分离培羊人体脂肪基质细胞，经过软骨定向诱导后复合藻酸盐凝胶，研究基异位软骨生成能力。方法将脂肪抽吸术获取的人体脂肪机械分割，通过I型胶原酶消化后得到脂肪10ug/LTCF-β，50mg/L维生素C的DMEM/F12培羊基中诱导培羊14d，获取的细胞按1×1010/L的细胞密度与质量分数为1.2%的藻酸钠复合、加入102mmol/LCaCl，充分泥匀，使之交联，将细胞-藻酸盐凝胶1ml注入每只体重为25g的BALB/C裸小隶鼠背部皮下（共4办），同时在裸小鼠臀部两侧皮下各注入相同量的无细胞藻酸盐及单纯细胞作为自岙对照、术后4、8周各处列2只动物，取材固定、脱钙、包埋后切自染色。镜下观察。结果经连续导培羊14d的脂肪基质细胞已具明显成骨表型（细胞基质中富含硫酸软骨素及II型胶原）。4、8周时，注射细胞-藻酸盐胶标本均显示成明显的软骨形成。肥大的软骨细非金属位于富含硫在术手3-4周已完全吸收。结论脂肪基质细胞过导培羊具有向软骨细胞表型分化的潜能。

This study was to determine the ectopic osteogenic ability of BMSCs in combination with a scaffolding material comprising hydroxyapatite and β-tricalcium phosphate matrix (HA/β-TCP). BMSCs were obtained from the SD rats and induced to osteogenesis. Then these induced cells were seeded into HA/β-TCP and the constructs were auto-implanted subcutaneously for up to 12 weeks. Histological analysis, immunostaing, RT-PCR and transmission electron microscopy of the retrieved specimens at various intervals showed obvious trends of ectopic bone formation with obvious alteration of cellular phenotype.

Human adipose tissue is a viable source of mesenchymal stem cells (MSCs) with wide differentiation potential for musculoskeletal tissue engineering research. The stem cell population, termed processed lipoaspirate (PLA) cells, can be isolated from human lipoaspirates and expanded in vitro easily. This study was to determine molecular and cellular characterization of PLA cells during chondrogenic differentiation in vitro and cartilage formation in vivo. When cultured in vitro with chondrogenic medium as monolayers in high density, they could be induced toward the chondrogenic lineages. To determine their ability of cartilage formation in vivo, the induced cells in alginate gel were implanted in nude mice subcutaneously for up to 20 weeks. Histological and immunohistochemical analysis of the induced cells and retrieved specimens from nude mice at various intervals showed obviously cartilaginous phenotype with positive staining of specific extracellular matrix (ECM). Correlatively, results of RT-PCR and Western Blot confirmed the expression of characteristic molecules during chondrogenic differentiation namely collagen type II, SOX9, cartilage oligomeric protein (COMP) and the cartilage-specific proteoglycan aggrecan. Meanwhile, there was low level synthesis of collagen type X and decreasing production of collagen type I during induction in vitro and formation of cartilaginous tissue in vivo. These cells induced to form engineered cartilage can maintain the stable phenotype and indicate no sign of hypertrophy in 20 weeks in vivo, however, when they cultured as monolayers, they showed prehypertrophic alteration in late stage about 10 weeks after induction. Therefore, it is suggested that human adipose tissue may represent a novel plentiful source of multipotential stem cells capable of undergoing chondrogenesis and forming engineered cartilage.