(685g) Motor Neuron Neurite Outgrowth and ECM Production In 3D Microenvironments

Despite great strides in the field of tissue engineering, we have yet to design responsive guidance channels for neuronal repair that are superior to autograft tissue. Three-dimensional (3D) culture models with improved physiological relevance are expected to bridge the gap between two-dimensional (2D) studies on petri-plates and the complex environment inside the body. We have recently demonstrated that the morphology and signaling pathways of sensory neurons are dramatically altered when the cells are placed in a 3D matrix, with the cellular response in vitro 3D environments being a better representation of that which occurs in vivo compared to 2D models. One of the fundamental differences between 2D and 3D culture is the distribution of cell-cell and cell-matrix interactions, which can alter signaling mechanisms regulating cell response. Moreover, we and others have demonstrated that neuronal response in 3D culture is dependent on cues from their local environment, including substrate physical properties as well as ligand concentration and geometry, indicating that neuronal growth and survival are improved by specific cell-matrix interactions that are different in 2D when compared to 3D. Cells alter these local cues as they secrete soluble factors and remodel their surrounding extracellular matrix (ECM). To date, the majority of neural tissue engineering studies have been carried out with model systems of neuronal differentiation (e.g., PC12 cells) or primary sensory neurons derived from dorsal root ganglia. To advance our understanding of how to design improved therapeutics for nerve regeneration, the specific goal of this work is to delineate mechanisms by which motor neurons respond to 3D environments. We are using a NCS-34 cell line, which is derived from a fusion of motor neuron enriched embryonic day 12-14 mouse spinal cord cells with mouse neuroblastoma. Herein we report the baseline characterization of NCS-34 morphology and ECM synthesis evoked by 2D and 3D collagen-based culture environments. In combination with investigations of cell-matrix signaling mechanisms evoked by motor neurons in 3D environments, this work will lead towards design rules for engineering new biomaterials with improved efficacy for treating nerve repair in vivo.