Veilleux N, Spector M
VA Boston Healthcare System, Boston Campus, 150 S. Huntington Avenue, Boston, MA 02130, USA.
Osteoarthritis Cartilage. 2005 Apr;13(4):278-86. doi: 10.1016/j.joca.2004.12.013.
Chondrocyte-seeded tissue engineering scaffolds hold the promise of enhancing certain cartilage repair procedures. The objective of this study was to evaluate the effects of selected growth factors [fibroblast growth factor (FGF)-2 and insulin-like growth factor (IGF)-1] individually and in combination on adult canine articular chondrocyte-seeded type II collagen-glycosaminoglycan (GAG) scaffolds grown in serum-free (SF) medium.
Approximately 500,000 second passage chondrocytes were seeded into discs of the scaffold, 4mm diameterx2 mm thick. The constructs were grown in the following media: serum-containing medium; a basal SF medium; SF with 5 ng/ml FGF-2; SF with 25 ng/ml FGF-2; SF with 100 ng/ml IGF-1; and SF with 5 ng/ml FGF-2 plus 100 ng/ml IGF-1. The DNA and GAG contents of the scaffolds were determined after 1 day and 2 weeks and the protein and GAG synthesis rates determined at 2 weeks using radiolabels. Histology and type II collagen immunohistochemistry were also performed.
FGF-2 at 5 ng/ml was found to substantially increase the biosynthetic activity of the cells and the accumulation of GAG. The histology demonstrated chondrocytes uniformly distributed through a matrix that stained intensely for GAG and type II collagen after only 2 weeks. Of interest were the rapid degradation of the collagen scaffold, despite the fact that the scaffold was carbodiimide cross-linked, and the contraction of the constructs. There were less pronounced effects using the higher dose of FGF-2 and the combination with IGF-1.
Chondrocyte-seeded type II collagen scaffolds cultured in SF medium supplemented with 5 ng/ml FGF-2 undergo contraction, demonstrate an increase in construct incorporation of radiolabeled sulfate, and display qualitative signs of chondrogenesis.
接种软骨细胞的组织工程支架有望改善某些软骨修复手术。本研究的目的是评估所选生长因子[成纤维细胞生长因子（FGF）-2和胰岛素样生长因子（IGF）-1]单独及联合使用对在无血清（SF）培养基中培养的接种成年犬关节软骨细胞的II型胶原-糖胺聚糖（GAG）支架的影响。
将约500,000个第二代软骨细胞接种到直径4mm×厚2mm的支架圆盘中。构建物在以下培养基中培养：含血清培养基；基础SF培养基；含5ng/ml FGF-2的SF培养基；含25ng/ml FGF-2的SF培养基；含100ng/ml IGF-1的SF培养基；以及含5ng/ml FGF-2加100ng/ml IGF-1的SF培养基。在1天和2周后测定支架的DNA和GAG含量，并在2周时使用放射性标记物测定蛋白质和GAG合成率。还进行了组织学和II型胶原免疫组织化学检测。
发现5ng/ml的FGF-2可显著提高细胞的生物合成活性和GAG的积累。组织学显示，仅2周后软骨细胞均匀分布在对GAG和II型胶原染色强烈的基质中。有趣的是，尽管支架经过碳二亚胺交联，但胶原支架仍迅速降解，构建物发生收缩。使用较高剂量的FGF-2以及与IGF-1联合使用时，效果不太明显。
在补充有5ng/ml FGF-2的SF培养基中培养的接种软骨细胞的II型胶原支架会发生收缩，显示出放射性标记硫酸盐在构建物中的掺入增加，并表现出软骨形成的定性迹象。
