Preparation Of Nano Calcium Phosphate Using Mussel Shells Resources

A large amount of mussel shells in the coastal areas caused environmental problems such as excitant odour and soil pollution. Mussel shells contains more than 95% of calcium carbonate and 1~5% of organic ingredients. In order to make full use of these abandoned mussel shell resources, in this work calcium phosphate were synthesized using mussel shells as calcium precursor. The mussel shells were characterized firstly, and then porous hydroxyapatite and nano calcium phosphate were synthesized using mussel shells. The calcium phosphate were characterized, and vitro degradation and cytotoxicity were tested. Quantum dots/calcium phosphate composite material were synthesized using two kinds of particles. The contents and results of the study as follows:(1) The structure and composition of mussel shell were studied. Calcite and vaterite is the main inorganic component in the mussel shells, which accounted for 49.34% and 51.66% of the mussel shell respectively. The decomposition temperature of calcium carbonate in the mussel shells were lower than most of calcium carbonate in the nature.(2) Hydroxyapatite were synthesized using mussel shells as calcium precursor, and the affect of synthesis conditions on the morphology of calcium phosphate were discussed. We draw a conclusion as follows: water bath temperature is 90 ℃. the amount of citric acid is 0.6 mmol. the amount of urea is 6 g. The particle size of the nano porous hydroxyapatite was 4.5 um. Specific surface area is 270.46 cm2/g. Aperture is 18.52 nm. There was carbonate in the hydroxyapatite.(3) Hydroxyapatite were used combining with quantum dots. Fluorescence microscope showed that the composite particles had good fluorescence strength. Transmission electron microscopy(TEM) showed that quantum dots successful combination on hydroxyapatite.(4) The hydroxyapatite in vitro degradation experiments showed that the hydroxyapatite had a good degradation speed at low pH value. After degradation the Ca/P of hydroxyapatite was changed, and the Ca/P decrease with the pH decreased.(5) The hydroxyapatite synthesized in the optimum conditions was no toxicity to osteoblast(MC3T3-E1), and could promote the proliferation of osteoblast under the concentration of 0.001 mg/m L,0.01 mg/m L,0.1 mg/m L.(6) Amorphous calcium phosphate were synthesized using mussel shells as calcium precursor. The particle size of amorphous calcium phosphate was 350~450 nm, Zeta potential was 27.5 mV. Sodium tripolyphosphate could complex calcium ions in solution, and had the function of preventing phase change of amorphous calcium phosphate.(7) Amorphous calcium phosphate and CdTe quantum dots had good combination. Under the excitation wavelength of 219 nm, the compound had strongest fluorescence intensity.Hydroxyapatite and nano amorphous calcium phosphate were synthesized using mussel shells as calcium precursor, This metiod can make use of the mussel shell resource, and alleviate environmental problems. The calcium phosphate synthesized from mussel shells has good biological compatibility, and have potential uses in areas such as bone substitute materials and drug carrier.