Weinand Christian, Pomerantseva Irina, Neville Craig M, Gupta Rajiv, Weinberg Eli, Madisch Ijad, Shapiro Frederic, Abukawa Harutsugi, Troulis Maria J, Vacanti Joseph P
Laboratory for Tissue Engineering and Organ Fabrication, Warren 11-1157, Massachusetts General Hospital, Harvard, Medical School, 55 Fruit Street, Boston, MA 02114, USA.
Bone. 2006 Apr;38(4):555-63. doi: 10.1016/j.bone.2005.10.016. Epub 2005 Dec 20.
Trabecular bone is a material of choice for reconstruction after trauma and tumor resection and for correction of congenital defects. Autologous bone grafts are available in limited shapes and sizes; significant donor site morbidity is another major disadvantage to this approach. To overcome these limitations, we used a tissue engineering approach to create bone replacements in vitro, combining bone-marrow-derived differentiated mesenchymal stem cells (MSCs) suspended in hydrogels and 3-dimensionally printed (3DP) porous scaffolds made of beta-tricalcium-phosphate (beta-TCP). The scaffolds provided support for the formation of bone tissue in collagen I, fibrin, alginate, and pluronic F127 hydrogels during culturing in oscillating and rotating dynamic conditions. Histological evaluation including toluidine blue, alkaline phosphatase, and von Kossa staining was done at 1, 2, 4, and 6 weeks. Radiographic evaluation and high-resolution volumetric CT (VCT) scanning, expression of bone-specific genes and biomechanical compression testing were performed at 6 weeks. Both culture conditions resulted in similar bone tissue formation. Histologically collagen I and fibrin hydrogels specimens had superior bone tissue, although radiopacities were detected only in collagen I samples. VCT scan revealed density values in all but the Pluronic F127 samples, with Houndsfield unit values comparable to native bone in collagen I and fibrin glue samples. Expression of bone-specific genes was significantly higher in the collagen I samples. Pluronic F127 hydrogel did not support formation of bone tissue. All samples cultured in dynamic oscillating conditions had slightly higher mechanical strength than under rotating conditions. Bone tissue can be successfully formed in vitro using constructs comprised of collagen I hydrogel, MSCs, and porous beta-TCP scaffolds.
松质骨是创伤和肿瘤切除术后重建以及先天性缺陷矫正的首选材料。自体骨移植的形状和尺寸有限；该方法的另一个主要缺点是供体部位并发症严重。为了克服这些局限性，我们采用组织工程方法在体外制造骨替代物，将悬浮在水凝胶中的骨髓来源的分化间充质干细胞（MSCs）与由β-磷酸三钙（β-TCP）制成的三维打印（3DP）多孔支架相结合。在振荡和旋转动态条件下培养期间，这些支架为在I型胶原、纤维蛋白、藻酸盐和普朗尼克F127水凝胶中形成骨组织提供了支撑。在1、2、4和6周时进行了包括甲苯胺蓝、碱性磷酸酶和冯·科萨染色在内的组织学评估。在6周时进行了放射学评估、高分辨率容积CT（VCT）扫描、骨特异性基因表达和生物力学压缩测试。两种培养条件均导致相似的骨组织形成。组织学上，I型胶原和纤维蛋白水凝胶标本的骨组织更优，尽管仅在I型胶原样本中检测到不透X射线。VCT扫描显示，除普朗尼克F127样本外，所有样本均有密度值，I型胶原和纤维蛋白胶样本中的亨氏单位值与天然骨相当。I型胶原样本中骨特异性基因的表达明显更高。普朗尼克F127水凝胶不支持骨组织的形成。在动态振荡条件下培养的所有样本的机械强度均略高于旋转条件下的样本。使用由I型胶原水凝胶、MSCs和多孔β-TCP支架组成的构建体可在体外成功形成骨组织。
