Bacteria are inactivated using a technique called photodynamic inactivation, which combines light with a photosensitizer with the right spectrum. The objective of this study is to ascertain the e­ciency of purple LEDs for photoinactivating Bacillus subtilis and Escherichia coli bacteria as well as the ideal purple LED exposure energy density. This study technique involves exposing bacteria to purple LED radiation. Two elements of variation are used during irradiation. The first variation is the illumination variation at distances of 3 cm, 6 cm, 9 cm, and 12 cm. The second variation involves changing the amount of radiation for 30, 60, 90, and 120 minutes. The Total Plate Count (TPC) method was used to count the number of colonies. Statistical tests were utilized in data analysis, namely the One Way Anova test (analysis of variance). The results of this study indicated that 395 nm purple LED irradiation caused a decrease in Log CFU/mL of Bacillus subtilis and Escherichia coli bacteria. Inactivation of Bacillus subtilis bacteria showed a higher mortality percentage than Escherichia coli bacteria. Changes in other irradiation distances also showed a higher percentage of death for Bacillus subtilis bacteria than Escherichia coli bacteria. The highest percentage of death was 98.5% for Bacillus subtilis bacteria and 94.3% for Escherichia coli bacteria at position C with an irradiation distance of 3 cm and an energy density of 524 J/cm² with an LED exposure time of 120 minutes. This shows that the percentage of death of bacteria Bacillus subtilis and Escherichia coli increased with increasing doses of LED energy with the greatest percentage of death in Gram-positive bacteria Bacillus subtilis.

A wide range of literature sources report on the potential benefits of transdermal drug delivery. Among these advantages, the following are distinguished – minimal injury, reduction of side effects, and prevention of degradation or metabolism in the gastrointestinal tract or liver. However, transdermal delivery of most molecules often excludes due to the barrier function of the skin, which prevents the penetration of exogenous substances. To overcome this barrier and increase skin absorption, ethosomal complexes use, by means penetration into the deep layers of the skin and/or systemic circulation is possible. This work devotes to the development of a non-invasive method for assessing the depth of penetration by ethosomes with methylene blue (MB) into the skin during application and photodynamic exposure. MB as photosensitizer (PS) was chosen, since there are a sufficient number of publications on its positive effect on the restoration of the cell’s respiratory chain of various organs and therefore the restoration of their metabolism. Besides MB has proven to be an effective PS, destructed pathogenic microbes and viruses, including SARS-CoV-2. However, for more effective Covid-19 therapy and antibiotic-resistant microbial diseases, the penetration of MB into the vascular system of the epidermis or mucous tissue is required. Nowadays, the existing methods for assessing the penetration depth of PS are time consuming and require the use of animal skin or model samples. The LESA-01 BIOSPEC system with specially designed optical adapters that allow assessing the drug fluorescence intensity on skin surface and at a depth of up to 2 mm in the investigation was used.

We report the experience of radical treatment by photodynamic therapy of patients with squamous cell carcinoma of oral cavity with serious side diseases. Completed treatment of two patients with serious side diseases (HIV infection with associated pulmonary hypertension of high degree and cardiac pathology) suffered from cancer of oral cavity. Extensive surgical treatment and/or aggressive course of chemoradiation therapy were not indicated to them due to concomitant pathology. Both patients were diagnosed with squamous cell carcinoma of oral cavity, with appropriate stage Ist. сT1N0M0. Patients received treatment by photodynamic therapy with chorine photosensitizer in dose 1 mg/kg. Options of photodynamic were: output power – 1.5W, power density – 0.31 W/cm², light dose – 300 J/cm². After one time session of photodynamic therapy, in both cases full response was diagnosed (according to RECIST 1.1). In one case the second session of photodynamic therapy was performed due to concomitant disease of oral cavity – multiply lesions of leukoplakia and after was diagnosed full remission of all lesions. Major adverse event was pain during the first 5-7 days after treatment, curable by painkillers. Follow-up (IQR) was 12 and 18 month respectively with no evidence of progression. It is available to avoid extensive surgical treatment and aggressive course of chemoradiation therapy (as an alternative) with the use of photodynamic therapy. Photodynamic therapy is minimally invasive method of radical treatment of localized squamous cell carcinoma of oral cavity with minimal adverse events, and could be especially relevant in patients with serious concomitant diseases.

The article presents the results of a study of survival after complex palliative treatment of patients with malignant tumors of the pancreas stage IV in two comparable groups of patients. The aim of the study is to determine the prognostic factors affecting survival in patients with stage IV pancreatic cancer who received local and systemic photodynamic therapy. In the main group, which consisted of 19 patients with histologically veried stage IV pancreatic maligant tumor, palliative treatment was performed using photodynamic therapy. In the comparison group, consisting of 28 patients with histologically veried malignant tumor of the pancreas stage IV, palliative treatment was performed without the use of photodynamic therapy. On the background of the use of local and systemic photodynamic therapy in the main group it was observed a statistically significant increase in life expectancy compared with the comparison group. The three-month survival of patients who received local and systemic photodynamic therapy is affected by the level of brinogen before treatment. The level of brinogen above 3.4 g/l makes it possible to predict a decrease in the probability of three-month survival after photodynamic therapy. Thus, complex treatment with the use of photodynamic therapy for stage IV malignant tumors of the pancreas can increase the survival rate of patients.

Fluorescent diagnostics is a promising method for diagnosing non-melanocytic skin tumors, which makes it possible to identify clinically undetectable skin cancer foci and clarify the margin of the tumor lesion. The main drugs for fluorescent diagnostics are drugs based on 5-aminolevulinic acid and its methyl ester. Sensitivity indicators of fluorescent diagnostics in basal cell, squamous cell carcinoma and extramammary Paget’s disease reach 79.0-100.0%, speci city – 55.6-100%. But the effectiveness of this method may be reduced due to hyperkeratinization, keratinization, and the presence of necrotic tissue on the surface of tumor foci. Comparative studies of the results of fluorescent diagnostics and histological mapping during tumor removal using Mohs micrographic surgery showed approximately equal results in the determining of the tumor edges by these methods, which indicates that safe and technically easily performed fluorescent diagnostics can serve as a good alternative to Mohs micrographic surgery, one of the most accurate, but rather labor-intensive and technically complex method for determining the margin of skin cancer foci.