Tissue Engineering A Disease Model for Spinal Cord Injury Repair
Supervisors: Dr Joanne Tipper (Institute of Medical & Biological Engineering, University of Leeds) and Professor Richard Hall (Institute of Medical & Biological Engineering, University of Leeds).
Background:Spinal cord injury (SCI) continues to challenge healthcare and the social welfare systems. The most serious injuries occur predominantly in young males and involve traumatic insults, particularly to the lower cervical spine and the thoracolumbar junction. It has been estimated that the cost of care in the first year following SCI can exceed US$250K, which continues at a level of US$25K per annum for the rest of the patients’ life. Once stabilised, those with SCI are faced with a number of ongoing obstacles including effective management of respiratory, genitounirary and dermatological problems. These societal challenges are significantly compounded by the rising number of SCIs in the elderly that arise from non-traumatic incidents.
Recent spinal cord injury research has focused on either the regeneration of cord tissues or pharmacological interventions to reduce the effects of the secondary pathological cascade that follows the initial insult, however, knowledge of the fundamental mechanics of the impact and the cellular responses to trauma is extremely rudimentary. The major challenges associated with spinal cord regeneration and repair are due to the formation of glial scar tissue, comprised mainly of reactive astrocytes, which forms a physical and physiological barrier to axon regeneration.
Aims, Objectives and rationale:The aims of this project are to investigate the response of specific spinal cord cell populations (neurons, astrocytes, microglia, oligodendrocytes) to tensile and compressive forces in 3D culture, in order to gain an understanding of the cellular responses under normal physiological strain and after a compressive impact to simulate trauma. The utilisation of advanced tissue engineered constructs within impact loading scenarios to elucidate the detailed cellular response to tightly controlled loads within defined laboratory environments will provide a unique insight into the mechanism of spinal cord injury leading to the development of a disease model using tissue engineering principles. This project may provide a route to promote the functional regeneration of spinal cord tissue following trauma and injury and has the potential to reduce animal experimentation. This project builds on awarding winning research elucidating the biomechanics of SCI utilising both in vitro and computational models and provides the opportunity to develop novel in vitro investigations of the interaction between mechanics and cellular response in this devastating injury – currently no other research group is considering this avenue of research in SCI.
Methodology: Appropriate cell lines or primary rat cells will be isolated and expanded in culture for up to 8 days before being seeded into collagen gels and cultured for 24-48h. Cell seeded constructs (individual cell types and mixed cell populations) will be subjected to uniaxial tensile strain and cyclic compressive strain at a range of different strain levels (0% - 15%) for up to 21 days, in order to determine the cellular response over a range of physiological strain levels. In addition, we will attempt to simulate a high compressive impact to determine cell responses at injurious strain levels utilising technology already available within iMBE. Cell reactivity phenotype, proliferation, axon degeneration, and viability, will be investigated and quantified using confocal microscopy, fluorescence microscopy, RT-PCR, ELISA, FEGSEM and immunocytochemistry.
Facilities:The student will make use of facilities in the Tissue Engineering laboratory in the School of Mechanical Engineering and Immunology Research Laboratories in the Faculty of Biological Sciences at the University of Leeds. The project will also involve secondment to the laboratories of Dr James Phillips at the Open University research facilities in Milton Keynes.