The article describes the process of developing a technology for producing nanoparticles based on a copolymer of lactic and glycolic acids (PLGA) containing dipropoxybacteriopurpurinimide (DPBPI) for photodynamic therapy of malignant tumors of various origins. Technological parameters for optimizing the method in order to obtain nanoparticles with specified characteristics are presented in this paper. As a result, the nanoparticles sample with an average particle diameter of 222.6±2.8 nm; ξ-potential 26.3±4.61 mV; polydispersity index 0.144; the total content of DPBPI in PLGA-DPBPI nanoparticles 13.6% were obtained. In accordance with the developed technique, the batch of PLGA-DPBPI nanoparticles was developed for further biological studies. In vitro experiments on A549 human non-small cell lung carcinoma for DPBPI, delivered as a part of PLGA-DPBPI nanoparticles, and an EL cremophor-based emulsion (CrEL-DPBPI) showed a similar intracellular distribution (concentrated in vesicular cell structures and diffusely distributed in cytoplasm), as well as high photo induced activity and the absence of dark cytotoxicity in case of PLGA-DPBPI nanoparticles. The study of the PLGA-DPBPI nanoparticles specific activity in vivo on the S37 mouse soft tissue sarcoma model showed the selective accumulation of DPBPI in tumor tissue and the almost complete elimination of DPBPI from the body within 48 hours, as well as significant antitumor efficacy in PDT.

The aim of the paper was to obtain a stable micellar emulsion of potent photosensitizer (PS) – O-propyloxime-N-propoxybacteriopurpurinimide methyl ester absorbing light in long-wave region of the spectrum (λ_max = 800±2 нм). Solubilizates of the dye based on different surfactants (Kolliphor ELP, Poloxamer 407, Emuxol 268) were obtained. Taking into account the physical and chemical parameters, the most potent micellar emulsion for injection was selected and characterized. The emulsion based on Kolliphor ELP remains stable for 4 months, with no changes in the fluorescence spectrum and absorption, as well as the particle diameter.

The aim of the study was to evaluate the immediate results of photodynamic therapy (PDT) in patients with intradermal metastases of skin melanoma. The study included 50 patients who received treatment at the department of hyperthermia and photodynamic therapy. The study included 23 (46%) men and 27 (54%) women with an average age of 60.7±10.4 years. PDT of tumors was carried out 3–4 hours after intravenous administration of a chlorine-based photosensitizer (Photolon) in doses of 1.5–3 mg/kg using a semiconductor laser «UPL-PDT» (Lemt, Belarus, λ=660±5 nm). The exposure doses varied from 100 to 400 J/cm²; power density – from 0.2 to 0.9 W/cm²; power – from 0.25 to 1 W and time of PDT of one focus was dependent on the size and location of the tumor and was 5 to 20 minutes. Evaluation of antitumor efficacy of PDT was carried out according to WHO criteria. The terms of follow-up of patients were between 3 and 23 months. At follow-up observation, 1–3 months after the treatment, complete regression of intradermal metastases of skin melanoma was achieved in 9 (18%) patients, partial – in 28 (56%), process stabilization in 8 (16%) and progression in 5 (10%)) patients. The objective effect was achieved in 74% of patients, the therapeutic – in 90%. PDT can be used in the treatment of intradermal metastases of disseminated skin melanoma with palliative purposes and allows reducing the tumor volume, which significantly improves the quality of life of patients.

This article presents the results of a clinical study that examined the diagnostic efficacy of fluorescent diagnostics (FD) of non-muscularinvasive bladder cancer using a photosensitizer of FD of malignant neoplasms – 5-aminolevulinic acid hexyl ester (5-ALA HE) compared with standard cystoscopy. The study involved 110 patients. The study began with intravesical administration of 50 ml of 0.2% solution of 5-ALA HE, the exposure time was 1 hour, after which the drug was removed from the organ. During the next hour, the mucous membranes were examined in two cystoscopy modes, followed by a standard transurethral resection of all urothelium sites with suspicion for tumor lesion based on white light and visible red fluorescence, and a control blind biopsy from the visually unchanged and non-fluorescent mucous tissue in each patient. The results of the study indicate the high effectiveness of the developed FD methodology with 5-ALA HE in detecting non-muscularinvasive bladder cancer during intravesical administration of the drug, due to selective accumulation of hexasens-induced PPIX in the tumor tissue compared with healthy mucosa. Compared with the results of standard cystoscopy, fluorescence diagnostics significantly increased diagnostic sensitivity by 24.4% (from 75.1% to 99.5%), diagnostic accuracy – by 15.8% (from 82.4% to 98.2%) and a negative predictive value – by 33.2% (from 65.8% to 99%) (p≤0.05). Additionally, a total of 37 (33.6%) patients was found to have 63 foci of fluorescence with a diameter of 2.5 to 3.0 mm. 59 of these were morphologically confirmed to contain cancer cells.

There are currently no effective measures to combat fibrosis in modern medical practice. One of the reasons for that is the late diagnosis associated with the lack of available clinical biomarkers and effective methods of non-invasive detection of the process. Fibrosis of the skin is characterized by fibrosis of the dermis, underlying tissues and is represented by a wide range of nosologies. Scleroderma and scars are of the greatest interest for the study. Skin changes in the development of bleomycin-induced fibrosis was studied in the experimental model using laser fluorescence spectroscopy and optical tissue oximetry. A significant increase in the rates of endogenous fluorescence of porphyrins, caused by inflammation and hypoxia, was detected at 7 and 21 days. An increased intensity of endogenous collagen fluorescence and a decreased specific oxygen uptake due to excess accumulation of the extracellular matrix were recorded on the 21st day after bleomycin treatment. Synchronous measurements of the collagen fluorescence and the specific oxygen uptake allowed to correlate the obtained data and the phases of the fibrogenic response described morphologically. The results allow to judge the severity of inflammation and hypoxia in the process of the fibrosis development. The objective and quantitative nature of the recorded parameters makes it possible to develop criteria for diagnosing the phases of fibrosis development.

Currently, the most promising method for the study of pharmacokinetics of drugs with fluorescent properties is the spectral-fluorescent method. In this article, we propose an algorithm for expanding the dynamic range of the spectrum analyzer by automatically monitoring the maximum spectral density in the recorded fluorescence spectrum and automatically controlled changes in the accumulation time depending on this value, followed by compensation of the output signal with regard to this change, as well as hardware circuit solutions that allow this algorithm.

Testing of LESA-01-"Biospeс" spectrum analyzer, upgraded using the proposed approach, was carried out on photosensitizer dispersions based on tetra-3-phenylthiophthalocyanine hydroxyaluminium of various concentrations (from 0.01 mg/l to 50 mg/l), approximately corresponding to the concentrations realized in the process of studying pharmacokinetics in calibration samples and tissues of experimental animals.

The proposed solutions that implement the algorithm for recording fluorescence spectra with automatic change of accumulation time depending on the signal level, ensured a significant expansion of the dynamic range of the spectrum analyzer (up to 3.5 orders of magnitude) and improved accuracy in pharmacokinetic studies.

In 1903, on the basis of Morozov Institute of the Moscow Imperial University (currently, P. Herzen Moscow Oncology Research Center, a branch of the National Medical Research Radiological Center, Ministry of Health of the Russian Federation), the first specialized unit in Russia was opened – department of radiation therapy of oncological diseases, in which scientific research in the field of medical radiology was officially launched in our country for the first time. The first studies in the field of radiation therapy can be attributed to this period.

The article presents a brief summary of the historical development of radiotherapy in the world and in Russia; provides information on the achievements of global importance, fundamental for this scientific field. The activities of leading Russian organizations in the field of radiation therapy are reviewed; names of scientists, doctors and other specialists who have made a significant contribution to its development are provided. The main literature sources relevant to the field are given.

The data in this article may be of interest and be useful for biomedical scientists, practicing radiologists and radiotherapists, oncologists, medical and graduate students, interns and other specialists.