Three-dimensional tissue cultures have been used as effective models for studying different diseases, including epilepsy. High-throughput, nondestructive techniques are essential for rapid assessment of disease-related processes, such as progressive cell death. An ultrahigh-resolution optical coherence microscopy (UHR-OCM) system with ∼1.5 μm axial resolution and ∼2.3 μm transverse resolution was developed to evaluate seizure-induced neuronal injury in organotypic rat hippocampal cultures. The capability of UHR-OCM to visualize cells in neural tissue was confirmed by comparison of UHR-OCM images with confocal immunostained images of the same cultures. In order to evaluate the progression of neuronal injury, UHR-OCM images were obtained from cultures on 7, 14, 21, and 28 days in vitro (DIVs). In comparison to DIV 7, statistically significant reductions in three-dimensional cell count and culture thickness from UHR-OCM images were observed on subsequent time points. In cultures treated with kynurenic acid, significantly less reduction in cell count and culture thickness was observed compared to the control specimens. These results demonstrate the capability of UHR-OCM to perform rapid, label-free, and nondestructive evaluation of neuronal death in organotypic hippocampal cultures. UHR-OCM, in combination with three-dimensional tissue cultures, can potentially prove to be a promising tool for high-throughput screening of drugs targeting various disorders.
An artificial muscle composed of electroactive nanowires or nanofibers would compare favorably to its biological counterpart in terms of generated force and speed, while devices based on discrete nanoactuators could perform functions similar to those of motor proteins in biological cells. A template synthesis method for producing polypyrrole nanowires is examined. Conductivity and electrochemical properties of resulting nanowires are evaluated, showing promise for future use as nanoactuators. Template synthesis is then extended to allow fabrication of polypyrrole nanowires directly on a planar substrate such as semiconductor wafer, enabling potential integration with semiconductor or microfluidic devices.