Department of Nanobiomedical Science & WCU Research Center, Dankook University Graduate School, Cheonan 330-714, Korea.
J Biomed Mater Res A. 2012 Sep;100(9):2431-40. doi: 10.1002/jbm.a.34163. Epub 2012 May 5.
New tissue-engineering tool for bone regeneration is described to facilitate homogeneous cell seeding and effective osteogenic development. Calcium phosphate (CaP) scaffolds with macrochanneled and well-defined pore structure was developed, however, a large portion of the cells seeded directly within the scaffold easily penetrates without good adhesion to the scaffold surface. To overcome this, a method was exploited to dispense cells evenly throughout the CaP scaffold using collagen hydrogel. Rat bone marrow-derived mesenchymal stem cells (MSCs) were mixed within a neutralized collagen solution, which was then infiltrated into the macrochanneled pore space and gelled to result in macrochanneled bioceramic scaffold combined with MSCs-hydrogel. MSCs contained within the hydrogel-CaP scaffolds were highly viable, with similar growth pattern to those in the collagen hydrogel. Cells seeded by this approach were initially almost double in number compared with those seeded directly onto the CaP scaffold and had an active proliferation more than 14 days. Assessments of the MSCs showed significantly higher alkaline phosphatase levels in the combined scaffold, which was accompanied by enhanced osteogenesis including the expression of genes [collagen type I, bone sialoprotein, and osteopontin (OPN)] and proteins (OPN and osteocalcin). Extracellular calcium was also elevated significantly in the combined scaffold compared to the CaP scaffold. In addition, mechanical strength of the constructs was improved significantly in the combined scaffold compared to the CaP scaffold. Based on these, the cell culturing and tissue engineering strategy within the macrochanneled bioactive ceramic scaffolds could be improved greatly by the combinatory approach of using collagen hydrogel.
一种新的组织工程骨再生工具被描述为促进均匀细胞接种和有效的成骨发育。已经开发出具有大通道和明确定义的孔结构的磷酸钙 (CaP) 支架，然而，大部分直接接种在支架内的细胞很容易穿透，而与支架表面的粘附性差。为了克服这个问题，利用一种方法利用胶原蛋白水凝胶在整个 CaP 支架中均匀分配细胞。大鼠骨髓间充质干细胞 (MSCs) 混合在中和的胶原蛋白溶液中，然后渗透到大通道孔空间并凝胶化，形成大通道生物陶瓷支架与 MSC-水凝胶结合。水凝胶-CaP 支架内的 MSC 具有高活力，其生长模式与胶原蛋白水凝胶中的相似。通过这种方法接种的细胞数量最初比直接接种在 CaP 支架上的细胞数量增加了近一倍，并且具有超过 14 天的活跃增殖。对 MSCs 的评估表明，在组合支架中碱性磷酸酶水平显著升高，伴随着增强的成骨作用，包括基因 [I 型胶原、骨涎蛋白和骨桥蛋白 (OPN)] 和蛋白质 (OPN 和骨钙素) 的表达。与 CaP 支架相比，组合支架中的细胞外钙也显著升高。此外，与 CaP 支架相比，组合支架中的构建体的机械强度显著提高。基于这些，通过使用胶原蛋白水凝胶的组合方法，可以大大改善大通道生物活性陶瓷支架内的细胞培养和组织工程策略。
