Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Biomaterials. 2011 Jul;32(21):4737-43. doi: 10.1016/j.biomaterials.2011.03.033. Epub 2011 Apr 11.
Neural stem cells (NSCs) have received much attention in cell-transplantation therapy for central nervous disorders such as Parkinson's disease. However, poor engraftment of transplanted cells limits the efficacy of the treatments. To overcome this problem, collagen-based hydrogels were designed in this study to provide microenvironments for embedded cells to survive and proliferate. Our approach was to incorporate epidermal growth factor (EGF), known as a mitogen for NSCs, into a collagen hydrogel. For the stable binding of EGF with collagen under mild conditions, EGF was fused with a collagen-binding polypeptide domain by recombinant DNA technology. A cell population containing NSCs was derived from the fetal rat brain and cultured in the composite hydrogels for 7 d followed by analysis for cell proliferation. It was shown that the number of living cells was significantly higher in hydrogels incorporating collagen-binding EGF. This effect is largely owing to the collagen-binding domain that serves to sustain presentation of EGF toward cells within the hydrogel. It is further revealed by gene expression analysis that cells proliferated in the EGF-incorporating collagen hydrogel contained subpopulations expressing the marker of stem cells, neurons, astrocytes, or oligodendrocytes.
神经干细胞（NSCs）在细胞移植治疗中枢神经系统疾病，如帕金森病中受到了广泛关注。然而，移植细胞的植入效果不佳限制了治疗效果。为了解决这个问题，本研究设计了基于胶原蛋白的水凝胶，为嵌入细胞提供生存和增殖的微环境。我们的方法是将表皮生长因子（EGF），一种 NSCs 的有丝分裂原，掺入胶原蛋白水凝胶中。为了在温和条件下使 EGF 与胶原蛋白稳定结合，通过重组 DNA 技术将 EGF 与胶原蛋白结合多肽结构域融合。从胎鼠脑中分离出包含 NSCs 的细胞群体，并在复合水凝胶中培养 7 天，然后分析细胞增殖情况。结果表明，掺入胶原蛋白结合 EGF 的水凝胶中活细胞数量明显增加。这种效果主要归因于胶原蛋白结合结构域，它有助于维持 EGF 在水凝胶内细胞中的呈现。通过基因表达分析进一步揭示，在含有 EGF 的胶原蛋白水凝胶中增殖的细胞包含表达干细胞、神经元、星形胶质细胞或少突胶质细胞标志物的亚群。
