This article presents a literature review on the molecular mechanisms of the inner ear damage and current approaches to restoring its cellular structures. The search for sources was carried out in the RSCI, Scopus, PubMed and Google Scholar databases. The advantages and limitations of various approaches to cochlear hair cell regeneration, as well as prospects for their development, are discussed. Particular attention is paid to discoveries in the field of gene therapy for inner ear diseases.

Cell therapy is increasingly used to treat a variety of medical conditions, including cancer, immune system disorders, and neurodegeneration. Stem cells secrete growth factors, signaling molecules, and extracellular vesicles, that can be used to treat neurological diseases and promote neuronal regeneration. Transgenic 5xFAD mice, which are a model for Alzheimer's disease (AD), were used in this study. The mice were 7 months old and received retro-orbital injections of glial progenitor cells (GPCs) once a week for 4 months. At 11 months, their behavior was analyzed using a multichannel actigraphy system. Brain tissues from the cortex, hippocampus, and midbrain were collected for postmortem analysis of mitochondrial respiratory chain enzyme activity. The results showed that the GPCs injection significantly improved the response of the hippocampal p2 mitochondrial fraction in 5xFAD mice to succinate, reaching a level observed in control animals. A similar trend was also observed for the cytochrome c oxidase complex. The oxygen consumption rate of mitochondria did not differ from that of clinically healthy mice after ascorbate/N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride administration. A similar decrease in the efficiency of the electron transport chain was detected in the midbrain of 5xFAD mice, but no recovery was observed after GPCs treatment. Behavioral differences between non-transgenic and transgenic groups were observed in a multiparameter analysis using the actigraphy system. The behavior of transgenic mice in the treated and untreated groups was similar, while the behavior of non-transgenic mice varied. Additional analysis of locomotor activity and transient events in particular revealed that the activity of the GPCs-treated 5xFAD mice was differed fundamentally compared to other groups. Specifically, GPCs-treated mice exhibited greater number of transitions between intermediate activity states. In contrast, untreated mice showed transitions between extreme activity states, such as from low to high activity or vice versa. These findings suggest that changes in behavior and activity of the AD mice may be associated not only with hippocampal dysfunction, but also with disruptions in midbrain structures.

Brain malignancies, such as glioblastoma, remain one of the most aggressive and difficult-to-treat cancers because of their heterogeneity, invasive growth, and resistance to conventional therapy. Significant recent progress in the treatment of these diseases has been associated with the development of gene and cell technologies, which open up new possibilities for targeted therapy, immunotherapy, and personalized approaches. The review systematically summarizes the data on current treatment strategies, including gene therapy, cell therapy, and combined approaches. Particular attention is paid to preclinical and clinical studies, as well as the prospects for overcoming major limitations, such as the blood-brain barrier, the immunosuppressive tumor microenvironment, and toxicity. Analysis of the literature demonstrates that integration of gene and cell technologies could provide a basis for developing effective treatments aimed at improving the survival of patients with central nervous system tumors.

The article provides an overview of data on the prevalence, conservative, and surgical treatment of chronic suppurative otitis media, which remains one of the most common and socially significant diseases of the otorhinolaryngological structures, accompanied by a high frequency of complications and persistent hearing loss. The evolution of treatment methods is traced, and special attention is given to the prospects for the use of tissue engineering constructs and tissue engineering in general. The possibilities of creating three-layer grafts are highlighted, taking into account the achievements of scientific and technological progress. It has been shown that classical methods of surgical correction of defects of the eardrum, including the use of autografts (temporal fascia, cartilage), do not always allow to achieve a sustainable anatomical and functional result, especially in large and persistent perforations. There is a tendency of active development of the direction of regenerative medicine and tissue engineering, allowing to create biocompatible grafts with specified properties, to introduce mesenchymal stem cells, as well as to use growth factors to stimulate reparative processes. The review analyzes data on the effectiveness of classical and innovative tympanoplasty methods, as well as the prospects for using 3D bioprinting, collagen matrices, and cellular technologies to restore the integrity of the eardrum. Special attention is paid to the results of clinical and experimental studies that demonstrate a significant increase in the frequency of successful closure of perforations when using tissue engineering constructs and growth factors compared to traditional methods. The article discusses unresolved issues related to the optimization of technologies, the standardization of protocols, and the need for further multicenter studies to widely implement innovative approaches in clinical practice.

Glioblastoma or grade IV glioma is characterized by extremely poor prognosis. Resistance to radio- / chemotherapy and recurrences are associated with tumor stem cells. Transmembrane protein CD133 is considered a potential marker of tumor stem cells. To overcome the limitations of detecting cellular CD133 by antibodies, potential of aptamers (nucleic acid-based molecular recognition elements) is being explored. To obtain reproducible results, it is necessary to study the interaction of fluorescent aptamers to CD133 with standard cell lines and cell cultures derived from patient tumors using various methods.

To analyze different methods for autologous transplantation of stromal-vascular fraction of adipose tissue combined with skin grafting with split-thickness skin graft 1:6 in patients with extensive deep burns.

To systematize current data on neurogenesis and its role in the pathogenesis of neurodegenerative conditions, such as Alzheimer's disease and Parkinson's disease, with a focus on molecular mechanisms of regulation, the nature of disorders in neurodegeneration, and the evaluation of therapeutic approaches aimed at stimulating neurogenesis.

The process of mesenchymal stromal cells (MSCs) senescence is accompanied by alterations in their extracellular matrix (ECM), which has the potential to compromise cellular interactions within the perivascular niche. In this study, the effect of the ECM of senescent MSCs obtained in a «stress-induced model» on the paracrine activity of endothelial cells (ECs) in vitro was investigated. Senescent MSCs exhibited reduced production of structural and adhesive ECM proteins (including type I collagens, fibulins, perlecan, et al.) and increased deposition of senescence-associated molecules (PAI-1, GDF-15). When ECs were cultured on decellularized ECM of senescent MSCs, a significant decrease in the secretion of angiogenic and chemoattractant factors (SDF-1, HGF) was observed compared to young ECM. These findings highlight a potential role of ECM-mediated mechanisms in the development of age-related vascular pathologies and may provide a foundation for the design of anti-senescent therapeutic strategies.

Head and neck paragangliomas (HNPGLs) are rare neuroendocrine tumors that originate in the parasympathetic paraganglia of the head and neck. The diagnosis of these tumors is challenging, and the therapeutic options are limited. The study of HNPGLs is fraught with challenges at every stage. One of the main problems is the absence of HNPGL cell lines in cell repositories, which is associated with the difficulty of their culturing and low division rate. In this regard, neither functional nor preclinical studies are available for this category of tumors. This significantly slows down the study of the molecular mechanisms of HNPGL pathogenesis and the development of effective therapeutic approaches. Here, we investigated the molecular genetic characteristics of the primary HNPGL culture. Using the single-cell RNA sequencing method, expression patterns were analyzed, and cell types were annotated. The results demonstrated that the HNPGL primary culture cells were optimally divided into three clusters and had different degrees of differentiation, expressing neural tissue cell and stem cell markers. Exome sequencing revealed genetic abnormalities in the HNPGL culture, including mutations in the IGSF3, DHH, EXOSC8, SERPINA1, TYR, and NQO1 genes, aneuploidy, as well as multiple chromosomal duplications and deletions. These results enhance our knowledge of the molecular genetic features of successfully cultured HNPGL tumor cells.

Stromal vascular fraction is a heterogeneous cell population with significant regenerative potential harvested from adipose tissue. Its cells stimulate angiogenesis, have anti-apoptotic and anti-inflammatory effects, stimulate cell growth and differentiation. This review highlights the mechanisms of action, as well as possibilities and results of local application of stromal vascular fraction in lower limb ischemia. Prospects of stromal vascular fraction for the treatment of lower limb ischemia are presented.

Traditional methods of treatment and prevention of cardiovascular disease (CVD) are not always effective, especially in severe myocardial injury. One of the promising areas for the treatment of cardiac pathologies is cell transplantation using tissue-engineered constructs from allogeneic stem cells, such as cell sheets. The success of cell therapy depends on the severity of local inflammatory reactions, angiogenesis activity, and the resistance of transplant cells to hypoxia and apoptosis, as well as on their production of the extracellular matrix. Single nucleotide polymorphisms (SNPs) in genes involved in the processes associated with CVD can serve as markers of genetic dysfunction of these genes in the cardiovascular system and be used to predict the efficacy of therapy for heart disease based on tissue-engineered constructs. This review systematizes the information, allowing us to form a panel of such SNPs and analyze it. We identified seven genes at the intersection of pathways that are key to the survival of cellular constructs, VEGFA, TGFB1, FN1, IL6R, ITIH4, NRP1, and CDH13, and selected SNPs rs998584, rs8108632, rs1250259, rs6689306, rs77347777, rs75082222, and rs6565060, which are located in the regions of these genes and associated with CVD according to the Genome-Wide Association Studies (GWAS). These polymorphisms may constitute a minimal panel to search for an association with the efficacy of cell therapy in heart disease.

To systematize current knowledge on biomarkers of fundamental aging mechanisms, their reference and target values for practical application in longevity medicine.

Study of cytocompatibility of hydroxyapatite coating for titanium implants applied by high-frequency magnetron sputtering at low pressures in an inert gas atmosphere.

Investigate the effect of platelet gel addition on the biological properties of 3D PLGA-based matrices impregnated with adenoviral constructs carrying the BMP2 gene.

To evaluate the osteogenic properties of porous polylactide granules (PLA) and hydroxyapatite granules (HA) impregnated with recombinant bone morphogenetic protein-2 (BMP-2) in vitro and in vivo.

Study of changes in the physico-mechanical and structural characteristics of highly porous matrices based on biocompatible biodegradable polyester - polylactoglycolide.

Traditional methods of nasal septum perforation surgery using vascularized flaps are quite effective, but at the same time they are associated with a long postoperative period (8-16 weeks), the risk of an inflammatory reaction, uncontrolled scarring in the area of the donor site. According to the literature, the use of collagen membranes and stem cells reduces the period of restoration of the integrity of the nasal septum to 4-6 weeks, but these methods remain expensive and inaccessible. An alternative may be autologous platelet growth factors that stimulate tissue repair and are already used in various branches of medicine. A study of the effectiveness and safety of the use of biocomposite materials in the surgical treatment of nasal septum perforation was conducted at the Sverzhevsky Research Clinical Institute of Otorhinolaryngology.

This study analyzed the outcomes of corneal epithelium reconstruction using the method of paralimbal oral mucosal epithelial transplantation (PLOMET) in patients with bilateral limbal stem cell deficiency.

Lung cancer occupies a leading position among malignant neoplasms throughout the world, and the issue of carcinogenesis of this disease today still remains relevant. This review examines in detail the issue of the participation of cancer stem cells in the development of lung cancer, the concept of the stem cell niche, and options for their detection using molecular and immunohistochemical studies. A separate section examines the impact of the new coronavirus infection COVID-19 on CSC and lung cancer carcinogenesis in general, as well as the successful results of the use of photodynamic therapy in the treatment of both diseases.

Lung adenocarcinoma (LAC) is one of the leading causes of cancer mortality, which is most likely due to the presence of cancer stem cells (CSC) in the tumor, which form a heterogeneous hierarchy and are responsible for the occurrence and progression of carcinoma, as well as its unfavorable prognosis. The ability of CSC to form heterogeneous tumor populations in lung cancer has not been sufficiently studied.