This paper describes the evaluation of the auto-catalytic anti-oxidant behavior and biocompatibility of Cerium oxide nanoparticles for applications in spinal cord repair and other diseases of the CNS. The application of a single dose of nano-Ceria at a nano-molar concentration is biocompatible, regenerative and provides a significant neuroprotective effect on adult rat spinal cord neurons.Retention of neuronal function is demonstrated from electrophysiological recordings and the possibility of its application to prevent ischemic insult is suggested from an oxidative injury assay. A mechanism is proposed to explain the auto-catalytic properties of these nanoparticles.

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While much is known about muscle spindle structure, innervation and function, relatively few factors have been identified that regulate intrafusal fiber differentiation and spindle development. Identification of these factors will be a crucial step in tissue engineering functional muscle systems. In this study, we investigated the role of the growth factor, neuregulin 1-β-1 EGF (Nrg1-β-1), for its ability to influence myotube fate specification in a defined culture system utilizing the non-biological substrate DETA. Based on morphological and immunocytochemical criteria, Nrg 1-β-1 treatment of developing myotubes increases the ratio of nuclear bag fibers to total myotubes from 0.019 to 0.100, approximately a five-fold increase. The myotube cultures were evaluated for expression of the intrafusal fiber specific alpha cardiac-like myosin heavy chain and for the expression of the nonspecific slow myosin heavy chain. Additionally, the expression of ErbB2 receptors on all myotubes was observed, while phosphorylated ErbB2 receptors were only observed in Nrg1-β-1 treated intrafusal fibers. After Nrg1-β-1 treatment, we were able to observe the expression of the intrafusal fiber specific transcription factor Egr3 only in fibers exhibiting the nuclear bag phenotype. Finally, nuclear bag fibers were characterized electrophysiologically for the first time in vitro. This data shows conclusively, in a serum-free system, that Nrg 1-β-1 is necessary to drive specification of forming myotubes to the nuclear bag phenotype.

In this study, we have demonstrated a method to organize cells in dissociated cultures using engineered chemical clues on the culture surface and determined their connectivity patterns. Although almost all elements of the synaptic transmission machinery between neurons or between neurons and muscle fibers can be studied separately in single-cell models in dissociated cultures, the difficulty of clarifying the complex interactions between these elements makes random cultures not particularly suitable for specific studies. Factors affecting synaptic transmission are generally studied in organotypic cultures, brain slices, or in vivo where the cellular architecture generally remains intact. However, by utilizing engineered neuronal networks, complex phenomenon such as synaptic transmission can be studied in a simple, functional, cell culture-based system. We have utilized self-assembled monolayers (SAMs) and photolithography to create the surface templates. Embryonic hippocampal cells, plated on the resultant patterns in serum-free medium, followed the surface clues and formed the engineered neuronal networks. Basic electrophysiological methods were applied to characterize the synaptic connectivity in these engineered two-cell networks.