Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd³⁺ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd³⁺ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd³⁺+:LaF NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs inVIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy.

The article shows possibilities in fluorescence imaging of malignant skin tumors with chlorin series photosensitizers (PS) photolon and fotoditazin. The regularities of photosensitizer accumulation from the data of local fluorescence spectroscopy depending on the PS and its dose, the clinical picture and the histological form of the malignant skin neoplasm is investigated. It is shown that the level and selectivity of PS accumulation in the tumor focus depends on the PS dose. In studies on 10 patients with basal cell skin cancer after the introduction of fotoditazin at a dose less than 1 mg/kg, fluorescent contrast between tumor and healthy tissue varied between 1.3 and 9.5, the average was 2.8±0.3; for patients who had the administered fotoditazin dose of 1 mg/kg, fluorescent contrast was 2.9±0.4, varying from 1.4 to 5. In a study with 127 patients after the introduction of photolon in the dose of 0.7-1 mg/kg, the average value of the fluorescence intensity in relative units in the intact skin was 6.9±0.3 (min 4.6, max 12.2), at a dose of 1.1 to 1.4 mg/kg – 8.0±0.3 (min 4.6, max 12.5), at a dose of 1.5-2 mg/kg – 9.9±0.7 (min 5.7, max 20.3). It is also shown that fluorescence intensity of malignant neoplasm of the skin with the same dose of the photosensitizer depends on the neoplasm’s clinical and histological forms. So, 3 hours after the introduction of photolon at a dose of 1.3 mg/kg the average fluorescent contrast in the surface type of skin cancer was 2.7±0.5, in the nodal form – 2.3±0.2, in erosive-ulcerative form – 3.6±0.3. In patients with nodular form of squamous skin cancer after the introduction of photolon at a dose of 1.3 mg/kg fluorescent contrast was significantly higher (p<0.05) (average of 2.8±0.2) than in the nodular form of basal cell carcinoma after the introduction of photolon at the same dose (average of 2.1±0.2).

The purpose of our study was to develop and implement a new invasive method of papillotomy – an antegrade dissection of the major duodenal papilla using high-energy holmium (YAG:Ho) laser. Results of antegrade laser papillotomy in 35 patients are presented. All surgical procedures were laparoscopic, no indications for conversion were found. The use of high-energy holmium laser helps perform an adequate papillotomy with minimal damage to the surrounding tissues. Studies have shown that antegrade laser papillotomy is feasible in the presence of parapillary diverticula, severe deformity of the duodenum, and also when retrograde interventions are extremely difficult or impracticable. The high efficiency of the applied technique (in all cases the stenosis of the major duodenal papilla has been successfully eliminated) and the absence of complications and deaths is shown. Based on the analysis of the study results, a therapeutic algorithm for managing patients with stenosis of the major duodenal papilla is proposed.

In this paper we analyze the possibility of using special methods and equipment of coherent photonics when working with multi-parameter information. Inverse two-phase coding and operational analysis of multi-parameter data can realize a number of probabilistic algorithms. The possibility and expediency of realization of not only the correlation algorithm underlying the holographic image recognition but also universal statistical algorithms using photonics methods is substantiated. A comparative analysis of photonic medical diagnostic systems running on a wide range of algorithms: search for precedent, correspondence diagnostics, deterministic diagnostics, Bayes algorithm. The results of experimental studies of medical diagnosis and the prediction of complex conditions is presented. Such an analysis is carried out by the means of vector-matrix multiplication using laser photonics methods. It is significant that with the widening of the range of probability algorithms, it is possible to preserve certain advantages of the holographic method: multidimensionality, efficiency, high information capacity and speed, visibility and flexibility of the result presentation. The methods described are of particular relevance in connection with the first photonic processors.

Non-contact optical diagnostics of structural disorders of the eye has a number of advantages: high speed, accuracy and a large range of parameters available for analysis. The paper presents the results of studies of the photoluminescence of the fibrous tunic of the eye, excited by polarized light, depending on the intraocular pressure. In the experiments, isolated de-epithelized eyes of the rabbit were used, inside of which pressure up to 50 mm Hg was artificially created. Under these conditions, the cornea and sclera were illuminated with linearly polarized light at wavelengths of 250, 350 and 450 nm, exciting photoluminescence in the wavelength range up to 700 nm. Cross and co-polarized photoluminescence spectra excited by linearly polarized light were obtained. It has been established that, when excited by polarized light, the photoluminescence of the cornea is partially polarized. Depending on the wavelength of the photoluminescence, the degree of polarization varies from 0.2 to 0.35. It is shown that the degree of polarization of the photoluminescence of the cornea of the eye upon excitation by linearly polarized light can be used as a measurable parameter for assessing the physiological state of the eye. It is shown that the photoluminescence spectrum consists of two bands with maxima near 460-470 and 430-440 nm. These bands are assigned, respectively, to pyridinnucleotides and glycosylated collagen. A significant contribution can be made by the epithelium of the eye, which contains riboflavin with characteristic absorption bands near 450 and 365 nm. When excited at 450 nm, the photoluminescence maximum is located near 540 nm, which corresponds to the spectrum of fluorophores in the endothelium and epithelium. The spectrum of photoluminescence upon excitation at a wavelength of 250 nm can be attributed to tryptophan located in the intraocular lens.

In the publication, the authors present a clinical case of successful application of photodynamic therapy with photolon – a chlorin series photosensitizer, in a young patient with leukoplakia of the glans penis. Photolon was administered in a dose of 2 mg/kg 2.5 hours before photodynamic therapy (light dose 50 J/cm²) The treatment included 3 sessions of photoirradiation with 1 month interval. The authors note complete regression of pathological foci and long-term clinical remission (more than 6 months).