Structure and function of elastic fibres in human lumbar intervertebral discs

Author: Salindi Herath

Herath, Salindi, 2021 Structure and function of elastic fibres in human lumbar intervertebral discs, Flinders University, College of Science and Engineering

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Abstract

The structure and function of elastic fibres are poorly understood in human intervertebral discs. It is hypothesized the elastic fibres play a role in the structural integrity of the disc by holding adjacent lamellae together. Previous research found that degenerated discs or discs that were susceptible to herniation had differences in elastic fibre structure and organization compared to healthy discs. Therefore, understanding the structure and function of elastic fibres is necessary for elucidating mechanisms of herniation and disc degeneration. The aim of this thesis was to visualise the ultrastructure of elastic fibres and understand their functional role in human intervertebral discs.

A partial alkali digestion protocol was developed for isolation of elastic fibres in sheep intervertebral discs that was firstly replicated in this project and then optimised for visualisation of elastic fibres in human intervertebral discs. Visualisation was performed by scanning electron microscopy in order to obtain high resolution images that can be quantitatively analysed. During the optimization process of the partial alkali digestion protocol, elastic fibres were found in the lamellae and the ILM region that support the hypothesis on the functional role of elastic fibres in the disc. Further experimentation is required to create a digestion protocol that can be used irrespective of disc region, level, or degeneration. An optimal alkali digestion protocol can be used to visualize differences in elastic fibres in different regions of a disc or discs of varying levels of degeneration. Micromechanical tests can also be conducted on a lamellar unit containing isolated elastic fibres between two lamellae to understand the mechanical contribution of elastic fibres in the disc.

Keywords: elastic fibres, lumbar discs, intervertebral discs, herniation, disc degeneration, partial alkali digestion, interlamellar region

Subject: Engineering thesis

Thesis type: Masters
Completed: 2021
School: College of Science and Engineering
Supervisor: John J. Costi