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Mitchell, S. C.

Publications and source records attributed to Mitchell, S. C..

2 recordsLinked to original sources

TRPV4 antagonist efficacy in a post-hemorrhagic hydrocephalus pig model

Hydrocephalus occurs across the age spectrum but is particularly prevalent in young and old individuals. One form of this disease is post-hemorrhagic hydrocephalus (PHH), which is a life-threatening sequela of intraventricular hemorrhage (IVH). There are no effective non-surgical interventions for the treatment of PHH or other forms of hydrocephalus. Progress has been limited by the lack of gyrencephalic animal models that exhibit high fidelity to human conditions. Here, we establish a pathophysiologically relevant novel swine model of IVH that recapitulates key features of severe PHH, including sustained ventriculomegaly, elevated intracranial pressure (ICP), neuroinflammation and white matter injury. Using this model, we test the therapeutic potential of pharmacologic inhibition of the transient receptor potential vanilloid 4 (TRPV4) non-specific cationic channel. The orally bioavailable TRPV4 antagonist GSK2789917 penetrates the blood-brain barrier, and prevents progression to PHH when administered 2 days after IVH. Specifically, GSK2789917 prevents the development of ventriculomegaly, suppresses early ICP elevations and prevents or reverses inflammasome activation. These findings establish a clinically relevant large-animal model of PHH and identify TRPV4 antagonism as a promising treatment for hydrocephalus.

neuroscience↗

Hybrid Scaffolds Decouple Biochemical & Biophysical Regulation of Cell Phenotype

The extracellular matrix changes dramatically during the progression of diseases like cancer. These complex, tissue-specific changes are not adequately replicated by most current biomaterial disease models. Here we demonstrate, for the first time, a biomaterial system allowing combined, independent control over stiffness, composition and 3D collagen architecture. We demonstrate successful perfusion of defined hydrogel formulations into ice-templated collagen scaffolds, controlling the composition of these hybrid scaffolds at constant stiffness. The Youngs moduli of these hybrid scaffolds can also be tuned independently of composition via chemical crosslinking. Encapsulation of human dermal fibroblasts reveals that fibroblast morphology depends on hybrid scaffold composition and on viscoelasticity, highlighting the importance of a system that decouples biophysical from biochemical properties. Finally, we demonstrate application of this system to exert combined control over biochemical and biophysical drivers of cell growth and invasion, focussing on breast cancer as proof-of-concept. We show that collagen fibre patterning enhances breast cancer cell proliferation, also directing the invasion of patient-derived breast cancer cells. These hybrid scaffolds are therefore promising new tools for dissecting the diverse but complementary roles played by the extracellular matrix in regulating cell phenotype, in a range of healthcare applications.

bioengineering↗