Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195-2120, USA.
J Biomed Mater Res A. 2012 Dec;100(12):3408-15. doi: 10.1002/jbm.a.34288. Epub 2012 Jul 6.
Increasing cell seeding efficiency in a tissue engineering construct can enhance cellular activity and tissue formation in vivo. Here, we demonstrate the use of alginate gel as a secondary phase material in 3D porous β-tricalcium phosphate scaffolds to improve cell seeding and provide controlled release of growth factors for bone tissue engineering. Cells were seeded in scaffolds in three ways: conventional seeding (CS), alginate gel-assisted seeding (GS), and alginate GS with bone morphogenetic protein-2 (BMP-2, GSB). In vitro study with MG-63 cells showed that cell seeding efficiency and cell population 1 week after seeding were significantly elevated in GS and GSB samples compared to CS samples. The GSB system demonstrated a sustained, steady release of BMP-2 over 2 weeks. In vivo, scaffolds seeded with rat mesenchymal stem cells were implanted ectopically into Sprague-Dawley rats for 8 weeks. GS and GSB samples exhibited improved osteogenic activity, with the GSB samples inducing the greatest osteocalcin and osteoid deposition. This study suggests that the alginate gel-assisted cell seeding increases seeding efficiency and allows for sustained release of growth factors. The use of the secondary phase polymer bolsters bone formation in vivo and has the potential for improving outcome in other tissue engineering applications.
在组织工程构建体中提高细胞接种效率可以增强细胞活性和体内组织形成。在这里，我们展示了海藻酸盐凝胶作为 3D 多孔β-磷酸三钙支架中的第二相材料的用途，以提高细胞接种效率，并为骨组织工程提供生长因子的控制释放。细胞通过三种方式接种到支架中：常规接种（CS）、海藻酸盐凝胶辅助接种（GS）和骨形态发生蛋白-2（BMP-2，GSB）的海藻酸盐凝胶辅助接种。体外研究表明，与 CS 样品相比，GS 和 GSB 样品中的细胞接种效率和接种后 1 周的细胞群体明显提高。GSB 系统在 2 周内持续稳定地释放 BMP-2。体内，用大鼠间充质干细胞接种的支架异位植入 Sprague-Dawley 大鼠体内 8 周。GS 和 GSB 样品表现出改善的成骨活性，GSB 样品诱导最大的骨钙素和类骨质沉积。本研究表明，海藻酸盐凝胶辅助细胞接种可提高接种效率并允许生长因子持续释放。使用第二相聚合物增强了体内的骨形成，并有可能改善其他组织工程应用的结果。
