Репозиторий Университета

© 2020 Elsevier B.V. Background: The present study focuses on investigation of Intra-articular PDT mechanisms for OA treatment. Also, a search for determination of the most effective dose of chlorin e6 (Ce6) for anti-inflammatory PDT of OA was carried out. Methods: The study was carried out on laboratory animals (11 Chinchilla rabbits, 1 year, 2.5 kg) with a gonarthritis model of post-traumatic OA. According to the instructions for using Photoditazin (Ce6 based PS) for PDT of human oncological and non-oncological diseases, the recommended dose is 0.7–1.2 mg/kg. For studies on rabbits, taking into account the conversion coefficient (3.2), the PS doses of 2.4, 3.2 and 6.4 mg/kg were selected. Fluorescence spectra were measured intra-articular before and after PDT using spectrometer with fiber-optic probe. The intrajoint PDT was carried out using a laser (662 ± 10 nm) and a fiber-optic catheter with a cylindrical diffuser inside a sapphire needle for a uniform distribution of the laser radiation. The immunohistochemical study was carried out by staining the samples with caspase-3. Results: Histological and immunohistochemical analysis showed that the best PS dose for intravenous administration for PDT of rabbit gonarthritis is 3.2 mg/kg. The PS concentration directly in the synovial tissue was 0.5 mg/kg, and this was enough to achieve the most positive results to reduce the caspase-3 level. Conclusion: The caspase-3 level correlates well with other signs of inflammation in the synovial membrane (edema, etc.). Therefore, to assess the PDT effectiveness in the treatment of gonarthritis accompanied by synovitis, it is sufficient to analyze only for caspase-3. The efficacy of PDT with Ce6 showed that 3.2 mg/kg PS dose (1 mg/kg for a human) is the most effective.

© 2020 Elsevier B.V. Background: The present study focuses on investigation of Intra-articular PDT mechanisms for OA treatment. Also, a search for determination of the most effective dose of chlorin e6 (Ce6) for anti-inflammatory PDT of OA was carried out. Methods: The study was carried out on laboratory animals (11 Chinchilla rabbits, 1 year, 2.5 kg) with a gonarthritis model of post-traumatic OA. According to the instructions for using Photoditazin (Ce6 based PS) for PDT of human oncological and non-oncological diseases, the recommended dose is 0.7–1.2 mg/kg. For studies on rabbits, taking into account the conversion coefficient (3.2), the PS doses of 2.4, 3.2 and 6.4 mg/kg were selected. Fluorescence spectra were measured intra-articular before and after PDT using spectrometer with fiber-optic probe. The intrajoint PDT was carried out using a laser (662 ± 10 nm) and a fiber-optic catheter with a cylindrical diffuser inside a sapphire needle for a uniform distribution of the laser radiation. The immunohistochemical study was carried out by staining the samples with caspase-3. Results: Histological and immunohistochemical analysis showed that the best PS dose for intravenous administration for PDT of rabbit gonarthritis is 3.2 mg/kg. The PS concentration directly in the synovial tissue was 0.5 mg/kg, and this was enough to achieve the most positive results to reduce the caspase-3 level. Conclusion: The caspase-3 level correlates well with other signs of inflammation in the synovial membrane (edema, etc.). Therefore, to assess the PDT effectiveness in the treatment of gonarthritis accompanied by synovitis, it is sufficient to analyze only for caspase-3. The efficacy of PDT with Ce6 showed that 3.2 mg/kg PS dose (1 mg/kg for a human) is the most effective.

© 2018, Pleiades Publishing, Ltd. Solubilization with pluronic F-127 gave water-soluble forms of hydrophobic photosensitizers—steroid derivatives of pyropheophorbide a. Solubilization was performed by evaporating the chloroform co-solutions of photosensitizer and pluronic (triple block copolymer of ethylene and propylene oxide) and subsequently dissolving the resulting dry residue in water. The concentration ratios of modified pyropheophorbide–pluronic at which the photosensitizer completely passed into the aqueous phase were determined. Among the starting hydrophobic photosensitizers, pyropheophorbide–dihydrotestosterone possessed the highest activity in photosensitized oxidation of anthracene with singlet oxygen in chloroform, while after solubilization, pyropheophorbide–testosterone was most active in the test (for photodynamic therapy) oxidation of tryptophan in aqueous solutions.

© 2018, Pleiades Publishing, Ltd. Abstract: Mono- and diethylene oxide derivatives of tetra(p-hydroxyphenyl)porphyrin (THPP) with different conformation states are synthesized. These compounds exhibit high photosensitization activity in the generation of singlet oxygen in organic and aqueous (in the solubilized state) phases. It is shown that introducing ethylene oxide moieties into the hydroxyphenyl substituents of THPP increases its solubility in chloroform. In addition, the activity of singlet oxygen 1Δg generation in the reaction of anthracene photooxidation by THPP tetra derivatives in chloroform, where the ethylene oxide fragments are introduced into two phenyl rings and hexadecyl fragments are introduced into another two, is higher than the activity of mono- and di-modified THPP molecules with enthylene oxide molecules at one hydroxyphenyl cycle. The activity of tetra-substituted porphyrin in chloroform, however, is comparable to that of nonsubstituted tetraphenylporphyrin, considered to be one of the most active photosensitizers. The produced ethylene oxide derivatives of THPP are solubilized with pluronic F-127 (triblock copolymer of ethylene- and propylene-oxides)—one of the least toxic and effective polymeric detergents—forming water-soluble forms of the respective porphyrins. It is established that the pluronic solubilization capability (the lowest molar concentration of pluronic required for the complete transfer of porphyrin of a particular molar concentration dissolved in organic phase to the water-soluble form) is higher for asymmetrical mono- and di-derivatives of the THPP than for symmetric tetra-substituted THPP. It is shown that the activity of the solubilized water-soluble form of mono- and tetra-derivatives in tryptophan photoxidation is higher than that of unsubstituted THPP and is comparable to the activity of tetraphenylporphyrin.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Tetra(aryl)tetracyanoporphyrazines are the promising group of dyes for photodynamic therapy of tumors with unique combination of photosensitizer properties and sensitivity of fluorescence parameters to the environment viscosity. However, in vivo application of such hydrophobic photosensitizers requires using of drug carriers ensuring efficient delivery to the tumor site. The present study is focused on obtaining liposomes loaded with tetrakis(4-benzyloxyphenyl)tetracyanoporphyrazine and examining their properties depending on lipid composition. An efficient loading of the dye and a high long-term stability were proved for the liposomes composed of phosphatidylcholine with cholesterol and phosphatidylglycerol. This can be explained by the presence of negatively charged lipids in the bilayer and, as a consequence, a high value of the surface potential. A high rate of cellular uptake and a strong photoinduced toxicity give the prerequisites for the further use of the liposomal form of the photosensitizer for photodynamic therapy of tumors.

© 2017 Elsevier B.V. The use of polymeric carriers to deliver hydrophobic photosensitizers has been widely discussed as a way to improve both fluorescence diagnostic and photodynamic therapy (PDT) of cancers; however, the photophysical and pharmacokinetic parameters, as well as the PDT activity, of such modifications have, until now, only been poorly investigated. The purpose of the present study was to explore the efficacy of PDT with the formulation of the photosensitizer chlorin e6 (Ce6) in combination with polyvinyl alcohol (PVA) in comparison with Ce6 alone and with the clinical drug, Photodithazine in a mouse tumor model. We also investigated the photoactivity of the Ce6-PVA in a model reaction of tryptophan oxidation, analyzed the polymer–Ce6 interaction using fluorescence spectroscopy and atomic-force microscopy, and tested the phototoxicity in vitro. Using fluorescence imaging in vivo we found that injection to mice of Ce6 in a formulation with PVA resulted in a higher tumor-to-normal ratio and greater photobleaching when compared with either the use of Ce6 alone, or with the effects of Photodithazine. Tumor growth study and histological examination of CT26 tumors revealed fast, reproducible tumor regression and more advanced necrosis after PDT with Ce6-PVA. The higher photoactivity of the Ce6-PVA complex was confirmed in a model reaction of tryptophan oxidation and in cultured cells. Therefore, encapsulation of Ce6 in PVA represents a promising strategy for further increasing the selectivity and efficacy of PDT.