Aims and objectives: The research aims and objectives of this study were: Firstly to determine the positive effects and possible disadvantages of three types of barrier creams on skin barrier function by determining skin barrier function by measuring stratum corneum hydration transepidermal water loss (TEWL) and skin surface pH. Secondly to compare different racial skin types (African skin to Caucasian skin) by determining the effects of barrier cream on skin barrier function. Finally to compare the effect of the three different barrier creams on four different anatomical areas. Methods: Thirty eight non-smoking male test subjects took part in this study where three different types of barrier creams were tested on their arms and hands in a controlled laboratory environment. The thirty eight test subjects consisted of nineteen African and nineteen Caucasian test subjects. Three parameters were measured namely TEWL, stratum corneum hydration and pH condition of the skin. TEWL was measured using a Vapometer (Delfin Technology Ltd. Finland). The Multi probe Adapter system (MPA) (Courage and Khazaka, Germany) was used with a temperature and humidity sensor and with the following probes all from Courage and Khazaka, Germany: a Corneometer measuring skin hydration and a pH-Meter measuring skin surface pH. The measurements were repeated on each of the four sampling areas (forearm, wrist, back of hand and palm) with a reasonable time interval between each measurement. After the baseline measurement the barrier cream was applied by the researcher on the test subjects’ dominant arm. The long term effects were determined after the baseline measurement in intervals of 2 hours. Directly after each measurement the barrier cream was reapplied. Results: Gloves In A Bottle™ increased stratum corneum hydration, had no effect on TEWL and increased skin surface pH, whereas Reinol™ increased stratum corneum hydration and decreased TEWL and had no effect on pH values. Travabon™ decreased stratum corneum hydration and TEWL and had no effect on skin surface pH. The results indicated that there were significant differences between Caucasian and African test subjects with the use of barrier creams, because of the baseline differences and the reaction to barrier creams showed different results. There were also statistically significant differences in the four different anatomical areas where the barrier creams were applied. Conclusion: Barrier creams are beneficial in the workplace, although it should be taken into consideration that different ethnicities react differently to barrier creams under different workplace situations and therefore this should be taken into account when selecting a barrier cream. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

Aims and objectives: The research aims and objectives of this study were: Firstly to determine the positive effects and possible disadvantages of three types of barrier creams on skin barrier function by determining skin barrier function by measuring stratum corneum hydration transepidermal water loss (TEWL) and skin surface pH. Secondly to compare different racial skin types (African skin to Caucasian skin) by determining the effects of barrier cream on skin barrier function. Finally to compare the effect of the three different barrier creams on four different anatomical areas. Methods: Thirty eight non-smoking male test subjects took part in this study where three different types of barrier creams were tested on their arms and hands in a controlled laboratory environment. The thirty eight test subjects consisted of nineteen African and nineteen Caucasian test subjects. Three parameters were measured namely TEWL, stratum corneum hydration and pH condition of the skin. TEWL was measured using a Vapometer (Delfin Technology Ltd. Finland). The Multi probe Adapter system (MPA) (Courage and Khazaka, Germany) was used with a temperature and humidity sensor and with the following probes all from Courage and Khazaka, Germany: a Corneometer measuring skin hydration and a pH-Meter measuring skin surface pH. The measurements were repeated on each of the four sampling areas (forearm, wrist, back of hand and palm) with a reasonable time interval between each measurement. After the baseline measurement the barrier cream was applied by the researcher on the test subjects’ dominant arm. The long term effects were determined after the baseline measurement in intervals of 2 hours. Directly after each measurement the barrier cream was reapplied. Results: Gloves In A Bottle™ increased stratum corneum hydration, had no effect on TEWL and increased skin surface pH, whereas Reinol™ increased stratum corneum hydration and decreased TEWL and had no effect on pH values. Travabon™ decreased stratum corneum hydration and TEWL and had no effect on skin surface pH. The results indicated that there were significant differences between Caucasian and African test subjects with the use of barrier creams, because of the baseline differences and the reaction to barrier creams showed different results. There were also statistically significant differences in the four different anatomical areas where the barrier creams were applied. Conclusion: Barrier creams are beneficial in the workplace, although it should be taken into consideration that different ethnicities react differently to barrier creams under different workplace situations and therefore this should be taken into account when selecting a barrier cream. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

Yes / A composite silicone skin adhesive material was designed to improve its water vapor permeability to offer advantages to wearer comfort compared to existing skin adhesive dressings available (including perforated silicone and hydrocolloid products). The chemical and mechanical properties of this novel dressing were analyzed to show that it has a high creep compliance, offering anisotropic elasticity that is likely to place less stress on the skin. A participant study was carried out in which 31 participants wore a novel silicone skin adhesive (Sil2) and a hydrocolloid competitor and were monitored for physiological response to the dressings. Trans-epidermal water loss (TEWL) was measured pre- and postwear to determine impairment of skin barrier function. Sil2 exhibited a higher vapor permeability than the hydrocolloid dressings during wear. Peel strength measurements and dye counter staining of the removed dressings showed that the hydrocolloid had a higher adhesion to the participants’ skin, resulting in a greater removal of proteins from the stratum corneum and a higher pain rating from participants on removal. Once the dressings were removed, TEWL of the participants skin beneath the Sil2 was close to normal in comparison to the hydrocolloid dressings that showed an increase in skin TEWL, indicating that the skin had been highly occluded. Analysis of the skin immediately after removal showed a higher incidence of erythema following application of hydrocolloid dressings (>60%) compared to Sil2, ( / T.S. received partial funding to study skin adhesive materials from a Medical Research Council Confidence in Concept grant obtained by John Bridgeman at the University of Bradford (MC_PC_19030). Initial formulation and characterization work benchmarking the Sil2 material was funded in part by Trio Healthcare Ltd., who have had no role in the analysis or interpretation of the data presented. All data was obtained independently by staff at the University of Bradford. We also wish to thank the Royal Society of Chemistry for funding Edward Dyson’s position as a research technician via a Research Enablement Grant (E21-8346952505).

Kůže chrání organismus zejména proti vlivům mikroorganizmů a chemickým látkám. Kůže se skládá ze čtyř základních částí: pokožka, bazální membrána, škára a podkožní tukové vazivo. Rohová vrstva je nejsvrchnější vrstvou pokožky a je důležitá v dermatologicko-kosmetickém průmyslu. Rohová vrstva je tvořena proteinovými buňkami, které jsou odklopeny lipidovou dvouvrstvou. Neporušeností lipidové dvouvrstvy je dána bariérová funkce kůže. Bariéra kůže není souvislá. Voda může difundovat k povrchu ze spodních, lépe hydratovaných vrstev kůže. Tento tok vody se nazývá přirozená ztráta vody pokožkou (TEWL) a může být měřen. TEWL se měří bioinženýrskymi metodami a je jím hodnocena bariérová funkce kůže. Hydratace rohové vrstvy se měří také bioinženýrskými metodami. tyto metody jsou založeny na elektrických vlastnostech kůže. Tato práce se zabývá hodnocením hydratace kůže, funkcí kožní bariéry a srovnáním měřících přístrojů. K měření bylo použito několik různých přístrojů. Tewameter měří evaporaci vody nad pokožkou, Skicon 200-EX měří elektrickou konduktanci, zatímco analogický i digitální Corneometr měří elektrickou kapacitanci. Měření byla uskutečněna před specifickým ošetřením a po specifickém ošetření, jako je stripování nebo aplikace kosmetického produktu. Ze získaných výsledků je možno říci, ze hodnoty TEWL se s stripováním zvyšují a hodnoty hydratace se po aplikaci hydratačního produktu také zvyšují. Srovnání měřících přístrojů se hodnotilo Pearson korelačním koeficientem. Koeficienty byly kladné a platné, což znamenalo lineární korelaci mezi dvěma určitými přístroji.

4 Summary Seasonal metabolic adjustments and partitioning of evaporative water loss in Wahlberg’s epauletted fruit bat, Epomophorus wahlbergi Student: Ingrid A. Minnaar Supervisor: Prof. A. E. McKechnie Co-supervisors: Prof. N. C. Bennett, Prof. Christian T. Chimimba Department: Zoology and Entomology, University of Pretoria Degree: MSc: Zoology The capacity to thermoregulate over a wide range of TaS is critical for maintaining homeostasis in endotherms. Several aspects of the thermoregulatory properties of bats remain poorly studied when compared to other mammals and birds. I examined two specific aspects of thermoregulation in bats: the seasonal variation of maximum metabolic heat production and the partitioning of total evaporative water loss (TEWL) into respiratory and cutaneous components. I measured basal metabolic rate (BMR) and summit metabolism (Msum) in captive and wild Wahlberg’s epauletted fruit bats, Epomophorus wahlbergi, during summer and winter. I measured metabolic rate using flow-through respirometry, and elicited Msum by exposing bats to low temperatures in a helox (21% O2, 79% He) atmosphere. BMR decreased by 22-25% during winter in both captive and wild bats, with the BMR of captive bats 9-13% lower than the wild individuals across seasons. Msum was approximately seasonally stable in both captive and wild bats, but Msum in captive individuals was 13-18% higher than their wild conspecifics during both seasons. The ratio between Msum and BMR (i.e., metabolic expansibility) was greater in winter than during summer for both captive and wild bats. One likely explanation for the greater resting thermogenic capacity of the bats in captive individuals concerns their reduced activity levels; compared to wild, free-ranging bats, heat produced as a by-product of activity probably contributed far less to thermoregulation, apparently leading to an increase in resting heat production capacity in captive individuals. 5 At the other end of the thermal scale, knowledge of heat tolerance and the evaporative cooling mechanisms employed by bats in hot weather remains rudimentary. At high air temperatures (Ta), endotherms avoid overheating by dissipating heat via evaporative water loss. TEWL may be partitioned into cutaneous evaporative water loss (CEWL) and respiratory evaporative water loss (REWL). I quantified CEWL and REWL in E. wahlbergi at Tas of 10-40 °C using a latex mask. When Ta exceeded normothermic Tb, bats drastically increased their TEWL, metabolic rate and Tb. The relative contribution of CEWL to TEWL was the greatest at moderate Tas where it represented up to 80% of TEWL. REWL was the major route of evaporative cooling at the highest Ta: at Ta = 40 ºC, REWL represented 45% of TEWL. To avoid hyperthermia, E. wahlbergi greatly increased metabolic rate at high TaS to avoid hyperthermia, further compounding the need to cool down. REWL is thought to be less efficient as than CEWL in offloading heat at high TaS as panting increases metabolic heat, whereas CEWL occurs passively. There is a need for further studies to be conducted on the thermoregulatory capabilities of bats in varying environmental conditions, both intra- and interspecifically. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Zoology and Entomology / unrestricted

Skin is the largest immune organ and an ideal site to administer vaccines. However, by nature, skin is not permeable to antigens, which are macromolecules. The major hurdle in skin permeation is the outermost stratum corneum layer. Microneedles have proven feasible to create micron-sized channels in the epidermis of the skin, through which protein and plasmid DNA antigens can penetrate into the viable skin epidermis and dermis. However, the immune responses induced by microneedle-mediated transcutaneous immunization with protein or plasmid DNA alone are generally weak, and a vaccine adjuvant is often required to induce strong immune responses. Data from numerous previous studies have shown that nanoparticles as a vaccine carrier can significantly enhance the immunogenicity of antigens, but the feasibility of utilizing nanoparticles as a vaccine carrier to enhance the immune responses induced by microneedle-mediated transcutaneous immunization has rarely been studied. In this dissertation, using protein antigen (OVA) chemically conjugated onto the surface of solid-lipid nanoparticles and plasmid DNA (pCMV-beta, pVax/opt-BoNT/C-Hc50, and pCI-neo-sOVA) physically coated on the surface of cationic polymeric nanoparticles, we showed that the immune responses induced by microneedle-mediated transcutaneous immunization with protein antigens or plasmid DNA vaccines are significantly enhanced by delivering the proteins and plasmid DNA with nanoparticles. Importantly, microneedle-mediated transcutaneous immunization with proteins or plasmid DNA induces not only systemic immune responses, but also mucosal immune responses. In addition, it is generally believed that microneedles are safe. However, it remained unclear whether the micropores created by microneedles on the skin will also facilitate the permeation of microbes such as bacteria into the skin. In this dissertation, we also designed an unique ex vivo model to evaluate the permeation of live bacteria through mouse skin pretreated with microneedles. The results demonstrated that the risk of potential bacterial infection associated with microneedle treatment is not greater than that associated with a hypodermic needle injection. / text

Nickel is one of the most commonly known sensitisers and has been classified by the International Agency for Research on Cancer (IARC) as a possible carcinogen to humans (group 2B). Workers at a South African base metal refinery packaging area are potentially exposed to many hazardous chemicals that include nickel. Aims and Objectives: The aim and objectives of this study were to assess dermal and respiratory exposure of workers exposed to nickel in a packaging section at a South African base metal refinery and to assess the change in skin barrier function during a work shift by measuring percentage change in trans epidermal water loss (TEWL), skin hydration and skin surface pH. Skin health was established with a skin questionnaire. Surfaces that workers may come into contact with were also assessed. Method: Respiratory and dermal exposure assessment was done concurrently. Respiratory exposure was assessed and analysed by using the National Institute for Occupational Safety and Health (NIOSH) method 7300. The Institute of Occupational Medicine (IOM) inhalable aerosol sampler was used for personal air sampling. The TEWL index, skin hydration and skin surface pH of the index finger, palm, forearm and forehead were measured before and at the end of the shift with a Derma Measurement Unit, EDS 12 and Skin-pH-Meter® pH 905. These measurements were reported as percentage change in skin barrier function during the shift. Dermal exposure samples were collected with Ghostwipes™ from the index finger and palm of the dominant hand before, during and at the end of the shift, while samples from the forearm and forehead were only collected before and after the shift. Surface sampling was collected and all wipes were analysed for nickel according the NIOSH method 9102, using inductively coupled plasma-atomic emission spectrometry. Results: Respiratory exposure for the whole group of workers in a packaging section was well below the eight hour Time Weighted Average (TWA) respiratory Occupational Exposure Limit (OEL) of 0.5 mg m-3 for nickel. Dermal nickel loading was detected for all the job categories on all the anatomical areas even before the shift had commenced. During the shift more nickel was detected on the index finger and palm of the hand. Levels on the forearm and forehead were much lower in comparison with the index finger and the palm of the hand. Workplace surfaces, which workers may come into contact with on a daily basis, were also contaminated with nickel. Forklift drivers showed high exposure on the index finger and palm of their hands, and this can be attributed to them not wearing any gloves for hand protection. An increase in percentage change for TEWL was seen for most of the job categories on all anatomical areas measured during the shift. Percentage change in skin surface pH and skin hydration varied among job categories. Conclusion: The research addressed the problem statement, with the stated objectives. It was hypothesised that workers at a packaging section of a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. The hypothesis was accepted and control measures together with future studies were recommended. The results confirmed that all workers at a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. Dermal exposure was evident on all anatomical areas for all job categories before the shift had commenced. Personal protective equipment was provided to all employees, but forklift drivers did not wear gloves when operating the forklift. Respirable exposure to nickel was below the OEL. Changes in TEWL and to a lesser extent skin hydration, suggest a deterioration in skin barrier function during the shift. Forklift drivers as well as plate washers may be the highest risk job categories in developing allergic contact dermatitis. Several measures to lower respiratory and dermal exposure to nickel are also recommended. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

Nickel is one of the most commonly known sensitisers and has been classified by the International Agency for Research on Cancer (IARC) as a possible carcinogen to humans (group 2B). Workers at a South African base metal refinery packaging area are potentially exposed to many hazardous chemicals that include nickel. Aims and Objectives: The aim and objectives of this study were to assess dermal and respiratory exposure of workers exposed to nickel in a packaging section at a South African base metal refinery and to assess the change in skin barrier function during a work shift by measuring percentage change in trans epidermal water loss (TEWL), skin hydration and skin surface pH. Skin health was established with a skin questionnaire. Surfaces that workers may come into contact with were also assessed. Method: Respiratory and dermal exposure assessment was done concurrently. Respiratory exposure was assessed and analysed by using the National Institute for Occupational Safety and Health (NIOSH) method 7300. The Institute of Occupational Medicine (IOM) inhalable aerosol sampler was used for personal air sampling. The TEWL index, skin hydration and skin surface pH of the index finger, palm, forearm and forehead were measured before and at the end of the shift with a Derma Measurement Unit, EDS 12 and Skin-pH-Meter® pH 905. These measurements were reported as percentage change in skin barrier function during the shift. Dermal exposure samples were collected with Ghostwipes™ from the index finger and palm of the dominant hand before, during and at the end of the shift, while samples from the forearm and forehead were only collected before and after the shift. Surface sampling was collected and all wipes were analysed for nickel according the NIOSH method 9102, using inductively coupled plasma-atomic emission spectrometry. Results: Respiratory exposure for the whole group of workers in a packaging section was well below the eight hour Time Weighted Average (TWA) respiratory Occupational Exposure Limit (OEL) of 0.5 mg m-3 for nickel. Dermal nickel loading was detected for all the job categories on all the anatomical areas even before the shift had commenced. During the shift more nickel was detected on the index finger and palm of the hand. Levels on the forearm and forehead were much lower in comparison with the index finger and the palm of the hand. Workplace surfaces, which workers may come into contact with on a daily basis, were also contaminated with nickel. Forklift drivers showed high exposure on the index finger and palm of their hands, and this can be attributed to them not wearing any gloves for hand protection. An increase in percentage change for TEWL was seen for most of the job categories on all anatomical areas measured during the shift. Percentage change in skin surface pH and skin hydration varied among job categories. Conclusion: The research addressed the problem statement, with the stated objectives. It was hypothesised that workers at a packaging section of a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. The hypothesis was accepted and control measures together with future studies were recommended. The results confirmed that all workers at a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. Dermal exposure was evident on all anatomical areas for all job categories before the shift had commenced. Personal protective equipment was provided to all employees, but forklift drivers did not wear gloves when operating the forklift. Respirable exposure to nickel was below the OEL. Changes in TEWL and to a lesser extent skin hydration, suggest a deterioration in skin barrier function during the shift. Forklift drivers as well as plate washers may be the highest risk job categories in developing allergic contact dermatitis. Several measures to lower respiratory and dermal exposure to nickel are also recommended. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

The aim of this diploma thesis was to investigate the effect of surfactants and cosmetic polysaccharides on skin parameters and its microbiome. Three surfactants were tested to determine their effect: Sodium Dodecyl Sulfate (SDS), Cocamidopropyl Betaine (CAPB), Decylglucoside (DG). Distilled water was also used for comparison. For the next part of the experimental work were selected 6 polysaccharides: high molecular weight Hyaluronic Acid (HMW HA), very low molecular weight Hyaluronic Acid (VLMW HA), Sodium Caproyl Hyaluronate (CaproylHA), Sodium Carboxymethyl -Glucan (NaCMG), Schizophyllan and Glucomannan. For comparison, placebo and untreated control (only CAPB treatment) were also included in the tests. The first part of the work is a literature search on the assigned topic, which contains the following parts: skin anatomy and its biophysical properties, skin microbiome and its functions, description of used surfactants and polysaccharides. The experimental part is mainly focused on bioengineering methods for evaluation of skin parameters and qRT-PCR to determine the relative proportion of main bacterial species of skin microbiome. First, the effect on the CT gene of 16S rDNA was analysed, and Propionibacterium acnes and Staphylococcus epidermidis strains were selected for further analysis. In conclusion are presented an overview of all properties of selected substances and assessment of their application in cosmetics.