Developing in vitro models of traumatic injury for neural tissue engineering applications

Abstract

Penetrating traumatic brain injury (pTBI) and spinal cord injury (SCI) cause significant neurological damage and debilitation. The management of these central nervous system (CNS) injuries is largely supportive, with no clinically available regenerative therapies. Regeneration is difficult to achieve because of the inhibitory microenvironment in CNS injury sites. Researchers are constantly developing and testing new therapies to aid regeneration of neural tissue, however, these are heavily reliant on live animal experimentation.

There is an urgent need for clinically predictive, in vitro models of neurological injury which satisfy requirements such as: mimicry of complex neural architecture, patho-mimicry, high throughput and facile technical procedures, and being in line with the Reduction, Replacement and Refinement of animal experimentation. Two important approaches for regeneration of damaged CNS tissue are biomaterial application and electrical stimulation (ES) therapy. This thesis aims to develop and evaluate novel in vitro models of CNS injury for evaluation of biomaterial and ES therapy. The thesis goals were to: i) compare and contrast an ex vivo (organotypic) model of SCI and TBI with implantation of a neurosurgical grade scaffold (DuraGenTM); ii) develop a technical method for a 2D and 3D culture model of cortical injury, and iii) establish a platform for electrophysiological studies of the injury environment using multi-electrode arrays (MEAs). Pathological responses such as glial scarring (astrogliosis), microglial activation and neuronal outgrowth were assessed.

I provide evidence that these newly developed models replicate key pathological features of injury, and can be reliably used for assessment of regenerative therapies, including neural cell responses to biomaterial implantation, and for interfacing with bioelectronic recording/stimulation systems.