人髁突骨髓间充质干细胞体内成骨的实验研究

目的 探讨人髁突来源骨髓间充质干细胞(bone marrow-derived mesenchymal stem cells,BMSC)体内分化成骨的能力,为构建组织工程髁突提供种子细胞.方法取切除的人髁突冲洗收集骨髓细胞,采用密度梯度离心和贴壁培养法进行培养和纯化BMSC,取第3或4代BMSC进行成骨细胞和成软骨细胞诱导分化后接种于珊瑚骨支架表面,扫描电镜观察细胞在支架表面的黏附和增殖状况.将成骨或成软骨细胞-珊瑚骨支架植入裸鼠背部皮下,6和9周后观察体内成骨和成软骨情况.结果 培养3～7d后扫描电镜显示细胞黏附于珊瑚骨支架表面,呈多层生长,并跨越微孔连成网状或片状；植入裸鼠体内9周,髁突形珊瑚骨支架均基本维持最初的形态,可见散在或片状的新生骨形成,新生软骨呈岛状分布.结论从人髁突骨髓中分离出的BMSC具有体内形成新骨和软骨组织的能力,可作为构建组织工程髁突的种子细胞.

New bone and cartilage tissues formed from human bone marrow mesenchymai stem cells derived from human condyle in vivo

Objective To investigate the ability to form new bone and cartilage tissues of bone marrow mesenchymal stem cells(BMSC) derived from human condyle in vivo,to search the new source of seed cells in constructing tissue engineering condyle. Methods Bone marrow was collected from the irrigation solution from resected human condyle,and was isolated by density gradient centrifugation and then purified by adherent separation and cultured in vitro. P3 or P4 BMSC populations were induced into osteoblasts and chondroblast under inductive medium in vitro and then seeded on porous coral scaffolds.The appearance and affinity of cells were investigated via scanning electron microscope.And then osteoblast or chondroblast/coral scaffolds composites were implanted into the dorsum of nude mice. The mice were sacrificed by anaesthesia overdose at six and nine weeks after surgery and the scaffolds were removed for analysis.Results Scanning electron microscope showed that BMSC were adhering to the surface of coral and having an overlapped growth or to contact each other as net and stride over the pores.The in vivo scaffold specimens maintained the initial shape of the coral scaffold. The new formed bone tissues were clearly evident and islands of cartilage tissues were also found at nine weeks after implantation.Conclusions These BMSC derived from human condyle possess the ability of forming bone and cartilage tissues when being implanted in vivo,and can be used as a kind of seed cells in constructing tissue engineering condyle.