碩士 / 國立雲林科技大學 / 化學工程與材料工程系 / 103 / In recent years, in situ tissue engineering is a novel technology that the growth factor is added into scaffold before implantation. The chemokine stromal cell-derived factor-1 (SDF-1) has been shown to recruit and mobilize bone marrow stromal cells to the site of injury and is suggested to be a promising candidate for bone tissue engineering. Strontium, a trace element in calcified tissue, plays a crucial role in bone mineralization and remodeling. In this study, gelatin/strontium-substituted hydroxyapatite composites with SDF-1 were prepared to assess the migration and differentiation of bone marrow mesenchymal stem cells and the repair of bone defects.
Firstly, strontium-substituted hydroxyapatite nanoparticles were synthesized by a co-precipitation method. The compositions, crystal structure and morphology of the nanoparticles were characterized by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction and transmission electron microscopy. The effect of strontium-substitution in hydroxyapatite on the cytotoxicity and differentiation of bone marrow mesenchymal stem cells were investigated using MTT and alkaline phosphatase activity assays. Secondly, alginate microspheres with SDF-1 were incorporated into the mixture of gelatin and hydroxyapatite particles to prepare composite with SDF-1. The effect of SDF-1 concentrations on the migration of mesenchymal stem cells was performed by using the transwell system. Moreover, the effects of the release of SDF-1 from gelatin-based composite on the migration, proliferation and differentiation of mesenchymal stem cells were assessed. Finally, the gelatin-based composites were implanted into the calvarial defects of rats to evaluate the effect of the incorporation of strontium and SDF-1 into composites on bone repair.
The results show that the d-spacing, lattice parameter values and particle size of hydroxyapatite increased with the increase of the extent of strontium substitution, while the crystallinity of hydroxyapatite decreased. The strontium-substituted hydroxyapatite exhibited higher cell viability and alkaline phosphatase activity when the degree of strontium substitution was 30 mol%. The incorporation of SDF-1 into gelatin-based composite effectively promoted the migration of mesenchymal stem cells. After 56 days of implantation, the repair quality of bone defect treated with gelatin/hydroxyapatite composite without SDF-1, gelatin/hydroxyapatite composite with SDF-1 and gelatin/strontium-substituted hydroxyapatite composite with SDF-1 was 34.2±2.8, 40.1±6.2 and 43.0±3.6, respectively, indicating that the scaffold with SDF-1 significantly enhanced bone repair.
| Identifer | oai:union.ndltd.org:TW/102YUNT0661032 |
| Date | January 2015 |
| Creators | Wei-Jyun Lian, 連偉竣 |
| Contributors | Kuo-Yu Chen, Chun-Hsu Yao, 陳國裕, 姚俊旭 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 75 |
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