tissue is a hot topic in the field of biomedical materials. Tissue engineering material with many advantages has been the direction of the material to repair bone deficiency over twenty years. Tissue engineering scaffolds goes through the developement from biodegradable poly and bioceramic materials to composite porous scaffolds.Hydroxyapatite/organic polymer biomedical composite is one of the hotspots of hard tissue biomaterials reasearch. Hydroxyapatite (HA), the main mineral composition of bone, can form strong bone-bonding with natural bone and has been used extensively for biomedical applications and bone regeneration based on its high biocompatible and bioactive properties. However, due to the brittleness, high modulus and fatigue failure in vivo, the application of HA is restricted in clinic. If HA can combine with a biomacromolecule which has a good elasticity and flexibitity and has the similar ingredients to nature bone, a new material to repair bone tissue may be obtained, which has good strength, flexibitity, plasticity, biocompatible and bioactive properties. In this experiment, HA combines with collagen which is a biomacromolecule. Their abilities can be developed well, then the use of HA can be extended in clinic.Collagens were extracted from the fish scale of grass crap with pepsin. The effects of pretreatment, extraction medium and the way of extraction on the yield of collagen were studied. The result shows that the optimum extraction conditions are dislodging the impurity with the help of microwave, decalifying with 0.1mol/L HCl, extracting the type I collagen with ultrasonic wave and 1% citric acid (contains 1% pepsin) as extraction solutions. Purified collagens were analyzed by IR which confirms the characteristic groups.In this paper, Ca(NO3)2·4H2O, (NH4)2HPO4 and NH4HCO3 were used as starting matrials. Calcium-deficient carbonated HA (d-CHA) nanoparticles, TCP, Calcium-deficient HA (d-CHA) nanoparticles, HA were synthesized using a precipitation method assisted with microwave irradiation. We use blending method and coprecipitation method to make different kinds of Hydroxyapatite/collagen composite scaffolds. The composites soaked in the simulated body fluid to study the biocompatible property. Its characters such as composition, microstructure, porosity were analyzed with XRD, IR, SEM and some chemical and physical methods. The result shows that: d-CHA powders synthesized using a precipitation method assisted with microwave irradiation were the ideal materials to prepare composite scaffolds. The components of d-CHA/collagen composites are similar to nature bone. The porosity could reach more than 65% which is suitable for bone cell fostering. The compressive strength, which can be adjusted by controling the porosity, satisfy the requirement of reparing bone deficiency. So the composites can be expected to be a kind of bone tissues engineering material with favorable biocompatibility, mechanical properties, biodegradability and suitability for bone tissue growing.
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