Igor Romanishkin

• Specialist in Physics
• PhD Student at Russian Academy of Sciences

The aim of the investigation is to study the interaction of methylene blue (MB) with NADH, FADH2 coenzymes and lactate, and to evaluate a long-term effect of its intravenous or oral introduction on tumor metabolism in vivo. Materials and Methods The MB interaction with NADH, FADH2 coenzymes and lactate was studied using absorption spectrophotometr...

The application of photosensitizers for inhibition of oxidative phosphorylation in order to temporally decrease oxygen uptake by tumor cells in the course of photodynamic therapy (PDT) evokes growing interest. The aim of the study is to overcome tumor hypoxia for further photodynamic therapy with simultaneous use of type I photosensitizer methylene...

SARS-CoV-2 infection can lead to potentiation of oncological diseases, including due to virus interaction with cancer stem cells (CSC). The aim of this paper is to analyze approaches and treatments that may be effective against both coronavirus infection and cancer at the same time. Lung cancer material was analyzed with pathomorphological and immu...

Decision support systems based on machine learning (ML) techniques are already empowering neuro-oncologists. These systems provide comprehensive diagnostics, offer a deeper understanding of diseases, predict outcomes, and assist in customizing treatment plans to individual patient needs. Collectively, these elements represent artificial intelligenc...

To reduce the frequency of relapses after surgical removal a brain tumor, it is critically important to completely remove all affected areas of the brain without disrupting the functionality of vital organs. Therefore, intraoperative differential diagnostics of micro-areas of tumor tissue with their subsequent removal or destruction is an urgent ta...

The difficulty of intraoperative delineation of glial tumors is due to the peculiarities of their growth along vessels and nerve fibers with infiltration of healthy white matter. Insufficiently complete removal of tumor tissues leads to recurrences, and excessive removal is fraught with neurological complications. Optical spectroscopy methods are c...

Hypoxia negatively affcts the effctiveness of all types of anticancer therapy, in particular photodynamic therapy (PDT). In this regard, various approaches to overcome the limitations associated with hypoxia are widely discussed in the literature, one of them is the use of photosensitizers (PS) operating through the fist mechanism of the photodynam...

PDT using PSs based on polycationic derivatives of synthetic bacteriochlorin against Lewis lung carcinoma provides effective inhibition of tumor growth with an increase in the lifespan and survival of mice in the group. PDT with polycationic photosensitizers destroys CSCs and tumor neovascularization, and activates the desmoplastic reaction. These...

Polycationic photosensitizers (PS) are not susceptible to aggregation in solutions, but their high local concentrations in Gram-negative bacteria can be sufficient for aggregation and reduced effectiveness of antibacterial photodynamic treatment. By measuring fluorescence spectra and kinetics we were able to evaluate the degree of aggregation of po...

Upconversion nanoparticles are promising for many applications. For triple-doped nanoparticles (NPs), the luminescence intensity shows a non-linear dependence on the rare-earth ion concentration, making it difficult to obtain bright phosphors with high energy output. We investigated the energy transfer processes in β-NaGdF4:Yb-Er-Tm NPs and conside...

The motivation for the present study was the need to develop methods of urgent intraoperative biopsy during surgery for removal of intracranial tumors. Based on the experience of previous joint work of GPI RAS and N.N. Burdenko National Medical Research Center of Neurosurgery to introduce fluorescence spectroscopy methods into clinical practice, an...

In the present study, various combinations of dimensionality reduction methods with data clustering methods for the analysis of biopsy samples of intracranial tumors were investigated. Fresh biopsies of intracranial tumors were studied in the Laboratory of Neurosurgical Anatomy and Preservation of Biological Materials of N.N. Burdenko Neurosurgery...

Novel tetragonal matrix Ba0.5−xLn0.5NaxF2.5−x with x = 0.08, doped by Yb³⁺, Ho³⁺, Er³⁺, was synthesized by molten salt synthesis (MSS) from nitrate flux. XRD data show that the tetragonal phase with a = 4.122(1) Å, c = 17.672(1) Å is stable in an argon atmosphere up to 960 °C. Luminescence spectra recorded in 500–900 nm and 1050–1700 nm upon 974 nm...

A spectroscopic study of the photophysical properties of methylene blue (MB) in aqueous solutions was carried out. Absorption and fluorescence spectra as well as fluorescence lifetime were recorded. The concentration dependence of the intensity and shape of the spectra allowed establishing the ranges of MB concentrations for in vitro and in vivo st...

Novel tetragonal matrix Ba0.5Gd0.5-xNaxF2.5-x, where x = 0.05, doped by Yb3+, Ho3+, Er3+, was synthesized by molten salt synthesis (MSS) from nitrate flux. XRD data show that tetragonal phase with a = 4.122(1) Å, c = 17.672(1) Å is stable in argon atmosphere up to 960 °C. Luminescence spectra recorded in 500-900 nm and 1050-1700 nm upon 974 nm pump...

Determination of the iron oxide nanoparticles (IONPs) local temperature during laser heating is important in the aspect of laser phototherapy. We have carried out theoretical modeling of IONPs local electromagnetic (EM) field enhancement and heating under the laser action near individual IONPs and ensembles of IONPs with different sizes, shapes and...

Background: One of the tasks of anticancer photodynamic therapy is increasing the efficacy of treatment of cancer nodes with large (clinically relevant) sizes using near-infrared photosensitizers (PS). Methods: The anticancer efficacy and mechanisms of the photodynamic action of PS based on polycationic derivatives of synthetic bacteriochlorin a...

Methylene blue (MB) is a promising photosensitizer (PS) for the treatment of pathological neoplasms, since it has both photodynamic activity (under laser irradiation) and redox and catalytic properties (in the absence of light). In the framework of this work, using spectroscopic methods, the effect of intravenous administration of MB on tissue oxyg...

Non-invasive detection of polarized macrophages in tumors is an urgent task in terms of combined antitumor therapy. By analyzing the fluorescence lifetime of the metabolic cofactors—the reduced form of nicotinamide adenine dinucleotide (NADH) and flavins—differences in cellular metabolism of normal tissue, tumor, inflammatory and anti-inflammatory...

Indocyanine green (ICG), when in free form in a liquid, can form stable nanoparticle structures or colloidal solution, while changing its spectroscopic properties. In the work, the aggregation degree and the average size of nanoparticles depending on the concentration of a colloidal solution of indocyanine green (ICG NPs) in the form of J-aggregate...

The study of phthalocyanines, known photosensitizers, for biomedical applications has been of high research interest for several decades. Of specific interest, nanophotosensitizers are crystalline aluminum phthalocyanine nanoparticles (AlPc NPs). In crystalline form, they are water-insoluble and atoxic, but upon contact with tumors, immune cells, o...

The neurosurgery of intracranial tumors is often complicated by the difficulty of distinguishing tumor center, infiltration area, and normal tissue. The current standard for intraoperative navigation is fluorescent diagnostics with a fluorescent agent. This approach can be further enhanced by measuring the Raman spectrum of the tissue, which would...

Background: One of the main tasks of anticancer photodynamic therapy is increasing the efficacy of treatment of cancer nodes with large (clinically relevant) sizes using near-infrared photosensitizers (PS). We study the photodynamic action against A549 human lung cancer cells using PS based on polycationic derivatives of synthetic bacteriochlorin....

Upconversion materials have several advantages for many applications due to their great potential in converting infrared light to visible. For practical use, it is necessary to achieve high intensity of UC luminescence, so the studies of the optimal synthesis parameters for upconversion nanoparticles are still going on. In the present work, we anal...

In view of their potential in the treatment of oncological diseases, photosensitizers (PS) have been the object of active research for the last years. The applied therapeutic photodynamic method involves the activation of a PS by light at a specific wavelength. PS interacts with oxygen and catalyzes the production of singlet oxygen molecules or rad...

Nanoparticles are used as drug carriers to increase the selectivity and effectiveness of therapy, as well as for combined therapy that utilizes different effects. Iron oxide nanoparticles are promising in this aspect. Due to magnetic properties, they can be used as a contrast agent for magnetic resonance imaging. Also, iron oxide nanoparticles coul...

Today, photodynamic therapy is one of the most promising minimally invasive methods of treatment of various diseases, including cancer. The main limitation of this method is the insufficient penetration into the tissue of laser radiation used to activate photosensitizer molecules, which makes it difficult to carry out therapy in the treatment of la...

Background The treatment of patients after mechanical ventilation of lungs suffering from a multi-species infection of the tracheobronchial tree has become complicated rapidly in recent years. The situation is aggravated in patients with post-intubation tracheal stenosis, where infection plays a leading pathogenetic role in damage to the tracheal w...

Background: There is a need to expand the possibilities of urgent analysis of intracranial tumor type during resection. These measures are necessary to improve resection quality with preservation of intact tissues and avoiding recurrence and neurological impairment in postoperative period. Objective: To create optical-spectral method for differe...

In this work, we tested a new approach to assess the presence of inflammatory process in the implant area using spectral methods and the technique of fiber fluorescence analysis of photosensitizers in nanoform. First of all, the spectral characteristics of the photosensitizer when interacting with the porous surface of the implant, based on hydroxy...

Spectroscopic approach with fluorescence time resolution allows one to determine the state of a brain tumor and its microenvironment via changes in the fluorescent dye’s fluorescence lifetime. Indocyanine green (ICG) is an acknowledged infra-red fluorescent dye that self-assembles into stable aggregate forms (ICG NPs). ICG NPs aggregates have a ten...

Background The efficient intraoperative identification of tumors requires the development of highly specific near-infrared (NIR) probes as contrast agents. One of the most effective dyes existing in clinic oncology is Indocyanine Green (ICG). However, ICG has a rapid excretion, thus ruling out its extended accumulation in pathological tissues there...

In this work, a new approach was tested to assess the cellular composition of tissues by time-resolved methods of fluorescence analysis of exogenous and endogenous fluorophores. First of all, the differences in fluorescence kinetics of endogenous fluorophores (coenzymes NADH and FAD) in tumour and immunocompetent cells were determined. After that,...

The paper presents a new approach to assessing the state of tissues that differ in phenotype and in the degree of immunocompetent cells activity using photosensitizers (PS) and time-resolved fluorescence analysis methods. The main attention is paid to the detection of differences between tumor cells and tumor-associated macrophages (TAM) using spec...

Any surgical intervention to a central nervous system requires special accuracy and selectivity of the effect on the cancer cells. The application of laser-spectroscopic methods provides a unique opportunity to non-invasively determine the most significant parameters that characterize the tissue states. Moreover, non-invasive state assessment of th...

Currently, there is a significant increase in the incidence of cancer of the central nervous system. Determination of the boundaries of intracerebral and intramedullary tumors is especially difficult. The urgency of the problem of determining the boundaries of astrocytic tumors is due to the peculiarities of their growth along myelinated nerve fibe...

The determination of pH in live cells and tissues is of high importance in physiology and cell biology. In this report, we outline the process of the creation of SypHerExtra, a genetically encoded fluorescent sensor that is capable of measuring extracellular media pH in a mildly alkaline range. SypHerExtra is a protein created by fusing the previou...

Atherosclerosis is associated with a chronic local inflammatory process in the arterial wall. Our previous studies have demonstrated the altered proinflammatory activity of circulating monocytes in patients with atherosclerosis. Moreover, atherosclerosis progression and monocyte proinflammatory activity were associated with mitochondrial DNA (mtDNA...

Neurosurgery of intracranial tumors, especially of glial origin, is a non-trivial task due to their infiltrative growth. In recent years, optical methods of intraoperative navigation have been actively used in neurosurgery. However, one of the most widely used approaches based on the selective accumulation of fluorescent contrast medium (5-ALA-indu...

The short-wave infrared region (SWIR) is promising for deep-tissue visualization and temperature sensing due to higher penetration depth and reduced scattering of radiation. However, the strong quenching of luminescence in biological media and low thermal sensitivity of nanothermometers in this region are major drawbacks that limit their practical...

Upconversion nanoparticles have attracted considerable attention as luminescent markers for bioimaging and sensing due to their capability to convert near-infrared (NIR) excitation into visible or NIR luminescence. However, the wavelength of about 970 nm is commonly used for the upconversion luminescence excitation, where the strong absorption of w...

Antibacterial photodynamic therapy is a promising method of treating local infected foci, especially surgical and burn wounds, trophic and diabetic ulcers. This work explores the photophysical and antibacterial properties of novel phthalocyanine- and synthetic-bacteriochlorin-based octacationic photosensitizers (PS). The results of the study confir...

Surgical removal of glial tumors is a challenge due to their infiltrative growth. At the moment, the main way to solve this problem is fluorescent intraoperative navigation. However, in the absence of accumulation of a fluorescent marker in tumor tissues, other diagnostic parameters are required to find the boundaries of such tumors. Raman spectros...

Current paper presents the results of the usage of indocyanine green and pheophorbide nanoform on 2D and 3D models of FaDu cells culture. The 2D model or monolayer was used for investigation of nanoparticles distribution within individual cells and their organelles. The 3D model or multicellular tumor spheroids were used for estimation of cells’ me...

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 considere...

Photo-theranostics is a therapeutic and diagnostic approach that uses photosensibilization. This approach makes part of the medicine of the future – subcellular therapy. Photo-theranostics targets cells and tissues that are affected by pathological changes inducing apoptotic cell death. However, the approach allows targeting cellular organelles, if...

To improve methods of laser hyperthermia for the treatment of bulk malignant neoplasms, an urgent task is the development of techniques and devices that automatically control heating at a given tissue depth and ensure its uniformity. The article proposes the concept of a system for performing hyperthermia with real-time spectroscopic temperature co...

Antibacterial photodynamic therapy (APDT) is a promising method of treating local infected foci, in particular, surgical and burn wounds, trophic and diabetic ulcers. Photodynamic inactivation (PDI) is able to effectively destroy bacterial cells without them developing resistance in response to treatment.This work was dedicated to the study of phot...

The work is devoted to the study of phase formation in the NaGd 0.8 Yb 0.17 Er 0.03 F 4 -NaY 0.8 Yb 0.17 Er 0.03 F 4 system. The effect of the Gd ³⁺ Y ³⁺ ions concentrations ratio on the phase composition and lattice parameters of the resulting solid solutions, the spectral-luminescent properties, and the heating temperature under laser irradiation...

Polycationic derivatives of synthetic bacteriochlorin with absorption in the near infrared range are promising for the creation of photosensitizers (PS) for antimicrobial photodynamic therapy. In the present work, the photophysical and antibacterial properties of PS based on tetracationic derivatives of synthetic bacteriochlorins: hydrophilic 3-Py4...

Aluminum phthalocyanine nanoparticles (NP AlPc) possess the features that make them a promising photosensitizer. In particular, AlPc NPs do not fluoresce in free nanoform, fluoresce weakly in normal tissue, strongly in tumors and very strongly in macrophages. Also, such particles fluoresce and become phototoxic when contacting certain biocomponents...

Making antibacterial PDT more effective is a task that calls for the development of photosensitizers (PS) based on polycationic synthetic bacteriochlorins and subsequent analysis of properties of such photosensitizers. This study aimed to explore photophysical and antibacterial properties of the nanostructured PS based on 3-Py4BSHp4Br4, tetracation...

Antibacterial photodynamic therapy is a promising method of treating local infected foci, in particular, surgical and burn wounds, trophic and diabetic ulcers. Both Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Pseudomonas aeruginosa are found in most infected wounds. Photodynamic inactivation (PDI) is able to effectively...

We compared the heating and cooling theoretical and experimental transient times of DyPO4 nanoparticles as a result of their heating by themultiphonon relaxation after femtosecond laser excitation in the near IR spectral range into different absorption spectral lines of the Dy³⁺ ion. We have shown that the relaxation of the heat flux to a stationar...

Laser hyperthermia is one of the promising methods for treatment of oncological diseases. For routine clinical use of hyperthermia, it is necessary to control the uniformity and localization of heat within the tumor. Local heating can be achieved by using special thermal agents, such as nanoparticles doped with rare-earth ions. Measurement of the t...