Chlorin e6 combined with albumin nanoparticles as a potential composite photosensitizer for photodynamic therapy of tumors

Aim: To synthesize and to study for photodynamic activity a composite photosensitizer consisting of chlorin e6 and human serum albumin nanoparticles (HSA NPs). Materials and Methods: Starting from sorption-purified HSA, the albumin nanoparticles with a different degree of lysine residues cross-linking (10; 20; 40, and 100%) were obtained by the coacervation method. The HSA NPs were used for synthesis of nanocomposites with chlorin e6 and fluorescein isothiocyanate (FITC)-labled preparations. Malignant lymphocytes of the MT-4 (human T-cell leukemia) line and normal lymphocytes of healthy donors served as cell targets. For photodynamic treatment, a semiconductor laser was exploited as a light source, and cell viability was assessed by MTT or trypan blue dye exclusion tests. For cell imaging and HSA NPs visualization, the fluorescence microscopy and transmission electron microscopy were applied, respectively. C57Bl/6 mice were used in animal experiments. Results: The absorption and fluorescence spectra of chlorin e6-HSA NPs composites were characterized, and by the electron microscopy investigation the size of NPs (nanospheres) was estimated: 100–120 nm. FITC-labled albumin preparations allowed to establish that HSA NPs have much higher exposition and concentration dependent affinity to malignant cell surface than initial HSA. In experiments with MT-4 cells on PDT activity of chlorin e6-HSA NPs, the nanocomposite effectiveness elevated along with increasing percentage of cross-linked aminoacid residues, and for the nanocomposite with 100% of albumin cross-linking it exceeded the activity of free chlorin e6. In contrast to malignant cells, the complexation of chlorin e6 with HSA NPs decreased its photodynamic effect on normal human lymphocytes. Intravenous introduction of the chlorin e6-HSA NPs composite to mice showed prolonged circulation of the nanocomposite in blood in comparison with free PS. Conclusion: Promising results obtained with chlorin e6-HSA NPs composites warrant conduction of full-fledged PDT studies in vivo using the nanocomposites as photosensitizers. Key Words: human serum albumin, nanoparticles, photodynamic therapy, chlorin e6, cell line MT-4, C57Bl/6 mice

Highly activated carbon enterosorbent mediates the suppression of paraneoplastic syndrome associated with lewis lung carcinoma in mice

Aim: To investigate the effect of enterosorption on the development of paraneoplastic syndrome in mice with Lewis lung carcinoma (LLC). Materials and Methods: The study was performed on male С57/ВL6 mice with transplanted LLC. As an enterosorbent, highly activated powder fraction of HSGD was administered per os daily at a dose of 0.625 g/kg for two weeks starting from the 7th day after tumor cell transplantation. Analysis of hemo- and myelograms, morphological alterations in vital organs, the activities of catalase and superoxide dismutase, biochemical analysis of blood and quantitative analysis of hydroperoxides, malonic dialdehyde, аdvanced oxidation protein products was carried out by standard methods after completing the course of enterosorption. Ligand loading of blood plasma proteins was estimated by the method of differential scanning microcalorimetry. Results: Administration of enterosorbent resulted in inhibition of LLC growth and in nearly 2-fold decrease of lung metastases number (p < 0.05). Activation of granulocytic line in the bone marrow with nearly 3-fold enhancement of mitotic activity took place after enterosorbent administration. Red cell lineage indices and bone marrow cellularity remained unaltered. After enterosorption session, the studied biochemical indices of peripheral blood evidenced on decreasing the endogenous intoxication and oxidative stress levels, improving the functional state of kidneys, increasing the resistance of erythrocyte membranes and lowering the ligand loading of blood plasma transport proteins. Morphological structure of kidneys and liver confirmed significant positive effect of enterosorption. The data of morphologic examination of gastric fundus, small intestine, and large bowel slides after 2-week administration of enterosorbent showed its high safety and proper evacuation from intestine. Conclusion: The two-week long enterosorption session in mice with LLC caused the suppression of tumor growth and metastasis, normalization of bone marrow hemopoiesis. Enterosorption exerted a positive influence on the structural-morphologic indexes and regenerative potential of kidneys and liver, mitigated manifestations of oxidative stress, decreased the level of endogenous intoxication, promoted deliganding of albumin molecule and deloading of erythrocyte membranes

Carbon adsorbents in oncology: achievements and perspectives

The results of own investigations and literature data are summarized to determine the place of the main methods of adsorption therapy in complex treatment of the patients with malignant tumors. New possibilities for the usage of new generation of carbon adsorbents and modern adsorptive technologies in cancer treatment are discussed

Optimization of physico-chemical properties of carbon enterosorbents and evaluation of their sorption activity for use in the treatment of paraneoplastic syndrome and other endogenous intoxications in cancer patients

Aim - development of carbon enterosorbents with optimal physical-chemical properties and high adsorptive capacity for their usage in the treatment of paraneoplastic syndrome and other endogenous intoxication in cancer patients. Methods: physical-chemical and biochemical methods of investigation. In the work it has been shown that performance of additional steam activation on pilot plant developed in R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology NAS of Ukraine, allows produce highly active granulated and fibrous carbon enterosorbents which possess well developed porous surface providing potent sorption potential toward compounds of hydrophilic and hydrophobic nature. Being placed in gastro-intestinal tract lumen these sorbents may cause certain effect on functional activity of detoxifying body systems and regeneration potential of many organs and tissues. Key Words: activated carbon, enterosorbents, porous surface, adsorptive capacity

The study of possibility to elevate antitumor activity and decrease of systemic toxic effects of cisplatin by its binding with deliganded albumin

Aim: To evaluate antitumor and toxic action of cisplatin (CP) in non-bound form and in a complex with deliganded albumin. Methods: To study complex-formation between CP and albumin, differential scanning and isothermic flow microcalorimetry were used. For quantitive evaluation of albumin-bound CP, the method of ultrafiltration was applied. Concentration of platinum in the samples was determined by atomic-absorption spectral analysis. Antitumor and toxic effect of CP and CP-albumin complex was studied in vivo using Guerin carcinoma (GC) model. Results: It has been shown that the second drug-binding site, located in the III domain of albumin molecule is one of the main points of binding of CP. Purification of officinal human serum albumin (HSA) on highly active carbon hemosorbents of HSGD mark allows to obtain deliganded albumin (dHSA) with elevated complex-forming ability toward CP. Administration of CP-dHSA complex provides higher rate of GC growth inhibition, than that of CP, and the content of creatinine in blood plasma of GC-bearing rats increases by 15% versus 40% in the case of CP administration. Conclusion: The data obtained allow recommend application of CP-dHSA to complex for enhancement of antitumor action and decrease of toxic effects of cisplatin.Цель: оценить противоопухолевое и токсическое действие цисплатина (ЦП) в свободной форме и в комплексе с делигандизированным альбумином. Методы: дифференциальную сканирующую и изотермичную проточную микрокалориметрию использовали для исследования комплексообразования ЦП с альбумином. Для количественной оценки связанного с альбумином цитостатика использовали метод ультрафильтрации. Концентрацию платины в образцах определяли методом атомно-абсорбционного спектрального анализа. Противоопухолевый и токсический эффекты ЦП и ЦП в комплексе с делигандизированным альбумином изучали на крысах с карциномой Герена. Результаты: показано, что одним из основных мест связывания ЦП является второй лекарственный сайт, расположенный в III домене молекулы альбумина. Очистка фармакопейного сывороточного альбумина (ЧСА) на высокоактивных углеродных гемосорбентах марки ГСГД позволяет получить делигандизированный альбумин (дЧСА) с повышенной комплексообразующей способностью в отношении ЦП. ЦП в связанной с дЧСА форме обеспечивает повышение ингибирующего влияния цитостатика на рост карциномы Герена, при этом содержание креатинина в плазме крови повышается на 15% по сравнению с 40% при использовании несвязанного ЦП. Выводы: результаты проведенных исследований дают основания рекомендовать использование ЦП в комплексе с альбумином для усиления его противоопухолевого действия и снижения токсических эффектов

Effect of enterosorption on paraneoplastic syndrome manifestations in mice with highly angiogenic variant of lewis lung carcinoma

Aim: To study the correcting effects of microgranulated HSGD enterosorbent on hematological, morphological and biochemical indices of paraneoplastic syndrome in mice with highly angiogenic variant of Lewis lung carcinoma LLC/R9. Methods: The study was performed on male С57/ВL6 mice with transplanted LLC/R9. Enterosorbent HSGD was administered daily at a dose of 0.625 g/kg for 2 weeks starting from 7th day after tumor cell transplantation. When enterosorption was completed, an analysis of peripheral blood, biochemical indices and morphological structure of tumor, lung, liver, spleen and thymus was carried out by standard methods. Results: It has been shown that administration of enterosorbent did not affect LLC/R9 growth but resulted in nearly two fold decrease of the volume of lung metastases (p < 0.05). Erythrocyte number and hemoglobin level were higher by 30.0% (p < 0.05) and 23.3% (p < 0.05), respectively, in mice treated with enterosorbents as compared to untreated animals. In addition sorbent treatment completely normalized the thrombocyte index resulting in elevation of platelet number by 54.5% (p < 0.01) up to their level in intact mice. The morphological examination of liver and biochemical analysis of peripheral blood evidenced on significant positive correcting effect of enterosorption on histological structure of this organ and its functional acti­vity. Normalization of total proteins and serum albumin level as well as significant decrease of total lipid concentration by 29% (p < 0.01) in blood of treated mice were observed. Conclusion: Positive influence of microgranulated carbon sorbent on some hematological, morphological and biochemical indices of tumor associated symptoms in LLC/R9-bearing mice denotes that enterosorption-based therapy can be considered as a prospective treatment for correction of some paraneoplastic syndrome signs in cancer patients. Key Words: paraneoplastic syndrome, Lewis lung carcinoma LLC/R9, enterosorption

CHLORIN e6 COMBINED WITH ALBUMIN NANOPARTICLES AS A POTENTIAL COMPOSITE PHOTOSENSITIZER FOR PHOTODYNAMIC THERAPY OF TUMORS

Aim: To synthesize and to study for photodynamic activity a composite photosensitizer consisting of chlorin e6 and human serum albumin nanoparticles (HSA NPs). Materials and Methods: Starting from sorption-purified HSA, the albumin nanoparticles with a different degree of lysine residues cross-linking (10; 20; 40, and 100%) were obtained by the coacervation method. The HSA NPs were used for synthesis of nanocomposites with chlorin e6 and fluorescein isothiocyanate (FITC)-labled preparations. Malignant lymphocytes of the MT-4 (human T-cell leukemia) line and normal lymphocytes of healthy donors served as cell targets. For photodynamic treatment, a semiconductor laser was exploited as a light source, and cell viability was assessed by MTT or trypan blue dye exclusion tests. For cell imaging and HSA NPs visualization, the fluorescence microscopy and transmission electron microscopy were applied, respectively. C57Bl/6 mice were used in animal experiments. Results: The absorption and fluorescence spectra of chlorin e6-HSA NPs composites were characterized, and by the electron microscopy investigation the size of NPs (nanospheres) was estimated: 100–120 nm. FITC-labled albumin preparations allowed to establish that HSA NPs have much higher exposition and concentration dependent affinity to malignant cell surface than initial HSA. In experiments with MT-4 cells on PDT activity of chlorin e6-HSA NPs, the nanocomposite effectiveness elevated along with increasing percentage of cross-linked aminoacid residues, and for the nanocomposite with 100% of albumin cross-linking it exceeded the activity of free chlorin e6. In contrast to malignant cells, the complexation of chlorin e6 with HSA NPs decreased its photodynamic effect on normal human lymphocytes. Intravenous introduction of the chlorin e6-HSA NPs composite to mice showed prolonged circulation of the nanocomposite in blood in comparison with free PS. Conclusion: Promising results obtained with chlorin e6-HSA NPs composites warrant conduction of full-fledged PDT studies in vivo using the nanocomposites as photosensitizers. Key Words: human serum albumin, nanoparticles, photodynamic therapy, chlorin e6, cell line MT-4, C57Bl/6 mice

HIGHLY ACTIVATED CARBON ENTEROSORBENT MEDIATES THE SUPPRESSION OF PARANEOPLASTIC SYNDROME ASSOCIATED WITH LEWIS LUNG CARCINOMA IN MICE

Aim: To investigate the effect of enterosorption on the development of paraneoplastic syndrome in mice with Lewis lung carcinoma (LLC). Materials and Methods: The study was performed on male С57/ВL6 mice with transplanted LLC. As an enterosorbent, highly activated powder fraction of HSGD was administered per os daily at a dose of 0.625 g/kg for two weeks starting from the 7th day after tumor cell transplantation. Analysis of hemo- and myelograms, morphological alterations in vital organs, the activities of catalase and superoxide dismutase, biochemical analysis of blood and quantitative analysis of hydroperoxides, malonic dialdehyde, аdvanced oxidation protein products was carried out by standard methods after completing the course of enterosorption. Ligand loading of blood plasma proteins was estimated by the method of differential scanning microcalorimetry. Results: Administration of enterosorbent resulted in inhibition of LLC growth and in nearly 2-fold decrease of lung metastases number (p < 0.05). Activation of granulocytic line in the bone marrow with nearly 3-fold enhancement of mitotic activity took place after enterosorbent administration. Red cell lineage indices and bone marrow cellularity remained unaltered. After enterosorption session, the studied biochemical indices of peripheral blood evidenced on decreasing the endogenous intoxication and oxidative stress levels, improving the functional state of kidneys, increasing the resistance of erythrocyte membranes and lowering the ligand loading of blood plasma transport proteins. Morphological structure of kidneys and liver confirmed significant positive effect of enterosorption. The data of morphologic examination of gastric fundus, small intestine, and large bowel slides after 2-week administration of enterosorbent showed its high safety and proper evacuation from intestine. Conclusion: The two-week long enterosorption session in mice with LLC caused the suppression of tumor growth and metastasis, normalization of bone marrow hemopoiesis. Enterosorption exerted a positive influence on the structural-morphologic indexes and regenerative potential of kidneys and liver, mitigated manifestations of oxidative stress, decreased the level of endogenous intoxication, promoted deliganding of albumin molecule and deloading of erythrocyte membranes