Separation And Application Of Hydroxyapatite From Bone In Ionic Liquid

Ionic liquids as a new green solvent which composed entirely of anion and cation can dissolve the animal collagen directly.Hydroxyapatite(HAP)was the main inorganic component of natural bone,with the biocompatibility and bone conduction function is a good biological bone repair materials.Animal bones can be used as raw materials with high HAP content and low cost.Glycerol choline chloride ionic liquid was applied to resolve chicken bone using different methods and the extraction process of HAP,the preparation of hydroxyapatite/collagen composite,the preparation process and biological compatibility of composite were studied.The optimal extraction parameters of HAP explored by orthogonal test were the penetrant dosage of 1%,pH of 9.5,solid-liquid ratio of 1:20,dissolved time of 8.5 h(dissolved 4h at 60?,then increase to 120? and continue to dissolve 4.5 h).The dissolution rate of chicken bone achieved a relative stable value of about 48.69%and the yield of HAP achieved a relative stable value of about 26.10%.The analysis result of FT-IR,XRD and SEM showed that the HAP with good crystallinity has the same component as human bone and display different particle morphology.The average particle size of HAP was 509.7nm and the bulk density was about 2.93g/cm3.The dissolution mechanism of chicken bone in ionic liquid was mainly of collagen dissolution.The ionic liquid had effects on spatial reticular formation,triple helical structure and hydrogen bonding in peptide chains of collagen in chicken bone,which caused collagen dissolved in ionic liquid directly and the HAP separated out.The optimal preparation parameters of composite materials explored by test were using deionized water as precipitant,adding 1.5 times relative to the ionic liquid mixture at a high temperature,sedimentation time of 60h.The yield of composite materials achieved a relative stable value of about 15.76%.The analysis result of FT-IR and XRD showed that the composite with good crystallinity has the same component as the chicken bone.The shrinkage temperature of collagen type ? in composite materials was 60?,which was similar with standard collagen type ?.The analysis result of TG showed that total percentage composition of volatiles and organic matter was 54.59%.The hydroxyapatite composite materials was of no pyrogen,no allergic reaction,no hemolytic effect and acute systemic toxicity,has acceptable biocompatibility.