Center for Craniofacial and Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, California; Advanced Prosthodontics, Ostrow School of Dentistry, University of Southern California, Los Angeles, California.
J Biomed Mater Res A. 2013 Nov;101(11):3285-94. doi: 10.1002/jbm.a.34546. Epub 2013 Aug 24.
Bone grafts are currently the major family of treatment options in modern reconstructive dentistry. As an alternative, stem cell-scaffold constructs seem to hold promise for bone tissue engineering. However, the feasibility of encapsulating dental-derived mesenchymal stem cells in scaffold biomaterials such as alginate hydrogel remains to be tested. The objectives of this study were, therefore, to: (1) develop an injectable scaffold based on oxidized alginate microbeads encapsulating periodontal ligament stem cells (PDLSCs) and gingival mesenchymal stem cells (GMSCs); and (2) investigate the cell viability and osteogenic differentiation of the stem cells in the microbeads both in vitro and in vivo. Microbeads with diameters of 1 ± 0.1 mm were fabricated with 2 × 10(6) stem cells/mL of alginate. Microbeads containing PDLSCs, GMSCs, and human bone marrow mesenchymal stem cells as a positive control were implanted subcutaneously and ectopic bone formation was analyzed by micro CT and histological analysis at 8-weeks postimplantation. The encapsulated stem cells remained viable after 4 weeks of culturing in osteo-differentiating induction medium. Scanning electron microscopy and X-ray diffraction results confirmed that apatitic mineral was deposited by the stem cells. In vivo, ectopic mineralization was observed inside and around the implanted microbeads containing the immobilized stem cells. These findings demonstrate for the first time that immobilization of PDLSCs and GMSCs in alginate microbeads provides a promising strategy for bone tissue engineering.
骨移植物是现代重建牙科的主要治疗方法。作为一种替代方法，干细胞-支架构建物似乎为骨组织工程带来了希望。然而，将牙源性间充质干细胞包封在支架生物材料（如藻酸盐水凝胶）中的可行性仍有待检验。因此，本研究的目的是：（1）开发一种基于包封牙周膜干细胞（PDLSCs）和牙龈间充质干细胞（GMSCs）的氧化藻酸盐微球的可注射支架；（2）研究微球中干细胞的体外和体内细胞活力和成骨分化。以 2×10(6)个细胞/mL 的藻酸盐制备直径为 1±0.1mm 的微球。将含有 PDLSCs、GMSCs 和人骨髓间充质干细胞的微球作为阳性对照植入皮下，在植入后 8 周通过 micro CT 和组织学分析分析异位骨形成。在成骨诱导培养基中培养 4 周后，包封的干细胞仍然存活。扫描电子显微镜和 X 射线衍射结果证实了干细胞沉积的磷灰石矿物质。在体内，在含有固定化干细胞的植入微球内和周围观察到异位矿化。这些发现首次证明，将 PDLSCs 和 GMSCs 固定在藻酸盐微球中为骨组织工程提供了一种有前途的策略。
