Abstract Dissolved organic matters are important photosensitizer for the photochemical reactions in natural water. In this study, the photochemical reactions sensitized by seawater were collected from Kaoshiung harbor and coastal areas. The steady-state concentrations of singlet oxygen [1O2]ss were determined by using furfuryl alcohol as a trapping agent. PNAP-PYR actinometer were used to measure the integrated intensity incident on the sample during sunlight irradiation. The objectives of this study are : ¡]1¡^ Measure the mean [1O2]ss of seawater in the Kaoshiung sea area. ¡]2¡^ Test the correlation between TOC and [1O2]ss ¡]3¡^ Test the correlation between UV-VIS A370 and [1O2]ss ¡]4¡^ Test the correlation between fluorescence and [1O2]ss According to the experimental results, we have found that sunlight of different seasons have quite an influence to [1O2]ss. Dissolved organic matters play an important role in photochemical reactions in natural waters although the results show non-significant correlation between dissolved organic matters and [1O2]ss. Then we use SPSS to calculate the correlation of [1O2]ss and TOC¡BUV-VIS A370¡Bfluorescence. Only UV-VIS A370 and [1O2]ss is apparently correlated ¡]P¡Õ0.05¡^. We suggest that [1O2]ss can be estimated via the following equation [1O2]ss¡Ñ1015 ¡× 11.81A370¡Ï6.49. On November 2000, the mean [1O2]ss of seawater observed in Da-Lin-Pu outfall area and Tso-Ying outfall area are 6.91 ¡Ñ 10-16 M and 2.13 ¡Ñ 10-16 M respectively.

1 / Tingting Feng

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Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Department of Biophysics and Physical Chemistry Candidate: Lenka Hrubá Supervisor: Assoc. Prof. Veronika Nováková, Ph.D. Title of Thesis: Optimization of methods for determination of singlet oxygen production and fluorescence emission of azaphthalocyanine derivatives Photodynamic therapy (PDT) with a singlet oxygen as an essential agent is believed to be an alternative way of cancer treatment or treatment of some cutaneous diseases. The principle of PDT is based on excitation of a photosensitizer by light absorption, followed by transfer of energy to tissue oxygen (3 O2) forming cytotoxic singlet oxygen (1 O2). The efficiency by which photosensitizer transforms absorbed energy to singlet oxygen is characterized by singlet oxygen quantum yields (ΦΔ). The aim of this thesis was to develop and optimize absolute method for determination of ΦΔ. In comparison to a relative method, no reference is needed in this case, which enables accurate results with lower error. Verification of the new method was performed in N,N- dimethylformamide with a zinc phthalocyanine as a model photosensitizer because of its well-known ΦΔ and with 1,3-diphenylisobenzofuran as a chemical quencher of 1 O2. Different sources of light for excitation...

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Department of Biophysics and Physical Chemistry Candidate Jiří Demuth Supervisor Assoc. Prof. Veronika Nováková, PhD. Title of Thesis Synthesis and photophysical study of hydrophilic tetrapyridoporphyrazines bearing charged substituents on the periphery Phthalocyanines are planar organic molecules, which have a metal cation coordinated in their centre. This work deals with their aza-analogues - tetra-3,4-pyridoporphyrazines (TPyPz). TPyPz can absorb light in red part spectrum and then produce singlet oxygen. Due to this ability, they may be used in photodynamic therapy (PDT) of cancer. PDT's mechanism is based on three components: photosensitizer, light and singlet oxygen. Photosensitizer transfers energy of absorbed light to oxygen making, thus, cytotoxic singlet oxygen. The goal of this thesis was to synthesize water soluble TPyPzs absorbing in red part of absorption spectrum. TPyPzs bearing different charged substituents will be compared within the series. The synthesis consisted of preparation of 2-chloro-5,6-dimethylpyridine-3,4-dicarbonitrile (1), which was the starting precursor for other reactions. Nucleophilic substitution of 1 was used for the introducing of various hydrophilic substituents. Prepared precursors...

In photodynamic therapy (PDT), the combination of light, photosensitizer and molecular oxygen generates reactive oxygen species, including singlet oxygen (1O2), which is regarded as the primary cytotoxin and effector with most clinical photosensitizers. PDT has gained some acceptance for the treatment of cancer and other conditions. However, its clinical utility and effectiveness has been limited by variability in treatment response and failure to integrate adequate treatment planning and dosimetry. Direct PDT dosimetry through the detection of ultra-weak near-infrared 1O2 luminescence emission at 1270 nm (SOL) collapses the complexity of PDT into a single parameter, the 1O2 concentration. Prior to the present studies, it was shown that SOL was well correlated with PDT response in vitro and in vivo under controlled experimental conditions. However, SOL detection is technically challenging because of the very low radiative probability of 1O2 (~ 10-8 in biological environments), dynamic background signals and limited sensitivity of suitable photodetectors in this wavelength region. A technologically simpler and less costly PDT dosimetry approach is to use photosensitizer photobleaching to estimate the 1O2 dose. The first objective in this thesis was to characterize the dynamics of SOL measurements, in particular the influence of oxygen depletion, in order to improve the quantification of SOL and its use as an accurate PDT dose metric. Subsequently, direct comparison of SOL and photobleaching-based dosimetry during in vitro PDT treatment with meso-tetra(hydroxyphenyl)chlorin (mTHPC) showed that SOL dosimetry is robust but that photobleaching-based dosimetry can fail under hypoxic conditions. However, the latter can be salvaged through the identification of a previously unreported 613 nm emission from mTHPC that indicates hypoxia. These studies were carried forward into an in vivo dorsal skin-fold window chamber tumor model, which showed promising initial correlation between 1O2 dose and tumor response. This work also identified SOL detection limitations and opportunities for further development. Additionally, SOL measurements were used as a ‘gold standard’ to evaluate novel activatable PDT beacons and a novel “PDT biodosimeter” based on STAT3 cross-linking. Future work includes further tumor dose-response studies, characterization of novel photosensitizing agents, improvement on signal detection and processing, and studies in normal human skin.

In photodynamic therapy (PDT), the combination of light, photosensitizer and molecular oxygen generates reactive oxygen species, including singlet oxygen (1O2), which is regarded as the primary cytotoxin and effector with most clinical photosensitizers. PDT has gained some acceptance for the treatment of cancer and other conditions. However, its clinical utility and effectiveness has been limited by variability in treatment response and failure to integrate adequate treatment planning and dosimetry. Direct PDT dosimetry through the detection of ultra-weak near-infrared 1O2 luminescence emission at 1270 nm (SOL) collapses the complexity of PDT into a single parameter, the 1O2 concentration. Prior to the present studies, it was shown that SOL was well correlated with PDT response in vitro and in vivo under controlled experimental conditions. However, SOL detection is technically challenging because of the very low radiative probability of 1O2 (~ 10-8 in biological environments), dynamic background signals and limited sensitivity of suitable photodetectors in this wavelength region. A technologically simpler and less costly PDT dosimetry approach is to use photosensitizer photobleaching to estimate the 1O2 dose. The first objective in this thesis was to characterize the dynamics of SOL measurements, in particular the influence of oxygen depletion, in order to improve the quantification of SOL and its use as an accurate PDT dose metric. Subsequently, direct comparison of SOL and photobleaching-based dosimetry during in vitro PDT treatment with meso-tetra(hydroxyphenyl)chlorin (mTHPC) showed that SOL dosimetry is robust but that photobleaching-based dosimetry can fail under hypoxic conditions. However, the latter can be salvaged through the identification of a previously unreported 613 nm emission from mTHPC that indicates hypoxia. These studies were carried forward into an in vivo dorsal skin-fold window chamber tumor model, which showed promising initial correlation between 1O2 dose and tumor response. This work also identified SOL detection limitations and opportunities for further development. Additionally, SOL measurements were used as a ‘gold standard’ to evaluate novel activatable PDT beacons and a novel “PDT biodosimeter” based on STAT3 cross-linking. Future work includes further tumor dose-response studies, characterization of novel photosensitizing agents, improvement on signal detection and processing, and studies in normal human skin.

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The diploma thesis compares the photophysical, photooxidative and photocytotoxic properties of four polymer nanofabrics with encapsulated 5,10,15,20 - meso - tetraphenylporphyrin (TPP). The main focus of the work lies especially in the study of the effect of polymer oxygen permeability on the ability of nanofabrics to produce singlet oxygen and the utilization of nanofabrics for measurement of the polymer oxygen permeability and polymer oxygen diffusion coefficients. A possible application of nanofabrics in the framework of oxygen detection, photooxidation of substrates and photodesinfection has been studied as well.

O licopeno é um composto bioativo que tem recebido atenção especial devido aos seus efeitos terapêuticos no combate e prevenção de doenças como câncer e doenças cardiovasculares. No entanto, por ser insolúvel em água, muito instável na presença de luz, oxigênio e calor, e altamente reativo, sua aplicação nos alimentos é limitada, o que prejudica o acesso do consumidor a produtos naturais como fontes de antioxidantes em substituição aos antioxidantes sintéticos. Assim, a utilização de nanocápsulas de compostos naturais, com ação antioxidante, pode ser considerada uma das tecnologias mais promissoras para disponibilizar compostos mais estáveis e disponíveis ao consumidor. Nesse contexto, nanocápsulas de licopeno extraído do tomate foram desenvolvidas e caracterizadas com o objetivo de conferir solubilidade aparente e estabilidade ao carotenoide em diferentes condições de armazenamento e processamento. O tipo de nanopartícula, a técnica de encapsulamento e o material de parede foram selecionados a partir de um levantamento na literatura, o qual originou os artigos de revisão apresentados. As nanocápsulas de licopeno (LYC-LNC) foram sintetizadas pela técnica de deposição interfacial do polímero pré-formado poli (Ɛcaprolactona) (PCL), mantidas em meio aquoso e caracterizadas com relação aos parâmetros de diâmetro médio, potencial zeta, índice de polidispersão, eficiência de encapsulação, morfologia, pH, cor, viscosidade e concentração de licopeno. Além disso, a estabilidade das nanocápsulas foi avaliada durante armazenamento a 5 °C e 25 °C, em experimentos de fotosensibilização a 5, 15 e 25°C em condições de saturação com ar e N2; e durante aquecimento a 60, 70 e 80 °C na ausência de luz. LYC-LNC apresentaram diâmetro médio de 193 ± 4,7 nm, índice de polidispersão de 0,069 ± 0,02, potencial zeta de -11,5 ± 0,4 mV, viscosidade de 1,09 ± 0,03 mPa.s e pH médio de 6,01 ± 0,04. Durante o armazenamento a 25°C, a suspensão LYC-LNC foi considerada estável pela ausência de alterações significativas no diâmetro, potencial zeta e apesar da redução significativa do pH, cor e concentração de licopeno, as nanocápsulas apresentaram estabilidade satisfatória com aproximadamente 50% do conteúdo total de licopeno após 14 dias de estocagem. Quando as amostras foram armazenadas a 5°C, LYC-LNC mostraram a mesma estabilidade para os parâmetros citados, exceto em relação à concentração do licopeno que teve uma melhora significativa com 40% do conteúdo total do carotenoide após 84 dias de estocagem. A degradação do licopeno durante a fotosensibilização e aquecimento seguiu uma cinética de degradação de primeira ordem e apresentaram energia de ativação de 67,0 kcal/mol e 24,9 kcal/mol respectivamente, valores superiores aos relatados pela literatura. Com base nos resultados obtidos, o presente estudo demonstrou que o nanoencapsulamento é uma técnica que pode, além de aumentar a solubilidade aparente do licopeno em meio aquoso, conferir melhoria na estabilidade em diferentes condições e por isso as LYC-LNC representam uma alternativa promissora para expandir o uso do licopeno em processos industriais, para melhorar a retenção deste composto em diferentes matrizes alimentares. / Lycopene is a bioactive compound that has received special attention due to their therapeutic effects in combating and preventing of diseases such as cancer and cardiovascular disease. However, lycopene is water insoluble, very unstable in presence of light, oxygen and heat and highly reactive, characteristics that can limit its application in food, affecting the access of consumer for natural products that can serve as sources of antioxidants, substituting synthetic antioxidants. Thus, the use of nanocapsules containing natural compounds with antioxidant action can be considered one of the most promising technologies to provide compounds more stable and available to the consumer. In this context, nanocapsules containing lycopene extracted from tomato have been characterized and developed with the objective of conferring apparent solubility and stability of this carotenoid in different storage and processing conditions. The type of nanoparticles, the encapsulation technique and the wall material were selected from a research in the literature, which resulted in review articles. The lycopene nanocapsules (LYC-LNC) were synthesized by the interfacial deposition of preformed poly(Ɛ-caprolactone) (PCL) maintained in an aqueous medium and characterized regarding to parameters such as mean diameter, zeta potential, polydispersity index, encapsulation efficiency, morphology, pH, color, viscosity and lycopene concentration. Furthermore, the stability of nanocapsules during storage was evaluated at 5 °C and 25 °C, in experiments of photosensitization at 5, 15 and 25 °C in saturated conditions with air and N2; and during heating at 60, 70 and 80 °C in the absence of light. LYC-LNC had an average diameter of 193 ± 4.7 nm, polydispersity of 0.069 ± 0.02, zeta potential of -11.5 ± 0.4 mV, viscosity of 1.09 ± 0.03 mPa.s and pH value of 6.01 ± 0.04. During storage at 25 °C, the LYC-LNC suspension remained stable and no significative changes in diameter and zeta potential were observed, and despite of significant reductions in pH, color and lycopene concentration, nanocapsules showed satisfactory stability containing approximately 50% the total content of lycopene after 14 days of storage. However, when the samples were stored at 5 °C, LYC-LNC showed the same stability for the mentioned parameters, except for the lycopene concentration that had a significant improvement, presenting approximately 40% of the total carotenoid content after 84 days of storage. The degradation of lycopene during photosensitization and heating followed a kinetic of first order and showed activation energy of 67.0 kcal/mol and 24.9 kcal/mol respectively, activation energy higher than those reported in the literature. Based on these results, this study demonstrated that the nanoencapsulation is a technique which can, in addition to increasing apparent solubility of lycopene in aqueous medium, confer better stability under different conditions and thus, LYC-LNC represent a promising alternative to expand the use of lycopene in industrial processes by improving the retention of this compound in different food matrices.