The goal of the study is to evaluate the effect of Radachlorin (OOO “RADA-PHARMA”, Russia) (RC) on platelet aggregation in ex vivo and in vivo experiments. The experiments were conducted on male Wistar rats. Platelet aggregation activity was determined in platelet-rich plasma (PRP) using a turbidimetric method and the aggregation inducer was ADP at a final concentration of 1.25 μM. PRP samples containing RC were irradiated with ALOD-Granat laser device (OOO “Alkom Medika”, Russia) at 662 nm wavelength with 0.05 W/cm² power density. After a 5-minute incubation of PRP with RC in the dark, dose-dependent inhibition of platelet aggregation was observed. Laser irradiation (12.5 J/cm² and, especially, 25 J/cm²) increased the inhibitory effect of RC. 3 hours after intravenous administration of RC, the rate and intensity of platelets aggregation did not change, while disaggregation slowed down significantly. Irradiation at a dose of 5 J/cm² did not affect the platelets aggregation kinetics, and disaggregation slowed down even more at 10 J/cm², and at 20 J/cm² the rate and intensity of platelets aggregation decreased, and no disaggregation occurred.

In vitro, RC inhibited the ADP-induced platelet aggregation in rats in a dose-dependent manner; after laser irradiation, this effect was enhanced significantly. The effect of RC on circulating platelets leads to a change in their functional state, which manifests in slowing down the disaggregation after exposure to ADP. After laser irradiation (10 J/cm² and, especially, 20 J/cm²), the severity of the functional changes increases. The role of decreasing the disaggregation activity of platelets in the mechanism of vascular thrombosis in the affected area of photodynamic therapy (PDT) is discussed.

Experimental model has been developed to study optoacoustic signal from model blood cells presented by polystyrene microspheres with nanoparticles. It was found out that nanoparticles due to their strong absorption of light significantly affect the coefficient of cellular optical absorption, while the thermophysical parameters, namely the coefficient of thermal expansion, compressibility and isobaric specific heat of cells remain unchanged, since nanoparticles occupy a small intracellular volume compared to the cell volume. Optoacoustic signals were obtained using model solutions at various concentrations of cells and nanoparticles using 1064 nm laser. The results of experimental measurements using LIMO 100–532/1064-U system based on Nd:YAG showed that the amplitude of the optoacoustic signal increased without increasing the temperature in the laser area.

Teeth whitening is one of the most sought-after procedures in aesthetic dentistry. Discolorites that are difficult to whiten, caused by dentin changes or enamel defects, can be eliminated by oxidizing the chromogens with chemical agents that penetrate to the enamel and dentin. In recent years, the method of photodynamic bleaching (PDB) is considered to be minimally invasive. It does not use hydrogen peroxide that leads to increased sensitivity of teeth, and is relatively effective over time. A convenient solution for PDB would be to use chlorin e₆ as a photosensitizer, which has a high quantum yield of singlet oxygen generation, low phototoxicity, rapid elimination, on the one hand, and photobleaching capability, on the other. This paper presents quantitative data on the study of the effectiveness of PDB with chlorine e₆: color change for 100 teeth after the procedure, chlorine e₆ penetration into the tooth tissues, evaluation of the interstitial efficiency of the generation of singlet oxygen and photobleaching of chlorine e₆ during laser exposure. It has been statistically established that for one PDB procedure, the tooth color saturation (C) varies on average by 0.5 tones on the VITA scale, and the lightness of color (L) in some cases increases by more than 10 units.

Infrared thermography is one of the widely used non-invasive diagnostic methods. While the procedure is mainly used for early malignant tumor diagnostics, a potential application for thermography was proposed in cardiovascular, skin, autoimmune diseases, arthritis, Reynaud’s syndrome, burns, surgery and therapeutic treatment monitoring. The method of thermographic evaluation has not changed significantly since the end of 20th century. In this study we attempted to characterize the influence of skin capillary blood flow on surface temperature recuperation following local hypothermia. To improve sensitivity and standardize the procedure we developed a study protocol that involves minimizing or excluding the influence of external factors on study results. An original applicator was used to apply dosed hypothermia. Massive porcine tissue block was chosen as a passive model without active heat and mass transfer but with heat capacity, structure and heat dissipation characteristics similar to human tissues. 51 healthy volunteers were assigned to control group, while 16 patients with diabetes mellitus constituted the main study group. Cumulative temperature difference was calculated in all cases. It was 121,8 ± 70,8 °С×s in the control group, 95,6 ± 54,4 °С×s in the main study group and 307,2 ± 43,4 °С×s in the passive model. Based on the study results, we made the following conclusions: absence of heat and mass transfer in the passive model complicates heat balance recuperation due to layered structure of the skin; heat balance recuperation curve is an individual parameter and is not influenced by age or gender.

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.

The authors describe a clinical observation with full clinical effect after multi-course photodynamic therapy of a patient with central lung cancer and cystic fibrosis using Photoditazine. Photoditazine was administered intravenously at a dose of 0.8 mg/kg 2 hours before the irradiation session. Irradiation parameters: power density – 150 mW/cm², energy density – 200 J/cm². In total, 3 courses of photodynamic therapy were performed. As a result of the treatment, a complete regression of the tumor was noted. The patient has been under dynamic observation for 2 years after treatment, no relapse was observed.