Background: Cultured meat holds significant potential as a pivotal solution for producing safe, sustainable, and high-quality protein to meet the growing demands of the global population. However, scaling this technology requires innovative bioengineering approaches integrated with software methods to assess the growth of cell cultures. This study aims to develop a technology for 3D printing a hybrid meat product and subsequently design a finely tuned You Only Look Once (YOLO) model for detecting and counting lipoblasts, fibroblasts, and myogenic cells. Methods: Cultures of multipotent mesenchymal stem cells (MMSCs) and fibroblasts were obtained from the domestic rabbit Oryctolagus cuniculus domesticus. Standard protocols were employed to induce adipogenic and myogenic differentiation from MMSCs. Fibroblasts were isolated from skin biopsy samples. The 3D printing process utilized bioinks. The engineering approach involved the development of a unique print head integrated into a 3D printer. Confocal and transmission electron microscopy of the cells within the construct was performed. A dataset of digital images of lipoblasts, myogenic cells, and fibroblasts was created. Four models based on the YOLOv8-seg architecture were trained on annotated images, implemented in the Telegram bot. Results: Stable cultures of lipoblasts, myogenic cells, and fibroblasts were obtained. 3D-printed tissue constructs composed of rabbit cells, sodium alginate, and sunflower protein were successfully fabricated. A unique print head for a 3D printer was assembled. Confocal microscopy confirmed cell viability within the tissue construct. Ultrastructural analysis revealed dense intercellular contacts and high metabolic activity. The resulting product replicated the organoleptic and structural properties of natural meat. In the IT segment, the single-class model trained on lipoblasts achieved metrics of recall 85%, precision 77%, and mean Average Precision at IoU threshold 0.50 (mAP50) 79%, which improved in the multiclass model to recall 92%, precision 92%, and mAP50 81%. The IT solution was implemented in a Telegram bot capable of detecting and counting different cell types. Conclusions: A 3D tissue construct was achieved. Detailed microscopic analysis demonstrated cell viability and high metabolic activity within the polymerized alginate hydrogel. The engineered tissue product presents a potential alternative to natural meat. Additionally, the trained neural network models, implemented in a Telegram bot, proved effective in monitoring culture growth and identifying cell types in digital images across three cell cultures. As a result, we developed four YOLOv8 models and demonstrated that the multiclass model outperforms the single-class model. However, all models exhibited reduced accuracy in high-density cultures, where overlapping cells led to undercounting.

Traumatic brain injury (TBI) is one of the most common forms of neurotrauma, accompanied by significant disruptions in neuronal homeostasis and intercellular communication. A key protein involved in these processes is connexin 43 (Cx43), which facilitates the formation of gap junctions in the astrocytic network. In this study, using confocal and immunofluorescence microscopy, ultrastructural analysis, and molecular modeling, we investigated the dynamics of Cx43 expression and structural changes in neuroglia during various post-traumatic periods following TBI. It was shown that in the acute phase, 24 h post-injury, there is a reduction in Cx43 expression, accompanied by apoptotic neuronal degradation, disruption of nuclear NeuN localization, and destruction of cellular ultrastructure. By 7 days post-injury, a significant increase in Cx43 levels was observed, along with the formation of protein aggregates associated with pronounced reactive astrogliosis. Peripheral blood analysis revealed persistent neutrophilia, lymphopenia, and reduced monocyte levels, reflecting a systemic inflammatory response and immunosuppression, which was corroborated by a custom-trained neural network-based computer vision model. Linear regression and correlation analyses further identified a strong positive association between normalized monocyte levels and Cx43 expression, a moderate negative correlation with lymphocytes, and no significant correlation with neutrophils. Using a custom-built computer vision model, we confirmed these hematological trends and detected subtle changes, such as early increases in platelet counts, that were not captured by manual evaluation. The model demonstrated strong performance in classifying common blood cell types and proved to be a valuable tool for monitoring dynamic post-traumatic shifts in blood. Molecular dynamics modeling of Cx43 identified a pH-dependent mechanism of conformational reorganization under post-traumatic acidosis, mediated by the interaction between protonated His142 and Glu103. This mechanism mimics the structural consequences of the pathogenic E103K mutation and may play a critical role in the neurotoxic effects of Cx43 in TBI. These findings highlight the complexity of Cx43 regulation under traumatic conditions and its potential significance as a target for neuroprotective therapy.

The ultrastructural and functional features of photosynthesizing callus cells are poorly known. Electron microscopy studies on green, compact Glycine max calluses have shown that they are composed of photosynthesizing cells characterized by clear ultrastructural signs of senescence. Studies on chlorophyll fluorescence and CO₂ assimilation kinetics have shown that such cells were still able to maintain photosynthesis but could not compensate for the respiratory CO₂ uptake. Having a one-step CO₂ assimilation kinetics, photosynthesis in calluses differed from photosynthesis in leaves, which had a two-step CO₂ assimilation kinetics. In contrast to leaves, the fluorescence induction curves in G. max calluses strongly differed in shape depending on the color of actinic light (red or blue). Red (in contrast to blue) light excitation did not lead to CO₂ assimilation in the calluses, thus suggesting anoxygenic photosynthesis in this case. In particular, the data obtained indicate that the actinic light spectrum should be considered when cultivating calluses for micropropagation of plants and for callus tissue research.

Our studies reveal changes in the expression of the main participants in the processing of amyloid precursor protein (APP) in neurons and astrocytes after photothrombotic stroke (PTS). Here we show the increase in the level of N- and C-terminal fragments of APP in the cytoplasm of ischemic penumbra cells at 24 h after PTS and their co-immunoprecipitation with caveolin-1. The ADAM10 α-secretase level decreased in the rat brain cortex on the first day after PTS. Levels of γ-secretase complex proteins presenilin-1 and nicastrin were increased in astrocytes, but not in neurons, in the penumbra after PTS. Inhibitory analysis showed that these changes lead to neuronal death and activation of astrocytes in the early recovery period after PTS. The caveolin-1 inhibitor daidzein shifted APP processing towards Aβ synthesis, which caused astroglial activation. γ-secretase inhibitor DAPT down-regulated glial fibrillary acidic protein (GFAP) in astrocytes, prevented mouse cerebral cortex cells from PTS-induced apoptosis, and reduced the infarction volume. Thus, new generation γ-secretase inhibitors may be considered as potential agents for the treatment of stroke.

A quarter of the world’s population has no access to safe foods of high quality due to the inability of traditional agriculture to meet the growing needs. Therefore, cultivated meat produced from a large mass of animal cells in a laboratory is becoming a promising alternative to animal products. In this study, we aimed to develop a technology for obtaining a hybrid cultured meat product from rabbit cells, sodium alginate, and sunflower protein, as well as to analyze its morphological and functional characteristics. We used rabbit stem cells isolated from the greater omentum and exposed to lipogenic and myogenic differentiation, as well as rabbit skin fibroblasts. The cells were placed in a hydrogel of sodium alginate and sunflower protein and cultured for 72 h to biofabricate tissue constructs by using 3D bioprinting. Confocal and transmission electron microscopy was applied to analyze the morphological and functional characteristics of the cells in the constructs. Using 3D bioprinting, we obtained tissue constructs of 30×40×3 mm from rabbit cells, sodium alginate, and sunflower protein. According to confocal microscopy, the cells in the tissue constructs remained viable for at least 72 h. Transmission electron microscopy showed that the cells formed tight junctions and were metabolically active for at least 72 h, with fibroblasts secreting procollagen and lipoblasts secreting lipid droplets. The resulting cellular meat was obtained from a combination of fibroblasts, lipocytes, and myogenic cells, as well as two ink components. The cellular meat product was safe and ready for consumption.

The phenomenon of unstable expression of gap junction’s proteins connexins remains a “visiting card” of astrocytic tumors with various degrees of malignancy. At the same time, it stays unclear what is detected by the positive expression of connexins in astrocytic tumors: gap junctions, hemi-channels, or connexin proteins in cytosol. In the present work, for the first time, we demonstrate an ultrastructural evidence of gap junctions in pleomorphic xanthoastrocytoma, a rare primary brain tumor, the intercellular characteristics of which are poorly studied and remain very discursive and controversial. The primary tumor mass was resected during craniotomy from a 57-old patient diagnosed with pleomorphic xanthoastrocytoma Grade II based on the histopathological analysis. The immunohistochemical study was conducted with primary antibodies: Neurofilament, Myelin basic protein, Glial fibrillary acidic protein, and Synaptophysin. For electron microscopic examination fragments of tumor tissue were fixed in a glutaraldehyde, postfixed in a 1% OsO₄, dehydrated and embedded into resin. After the detailed clinical, histological, and immunohistochemical study we revealed some ultrastructural characteristics of the tumor, as well as the first evidence of direct intercellular connection between the tumor cells via gap junctions. Regularly arranged gap junctions connected the somas of xanthastrocytes with dark cytoplasm containing lipid drops. Besides the localization between the cell bodies, from one to several gap junctions were found between the branches of xanthoastrocytoma in tumor intercellular space in close proximity to tumor cell. Our results may indicate gap junctions as a possible structure for intercellular communication between pleomorphic xanthoastrocytoma cells.