Development technique of bone regeneration using Mesenchymal Stem Cell

近年来，组织工程领域的研究已经发展并建立了骨髓间充质干细胞（MSCs）培养骨再生技术。这些研究已经阐明了再生的大部分特征。总的来说，它描述了一种被称为组织工程的新技术，它涉及到由分离细胞、生物相容性支架和生长因子形成的新组织的形态发生。本研究以MSCs为细胞源，以陶瓷和可吸收胶原为基质，以rhBMP-2和富血小板血浆为生长因子。为了检验培养骨再生在临床应用中的有效性，我们从以下五个方面进行了研究：1)基质的发育，2)体内成骨发生，3)建立更大规模的成骨细胞培养方法，4)生长因子促进骨形成的有效性。5)人体临床应用的可能性。在基质方面，我们研究了不可吸收的透明质酸和一种新的可生物降解的β-磷酸三钙（β-TCP）的成骨潜能，表明β-TCP将是一种理想的骨再生支架。此外，我们发现可吸收的胶原蛋白可以作为鼻窦和自体骨中rhBMP-2的有效支架。然而，大多数关于骨形成的研究都是采用二维组织形态学评价和分子生物学方法，而不是显微CT等三维方法。我们也成功地评估了人类临床病例中小梁骨的微观结构。今后几年，我们将进一步研究利用具有可塑性的间充质干细胞进行培养骨再生的技术，以提高牙周或牙槽骨缺损移植的实用性。

Recent studies in the field of tissue engineering have developed and established the technique of cultured bone regeneration with mesenchymal stem cells (MSCs) derived from bone marrow. Most of characteristics of the regenerat ion have been clarified by these recent studies. Generally, it have described a new technology called tissue engin eering that involves the morphogenesis of new tissue from constructs formed of isolated cells, biocompatible scaff olds and growth factors. In the present studies, we used MSCs as cell sources, ceramics and absorbable collagen as matrices, and rhBMP-2 and Platelet Rich Plasma as growth factors. In order to examine the effectiveness of cultur ed bone regeneration for clinical use, we investigated the following five things : 1) development of matrix, 2) ost eogenesis in vivo, 3) establishment of the method of larger scale of osteoblast culture, 4) the effectiveness of growth factors to improve the bone formation. 5) A possibility of clinical application in human. In regard to the matrix, we investigated the osteogenic potential of non resorbable HA and a new biodegradable β-tricalcium phosph ate (β-TCP), showing that β-TCP would be an ideal scaffolds for bone regeneration. In addition, we found that absorbable collagen would be an effective scaffold for rhBMP-2 in the sinus as well as autogenous bone. However, m ost studies regarding bone formation have adopted two dimensional histomorphometric evaluations and molecular biol ogys, not three dimensional such as micro CT. We also successfully evaluated microstructure of trabecular bone in human clinical cases. In some years from now, we are going to perform studies to improve the utility of the graft for the periodontal or alveolar defect for clinical use of technique of the cultured bone regeneration using MSCs with plasticity.