Abstract
Spinal cord (SCI) and traumatic brain (TBI) injuries have a devastating effect of the lives of patients and their support networks, due to the inherently poor ability of the central nervous system (CNS) to spontaneously regenerate. Clinical management of these injuries requires extensive, long-term rehabilitation and therefore places a considerable financial burden on the healthcare systems that must provide this care (£1bn per year in the UK).There is currently no known cure for these types of injury but electrical stimulation has been shown to have a profound effect on transplanted neuronal cell; increasing genesis of neurons, guiding stem cells to the site of injury and increasing expression of regenerative factors. In the past this has been achieved by incorporation of electrodes or conductive scaffolds in neural tissues but the need for wiring to an external power source comes with risks of additional surgical complications.
Piezoelectric materials have been proposed as power autonomous system for delivering direct electrical stimulation, and have seen success in the stimulation of bone, skeletal muscle, skin, cartilage and neuronal cells and tissues. Despite this success the literature focuses mainly on the outcomes of the piezoelectrically induced electrical stimulation (PIES) and there is urgent need to understand the underlying mechanism for PIES if it to become clinically applicable.
In-situ dielectrophoretically poled (PDEP) piezoceramic composites can be produced in batch with varied piezoelectric properties. DPEP aligned composites based on potassium sodium niobate (KNN) and polydimethyl siloxane (PDMS) was shown to facilitate neurogenesis in neural stem cell (NSC) cultures and therefore can be used as a potent tool for understanding the minutia of PIES with varying piezoelectric properties.
The neuropathophysiology of degenerative events like SCI and TBI is multifaceted and therefore electrical stimulation alone cannot overcome the CNS’s poor ability to regenerate. A combinatorial approach which incorporates multiple therapies capable to addressing the complexity of a neurodegenerative event is required. Novel porous, directionally aligned, enzymatically digestible piezoelectric composites based on KNN and cellulose was shown to support NSC differentiation and topographically guide cell alignment. Furthermore, the versatility of cellulose allows for additional future functionalisation, with surface decoration, protein immobilisation and controlled biodegradation as part of a powerful combinatorial therapeutic system.
| Date of Award | 24 May 2023 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Hamideh Khanbareh (Supervisor) & Chris Bowen (Supervisor) |
Keywords
- piezoelectric
- tissue engineering