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dc.contributor.advisorTobin, Desmond J.
dc.contributor.advisorUzunbajakava, N.E.
dc.contributor.advisorBotchkareva, Natalia V.
dc.contributor.advisorZeitouny, M.
dc.contributor.authorMignon, Charles*
dc.date.accessioned2018-05-30T09:36:03Z
dc.date.available2018-05-30T09:36:03Z
dc.date.issued2017
dc.identifier.urihttp://hdl.handle.net/10454/16064
dc.description.abstractThe thesis presents a rational path for the optimization of the selection of optical treatment parameters in photobiomodulation of human skin fibroblasts. The project begins with an extensive analysis of 90 bibliographic reports in photobiomodulation published between 1985 and 2015, and revealed major inconsistencies in optical parameters selected for clinical applications. Seeking greater clarity for optimal parameter choice, a systematic approach to disentangle the multiple factors underpinning the response of human dermal fibroblasts in vitro to visible and near-infra red (NIR) light was employed. Light-based devices were constructed to specifically and systematically screen the optical parameter window (i.e. wavelength, irradiance and dose) observed in literature. Additionally, critical culture and treatment conditions that have dramatic impact on the outcome of specific light treatment of these human skin dermal cells were identified. In particular, environmental oxygen concentration, cell confluency and serum concentration were all found to have a great effect on the response of dermal fibroblasts to light. In parallel, the induction of reactive oxygen species (ROS) by short visible wavelengths on two dermal fibroblast sub-populations or lineage, reticular and papillary, was monitored by live-cell imaging. The ROS species were found to be created in or close to mitochondria. Lastly, gene expression studies revealed a strong impact of short visible wavelengths, as compared to long and NIR wavelengths on both subpopulations of human dermal fibroblasts. In particular, blue light (450 nm) specifically down-regulated proliferation, metabolism and protein synthesis molecular pathways. At the protein level, 450-nm light inhibited the production of procollagen I in human reticular and papillary fibroblasts in a dose-dependent manner. Gene expression results were in agreement i.e., the same light parameter down-regulated collagen fiber genes, integrins and up-regulated collagenase MMP1. This thesis concludes with a chapter presenting a characterization of the accuracy of a potential translation tool for the prediction of optical photon density inside human skin.en_US
dc.description.sponsorshipMarie Skłodowska-Curie Actions.en_US
dc.language.isoenen_US
dc.rights<a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.eng
dc.subjectPhotobiomodulationen_US
dc.subjectSkinen_US
dc.subjectLighten_US
dc.subjectSubpopulationsen_US
dc.subjectDesign of experimenten_US
dc.subjectMonte Carlo methoden_US
dc.subjectHuman dermal fibroblasts (HDF)en_US
dc.titlePhoto-biomodulation of human skin fibroblast sub-populations: a systematic approach for the optimization of optical treatment parametersen_US
dc.type.qualificationleveldoctoralen_US
dc.publisher.institutionUniversity of Bradfordeng
dc.publisher.departmentCentre for Skin Science, Faculty of Life Sciencesen_US
dc.typeThesiseng
dc.type.qualificationnamePhDen_US
dc.date.awarded2017
refterms.dateFOA2018-07-29T02:23:42Z


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