Peretz H, Blinder P, Segal L, Baranes D, Vago R
Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel.
J Tissue Eng Regen Med. 2008 Dec;2(8):463-71. doi: 10.1002/term.118.
The ability to mimic cell-matrix interactions in a way that closely resembles the natural environment is of a great importance for both basic neuroscience and for fabrication of potent scaffolding materials for nervous tissue engineering. Such scaffolding materials should not only facilitate cell attachment but also create a microenvironment that provides essential developmental and survival cues. We previously found that porous aragonite crystalline matrices of marine origin are an adequate and active biomaterial that promotes neural cell growth and tissue development. Here we studied the mechanism underlying these neural cell-material interactions, focusing on the three-dimensional (3D) surface architecture and matrix activity of these scaffolds. We introduced a new cloning technique of the hydrozoan Millepora dichotoma, through which calcein or (45)Ca(2+) were incorporated into the organism's growing skeleton and neuronal cells could then be cultured on the labelled matrices. Herein, we describe the role of matrix 3D architecture on neural cell type composition and survival in culture, and report for the first time on the capacity of neurons and astrocytes to exploit calcium ions from the supporting biomatrix. We found that hippocampal cells growing on the prelabelled aragonite lattice took up aragonite-derived Ca(2+), and even enhanced this uptake when extracellular calcium ions were chelated by EGTA. When the aragonite-derived Ca(2+) uptake was omitted by culturing the cells on coral skeletons coated with gold, cell survival was reduced but not arrested, suggesting a role for matrix architecture in neural survival. In addition, we found that the effects of scaffold architecture and chemistry on cell survival were more profound for neurons than for astrocytes. We submit that translocation of calcium from the biomaterial to the cells activates a variety of membrane-bound signalling molecules and leads to the subsequent cell behaviour. This kind of cell-material interaction possesses great potential for fabricating advanced biomaterials for neural tissue-engineering applications.
以与自然环境极为相似的方式模拟细胞与基质相互作用的能力，对于基础神经科学以及用于神经组织工程的高效支架材料的制备而言都极为重要。此类支架材料不仅应促进细胞附着，还应营造一个能提供关键发育和存活线索的微环境。我们先前发现，源自海洋的多孔文石晶体基质是一种合适且具有活性的生物材料，可促进神经细胞生长和组织发育。在此，我们研究了这些神经细胞与材料相互作用的潜在机制，重点关注这些支架的三维（3D）表面结构和基质活性。我们引入了一种新的水螅虫二叉千孔螅克隆技术，通过该技术将钙黄绿素或（45）Ca（2+）掺入生物体不断生长的骨骼中，然后可在标记的基质上培养神经元细胞。在此，我们描述了基质3D结构对培养中神经细胞类型组成和存活的作用，并首次报告了神经元和星形胶质细胞从支持性生物基质中摄取钙离子的能力。我们发现，在预先标记的文石晶格上生长的海马细胞摄取了源自文石的Ca（2+），当细胞外钙离子被EGTA螯合时，这种摄取甚至会增强。当通过在涂有金的珊瑚骨骼上培养细胞来省略源自文石的Ca（2+）摄取时，细胞存活率降低但并未停止，这表明基质结构在神经存活中发挥了作用。此外，我们发现支架结构和化学性质对细胞存活的影响对神经元比对星形胶质细胞更为显著。我们认为，钙从生物材料向细胞的转运激活了多种膜结合信号分子，并导致随后的细胞行为。这种细胞与材料的相互作用在制造用于神经组织工程应用的先进生物材料方面具有巨大潜力。
