engleski

Response of mouse embryonic stem cell-derived neural precursors to biomaterial surface topology and roughness

The major promise of Embryonic Stem (ES) cells is their potential for generating an unlimited supply of specialized cells, which can be used for tissue repair and for curing neurological disorders. Future progress of transplant of ES- derived neurons depends on different factors: 1) their ability to form networks able to signal and process information as networks of adult neurons do ; 2) purity of the cell population to be grafted ; 3) properties of the substrate on which ES cells grow prior transplantation. We recently demonstrated (Ban et al, 2007) that mouse ES cells are capable to form functional networks with properties similar to those of hippocampal neurons and we are currently studying the influence of the substrate on the differentiation process. The surface topology of the extracellular matrix (ECM) to which cells adhere not only offers structural support but activates transduction signals that have a fundamental role in cell survival, differentiation and overall tissue organization and function. Micrometer-size features on a culture surface can affect migration, adhesion and morphology. Since the ECM has topographic detail at the nanometer- scale, such as the 66nm repeat of collagen fibers, by mimicking the nanoscale topography of these features, biomaterials could be used in tissue engineering to induce the same effects. We tested the survival, adhesion and differentiation of ES-derived neural precursors plated on gold substrates with different nanophase surface roughness and different micro-metric surface topology. ES-derived neural precursors were prepared as previously described, plated on different surfaces without pre-coating and induced to differentiate. The cells were fixed and analyzed by scanning electron microscopy and immunofluorescence. Preliminary results show that the precursors not only attached to non pre-coated surface, but the yield of differentiated neurons was significantly larger compared to the standard protocol. In fact, we observed an increase of 25% in the number of neurons compared when precursors were grown on standard glass coverslips pre-coated with polyornithine and laminin. A detailed analysis of the composition of the culture on different substrates and at various time points of differentiation will be presented.

embryonic stem cells ; neuronal differentiation

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