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—Ozone-photodynamic effects on tumor growth rate and oxidative modification of proteins in rat tissues were studied using a model of PA kidney carcinoma. It was shown that the developed experimental therapeutic method based on the joint parenteral intraperitoneal administration of an ozonated saline solution with a concentration of ozone in the ozone–oxygen mixture of 400 μg/L and a 0.3% solution of the Photosens photosensitizer intratumorally with the local action of light with a wavelength of 660 ± 10 nm for 10 min reduced the intensity of tumor growth. Normalization of the prooxidant/antioxidant balance in experimental animals was observed upon combined use of ozonated saline solution and photodynamic therapy.

Background: Anti-cancer therapy is more successful when it can also induce an immunogenic form of cancer cell death (ICD). Therefore, when developing new treatment strategies, it is extremely important to choose methods that induce ICD and thereby activate anti-tumor immune response leading to the most effective destruction of tumor cells. The aim of this work was to analyze whether the clinically widely used photosensitizers, photosens (PS) and photodithazine (PD), can induce ICD when used in photodynamic therapy (PDT). Methods: Cell death in murine glioma GL261 or fibrosarcoma MCA205 cells was induced by PS- or PD-PDT and cell death was analyzed by MTT or flow cytometry. Intracellular distribution of PS and PD was studied by using the laser scanning microscope. Calreticulin exposure and HMGB1 and ATP release were detected by flow cytometry, ELISA and luminescence assay, respectively. Immunogenicity in vitro was analyzed by co-culturing of dying cancer cells with bone-marrow derived dendritic cells (BMDCs) and rate of phagocytosis and maturation (CD11c(+)CD86(+), CD11c(+)CD40(+)) of BMDCs and production of IL-6 in the supernatant were measured. In vivo immunogenicity was analyzed in mouse tumor prophylactic vaccination model. Results: We determined the optimal concentrations of the photosensitizers and found that at a light dose of 20 J/cm(2) (lambda ex 615-635 nm) both PS and PD efficiently induced cell death in glioma GL261 and fibrosarcoma MCA205 cells. We demonstrate that PS localized predominantly in the lysosomes and that the cell death induced by PS-PDT was inhibited by zVAD-fmk (apoptosis inhibitor) and by ferrostatin-1 and DFO (ferroptosis inhibitors), but not by the necroptosis inhibitor necrostatin-1 s. By contrast, PD accumulated in the endoplasmic reticulum and Golgi apparatus, and the cell death induced by PD-PDT was inhibited only by z-VAD-fmk. Dying cancer cells induced by PS-PDT or PD-PDT emit calreticulin, HMGB1 and ATP and they were efficiently engulfed by BMDCs, which then matured, became activated and produced IL-6. Using dying cancer cells induced by PS-PDT or PD-PDT, we demonstrate the efficient vaccination potential of ICD in vivo. Conclusions: Altogether, these results identify PS and PD as novel ICD inducers that could be effectively combined with PDT in cancer therapy.

In recent years, an increase in the incidence of breast cancer has been observed throughout the world, and in 20% of cases, with the development of intradermal metastases. The possibilities of surgical and radiation treatment of intradermal breast metastases are quite limited, and the effectiveness of polychemotherapy using standard regimens does not exceed 22–27%, while the period of remission, in general, is only 2–3 months. Photodynamic therapy (PDT) is a promising treatment for intradermal metastases of breast cancer. The experience of using PDT in this nosology is quite limited, but the results show its high efficiency and safety. Thus, several Russian studies are devoted to assessing the effectiveness of PDT of intradermal breast metastases with Photolon, a chlorin series photosensitizer. According to the authors, the therapeutic effect was achieved in 85–97% of patients (the percentage of patients with full and partial effect was 73–85%). Studies on the effectiveness of PDT in patients with the same nosology using the Photosens photosensitizer show a slightly lower effectiveness – the therapeutic effect was achieved in 81.8% of cases, while the proportion of patients with full and partial effect was only about 50%. Several studies have been carried out abroad on models of metastatic breast cancer using new photosensitizers (e.g. sodium sinoporphyrin) and new combined PDT regimens (e.g. adjuvant PDT with fluorouracil or Capecitabine). The obtained results demonstrate the promise of new approaches: PDT with sodium sinoporphyrin inhibited the growth of both the tumor itself and its metastases; the use of adjuvant regimens led to an increase in the tumor cells differentiation in the animal model, the cessation of tumor and metastatic foci growth.

Photobiological properties of phthalocyanine photosensitizers, namely, clinically approved Photosens and new compounds Holosens and Phthalosens were analyzed on transitional cell carcinoma of the urinary bladder (T24) and human hepatic adenocarcinoma (SK-HEP-1). Photosens is a sulfated aluminum phthalocyanine with the number of sulfo groups 3.4, which is characterized by a high degree of hydrophilicity, slow cellular uptake, localization in lysosomes and the lowest photodynamic activity. Holosens is an octacholine zinc phthalocyanine, a cationic compound with significant charge. Holosens more efficiently enters the cells; it is localized in Golgi apparatus in addition to lysosomes and exhibits a significant inhibitory effect on cell viability upon irradiation. The highest photodynamic activity was demostrated by Phthalosens. Phthalosens is a metal-free analog of Photosens with a number of sulfo groups 2.5, which determines its amphiphilicity. Phthalosens is characterized by the highest rate of cellular uptake through the outer cell membrane, localization in cell membrane as well as in lysosomes and Golgi apparatus, and the highest activity upon irradiation among the photosensitizers studied. In general, changes in the physicochemical properties of Holosens and Phthalosens ensured an increase in their efficiency in vitro compared to Photosens. The features of accumulation, intracellular distribution and their interrelation with photodynamic activity, revealed in this work, indicate the prospects of Phthalosens and Holosens for clinical practice.

Photodynamic therapy is a minimally invasive cancer treatment modality based on the production of the reactive oxygen species by photoactive dye under light irradiation in the presence of molecular oxygen. During the development of the photodynamic reaction, various types of reactive oxygen species are formed, among which hydrogen peroxide is of the greatest interest since it can act as an extracellular and intracellular signaling molecule. Using a genetically encoded sensor of hydrogen peroxide, we have registered the development of oxidative stress in non-irradiated cells in response to local photodynamic exposure of a single cell using Photosens as a photosensitizer. The effect manifested when the cells were closely contacted to each other; if the irradiated cell was at some distance from the bulk of the population, the response of non-target cells was not observed. The oxidative stress in the irradiated cell is assumed to be the initiator of the signal transmission and triggering the response of non-target cells. That this response is more likely mediated by gap junction intercellular signaling. Нowever, the mechanisms involved in the propagation of damaging effects to cells outside the area of photodynamic exposure have to be further investigated.

Photodynamic therapy (PDT) is based on the production of the cytotoxic reactive oxygen species (ROS) by light irradiation of a photosensitizer dye in the presence of molecular oxygen. Along with photochemical ROS production, it becomes evident that PDT induces massive secondary production of ROS which is registered long after the irradiation is completed. We created cell lines of human epidermoid carcinoma with the cytoplasmic and mitochondrial localization of protein sensor HyPer sensitive to hydrogen peroxide to compare its concentration in two cellular compartments. The lag-period between irradiation and accumulation of hydrogen peroxide in cells was registered; its duration was dose-dependent and increased up to 80 min when lowering the exposition dose from 50 to 15 J/cm2. We have shown that localization of the photosensitizer determines the spatiotemporal pattern of the cell response to PDT: secondary hydrogen peroxide accumulation in cell cytoplasm induced by photodynamic treatment with lysosome-localized phtalocyianine Photosens occurs several minutes prior to that in mitochondria; on the contrary, membranotropic arylcyanoporphyrazine dye leads to massive mitochondrial hydrogen peroxide production followed by its cytoplasmic accumulation. We hypothesize that photosensitizers with various physicochemical properties and intracellular localization can trigger different patterns not only of primary but also secondary ROS production leading to different cell fate outcomes.

To improve a cancer patient’s quality of life, short treatment duration resulting in rapid tumour removal while sparing normal tissue are highly desirable. Photodynamic therapy (PDT) commonly applied in a single treatment, while often effective can be limited at low photosensitizer or light doses. Combination therapies can overcome the efficacy limitations while not increasing treatment-associated morbidity. Here the efficacy of combination therapy comprised of doxorubicin (DOX) or methotrexate (MTX) with Photosens mediated PDT was investigated in three cell lines in vitro, employing multiple incubation sequences. Photosense is a mixture of aluminium phthalocyanines with different sulfonation. The results demonstrated higher synergistic effects when DOX or MTX-mediated chemotherapy preceded PDT light activation by 24 h. MTX is marginally more cytotoxic than DOX, when combined with Photosens (AlPcS2-4) mediated PDT. While MTX and DOX exposure prior to AlPcS2-4 incubation may enhance mitochondrial localisation photosensitizer, the simultaneous targeting of DNA, proteins, and lipids of the combination therapies leads to the observed high cytotoxicity at sub μM drug doses. Keywords: Photodynamic Therapy, Chemotherapy, Cancer, Combination therapy

An interest to H2O2 accumulation under photodynamic treatment can be explained by its participation in intracellular signal cascades. It is important not only to detect H2O2 generation, but also to trace the dynamics of its intracellular content. In the present study the dynamics of cellular H2O2 content under photodynamic treatment was analyzed using genetically encoded reversible H2O2-sensitive sensor HyPer. Real-time detecting of H2O2 production after photodynamic treatment was performed using the protein sensor and individual features of action of different photosensitizers were revealed. Photodynamic treatment with a number of chlorin and phthalocyanine photosensitizers was found to induce secondary production of H2O2 in the cells. Three types of dynamic responses were registered: monotonous increase of H2O2 level during the entire observation time in the presence of Fotoditazin and Holosens; transient short-term accumulation in the presence of Radachlorin and Phthalosens; and relatively low-level stable increase in the presence of Photosens. The listed photosensitizers differ significantly in intracellular localization and physicochemical properties, which can determine the differences in the response of H2O2 after the photodynamic treatment. In general, it has been shown that the rapid transient H2O2 response is typical for hydrophobic compounds localized in membrane cell structures, whereas in the presence of more hydrophilic dyes a prolonged monotonous H2O2 accumulation occurs.

The authors describe a dual-use sorbent for solid phase extraction (SPE) in combination with surface-enhanced Raman spectroscopy (SERS). The sorbent consists of calcium carbonate microparticles with incorporated silver nanoparticles (AgNPs) and magnetic nanoparticles (Fe3O4). It can be simply prepared, is cost-effective, disposable, and possesses high sorption capabilities together with a Raman enhancement of 109 in the best case. Following magnetic separation of the microsphere from the liquid sample, the sorbent matrix (CaCO3) is dissolved in acid so that the AgNPs and the analyte are released. This provides an optimal interaction between them and warrants a strong SERS signal. A new SPE-SERS protocol was worked out and applied to the following model analytes: Rhodamine 6G (a fluorescent dye; R6G), Photosens (a photodynamic dye), and sulfadimethoxine (an antibiotic). The first two possess a high Raman cross-section, while the last one displays comparatively low intrinsic Raman intensity. It is found that coating the surface of the sorbent with polyethyleneimine (a cationic polyelectrolyte) leads to a 2-fold increase in the sorption of Photosens (from 40% to 90%) and to a 6-fold enhancement of the SERS signal. The limits of detection for R6G, Photosens, and sulfadimethoxine (with 78%, 94%, and 41% sorption values, respectively) are 29 pM, 12 nM, and 69 nM, respectively. Raman enhancements are in the range between 106 and 109 depending on the analyte.

The results of the pilot study of combined treatment for non-resectable cholangiocarcinoma complicated with obstructive jaundice are represented this paper. Method included percutaneous transhepatic biliary drainage, endoscopic fluorescence diagnosis, photodynamic therapy of tumor stricture, and stenting of bile ducts. Fourteen patients who underwent the treatment in the surgery department clinic of I.M. Sechenov First Moscow State Medical University were enrolled in the study. Fluorescence diagnosis and photodynamic therapy were carried out using photosensitizers photosens (0.5 mg/kg), fotolon (1 mg/kg), and radachlorin (1 mg/kg). The average light dose for one session was 115±5 J/cm2. Fluorescence diagnosis using endoscopic video-fluorescence system for endoscopy and minimally invasive surgery allowed to obtain videoassisted fluorescence image of the tumor and to measure level of photosensitizer fluorescence in tumor in all patients. Malignant tumor was confirmed by morphological study in 12 patients, biopsy of material for morphological study failed in 2 patients with Klatskin tumor. The preliminary results of combined minimally invasive treatment were assessed as promising. The survival time in 4 patients after treatment accounted for 21, 17, 13 and 11 months, respectively. For now 5 patients are under follow-up. Follow-up periods are 13 and 19 months in 2 of them and from 4 to 6 months in 3 of them. Five patients with multiple distant metastases before the treatment died in 3±1 months after therapy. The average lifetime in the treatment group is 9.5 months up to date, however the duration is expected to belonger because 5 of 14 patients are alive.

The elaboration of biocompatible and biodegradable carriers for photosensitizer targeted delivery is one of the most promising approaches in a modern photodynamic therapy (PDT). This approach is aimed at reducing sides effects connected with incidental toxicity in healthy tissue whilst also enhancing drug accumulation in the tumour area. In the present work, Photosens-loaded calcium carbonate (CaCO3) submicron particles in vaterite modification are proposed as a novel platform for anticancer PDT. Fast penetration of the carriers (0.9±0.2μm in diameter) containing 0.12% (w/w) of the photosensitizer into NIH3T3/EGFP cells is demonstrated. The captured particles provide the dye localization inside the cell increasing its local concentration, compared with "free" Photosens solution which is uniformly distributed throughout the cell. The effect of photosensitizer encapsulation into vaterite submicron particles on cell viability under laser irradiation (670nm, 19mW/cm(2), 10min) is discussed in the work. As determined by a viability assay, the encapsulation renders Photosens more phototoxic. By this means, CaCO3 carriers allow improvement of the photosensitizer effectiveness supposing, therefore, the reduction of therapeutic dose. Summation of these effects with the simplicity, upscalability and cheapness of fabrication, biocompatibility and high payload ability of the vaterite particles hold out the prospect of a novel PDT platform.

Background: Laser fluorescence spectroscopy (LFS) is widely used in various medical areas, oncology being the most known of them. In general, the LFS is used for in vivo diagnostics of tumors. Recent studies have shown that this method could be used for diagnostics of local inflammation, induced by thermal or mechanical injury. It is of interest if LFS could be used for assessment of soft biological tissue injury caused by radiation exposure. Aim: To study fluorescence of an exogenous photosensitizer and its changes over time in the radiation injury area by LFS method in vivo. Materials and methods: The experiment was done in 12 outbred SHK mice whose right hind limbs were irradiated using a gamma-therapy device ROKUS-AM (source, 60Co, at dose of 15 Gy). Before irradiation, the photosensitizer Photosens was administered to all animals intraperitoneally at dose of 2.5 mg/kg. For 21 days fluorescence was assessed in vivo with a laser diagnostic system LAKK-M in the “fluorescence” operation mode, with an excitation wavelength of 635 nm. At days 7 and 21, tissue samples from the irradiated areas of the model animals were studied histologically and differential blood cell counts were assessed simultaneously. Results: The LFS method showed an increase in the accumulation of the photosensitizer in the affected area, compared to an intact contralateral area, with higher signal intensity from the irradiated limb. The changes in the fluorescence signal from the affected over time had two characteristic peaks at days 3 and 14, probably reflecting the stage of local radiation injury. Conclusion: The use of LFS with an exogenous photosensitizer has a potential for a personalized assessment of radiation reactions in radiology.

We investigate the structure formation of sol–gel synthesized epoxy–siloxane compositions with a ratio of the main precursors of RTEOS/EPONEX 1510 = 27/27 wt %, modified with biocidal additives of detonation nanodiamonds (cDND = 0.13, 0.27, and 0.58 wt %), titanium dioxide (\(^cTi{O_2}\) = 0.1, 0.3, and 0.5 wt %), and Photosens (cPh = 0.04, 0.1, and 0.27 wt %), by small-angle X-ray scattering. Based on small-angle X-ray scattering (SAXS) data, it is revealed that the synthesized epoxy–siloxane xerogels are systems with a twolevel fractal structure, in the formation of which the siloxane component plays the dominant role. It is found that the introduction of small additions of detonation synthesis, titanium dioxide, or Photosens (less than 1 wt %) into the epoxy–siloxane compositions affects both the fractal dimension DS of the surface and the size dc1 of primary particles, and the fractal dimension DM and sizes dc2 of mass fractal clusters formed from them.

The original method of intraoperative photodynamic therapy for multimodality treatment of primary and recurrent breast cancer for devitalization of malifnant cells at wound surface and for prevention of further cancer dissemination was developed in P.A. Herzen Moscow Cancer Research Institute. The developed method was approved in 79 patients with locally advanced breast cancer stage IIB and IIIA,B,C with poor prognostic factors. For photodynamic therapy the photosensitizer photosens (30 min intravenous infusion at dose of 0.3 mg/kg of body weight 2 h before surgery) was used in 56 patients; alasens (solution in 100 ml of still drinking water, orally at dose of 30 mg/kg of body weight 2 h before general anesthesia) — in 23 patients. The surgical field was irradiated on a single occasion: the dose of laser irradiation on the bed of removed primary or recurrent tumor was 20–30 J/cm2, in the removed regional lymph nodes area – 50 J/cm2. Long-term results of the treatment were assessed in 34 patients: there were no disease progression in 50% of patients, 14.7% of patients had locoregional recurrence, distant metastases were in 35.3% of patients. The level of photosensitizer accumulation in tissue was additionally analyzed in 26 patients by fluorescence intensity in tumor and in normal breast tissue. After injection of alasens the increase in level of alasens-induced protoporphyrin IX fluorescence was recorded in tumor (the average diagnostic parameter was 6.5 a.u.) and in intact breast tissue (an average of 0.47 a.u.), tumor/normal tissue fluorescence contrast varied from 3 to 33. The level of protoporphyrin IX accumulation was noticed to be lower in tumors with pathomorphological response after neoadjuvant therapy. For photosens value of the average diagnostic parameter in normal breast tissue was 5.6 a.u., in tumor – 34.3 a.u., tumor/normal tissue fluorescence contrast – from 2 to 9.

The immobilization of dyes (rhodamine 6G, photosens, and photoditazine) into porous spherical calcium carbonate microparticles (vaterite modification) has been performed, and the desorption of dyes in water and sodium chloride solution of physiological concentration has been investigated. Dyes were immobilized in two ways: (i) by the adsorption of fluorophore onto previously prepared calcium carbonate particles and (ii) by adding a material to the reaction mixture when forming particles. It is found that the highest degree of particle loading (12.4 wt %) is obtained when using the second way for photoditazine. Desorption of dyes occurs mainly because of the recrystallization of particles; however, the carrier can retain photodynamic preparations for a long time.

Pilot studies of pharmacokinetics and pharmacodynamics of new photosensitizer liposomal boronated chlorine in mice with melanoma В16 were performed. Dynamics of drug accumulation in tumor and normal tissue (level of accumulation in tissues was assessed by means of fl uorescence) was studied. For intraperitoneal injection at a dose of 5 mg/kg the drug was shown to accumulate gradually in tumor and normal tissues with maximal fl uorescence values in 2–3 h after injection. Then fl uorescence intensity in tissues gradually decreased, achieving nearly initial base-line in 120 h after beginning of the study. The hotosensitizer accumulated in tumor tissue with average selectivity: contrast index for maximal drug accumulation in tissues accounted for 1.7–2.8. According to obtained data for following research the time interval between drug injection and irradiation of 3h was chosen. On the second stage of the study dependence of photodynamic therapy effi cacy on different parameters including photosensitizer dose for intraperitoneal injection (5–10 mg/kg), light dose (150–300 J/cm2) and power density (0.25–0.51 mW/cm2). The irradiation was performed by semiconductor laser on wavelength of 662±1 nm. The effi cacy was maximal for following regimen: photosensitizer dose of 5 mg/kg, light dose of 300 J/cm2, power intensity of 0.44 mW/cm2. For this regimen at the end of follow-up (21 days) complete tumor regression was obtained in 75% of animals and average coeffi cient of absolute tumor growth accounted for only 7.82.

The main stages of development and establishment of photodynamic therapy (PDT) in Russia are described in the article. Brief description of photosensitizers approved for clinical use in Russia including fotogem, photosens, alasens, radachlorine and fotoditazin is represented. Their physical and chemical and spectral characteristics, drug formulations, results of pre-clinical studies and post-marketing experience are shown. Main research centers dealing with PDT are listed.

New medical technology of photodynamic therapy for cancer of hollow organs with photosens determines parameters of irradiation (sites of placement and position of light guide, number of positions and duration of irradiation) to reduce probability of injury during irradiation of intact mucosa in hollow organ due to optimization of light dose. The technology allows to avoid inflammatory and necrotic injury of intact mucosa on the contralateral wall of organ and late complications and to achieve complete tumor regression depending on localization in 73–87% of cases for follow-up period from 1 to 11 years.

Purpose The aim of this study was evaluating changes in the photosensitizer fluorescence in vivo in the radiation-induced damage area in comparison of intact areas with a simultaneous assessment of changes both in blood parameters and in histological data. Materials and methods The study was conducted in white outbred SHK mice (n = 21). Their right hindlimbs were irradiated with a dose of 25 Gy after the intraperitoneal injections of photosensitizer 'Photosens'. Fluorescence intensity was traced in vivo by a laser diagnostic system for seven weeks. Simultaneously, histological examination of the damaged areas and blood tests were performed. Results An increased intensity of the laser-induced fluorescence of the photosensitizer 'Photosens' in the damaged areas, compared to the intact symmetrical ones was observed. Laboratory blood tests and histological examination showed changes that may indicate the occurrence of inflammation. Conclusion Enhanced intensity of the exogenous fluorescence of the photosensitizer in the radiation-induced inflammation of noncancerous tissues was observed. The obtained results may potentially affect an interpretation of the results of intraoperative tumors navigation that have been previously irradiated and can be used for selection of an individualized dose fractionation algorithm in radiology.

International audience; A gold surface immersed in an aprotic iodonium salt solution containing a photosensitizer is patterned by irradiation with a blue light through a mask. The photochem-ical behavior of three photosensitizers in the presence of (4-nitrophenyl)(2,4,6-trimethylphenyl)iodonium triflate I is fully characterized [luminescence quantum yield Φ L and lifetime τ L , quenching rate constant (k q), ΔG°, and quantum yield (Φ R)]. The key species for the surface modification are aryl radicals formed under irradiation through reduction of the iodonium salt by the excited state of the photosensitizer. The pattern consists of a polyaryl film obtained from aryl radicals that react with the surface and also with the first grafted aryl groups. The modified surface is characterized by IR, XPS, AFM, and electrochemistry. The submillimetric pattern is observed by condensation and scanning electrochemical microscopy. This method permits strongly bonded patterns with variable substituents on the aryl ring to be obtained; it allows preparing various patterns of multifunctional surfaces that can be used for sensors and diagnostics, or to limit hydrophilic paths within hydrophobic films for surface tension confined microfluidic devices.

The main steps of development of fluorescence diagnosis and photodynamic therapy were overviewed. Brief historical data were presented about Photohem, Photosens, Alasens, Radachlorin, and Photoditazine photosensitizers, along with their corresponding pharmacokinetic properties, mechanisms of action, and specific features of use. Key aspects of development of fluorescence diagnosis and photodynamic therapy in Gertsen Moscow Research Oncological Institute were described. The main indications for photodynamic therapy and its efficiency in patients with oral, tongue, stomach, esophageal, skin, cervical, and central lung cancer and vulval lesions were demonstrated. It was shown that photodynamic therapy is effective for adjuvant or intraoperative treatment in patients with high risk of local recurrence after surgical treatment, and palliative photodynamic therapy increases the quality of life and survival rates in the most challenging group of cancer patients. The results of photodynamic therapy for cervical pre-cancer and cancer associated with human papillomavirus were reported. The main trends of intraoperative “fluorescence guidance” with Alasens were covered. Clinical experience allows rating photodynamic therapy among the most encouraging methods for the current medicine.

The results of 4-year clinical follow-up in the patient with obstructive inoperable retropericardial esophageal cancer are represented. According to cardiac co-morbidity (myocardial infarction, postinfarction cardiosclerosis) the palliative care for patient was managed. To preserve patency of esophagus multiple courses of endoscopic photodynamic therapy by means of the approach developed in P.A. Herzen MCRI were performed. From 2011 to 2014 thirteen courses of photodynamic therapy with photosens were conducted. The patient was under follow-up for 4 years and 3 months to his death in 2015. For follow-up period the patient had oral feeding with no signs of dysphagia, not significant weight loss and with good quality of life.

Polymeric nanoparticles (NPs) are widely used for drug delivery applications due to high biodegradability, low toxicity and high loading capacity. The focus of this study is the development of photosensitizer Photosens (PS) loaded albumin NPs for efficient photodynamic therapy (PDT). To fabricate PS-loaded bovine serum albumin nanoparticles (BSA-PS NPs), we used a coacervation method with glutaraldehyde followed by passive loading of PS. Successful loading of PS was confirmed by appearance of characteristic peak in absorption spectrum which allows to determine the PS loading in BSA NPs. The synthesized BSA-PS NPs demonstrated low toxicity to HeLa cells at therapeutic concentrations of loaded PS. Compared to free PS solution, the synthesized BSA-PS NPs generated the singlet oxygen more effectively under laser irradiation at 660 nm. In addition, due to presence of various chemical groups on the surface of BSA-PS NPs, they are capable to adsorb on cell surface and accumulate in cells due to cellular uptake mechanisms. Owing to combination of PD and cell uptake advantages, BSA-PS NPs demonstrated higher efficacy of photodynamic damage to cancer cells as compared to free PS at equivalent concentrations. These results suggest that non-targeted BSA-PS NPs with high PD activity and low-fabrication costs of are promising candidates for transfer to PD clinic treatments.

Calcium carbonate microparticles with a size of 0.9 ± 0.2 μm containing a photosensitizer Photosens in a concentration of 2.0 ± 0.2 wt % were prepared by ultrasound-stimulated coprecipitation (20 kHz, 1W/cm2). It is shown that the encapsulated photosensitizer can be released by ultrasonic irradiation (0.89MHz, 1 W/cm2, 5 min) as a result of the destruction and recrystallization of calcium carbonate micro-particles. It is established that the combined ultrasonic (0.89 MHz, 1 W/cm2) and light (670 nm, 10 mW/cm2) in vivo influence on the transferred PC-1 strain tumors of rat liver containing intratumorally injected micro-containers with a photosensitizer gives rise to dystrophic changes in tumor cells and to the appearance of extensive necrotic centers, pointing to the presence of the evident destructive effect. Such microcontainers are proposed for use in treating external tumors or tumors accessible for ultrasonic and optical irradiation.

The template synthesis of mesoporous silica nanoparticles with predetermined size and porous structure is carried out. Water-soluble photosensitizer Photosens is used to study the possibility of applying such particles as containers for photosensitizers of a phthalocyanine series. In vivo experiments have shown that the application of such nanocontainers for the delivery of Photosens to a tumor makes it possible to improve the efficiency of fluorescence diagnostics and the photodynamic therapy of cancer.

Results of clinical follow-up of the patient with squamous cell skin carcinoma of the nasal dorsum are represented. The patient underwent a course of combined photodynamic therapy (PDT) with distant gamma-ray therapy. Distant gamma-ray therapy was performed daily during 12 days (single dose of 3 Gy, total dose of 36 Gy) with the first session 24 h after injection of the photosensitization. For PDT the photosensitizer photosens at dose of 0,3 mg/kg was used. The method of prolonged PDT was applied, sessions of laser irradiation were performed daily during 7 days. The PDT sessions were carried out 2 h after session of gamma-ray therapy using distant (150 J/cm2, 40 mW/cm2) and contact (500 J/cm2, 100 mW/cm2) modalities. According to multiple cytological studies after treatment there were no signs of tumor, but inflammation. Four months after treatment according to cytological data continued tumor growth was detected. The patient underwent an additional course of PDT. Currently the patient is under follow-up: no recurrence during 8 months after repeated treatment.

229 As known, fullerenes are photoexcited to a triplet state in 100% quantum yield, which then is deacti vated to generate, depending on the polarity of a medium, either singlet oxygen О2 or superoxide radi cal anions and other active radicals [1]. Numerous studies have addressed the photodynamic effect of fullerene and their derivatives: the generation of active radicals upon photoexcitation is responsible for dam age of DNA, proteins, and membranes, as well as for the suppression of the reproduction of tumor cells, viruses, and bacteria [2]. However, the efficiency of the photodynamic action of fullerenes and the pros pects for their application in medicine are essentially limited by the weak absorption by fullerenes of visible light, especially in the range 650–800 nm, which is most suitable for photodynamic therapy. The photodynamic effect of fullerenes can be con siderably enhanced by creating hybrid nanostructures − О2 . (HNSs) via the formation of a fullerene complex with a dye that efficiently absorbs visible light [3]. In such a complex, the dye can efficiently absorb light and transfer excitation energy or electron to the fullerene. Further excitation transfer or electron transfer from the fullerene to molecular oxygen will generate active oxygen species. The creation of such an HNS based on fullerene and a dye can thereby significantly enhance the efficiency of photodynamic therapy.