Atopic dermatitis (AD) is a common, chronic relapsing inflammatory skin disease associated with cutaneous hyper-reactivity to environmental triggers that are innocuous to normal nonatopic individuals. AD affects 10% to 15% of children and 2% to 10% of adults in industrialized countries. There has been increasing interest in this disease triggered by its increasing prevalence in western societies and its contribution to the increasing health care costs. Yet, the underlying pathophysiologic and genetic mechanisms leading to the manifestation of AD are not clear. AD results from a complex interplay between environmental triggers, susceptibility genes including mutations in the keratinocyte protein filaggrin and altered immune responses resulting in allergic CD4+ T cell (Th2) immunity to epidermally encountered antigens. Regulatory T cells (Tregs) play an important role in controlling responsiveness to self-antigens and preventing autoimmune diseases, as well as in limiting inflammatory responses during inflammation and infection. Currently, studies investigating the number and function of Tregs in patients with AD have shown controversial results. It has been long established that symptoms of AD improve on exposure to sunlight. Narrowband UVB (NB-UVB) phototherapy is a common treatment modality for a variety of skin diseases. Considering the adverse effects for systemic treatment for severe adult AD, phototherapy, especially NB-UVB phototherapy may be a more practical long-term treatment. However, approximately 50% of patients over an 8-week treatment course do not improve after NB-UVB phototherapy. Therefore, it is important to identify characteristics of AD patients to determine whether they will respond to phototherapy and to avoid adverse effects for unresponsive patients. UVB exposure has also been associated with induction of Tregs in mice and increasing their numbers and/or functional capacity may offer benefit to patients with chronic AD. Active vitamin D (1,25(OH)2D3), one of the factors induced by UV-B radiation induces Tregs and is suggested to contribute to the suppressive effect of NB-UVB phototherapy. However, UV radiation could also have beneficial effects through other pathways known to affect immunoregulation. UVB exposure upregulates production of nitric oxide (NO) in the skin which also affects immune cell function. The protein filaggrin is broken down in differentiating keratinocytes to form the natural moisturizer of the skin. The gene encoding filaggrin (FLG) has been shown to be a major predisposing factor for AD. A key breakdown product is urocanic acid (UCA) which also acts as a natural sunscreen and undergoes trans-cis isomerisation on exposure to UV-B. Cis-UCA is known to modulate immune responses, however, the mechanisms of its action remain elusive. The production of all three compounds, vitamin D, cis-UCA and NO might all increase in the circulation of patients undergoing UVB phototherapy. While the immunomodulatory effect of Vitamin D is well described, cis-UCA and NO may also affect the behaviour of T lymphocytes systemically. Therefore, I investigated the effect of NO and cis-UCA on the phenotype and function of CD4+T cells and monocyte-derived dendritic cells (Mo-DCs) derived from peripheral blood mononuclear cells (PBMCs) from healthy volunteers. I also investigated the correlation between plasma concentration of 25(OH) vitamin D and nitrate, FLG genotype, circulating Tregs and clinical efficacy of NB-UVB phototherapy. My results showed that NO did not affect the phenotype of human mo-DCs and directly affected peripheral CD4+ T cells by inducing functional CD25+Foxp3+CD127-Tregs from CD4+CD25lo/- effector T cells. Moreover, NO increased expression of the of skin homing marker CLA on these Tregs, suggesting an increased ability of NO-induced Tregs to migrate to the skin. These NO-induced CD25+Foxp3+CD127-Tregs had immunosuppressive functions and inhibited autologous CD4+ T cell proliferation. Cytokines, at least IL-10, secreted by NO-treated CD4+ T cells were not sufficient for the suppressive function of NOinduced Foxp3+Tregs. The immune regulatory function of NO-induced Fopx3+Tregs required cell-cell contact and was mediated by membrane bound TGFβ and PD-1/PD-L1 but not CTLA-4. Results also showed that cis-UCA might have both pro- and anti-inflammatory effects. Cis- UCA significantly decreased the proportion of CD25hi Foxp3+ cells from activated CD4+ T cells. It also decreased the expression of vitamin D receptor in CD4+ T cells which may interfere with the immune regulatory function of vitamin D. These results suggested that there might be a fine balance between UV-induced anti-inflammatory molecules’ effect on CD4+ T cells. However, Cis-UCA also modulated CD4+ T cell directly by decreasing CD4+ T cell proliferation, decreasing phosphorylation of ERK after TCR activation, enhancing immune suppressive cytokines secretion, and inhibiting the percentage of CLA+CD4+T cells suggesting a decreased ability to migrate to the skin, . Cis-UCA also affected the phenotype and function of antigen presenting cells by decreasing the expression of HLA-DR, CD86 and CD40 on immature mo-DCs, which led to increased proportion of CD25+Foxp3+CD127- T cells when co-cultured with allogenic CD4+ T cells. Results generated from the clinical study in which all 29 patients got better after phototherapy suggested although circulating 25 (OH) vitamin D concentration was significantly increased after NB-UVB phototherapy, the change of circulating 25 (OH) vitamin D concentration did not correlate with disease improvement. This suggests that vitamin D is not the only pathway involved and that other molecules contribute to UVB-induced immune-regulation. The data also show that of the levels of circulating nitrate and the FLG genotype did not correlate with improvement / change with phototherapy. However, the expression of CD69 and CLA on circulating CD4+ T cells was decreased after treatment suggesting that UVB affected T cell activation and migration to the skin, and their importance in determining clinical responses requires further investigation. Taken together, the results from my study provide evidence that vitamin D is not the only molecule responsible for the beneficial effect of NB-UVB phototherapy. NO and cis-UCA may down-regulate immune responses by affecting human peripheral CD4+ T cells and mo- DCs phenotype and function. A further understanding of the effect of NO and cis-UCA on skin resident immune cells will provide more insights for narrowing NB-UVB phototherapy which will help to select patients that most likely to benefit from a mechanism-based treatment.

Made available in DSpace on 2014-06-11T19:24:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-18Bitstream added on 2014-06-13T19:51:30Z : No. of bitstreams: 1 zambon_aplb_me_arafcf.pdf: 681314 bytes, checksum: 5de628ca0606efd6f2252b3fc61e5c74 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Os raios ultravioletas podem desencadear queimadura solar, fotoenvelhecimento e câncer de pele e, por este motivo, foram desenvolvidos os filtros solares. Atualmente considera-se que uma formulação fotoprotetora ideal e de maior fotoestabilidade deve conter em sua formulação associação de filtros solares com ampla capacidade de absorção da radiação UVB e UVA. Dentre os filtros solares utilizados neste trabalho estão o p-metoxicinamato de octila (OMC), um dos mais utilizados globalmente na proteção frente à radiação UVB, a Benzofenona-3, absorvedor de radiação UVB e UVA II, o Ácido Sulfônico Fenilbenzimidazol, um filtro solar UV-B hidrossolúvel e o Bemotrizinol, com amplo espectro. O sítio de ação desejável de um filtro solar é restrito à superfície da pele e sua função é perdida quando este permeia a pele e atinge a circulação sistêmica. Estudos in vivo e in vitro têm demonstrado a permeação e absorção sistêmica de filtros solares através da pele. Este trabalho teve como objetivo avaliar a interferência da associação dos filtros solares benzofenona 3, ácido sulfônico fenilbenzimzidazol e BEMT nos estudos de estabilidade, liberação, permeação e retenção cutânea in vitro do OMC. A metodologia de identificação e quantificação do OMC foi validada, levando-se em consideração a análise dos limites de confiança. Foram realizados estudos de estabilidade preliminar e acelerada das formulações e do OMC em virtude da fotoinstabilidade do mesmo. Os estudos de liberação, permeação e retenção cutânea foram realizados utilizando-se o equipamento de célula de difusão vertical de Franz modificada e as membranas utilizadas foram acetato de celulose para o estudo de liberação e orelha de porco para permeação e retenção cutânea. Os resultados obtidos permitiram concluir que as formulações estudadas apresentaram comportamento... / Ultraviolet rays can cause sunburn, photoaging and skin cancer and, because of this, sunscreens were developed. Currently it is considered that an ideal sunscreen formulation and greater photostability must contain in its formulation association of solar filters with high capacity to absorb UVB and UVA. Among the solar filters used in this work are p-octyl methoxycinnamate (OMC), one of the most globally used in the protection against UVB radiation, Benzophenone-3, UVB and UVA II absorber Fenilbenzimidazol Sulfonic Acid, a UV-B hidrosoluble solar filter and Bemotrizinol with broad spectrum. The desirable site of action of a solar filter is limited to the skin surface and its function is lost when it permeates the skin and reaches the systemic circulation. In vivo and in vitro studies have demonstrated the permeation and systemic absorption of solar filters across the skin. This study objective was to evaluate the interference of association of the solar filters benzophenone-3, fenilbenzimzidazol sulfonic acid and BEMT on the stability, release, in vitro skin permeation and retention of the OMC. The methodology for OMC’s identification and quantification was validated, taking into account the confidence limits analysis. Preliminary and accelerated stability studies of the formulations and the OMC, because of it’s photoinstability. The release studies, skin permeation and retention were performed using the equipment Franz’s vertical diffusion cell modified, and the membranes used were cellulose acetate for the release study and pig ear skin for permeation and retention. The results showed that the formulations studied showed similar behavior stability and OMC’s release, regardless of the association of the solar filters... (Complete abstract click electronic access below)

Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-05T14:37:36Z No. of bitstreams: 1 arquivototal.pdf: 798401 bytes, checksum: 41671bb8b384bd28413ef4c5851e99ce (MD5) / Made available in DSpace on 2017-09-05T14:37:36Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 798401 bytes, checksum: 41671bb8b384bd28413ef4c5851e99ce (MD5) Previous issue date: 2015-02-27 / It is well established that solar UV radiation can cause mutations in DNA and increase the risk of developing skin cancer. However, little is known about the ability of UV radiation to cause epigenetic changes in the skin. DNA methylation, characterised by the addition of a methyl group in cytosines within CpG dinucleotides, can modify gene transcription, leading to decreased expression or even silencing of a gene. Epigenetic changes could represent an important pathway by which environmental factors influence aging and disease risks, with a tissue-specific manner. Epithelial keratins are called cytokeratins, the main function of cytokeratins is to maintain the integrity and mechanical stability through cell-cell contacts with epithelial tissue. The aim of this study was to investigate the sun exposure influence on DNA methylation status in the cytokeratin 14 (KRT14) and 19 (KRT19) genes of skin cells of subjects whithout history of skin disease. Skin biopsies were obtained by punch of sun-exposed (outer forearm) and sun-protected areas (inner arm) from 30 corpses of the Brazilian Services of Death Investigation. The KRT14 gene DNA methylation analysis was performed using Methylation-Specific PCR (MSP), and the KRT19 gene DNA methylation analysis was performed using Methylation-Sensitive Restriction Enzymes (MSRE) of sun-exposed and sun-protected skin areas. Statistical analysis showed no significant differences between sun-protected and sun-exposed areas and the most frequently methylated condition for CpG studied for KRT14 and KRT19 genes (p> 0.05; McNemar). We conclude that sun exposure does not induce changes in DNA methylation status in the KRT14 and KRT19 genes. / Pesquisas tem mostrado que a radiação UV do sol pode causar mutações no DNA e aumentar o risco para o desenvolvimento de câncer de pele. Entretanto, ainda pouco se sabe sobre a capacidade da radiação UV em causar alterações epigenéticas na pele. A metilação do DNA é caracterizada pela adição do grupo metil em uma citosina precedida por uma guanina (dinucleotídeo CpG), o que pode alterar a transcrição gênica, diminuindo a expressão ou silenciando um gene. Alterações epigenéticas podem representar um importante caminho de como os fatores ambientais influenciam no envelhecimento e no desenvolvimento de certas doenças de maneira tecido específica. Queratinas epiteliais são chamadas de citoqueratinas, e sua principal função é manter a integridade e estabilidade mecânica do tecido epitelial. Neste trabalho investigamos se há influência da exposição solar sobre o perfil de metilação de DNA nos genes das citoqueratinas 14 (KRT14) e (KRT19), em células da pele de indivíduos sem histórico de doenças de pele. Biopsias de pele foram obtidas através de um Punch circular da de área exposta e não exposta ao sol de 30 cadáveres do Serviço de Verificação de Óbito. A análise de metilação do gene KRT14 foi realizada pelo método de PCR Específica para Metilação (MSP), e para o gene KRT19 foi realizado o método de Restrição Enzimática Sensível à Metilação (MSRE) das áreas expostas e protegidas do sol. A análise estatística mostrou que não há diferenças significativas entre as regiões exposta e não exposta ao sol, sendo a condição metilada a mais frequente tanto para o gene KRT14 quanto para o gene KRT19 (p>0,05; McNemar). Assim, concluímos que não há influência da exposição solar no perfil de metilação de DNA nos genes KRT14 e KRT19.

Exposure to solar radiation, particularly its ultraviolet (UV), has a variety of harmful effects on human health. Some of these effects include sunburn cell formations, erythema, edema, melanoma, photoaging of the skin, and immune suppression. A plant that has been widely used in tropical folk medicine for a number of conditions is the Morinda citrifolia Linn. (Rubiaceae), commonly known as noni. The beneficial photoprotective effects of topical formulations based on extract from Morinda citrifolia leaves, have not yet been investigated. Thus, the present study aims to investigate the potential benefits of M. citrifolia topical application on the dorsal skin of mice, exposed to UVA-UVB light. Firstly, the absorption spectrum of the formulations extracts (10 and 15%) was evaluated by spectroscopy. The spectrum showed peaks at 200 nm and at 240 nm and absorption in the UVA and UVB regions. After 7 days of treatment and exposition to UVA-UVB light, the thickness, transepidermal water loss (TEWL), erythema and histological alterations were evaluated. The results from in vivo effectiveness showed that the thickness, TEWL values and erythema indexes were significantly decreased by treatment with formulations containing the extract. The histological measurements in hematoxilina eosin showed that in the non-irradiated group showed that the epidermis was represented by a thin, and continuous surface. No inflammatory infiltrate were found in the dermal tissues. Both irradiated and vehicle groups presented increased epidermal thickness associated to hyperorthokeratosis. The papillary dermis exhibited intense inflammatory infiltrate, mainly composed of lymphocytes, mild interstitial edema and prominent capillary and venular hyperemia. The treated groups presented remarkable reduction in the inflammatory content, as well as less expressive hyperemia. In the Sirius Red, the irradiated and vehicle groups, papillary dermis showed the presence of a gross, thick, parallel-arranged, collagen fibers. Both treated groups (10 and 15% formulations) presented similar features regarding the collagenization pattern, showing a mixture of yellowish type I and greenish type III collagen fibers. The interfibrillary spaces were more evident than in irradiated and vehicle groups. Such morphological appearances were very similar to that observed in non irradiated group. Areas treated with the formulation containing Morinda citrifolia extract (10% and 15%) have enhanced protection against UV radiation. Finally, the extract was evaluated on murine malignant melanoma (cell line B16F10) in order to examine their cytotoxic effects on malignany cells. The extract at concentrations of 0.05 to 12.8 mg/mL did not show any cytotoxic effects in the B16F10 cell line. These can suggest that the extract showed no potential anti cancer in melanoma cells, and the extract have only photoprotection effects. In conclusion, the results showed that the formulations containing the extract protected the skin against UV-induced damage. / A exposição à radiação solar, particularmente a radiação ultravioleta (UV), tem uma variedade de efeitos nocivos à saúde humana. Alguns destes efeitos incluem formações de queimaduras solares, eritema, edema, melanoma, fotoenvelhecimento da pele e da supressão imune. Uma planta medicinal que tem sido vastamente utilizada para as mais variadas formas de manutenção da saúde, tem sido a Morinda citrifolia Linn. (Rubiaceae), comumente conhecida como noni. Os efeitos fotoprotetores de formulações para uso tópico com o extrato aquoso das folhas da Morinda citrifolia não foram investigados previamente. Assim, o presente estudo teve como objetivo estudar os benefícios potenciais da M. citrifolia em aplicação tópica na pele dorsal de camundongos expostos à radiação UVA-UVB. Primeiramente, o espectro de absorção das formulações com extrato (10% e 15%) foi avaliada por espectroscopia. O espectro mostrou bandas a 200 nm e em 240 nm e em regiões de absorção no UVA e UVB. In vivo, após 7 dias de tratamento e exposição à radição UVA-UVB, a espessura, perda transepidérmica de água (TEWL), eritema e alterações histológicas foram avaliadas. Os resultados de eficácia in vivo mostraram que os valores de espessura, TEWL e índices de eritema foram significativamente reduzidos pelo tratamento com as formulações contendo o extrato, comparados aos grupos controle irradiado e veículo irradiado. As medições histológicas em hematoxilina eosina mostraram que no grupo não irradiado a epiderme foi representada por uma superfície delgada e contínua. Não foram encontrados infiltrados inflamatórios nos tecidos dérmicos. Ambos os grupos irradiados e veículo apresentaram aumento da espessura da epiderme e hiperortoqueratose. A derme papilar apresentou intenso infiltrado inflamatório, composto principalmente de linfócitos, edema intersticial leve e hiperemia capilar e venular proeminente. Os grupos tratados apresentaram redução notável no conteúdo inflamatório e da hiperemia. Na coloração picrossírius, nos grupos controle irradiado e veículo irradiado, a derme papilar mostrou a presença de feixe de fibras colágenas espessas, grosseiras, de comprimento variável e disposição paralela. Ambos os grupos tratados (formulações de 10% e 15%) apresentaram características semelhantes quanto ao padrão de colagenização, mostrando uma mistura de fibras de colágeno tipo I e fibras de colágeno tipo III. Os espaços interfibrilares nos grupos tratados foram mais evidentes que nos grupos irradiados e do veículo. Tais aspectos morfológicos foram semelhantes às observadas no grupo não irradiado. Ficou evidente, através da morfologia e histologia, que as áreas tratadas com a formulação contendo Morinda citrifolia (10% e 15%) tiveram uma maior proteção contra a radiação UV Finalmente, o extrato foi avaliado em melanoma (linha de células B16F10), a fim de examinar os seus efeitos citotóxicos em células malígnas. O extrato com concentrações de 0,05 a 12,8 mg/mL não mostrou quaisquer efeitos citotóxicos na linhagem de células B16F10. Estes podem sugerir que o extrato não combate danos já estabelecidos em células, tendos efeitos apenas de fotoproteção, dos quais os mecanismos ainda precisam de estudo mais aprofundado. Em conclusão, os resultados demonstraram que as formulações contendo o extrato protegem a pele contra danos induzidos por radiação UV.

O aumento do conhecimento em relação aos danos provocados pela radiação solar, tanto na faixa do UVB quanto na faixa do UVA, o avanço nas tecnologias relacionadas ao produto e às formas de avaliação bem como a disponibilização de novas moléculas no mercado levaram ao aumento da qualidade da proteção proporcionada pelos fotoprotetores. Entretanto, ainda há preocupações em relação à segurança de alguns filtros solares devido a sua fotoinstabilidade e penetração cutânea. Dessa forma, torna-se necessário o desenvolvimento de novos filtros solares mais efetivos e seguros, que apresentem relevância científica e potencial de inovação. Assim, a presente pesquisa teve como objetivo desenvolver novos análogos ao filtro solar benzofenona-3 e determinar o seu potencial fotoprotetor por meio da avaliação da absorção UV e avaliação da fotoestabilidade, fototoxicidade e atividade antioxidante. Para tal, inicialmente seis análogos ao filtro solar químico benzofenona-3 foram sintetizados visando aumentar o tamanho da molécula e aumentar a sua absorção no UVA longo (340-400nm). Foram avaliados os espectros de absorção no UV e a fotodegradação dessas substâncias. A fototoxicidade das substâncias selecionadas foi avaliada por meio do uso de cultura de fibroblastos 3T3, para a determinação da viabilidade celular na presença e ausência da radiação. A atividade antioxidante das substâncias foi avaliada por meio da quimioluminescência gerada pela reação HRP-H2O2-luminol. Os resultados permitiram demonstrar a importância da relação entre a estrutura molecular dos compostos e sua absorção no UV. As moléculas benzofenona-3 fenil amino (B5) e o carbazol da benzofenona-3 fenil amino (B6) apresentaram maior absorção no UVA, longo e curto, e no UVB, quando comparadas com a molécula de partida (benzofenona-3). Apenas as substâncias que apresentavam ponte de hidrogênio intramolecular (B5 e B6) foram consideradas fotoestáveis. Somente a molécula B5 não apresentou potencial para fototoxicidade aguda. Além disso, essa molécula apresentou atividade antioxidante, o que sugere o seu grande potencial para utilização com filtro solar. / The increase of our knowledge of not only UVB but also UVA-induced damages, the advances on product and testing technologies as well as new sunscreen molecules leaded to and enhancement of quality of UV protection provided by topical sunscreens. However there are some safety concerns involving some UV-filters due to their photoinstability and skin penetration. Therefore it is necessary to develop new safer and more effective UV-filters, which also presents scientific relevance and innovation potential. Thus, the aim of the present research was to develop new analogues based on benzophenone-3, and to evaluate their photoprotective potential through their photostability, phototoxicity and antioxidant activity. For this purpose, firstly six new synthetic analogues based on benzophenone-3 were prepared in order to promote molecular weight enhancement as well as improve long-wave UVA absorption (340-400 nm). The UV absorption spectra and photodegradation of these compounds were also analyzed. Phototoxicity of selected compounds was evaluated by using 3T3 monolayer fibroblast culture to determine cell viability in the presence and absence of UVA radiation. The antioxidant activity was evaluated by HRP-H2O2-luminol induced chemiluminescence. The results showed that relationship between the molecular structure and UV absorption. Me molecules phenylamine benzophenone-3 (B5) and phenylamine benzophenone-3 carbazol (B6) showed higher short and long-wave UVA and UVB absorption, when compared to benzophenone-3. Only B5 and B6, which presented intermolecular hydrogen bond, were considered photostable. B5 did not present any acute phototoxicity potential; in addition it has antioxidant activity, which suggests its high UVfilter potential.

The contamination of renal failure patients by metals can be associated to the presence of these metals in the medication, since they can be absorbed by the organism. The level of contamination caused by medication, in these cases, depends strongly on the quality of medication used in the treatment. Among the possible contaminants, there are metals such as aluminum, chromium and nickel. Therefore, the development of analytical methodologies for the quality control of medicaments used by anemic patients is of great importance. In the present work, the presence of Al, Cr and Ni as contaminants in erythropoietin formulations (EPO), a renal antianemic, was investigated by developing and optimizing an adsorptive cathodic stripping voltammetric (AdCSV) method. It involves the optimization of a pretreatment step of samples by using UV irradiation for decomposition of matrix organic components. The AdCSV method is based on the adsorptive deposition of the complex formed at the electrode surface and the subsequent reduction of ligand (or metal) during the cathodic potential scan. The results found for Al, Cr and Ni in the studied samples, after performing the pretreatment step, show the applicability of the method for the determination of Al, Cr and Ni as contaminants in this kind of samples. The developed voltammetric methods are advantageous in relation to other existing methods concerning the high sensitivity of measurement if associated to the pretreatment step by UV irradiation associated with the addition of H2O2. / A contaminação de pacientes com insuficiência renal por espécies metálicas pode estar associada à presença destas na medicação empregada, uma vez que estas espécies podem ser absorvidas pelo organismo do paciente. O nível de contaminação através da medicação, nestes casos, dependerá da qualidade da medicação utilizada no tratamento. Dentre os possíveis contaminantes, estão metais como alumínio, cromo e níquel. Desta forma, o desenvolvimento de metodologias analíticas adequadas ao controle de qualidade dos medicamentos administrados ao paciente é de grande importância. No presente trabalho, investigou-se a presença de Al, Cr e Ni como contaminantes em formulações de eritropoetina (EPO), um antianêmico renal, através do desenvolvimento e otimização de um método voltamétrico adsortivo de redissolução catódica (AdCSV) com a otimização de uma etapa de pré-tratamento das amostras empregando radiação UV para a decomposição dos componentes orgânicos da matriz. O método está baseado na deposição adsortiva do complexo formado (metal-ligante) na superfície do eletrodo e na redução do ligante ou do metal durante a varredura catódica dos potenciais. Os valores de Al, Cr e Ni encontrados nas amostras estudadas, após a etapa de pré-tratamento, demonstram a aplicabilidade do método para a determinação de Al, Cr e Ni como contaminantes neste tipo de matriz. O método voltamétrico desenvolvido é vantajoso em relação a outros métodos existentes, devido à alta sensibilidade da medida quando associada a uma etapa de pré-tratamento da amostra com radiação UV combinado com adição de H2O2.

Textile UV-radiation sensors has lately been introduced to the field of smart textiles. Inkjet printing has been used as means of application due to the effective and resource efficient process. UV-LED radiation curing has been used in combination with inkjet printing in favour of low energy requirements, solvent free solution and reduced risk of clogging in the print heads. The problems arising when exposing photochromic prints to UV-radiations are that oxygen inhibition during the curing and photo-oxidation in the print reduces the prints ability to develop colour. It is the oxygen in the air in combination with UV-radiation that gives the photo-oxidating behavior. The aim of the study is to with the aid of physical protection reduce the effect of oxygen inhibition and photo-oxidation in the prints. Three types of physical treatments were used, wax coating, protein based impregnation and starch based impregnation. Treatments were applied before curing as well as after curing and the colour development after activation during 1 min of UV-radiation was measured with a spectrophotometer. Multiple activations were also tested to see how the treatments affected the fatigue behaviour of the prints over time. The aim was to have as high colour development as possible reflecting reduced oxygen inhibition and photo-oxidation. Results showed significantly higher colour development for samples treated with wax and whey powder before curing, but reduced colour development for amylose impregnation. Over time whey powder before curing showed highest colour development due to highest initial colour development. Lowest fatigue was seen for washed samples containing the chemical stabiliser HALS, showing an increased colour development. In reference to earlier studies the protective properties of wax and whey powder is due to their oxygen barrier properties protecting the print. The tested treatments have shown that it is possible to reduce the effect of photo-oxidation during curing leading to prints giving higher colour development. This gives a great stand point when improving existing and future application of photochromic prints on textiles.

This thesis focuses on the study of UV light-generated zinc complexes with cadmium and organic molecules SAM, SAH, CYS, HCYS and GSSG, specifically at 375 nm. Furthemore, the aim of the work is to characterize the precursors spectrally and temporally before and after irradiation in the transilluminator at 250 nm. Study of genesis these complexes was performed by FLIM. Thanks to this method, it was found that the formation of complexes occurs only with Zn:SAH, Zn:GSSG and Zn:Cd. The formation of complexes is influenced by the method of preparation. The spectral characteristic was performed on a fluorimeter where the increase in fluorescence intensity of the irradiated solution with the precursors was expected. These were turbid solutions where sedimentation of the particles was observed and the intensity of fluorescence was changed. In the Zn:SAM and Zn:CYS sample, the sedimentation increased in intensity, while in Zn:SAH and Zn:HCYS decreased. The Zn:Cd precursor solution was clear and there was no change in intensity. Zn:Cd showed the best spectral properties, while the Zn:SAM sample, whose excitation and emission maxima are very close to each other, appeared to be the worst. A sample with Zn:CYS and Zn:HCYS showed almost the same spectra and respective peak results. Based on lifetime characteristics by TCSPC, the sample with Zn:CYS, Zn:HCYS and Zn:GSSG, which showed 3 lifetimes, was best treated. Lifetime could not be unambiguously determined for SAM and SAH samples. Zn:Cd had 4 lifetimes

Within the theoretical part of the diploma thesis, a list of the main types of accelerated tests designed for the resistance of metal and polymer surface finishes. In the experimental part of diploma thesis, the rate of biological resistance of wood-based board materials is evaluated. Furthermore, the resistance of coating systems is assessed by means of accelerated tests. Resistance of modular building shells is primarily focused on degradation of coatings applied primarily on metal materials and wood materials. The tested coating systems analyze the influence of the materials and chemical base on the final weather resistance.

Inkjet printing technology became a popular technology for printing digital photographs in the last decade. There is a big variety of both original and alternative (cheaper) inks and print media for the consumers. But there is a question if the cheaper material provides also comparable printout quality. For this reason, it is important to test the properties of such inkjet printouts. There are several ways how to test the lightfastness of the printouts: long term storage under environmental conditions, or short, accelerated ageing tests. The stability of printouts is affected by many factors, such as ink-receiving layer, ink composition, UV and visible light intensity and air pollutants concentration in the environment. Some inkjet printouts exposed to light usually undergo surprisingly fast fading, but light is not the only dangerous condition for inkjet printout. The two types of test targets printed with dyebased inkjet inks on various paper types were subjected to both accelerated test in a xenon test chamber and light and environmental pollutants long-term test in a sunny indoor corridor. The values of light intensity were continuously monitored and samples properties were regularly measured with a spectrophotometer. Another type of testing included accelerated ozone ageing of inkjet dyes. The colour gamuts and gamut volumes were calculated from collected spectral data. Total colour difference E*ab was also evaluated, its increase served as a tool for finding the formal printout degradation rate constant. It was found out that the dyes in ink-receiving layers of printouts underwent significant degradation in all tested conditions. The degradation rate depended on the type of used print media. The reciprocity behaviour of printouts was also studied. Recent inkjet printouts testing miss some actual ISO norm which should show the way of effective lightfastness evaluation. One of the main aims of this work was to find some new and alternative ways of inkjet printouts lightfastness evaluation. The method of printed inks concentration determination from the test charts spectrophotometric measurements was also proposed.