Radiotherapy has major therapeutic benefits for cancer patients, but ionizing radiation causes damage of surrounding healthy tissues with poor wound healing a common side effect. Therefore, further oncoplastic, reconstructive surgery is challenging and often problematic. Current research models use normal human dermal fibroblasts irradiated in vitro to mimic radiation damage, but this is not comparable to ionising radiation and only measures acute changes. Since radiotherapy may induce epigenetic changes leading to alterations in dermal fibroblast phenotype, the first aim of this study was to compare fibroblasts cultured from irradiated skin with non-irradiated skin. As mesenchymal stem cells isolated from adipose tissue may offer beneficial effects in the regenerative capacity of irradiated tissue, the second part of this study was to compare those cultured from non-irradiated and irradiated breast tissue. Histological changes in the structural organisation of breast tissue in situ from donors exposed to radiotherapy was compared to untreated breast. Primary cultures of dermal fibroblasts from irradiated and non-irradiated breast skin were established and comparisons quantitated in proliferation (CyQuant), metabolism (Alamar Blue), migration (scratch-wound assay), collagen production (Sircol), levels of proteases and protease inhibitors (human protease/protease inhibitor array) and gene expression of COL1A1, COL3A1, MMP1, MMP2, TIMP1 and PPAR-γ mRNA (qPCR). Cells from the stromal vascular fraction (SVF) were cultured and characterised by immunocytochemistry and compared to human preadipocytes sourced commercially. The secretion of FGF, adiponectin and VEGF by the preadipocyte and the SVF mesenchymal cells was compared and the ability of their secretome to modulate dermal fibroblast proliferation, metabolism and migration was evaluated. Radiotherapy caused extensive disorganisation of the reticular dermis and flattening of the epidermal-dermal junction. Dermal fibroblasts cultured from irradiated skin had a pronounced spindle shaped morphology with longer thinner projections and took approximately twice as long to explant and grow. They had a lower proliferative and higher basal metabolic rate and did not respond to FGF-2. While they secreted similar amounts of total collagen they demonstrated distinct differences in proteolytic enzyme and protease inhibitor expression. This is the first report to culture cells from the SVF of irradiated breast tissue. The cells expressed the preadipocyte markers CD10, CD73 and CD105 and no CD45 (negative marker). SVF cells cultured displayed a typical ASC fibroblastoid morphology. Analysis of the secretome identified the presence of FGF, adiponectin and VEGF, while functional analysis demonstrated a stimulatory effect on normal dermal fibroblast migration, although irradiated dermal fibroblasts were unresponsive. Radiotherapy induces long term, detrimental changes in breast skin. This is the first quantitative characterisation of dermal fibroblasts and mesenchymal cells from the SVF, subjected to ionising radiation in situ. Changes in their phenotype that alter their function will impact on wound healing. Further characterisation of these cells may explain their dysfunctional behaviour, and lead to therapies to reverse or reduce this deleterious side-effect and significantly improve treatments facilitating wound healing following radiation injury. / Plastic Surgery and Burns Research unit

No description available.

Interleukin 17F (IL17F) has been found to be involved in various inflammatory pathologies and has recently become a target for therapeutic purposes. In contrast to IL17F secreted by immune cells, the focus of this study is to describe the triggers of IL17F release in non-immune cells with a particular focus on IL17F-induced fibrosis. IL17F induction was examined in human lung epithelial (BEAS-2B) and myeloid cell lines as well as in peripheral blood mononuclear cells after in vitro exposure to aqueous cigarette smoke extract (CSE), inorganic mercury, cadmium or the apoptosis inducer brefeldin A. Fibrosis was examined in vitro, evaluating the transition of human primary dermal fibroblasts to myofibroblasts. We observed that all stressors were able to induce IL17F gene expression regardless of cell type. Interestingly, its induction was associated with cytotoxic/apoptotic signs. Inhibiting oxidative stress by N-acetylcysteine abrogated CSE-induced cytotoxic and IL17F- inducing effects. The induction of IL17F was accompanied by IL17F protein expression. The transition of fibroblasts into myofibroblasts was not influenced by either recombinant IL17F or supernatants of CSE-exposed BEAS-2B. In addition to IL17F secretion by specialized or activated immune cells, we underscored the cell type-independent induction of IL17F by mechanisms of inhibitable oxidative stress-induced cytotoxicity. However, IL17F was not involved in dermal fibrosis under the conditions used in this study.

Yes / Beneficial effects have been observed following the transplant of lipoaspirates containing adipose-derived stem cells into chronic wounds caused by oncologic radiotherapy. It is not yet certain whether adipose-derived stem cells are resistant to radiation exposure. Therefore, the aims of this study were to isolate stromal vascular fraction from human breast tissue exposed to radiotherapy and determine the presence of adipose-derived stem cells. Stromal vascular fraction from irradiated donor tissue was compared to commercially sourced pre-adipocytes. Immunocytochemistry was used to determine the presence of adipose-derived stem cell markers. Conditioned media from stromal vascular fraction isolated from irradiated donors was used as a treatment in a scratch wound assay of dermal fibroblasts also isolated from irradiated donors and compared to pre-adipocyte conditioned media and serum free control. This is the first report of human stromal vascular fraction being cultured from previously irradiated breast tissue. Stromal vascular fraction conditioned media from irradiated donors had a similar effect in increasing the migration of dermal fibroblasts from irradiated skin to pre-adipocyte conditioned media from healthy donors. Therefore, the ability of adipose-derived stem cells in the stromal vascular fraction to stimulate dermal fibroblasts in wound healing appears to be preserved following radiotherapy. This study demonstrates that stromal vascular fraction from irradiated patients is viable, functional and may have potential for regenerative medicine techniques following radiotherapy. / This research was funded by a Bradford City FC Supporters Fellowship for L.V.T. administered through the Plastic Surgery and Burns Research Unit, University of Bradford. / Research Development Fund Publication Prize Award winner, Mar 2023.

Este trabalho investigou, pela primeira vez, a influência do CH na modulação do metabolismo e proliferação de fibroblastos dérmicos humanos (FDHs) derivados de áreas fotoprotegida e fotoexposta, cultivados em modelo de monocamada. Além disto, foram investigados os efeitos da suplementação com CH na secreção de colágeno tipo I, em modelo de cultura 3D de equivalente dérmico, derivado de matriz produzida exclusivamente por FDHs. O tratamento com CH não influenciou a proliferação celular dos fibroblastos derivados de ambas as áreas, porém modulou expressivamente o metabolismo dos FDHs cultivados em monocamada, elevando o conteúdo de pró-colágeno I e colágeno I e diminuindo a atividade de metaloproteinases de matriz (MMP) 1 e 2. Concentrações menores de CH foram suficientes para estimular as células de área fotoexposta, sugerindo efeitos mais pronunciados do CH nestas células. Este estudo é uma contribuição importante para compreensão dos efeitos biológicos do CH nas células da pele e viabilidade do seu uso como ingrediente funcional de suplementos alimentares. / This study investigated, for the first time, the influence of CH on the extracellular matrix metabolism and proliferation of human dermal fibroblasts (HDFs) derived from sun-protected and sun-exposed body sites, cultured in monolayer in vitro model. Moreover, CH effects on the secretion of type I collagen were investigated in dermal equivalent 3D model derived from dermal matrix produced exclusively by HDFs. CH treatment did not affect cellular proliferation of either cell cultures, but notably modulated cell metabolism in monolayer model, increasing the content of procollagen I and collagen I and decreasing metalloproteinase activity (MMP) 1 and 2. These effects were confirmed in the human dermal equivalent model. Lower concentrations of CH were enough to stimulate sun-exposed-derived HDFs, suggesting more pronounced effect in these cells. This study presents an important contribution to understanding the biological effects of CH in skin cells and viability of its use as a functional ingredient in food supplements.

Este trabalho investigou, pela primeira vez, a influência do CH na modulação do metabolismo e proliferação de fibroblastos dérmicos humanos (FDHs) derivados de áreas fotoprotegida e fotoexposta, cultivados em modelo de monocamada. Além disto, foram investigados os efeitos da suplementação com CH na secreção de colágeno tipo I, em modelo de cultura 3D de equivalente dérmico, derivado de matriz produzida exclusivamente por FDHs. O tratamento com CH não influenciou a proliferação celular dos fibroblastos derivados de ambas as áreas, porém modulou expressivamente o metabolismo dos FDHs cultivados em monocamada, elevando o conteúdo de pró-colágeno I e colágeno I e diminuindo a atividade de metaloproteinases de matriz (MMP) 1 e 2. Concentrações menores de CH foram suficientes para estimular as células de área fotoexposta, sugerindo efeitos mais pronunciados do CH nestas células. Este estudo é uma contribuição importante para compreensão dos efeitos biológicos do CH nas células da pele e viabilidade do seu uso como ingrediente funcional de suplementos alimentares. / This study investigated, for the first time, the influence of CH on the extracellular matrix metabolism and proliferation of human dermal fibroblasts (HDFs) derived from sun-protected and sun-exposed body sites, cultured in monolayer in vitro model. Moreover, CH effects on the secretion of type I collagen were investigated in dermal equivalent 3D model derived from dermal matrix produced exclusively by HDFs. CH treatment did not affect cellular proliferation of either cell cultures, but notably modulated cell metabolism in monolayer model, increasing the content of procollagen I and collagen I and decreasing metalloproteinase activity (MMP) 1 and 2. These effects were confirmed in the human dermal equivalent model. Lower concentrations of CH were enough to stimulate sun-exposed-derived HDFs, suggesting more pronounced effect in these cells. This study presents an important contribution to understanding the biological effects of CH in skin cells and viability of its use as a functional ingredient in food supplements.

Background: Workers in a platinum group metals (PGMs) refinery are potentially exposed to various precious metals (iridium, osmium, palladium, platinum, rhodium and ruthenium) and their metal-salt compounds which may cause rhinitis, asthma, contact urticaria and conjunctivitis. Some cases revealed that sensitisation occurred in employees where it was not possible to detect any airborne soluble platinum or where the respiratory soluble platinum exposure was below the occupational exposure limit. It is unclear whether respiratory exposure or a combination of respiratory and dermal exposure may be involved in sensitisation and the possible elicitation of skin symptoms. Objectives: To determine if dermal exposure to PGMs took place during the refining process and in the administration area by using a removal method and to compare dermal exposure on the different anatomical areas and in two different working areas, Areas A and B for each of the PGMs. Methods: Dermal exposure samples were collected with a removal method using GhostwipesTM. The samples were collected from the palm of the hands, the wrists and the necks of the workers, before the shift started, before tea time, before lunch time and after the shift ended. The skin wipes were analysed for the PGMs (iridium, osmium, palladium, platinum, ruthenium and rhodium) according to Methods for the Determination of Hazardous Substances (MDHS) method 46/2, using Inductively Coupled Plasma-Mass Spectrometry. Results: No published data is available on occupational dermal exposure to PGMs in a precious metals refinery. This study proved that dermal exposure to PGMs in the refinery took place and was quantified. The PGM dermal exposure results in general, were very low (measured in nano grams), with platinum having the overall highest exposure. Exposure also occurred the most frequently during the last two intervals of the day, before lunch time and at the end of the shift. Exposure on all three the anatomical areas that were tested in the study, varied much with the palm of the hands having the highest exposure levels. There were also variations in exposure between areas A and B due to the fact that the processes in these two areas differ. Conclusions: It was confirmed that dermal exposure to PGMs took place at the precious metals refinery. The highest exposure took place before lunch time and towards the end of the shift. The metal to which the workers were exposed the most was platinum and the production area where the workers had the highest exposure to most of the metals was Area B. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

Copper exposure is known to be a rare cause of skin irritation and allergic reactions and according to our knowledge occupational dermal exposure to copper sulphate has not yet been characterised. As a result, the objectives of this study were to assess the dermal exposure of workers at a chemical industry to copper sulphate and to characterise the change in the their skin barrier function from before to the end of the work shift, as the skin’s barrier function can greatly influence the permeation of chemical substances. Methods: The change in skin barrier function of reactor workers, crystal and powder packaging workers at the chemical industry were assessed by measuring their dominant hand’s palm, back and wrist as well as their foreheads’ skin hydration, transepidermal water loss (TEWL) and skin surface pH before and at the end of the work shift. Commercial GhostwipesTM were used to collect dermal exposure samples from the same four anatomical areas before and at the end of the shift. Additional dermal exposure samples were collected from the palm and back of hand, prior to breaks 1 and 2. Surface wipe sampling was also conducted at several work and recreational areas of the chemical industry. Wipe samples were analysed by an accredited analytical laboratory, according to NIOSH method 9102 by means of Inductively Coupled Plasma-Atomic Emission Spectrometry. Results: Changes in skin hydration of the workers and anatomical areas at the end of the work shift were highly variable, while in general TEWL increased and skin surface pH decreased. Copper was collected from the skin of all workers before the shift commenced, and dermal exposure increased throughout the work shift. All of the work and recreational areas from which surface samples were taken, were contaminated with copper. Conclusion: As a result of intermittent use of inadequate protective gloves and secondary skin contact with contaminated surfaces and work clothing, workers at the chemical industry are exposed to copper sulphate via the dermal exposure route. The decrease in the workers’ skin barrier function (increased TEWL) and skin surface pH is most likely the result of their dermal exposure to sulphuric acid, and may lead to enhanced dermal penetration. The low account of skin irritation or reaction incidences among these workers is contributed to their ethnicity as well as to the low sensitisation potential of copper. Recommendations on how to lower dermal exposure and improve workers’ skin barrier function are made. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

Background: Workers in a platinum group metals (PGMs) refinery are potentially exposed to various precious metals (iridium, osmium, palladium, platinum, rhodium and ruthenium) and their metal-salt compounds which may cause rhinitis, asthma, contact urticaria and conjunctivitis. Some cases revealed that sensitisation occurred in employees where it was not possible to detect any airborne soluble platinum or where the respiratory soluble platinum exposure was below the occupational exposure limit. It is unclear whether respiratory exposure or a combination of respiratory and dermal exposure may be involved in sensitisation and the possible elicitation of skin symptoms. Objectives: To determine if dermal exposure to PGMs took place during the refining process and in the administration area by using a removal method and to compare dermal exposure on the different anatomical areas and in two different working areas, Areas A and B for each of the PGMs. Methods: Dermal exposure samples were collected with a removal method using GhostwipesTM. The samples were collected from the palm of the hands, the wrists and the necks of the workers, before the shift started, before tea time, before lunch time and after the shift ended. The skin wipes were analysed for the PGMs (iridium, osmium, palladium, platinum, ruthenium and rhodium) according to Methods for the Determination of Hazardous Substances (MDHS) method 46/2, using Inductively Coupled Plasma-Mass Spectrometry. Results: No published data is available on occupational dermal exposure to PGMs in a precious metals refinery. This study proved that dermal exposure to PGMs in the refinery took place and was quantified. The PGM dermal exposure results in general, were very low (measured in nano grams), with platinum having the overall highest exposure. Exposure also occurred the most frequently during the last two intervals of the day, before lunch time and at the end of the shift. Exposure on all three the anatomical areas that were tested in the study, varied much with the palm of the hands having the highest exposure levels. There were also variations in exposure between areas A and B due to the fact that the processes in these two areas differ. Conclusions: It was confirmed that dermal exposure to PGMs took place at the precious metals refinery. The highest exposure took place before lunch time and towards the end of the shift. The metal to which the workers were exposed the most was platinum and the production area where the workers had the highest exposure to most of the metals was Area B. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

Copper exposure is known to be a rare cause of skin irritation and allergic reactions and according to our knowledge occupational dermal exposure to copper sulphate has not yet been characterised. As a result, the objectives of this study were to assess the dermal exposure of workers at a chemical industry to copper sulphate and to characterise the change in the their skin barrier function from before to the end of the work shift, as the skin’s barrier function can greatly influence the permeation of chemical substances. Methods: The change in skin barrier function of reactor workers, crystal and powder packaging workers at the chemical industry were assessed by measuring their dominant hand’s palm, back and wrist as well as their foreheads’ skin hydration, transepidermal water loss (TEWL) and skin surface pH before and at the end of the work shift. Commercial GhostwipesTM were used to collect dermal exposure samples from the same four anatomical areas before and at the end of the shift. Additional dermal exposure samples were collected from the palm and back of hand, prior to breaks 1 and 2. Surface wipe sampling was also conducted at several work and recreational areas of the chemical industry. Wipe samples were analysed by an accredited analytical laboratory, according to NIOSH method 9102 by means of Inductively Coupled Plasma-Atomic Emission Spectrometry. Results: Changes in skin hydration of the workers and anatomical areas at the end of the work shift were highly variable, while in general TEWL increased and skin surface pH decreased. Copper was collected from the skin of all workers before the shift commenced, and dermal exposure increased throughout the work shift. All of the work and recreational areas from which surface samples were taken, were contaminated with copper. Conclusion: As a result of intermittent use of inadequate protective gloves and secondary skin contact with contaminated surfaces and work clothing, workers at the chemical industry are exposed to copper sulphate via the dermal exposure route. The decrease in the workers’ skin barrier function (increased TEWL) and skin surface pH is most likely the result of their dermal exposure to sulphuric acid, and may lead to enhanced dermal penetration. The low account of skin irritation or reaction incidences among these workers is contributed to their ethnicity as well as to the low sensitisation potential of copper. Recommendations on how to lower dermal exposure and improve workers’ skin barrier function are made. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014