Airantzis, Dimitrios;
(2020)
A novel treatment for pathogen reduction.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
The body routinely encounters new micro-organisms and epithelial surfaces provide the first line of defence. Most micro-organisms that get passed this barrier are detected and eliminated by the immune system. The liver plays an important role. Patients suffering from acute liver failure (ALF) are more prone to bacterial infections, and death from sepsis is not uncommon. Liver transplantation, is a successful therapy available for ALF, but too few donor organs are available. A bio-artificial liver (BAL) machine could “buy time” for a patient to recover or to bridge to eventual transplantation. An extracorporeal device was developed that can be integrated into the BAL, to treat in real time plasma infections, eliminating pathogens whilst conserving the integrity and functionality of plasma components, as one component of the BAL. Our hypothesis was that phototreatment is the most suitable pathogen reduction technology (PRT) for real time applications. The efficacy of a number of photosensitisers and light sources were evaluated. Custom equipment was developed to investigate the characteristics of semiconductor light sources. Their optimum operating conditions were investigated in terms of operating temperature, supply current and placement. Further experiments were performed to select appropriate materials for the construction of the phototreatment exposure unit. A first PRT prototype was developed and used to illuminate samples of E. coli in saline solution. The experiments demonstrated more than 4 log 10 reduction of surviving colony formation units, thus proving the method antimicrobial. A second PRT prototype was developed and used with a wider choice of light intensity, wavelengths and photosensitisers. It was used to perform further phototreatment experiments against E. coli, S. warneri and C. albicans. Significant reduction of pathogens was demonstrated in all cases. This thesis has demonstrated the initial proof of this hypothesis, leading to further in- vestigations being performed and the development of a clinical scale model.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | A novel treatment for pathogen reduction |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2020. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Med Phys and Biomedical Eng |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10093746 |
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