Functional classification of bone marrow dtromal cells (BMSCs) using DNA microarray, and development ofculture methods which can maintain differentiation potential of BMSCs

人骨髓基质细胞（hBMSCs）因其分化能力和增殖能力而成为骨组织工程应用的重要来源。然而，尽管骨髓间充质干细胞具有潜力，但在标准培养条件下经过多次加倍过程后，它们失去了分化潜力1。我们假设地塞米松可以增强骨髓间充质干细胞对分化试剂的反应性，持续地塞米松治疗可以使骨髓间充质干细胞具有更高的分化潜能。我们的研究结果表明，地塞米松处理的细胞比对照组具有更高的成骨能力和骨形成能力。为了利用细胞和多孔支架进行有效的骨再生，必须向多孔支架中引入足够数量的细胞。为了提高细胞播种的效率，我们改进了以前报道的细胞播种技术，使用低压条件和设备，并为该方法设计了一个简单的装置。操作步骤如下。在第一步中，多孔β-TCP块被放入一个玻璃腔中，在第二步中，用注射器将腔中的空气抽走以形成真空。第三步，将细胞悬浮液缓慢注入腔室，保持低压状态，并将块浸泡在悬浮液中。在最后一步，释放阀门，使腔内的压力恢复正常。与自然渗透（对照组）相比，该方法的细胞播种效率提高了3倍，所制备的种植体成骨率是对照组的3倍以上。我们还开发并测试了一种细胞播种系统，使用等离子体将其植入多孔植入物中，期望由纤维蛋白原形成的纤维蛋白网络能在几分钟内容纳引入的细胞并促进骨形成。将骨髓间充质干细胞悬浮在血浆中，导入多孔支架中，纤维蛋白凝胶在几分钟内形成。然后移植植入物。血浆制备的骨形成明显高于悬浮在培养基中的骨髓间充质干细胞。少

Human bone marrow stromal cells (hBMSCs) are an attractive source for bone tissue engineering applications because of their differentiation capability and their proliferation capability. However, despite the potential of BMSCs, they lose their differentiation potential after multiple doubling processes under standard culture conditions1. We hypothesized that dexamethasone could augment the responsiveness of BMSCs to differentiation reagents, and continuous dexamethasone treatment would establish BMSCs with higher differentiation potentials. The results of our studies indicated that the dexamethasone-treated cells showed higher osteogenic capability and bone formation capability than the control group.2. To develop efficient bone regeneration using cells and porous scaffolds, it is essential to introduce an adequate number of cells into porous scaffolds. To improve cell seeding efficiency, we modified the previously reported cell seeding techniques using low-pressure conditions and devi … More sed a simple device for this method. The procedures are as follows. In the first step, porous β-TCP blocks are placed into a glass chamber, and in the second step, the air in the chamber is removed by a syringe to create a vacuum. In the third step, the cell suspension is slowly infused into the chamber, maintaining the low-pressure condition, and the blocks are soaked in the suspension. In the final step, the valve is released so that the pressure in the chamber normalizes. Compared to spontaneous penetration (control), cell seeding efficiencies by this method were three fold higher, and the implants prepared by the method showed bone formation more than three folds of the control.3. We also developed and tested a cell seeding system into porous implants using plasma, expecting that the fibrin network formed from fibrinogen would hold introduced cells within minutes and promote bone formation. BMSCs were suspended in plasma and introduced into porous scaffolds, and fibrin gel was formed within minutes. Then the implants were transplanted. The implants prepared using plasma showed significantly more bone formation than that by the implants using BMSCs suspended in culture medium. Less