Validation of an ex vivo, loaded, circumfusion culture for living cancellous bone explants

Davies, Catrin Meleri 2005. Validation of an ex vivo, loaded, circumfusion culture for living cancellous bone explants. PhD Thesis, Cardiff University.

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Abstract

The goal of this project was to validate a novel, mechanically loaded culture system, for the maintenance of cancellous bone explants ex vivo. The Zetos system utilised cancellous biopsies (5 mm high, 10 mm diameter) from ovine distal femora, bovine distal metacarpals and human femoral heads loaded daily for 300 cycles, at 1 Hz, giving 4,000 microstrain. Prior to culture, qualitative evaluation of bone density and overall morphology was conducted. These tissues were highly variable with bovine tissue being the most homogenous with regards to density and that each species contained different ratios of red and yellow marrow. The viability of bone cells and matrix synthesis were analysed using a variety of techniques. The outcome of this study was that diffusion constraints were the major limitation of this system. Chamber design was not optimal for bathing the explants, which was inferior to submerged static culture in centrifuge tubes. Harvesting the tissue created damage to the bone core that resulted in a maximal volume loss of 36%, which also encouraged unwanted growth of a fibrous-like tissue over the explant periphery in a wound-like response, possibly enhanced by foetal calf serum in the media. Nevertheless, 3H-glycine incorporation detected proteins synthesised during day 7 and 14 of culture. Collagen was the predominant protein synthesised. Fluorochrome labelling demonstrated human bone apposition during culture, but was unsuccessful with bovine and ovine tissue. Mechanically loaded explants were qualitatively more viable than unloaded disuse explants and submerged static controls. These results demonstrate cell viability at least 15 days post-harvest. If the limitations can be improved, then there is potential for this system to become routinely used in bone research. This system would provide a future means to allow bone-biomaterial interactions and interfaces to be studied, reducing, refining and replacing the need for animal experimentation.

Item Type:	Thesis (PhD)
Status:	Unpublished
Schools:	Biosciences
Subjects:	Q Science > QR Microbiology
ISBN:	9781303203688
Funders:	3R Foundation grants 78/01 & 86/0, Swiss Society for Biomaterials
Date of First Compliant Deposit:	30 March 2016
Last Modified:	25 Aug 2022 13:00
URI:	https://orca.cardiff.ac.uk/id/eprint/54559

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