Oncological diseases represent a global healthcare challenge, and the development of new effective therapeutic strategies remains a pressing task. Chemotherapy and photodynamic therapy (PDT) are key treatment modalities, however, their application is associated with side effects, systemic toxicity, and the development of drug resistance. In recent years, combined approaches, including the use of pH-sensitive delivery systems, have been actively investigated. The present study was dedicated to the investigation of the pH-dependent hydrolysis of a chlorin e6 hydrazide derivative, acting as a potential photosensitizer (PS) for combined anticancer therapy. Hydrazide fragments, due to their lability in the weakly acidic environment of the tumor microenvironment (pH 4.5-6.0), are promising for the creation of targeted drug delivery systems. The decomposition of the hydrazide fragment was studied spectrophotometrically in an acetate buffer (pH 5.0) over 120 minutes. Spectral changes (bathochromic shift, appearance of a maximum at 688 nm) were recorded, indicating the formation of a protonated precursor compound. A linear dependence of product accumulation on time was obtained, characteristic of zero-order reactions. A high coefficient of determination confirmed the adequacy of the obtained model. This approach ensures controlled release of active components and demonstrates the potential of the developed PS for enhancing PDT efficacy and reducing the systemic toxicity of chemotherapy.

Ciliary body melanoma (CBM) accounts for up to 20% of uveal melanoma cases and presents challenges for organ-preserving treatment due to its peripheral location and proximity to critical ocular structures. This study presents the first clinical results evaluating the efficacy and safety of isolated transscleral photodynamic therapy (TSPDT) with a chlorin e6 photosensitizer in 7 patients with CBM. The procedure was performed using an «ALOD-01» laser system (λ=662 nm) and standardized irradiation parameters (energy density 519.5 J/cm², accounting for power loss during scleral transmission). The mean follow-up period was 19.0±5.9 months and demonstrated high local tumor control: complete regression was achieved in 4 patients, and partial regression in 3 patients. A statistically significant reduction in tumor height (from 4.69±2.58 mm to 1.36±1.14 mm; p=0.0062) and basal diameter (from 8.54±3.56 mm to 6.65±3.70 mm; p=0.016) was accompanied by a pronounced vasculo-occlusive effect, manifested as complete tumor avascularity in the majority of patients according to ultrasound with color Doppler Imaging (CDI). Echodenstitometry recorded a statistically significant decrease in mean acoustic density from 35.53±1.26 dB to 28.97±0.83 dB (p=0.0002), which may indicate tumor tissue destruction. No intra– or postoperative complications were recorded throughout the observation period, and a trend towards stable visual acuity was noted. The obtained data suggest that TSPDT is a promising minimally invasive organ-preserving method for treating CBM, requiring further investigation to define its role as either a standalone or combined therapy.

The task of developing a decision support system in neurooncology based on optical-spectral analysis of intracranial tumor tissue is associated with several challenges inherent in working with biomedical data. These include the high dimensionality of the feature vector with a relatively small sample size, data gaps, and sample imbalances due to the varying frequencies of various diagnoses. Analysis of correlations between features of the tumors under study will allow both the restoration of data gaps and their augmentation (artificial expansion of the training dataset by creating modified versions of existing examples). This paper presents an analysis of the dependence of various optical-spectral characteristics on the tumor cell/tissue content in the sample and the cross-correlations between various features.

Nowadays, the problem of malignant neoplasms management remains a priority task. To achieve further progress in cancer treatment, it is necessary to focus on existing but still undervalued methods. One of these approaches is photodynamic therapy (PDT), which can be used in combination with surgery as well as with other antitumor drugs without any risk of inducing cross-resistance. Being miner invasive and selective in tumor targeting, and having no risk of complications, the technique is attractive for application in oncologic pediatrics as an innovation capable of expanding the range of therapeutic techniques. The aim of the study was to investigate the effectiveness of intraoperative photodynamic therapy in children with stage III–IV nephroblastoma. The study included 66 patients aged 0–11 years with stage III and IV nephroblastoma. The patients of the control group (35 children) underwent surgical treatment in combination with chemotherapy and radiation therapy according to the SIOP protocol. The patients of the main group (31 children) underwent therapy according to the SIOP protocol, but in combination with intraoperative PDT. The 5-year survival rate in the main group was 90.3%, in the control group – 71.4% (p = 0.05). The recurrence rate in the main group was 9.7%, in the control group – 11.4%. Thus, high therapeutic efficacy of PDT during intraoperative irradiation of the tumor bed after its removal has been demonstrated. The technique contributes to the increased survival rate of patients with retroperitoneal tumors, which is a promising method to be used in pediatric oncological practice.

Acne is one of the most common dermatosis in young people. 85% of cases occur in patients between 12 and 24 years old. Duration of the disease, severe form, frequent recurrences of acne, autotraumatization lead to development of symptoms complex postural, manifested in the form of scarring changes, dyschromia, reduced elasticity, increased porosity and mildew. Acne complications occur in 95% of patients. Development of an effective method for the correction of acne complications is a topical problem of modern dermatology and cosmetology. The article describes the method of application of photodynamic therapy with an outer gel photosensitizer based on E6 chloride in patients with severe form of acne after prior treatment with systemic retinoids. The morphofunctional indicators of the skin and the composition of the microbiome in the dynamics were studied. As a result of the course of photodynamic therapy, resolution of scarring was observed in 97,2% of patients, disappearance of pigmentation on cheeks and skin on the forehead in 89,1% and 91,9% of patients respectively, restoration of elasticity in 100% of subjects, decrease in oiliness on the cheeks and skin in 91% and 94,5 % of patients respectively.
The exact exposure of the photosensitizing gel when applied externally to the scar tissue, the time range of its highest concentration and optimal duration of the procedure were determined. As a result of the application of photodynamic therapy, the skin relief was leveled, its oiliness decreased, the pigmentation disappeared and the elasticity was restored. In the microbiota of seborrheic sites, normal flora predominated over pathogenic. This method proved to be effective in the correction of the postural.

The Center for Photodynamic Therapy of the Hospital of the Medical Center of the Administrative Department of the President of the Republic of Kazakhstan has clinical experience in treating cutaneous metastases of breast cancer. This paper presents the results of clinical observation of a patient with metastatic breast cancer who underwent combined photodynamic therapy, including systemic photomodification of blood and local irradiation of metastatic lesions. This clinical case is of particular interest since the patient did not receive standard antitumor treatments such as chemotherapy or hormone therapy. This was due to advanced age and decreased tolerance to aggressive treatment regimens associated with comorbidities, which limited the feasibility of conventional therapy. Despite the absence of systemic treatment, the use of combined photodynamic therapy resulted in a pronounced positive clinical response. A reduction in the size and infiltration of cutaneous metastatic lesions, as well as an improvement in the patient’s general condition and quality of life, were observed. These findings demonstrate the potential of photodynamic therapy as an effective and safe alternative therapeutic approach for metastatic breast cancer, particularly in clinical situations where the use of standard treatment protocols is impossible or contraindicated.