Fibronectin supports neurite outgrowth and axonal regeneration of adult brain neurons in vitro

AbstractThe molecular basis of axonal regeneration of central nervous system (CNS) neurons remains to be fully elucidated. In part, this is due to the difficulty in maintaining CNS neurons in vitro. Here, we show that dissociated neurons from the cerebral cortex and hippocampus of adult mice may be maintained in culture for up to 9days in defined medium without added growth factors. Outgrowth of neurites including axons was observed from both CNS sources and was significantly greater on plasma fibronectin than on other substrata such as laminin and merosin. Neurite outgrowth on fibronectin appears to be mediated by α5β1 integrin since a recombinant fibronectin fragment containing binding sites for this receptor was as effective as intact fibronectin in supporting neurite outgrowth. Conversely, function-blocking antibodies to α5 and β1 integrin sub-units inhibited neurite outgrowth on intact fibronectin. These results suggest that the axonal regeneration seen in in vivo studies using fibronectin-based matrices is due to the molecule itself and not a consequence of secondary events such as cellular infiltration. They also indicate the domains of fibronectin that may be responsible for eliciting this response

Prescreening evaluation of a brush-based faecal immunochemical test for haemoglobin

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The development of nanoscale morphology in polymer: fullerene photovoltaic blends during solvent casting

The power conversion efficiency in a conjugated polymer-functionalized fullerene bulk heterojunction organic photovoltaic (OPV) device is dependent both on the electronic properties of the constituent materials and on the nanoscale morphology of the active semiconductor layer thin-film. Here we use in situ ellipsometry and grazing incidence X-ray scattering (GI-XS) to study molecular self-organization in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend films in real time, during the drying process as they are cast from solution. We illustrate the evolution of the extinction coefficient from a solution to a solid, semi-crystalline state. We show that once the solvent fraction in the film falls below 50%, the P3HT undergoes rapid crystallization via heterogeneous nucleation; a process that is complete in seconds. We also evidence a rapid, dynamic self-annealing process that reduces the characteristic lamella spacing in the P3HT crystallites. The mechanistic understanding of film-formation demonstrated here is an important component in optimizing deposition processes suitable for large-area OPV manufacture