The Extraction Process, Dissolution Mechanism And Biocompatibility Of Hap Separated From Bovine Bone

The ionic liquid composed entirely of anion and cation can dissolve the animal collagen directly. Animal bones can be used as raw materials with high HAP content.[Emim]Br ionic liquid was applied to resolve bovine bone and different dissolved technologies, extraction process, dissolution mechanism, dissolution kinetics of bovine bone and biocompatibility of HAP separated from bovine bone were studied.The optimal dissolution parameters explored by orthogonal test were solid-liquid ratio of 1:10, the dissolved time of 3 h, the dissolved temperature of 220?. The dissolution rate of bovine bone achieved a relative stable value of about 82% and the yield of HAP achieved a relative stable value of about 45%. The Ca/P of hydroxyapatite in bovine bone was 1.53 and the crystalline is compliant with the standard (JCPDS 09-0432). The shrinkage temperature of collagen type I in bovine bone was 90?, which was higher than standard collagen type I. The total percentage composition of volatiles and organic matter was 50.39%. The HAP derived from bovine bone is similar to the PDF standard card of HAP and the HAP with good crystallinity has the same component as human. bone. TheHAP contained C,O,Na,Mg,P,Ca and superconducting metal such as Nb,Tc and its atomic ratio of Ca/P is 1.67.The dissolution mechanism of bovine bone was to conform to electron donor-acceptor theory and hydrogen-bonded theory. The ionic liquid had effects on collagen fibers and the quaternary structure, triple helical structure, hydrogen. bonding between peptide chain and peptide chain, even hydrogen bonding in peptide chains of collagen in bovine bone. The crystalline portion of bovine bone collagen was destroyed and the collagen denaturation was irreversible. The collagen was directly dissolved in ionic liquid and the HAP was separated out.The integral method, Powell curve method and concentration-time ratio method were applied to compute the reaction order and activation energy. The higher the temperature was, the better the solubility was, and the closer to first order reaction with the activation energy Ea of 88.5 KJ/mol.The HAP derived from bovine bone showed no pyrogen, no hemolysis, but showed mild acute systemic toxicity and mild skin sensitization. The HAP conform to the requirement of biological material safety evaluation of pyrogenic reaction test, hemolytic test and test for skin irritation.