| dc.description.abstract | A human induced pluripotent stem cell (iPSC)-derived neural tissue model for spatiotemporal analysis of tau pathology was investigated in a polydimethylsiloxane (PDMS) microfluidic platform. Three-dimensional (3D) in vitro cortical glutamatergic neurons demonstrated prolonged survival and neurite outgrowth in a biofunctionalized, gelatin-based hydrogel. The artificial cellular scaffold was characterized by analytical techniques including 1H-NMR as well as porosity and morphology analysis conducted by Scanning Electron Microscopy (SEM). The neural tissue constructs were maintained in the central chamber of the dual reservoir microfluidic device for controllable gradient exposure of a disease-relevant, aggregation-prone mutant of tau. COMSOL Multiphysics software was utilized to build a simulation of the system to define a time-dependent transport model predicting diffusion of fluorescently labeled monomer in the porous media. After validating the transport model against the physical system, timed delivery and end-point assays were used to assess viability and hypothesize whether internalization and propagation occurred. At the conclusion of the incubation period, fewer than half the cells remained viable. The homogeneous and dramatic toxic response suggests neurons actively internalized the extracellular monomer and initiated some pathologic response, potentially aggregation induced neural dysfunction. Finally, immunofluorescence assays and image analysis were used to detect and quantify a potentially significant enhanced phosphorylation of tau in treated cells, further suggesting evidence of tau-induced neurotoxicity. These findings represent important preliminary steps in generating a synaptically connected 3D neural network for studying mechanisms of tau-induced neurodegeneration. Such analyses could help elucidate mechanisms of disease pathogenesis and provide valuable insight into tauopathies and other neurodegenerative diseases. | |
