兔骨髓基质干细胞与软骨细胞共培养体内成软骨的实验观察

Experimental study on chondrogenesis by co-culture of rabbit mesenchymal stem cells and chondrocytes

目的:探讨骨髓基质干细胞(MSCs)与软骨细胞混和培养体内成软骨的可行性.方法:分离、培养、扩传兔MSCs及软骨细胞,二者按一定比例混和(3∶1),以6.0×1010/L的细胞密度接种于PGA(聚羟基乙酸)支架作为共培养组,以相同密度的单纯MSCs和单纯软骨细胞分别接种以作为阴性与阳性对照.将细胞PGA材料复合物种植在成兔皮下,各标本于体内培养8wk时取材,通过大体观察、组织学等方法对新生软骨进行初步评价.结果:各组细胞与PGA支架的黏附良好.混和培养组及阳性对照组(软骨细胞组)体内培养8wk后均形成了成熟的软骨组织,并基本保持了复合物初始的大小和形状,两组新生软骨外观及组织学特征基本相同.阴性对照组(单纯MSCs组)在体内培养过程中未形成软骨组织,而是形成了纤维结缔组织.结论:软骨微环境在MSCs成软骨分化及体内软骨形成中具有重要作用,软骨细胞能有效地诱导MSCs向软骨细胞分化并促进MSCs体内软骨形成.

AIM： To explore the feasibility of in vivo chondrogenesis by co-culture of mesenchymal stem cells （MSCs） and chondrocytes. METHODS： Rabbit MSCs and chondrocytes were in vitro isolated, cultured and expanded respectively and then were mixed at a ratio of 3 ： 1 （ MSCs： chondrocytes）. The mixed cells were seeded onto PGA scaffold at the ultimate concentration of 6.0 × 10^10/L as co-culture group. MSCs and chondrocytes of the same ultimate concentration were seeded respectively onto the scaffold as negative control group（ MSCs group）and positive control group（ chondrocyte group）. Then, the cell-scaffold constructs were transplanted into subcutaneous tissue of adult rabbits. All specimens were harvested after in vivo culture for 8 weeks. Gross observation and histology were used to evaluate the new cartilage. RESULTS： Cells in all groups had a fine adhesion to the scaffold. In both co-culture group and positive control group, the cellscaffold constructs could maintain the original size and shape during in vivo culture and formed homogenous mature cartilage after 8 weeks of in vivo culture. Furthermore, the neo-cartilages in both groups were similar to each other in gross appearance and histological features. In negative control group, the cartilage was not formed but the connective tissue. CONCLUSION： Chondrocytes can provide a chondrogenic to induce a chondrogenic differentiation of MSCs and thus promote the chon-drogenesis of MSCs in vivo.