| The purpose of the first part study is to investigate the effects of nanophase hydroxyapatite (nHAP) particles, a promising scaffold biomaterial for bone tissue engineering, on proliferation and differentiation of MC3T3-E1, the osteoblast precursor cell. nHAP particles were prepared using Hexadecyl(cetyl)trimethyl ammonium bromide (CTAB) as surface modifier and stabilizer. MC3T3-E1 cells were treated with nHAP particles suspension. At different timepoint, MTT assay, ALP activity and ALP/vonkossa staining were used to analyze the effect of nHAP on proliferation and differentiation of MC3T3-E1 cells. In addition, contribution of ion released and protein absorbed by nHAP particles on those effects were evaluated. The results showed that nHAP inhibit proliferation of MC3T3-E1 cells in a dose dependent manner. Concentration of 10μg/ml promote differentiation of MC3T3-E1 cells. No significant contribution of ion release and protein absorption by nHAP was found.In the second part, we studied osteogenic differentiation from embryonic stem cells. Osteoblasts derived from embryonic stem cells have many advantages. First of all, the unlimited proliferation capability of ESCs made it possible to generate enough differentiatiated cells; secondly, osteoblasts derived from embryonic stem cells can not only express bone associated proteins but also synthesize bone matrix that are similar to natural bone. In this study, we induced ES cells into osteoblast-like cells through monolayer pathway without embryonic body formation High dose of ratinoic acid was used to induce the differentiation of mesenchymal cells and osteoblastic induction media was followed to obtain mature osteoblasts. RT-PCR and alizarin red stain is used for assessemt. The results show that neural crest mesenchymal cells were induced by ratinoic acid and a lot of mineralized nodules were obtained at the end. |
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