New in vitro model of traumatic brain injury to assess biomaterial based regenerative strategies

Penetrating traumatic brain injury (pTBI) causes significant neural damage and debilitation. The management of pTBI is largely supportive currently, with no clinically established regenerative therapies. Researchers have previously evaluated the regenerative potential of biomaterial constructs called hydrogels in pTBI. To screen biomaterials for regenerative application, clinically predictive models of pTBI are required. However, there is a lack of facile, high throughput, pathomimetic in vitro pTBI models capable of evaluating biomaterial implantation. This thesis aimed to develop methods to i) establish a high throughput and facile culture system containing the major glial cell types, which play an important role in biomaterial handling in the central nervous system ii) introduce reliable and characterizable penetrating lesions into the cultures iii) implant DuraGen PlusTM – an Food and Drug Administration (FDA) approved neurosurgical grade biomaterial into the lesion iv) visualize cell-biomaterial interactions using simple light microscopy v) refine the model to establish a high throughput neuronal model containing all of the neural cell types. The findings of this study show that the key pathological features of injury seen in pTBI can be reliably replicated, in this novel, facile, high throughput, multi-glial model. Specifically, peri-lesional astrocytes have markedly different responses to injury versus distal astrocytes showing hypertrophic palisading astrocytes and glial fibrillary acidic protein (GFAP) upregulation analogous to reactive astrogliosis in vivo. In addition, microglia and oligodendrocyte precursor cells (OPCs) were observed to infiltrate the lesion core similar to processes seen in pTBI models in vivo. Furthermore, DuraGen PlusTM could be implanted into the lesions to visualize cell-biomaterial interactions. Finally, early pilot data shows that use of an alternative chemical medium can further support the growth of neurons, resulting in a model containing all neural cell types in a technically simple and high throughput experimental system