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Biology subjects

Gelinsky, M.

Publications and source records attributed to Gelinsky, M..

3 recordsLinked to original sources

Understanding Virtual Staining with generative adversarial networks for Osteoclast Imaging

Virtual staining with generative adversarial networks is an efficient, non-invasive and scalable alternative to conventional cell staining, minimizing the need for destructive and time-consuming protocols. In this study, we investigate the explainability of a network trained to virtually stain osteoclast cultures, using intensity-based label-free input images. The model enables analysis of cell cultures without immunostaining. Explainability assessments, including receptive field and feature map analyses, show that the background in input images significantly influences staining predictions within cellular regions and the trained network performs an internal segmentation during the image transformation process. This suggests that contextual cues beyond cell boundaries are implicitly learned and integrated during training. By eliminating repetitive staining procedures, virtual staining enables longitudinal studies, allows multiplexing of individual samples, and reduces reagents and laboratory waste. Our findings enhance understanding of the virtual staining process and highlight its potential for biomedical research applications.

bioengineering↗

Prolonged cell encapsulation and rapid filamented light biofabrication of muscle constructs in microgravity

The prospects of fabricating human tissue grafts or models using cell-laden bioresins in space has garnered significant interest in recent years. While there has been tremendous progress in extrusion or light-based bioprinting in microgravity conditions, printing of aligned tissues, such as those featuring anisotropic organization of cells and extracellular matrices (e.g., muscle, tendon, cardiac, etc.), remains a challenge. Furthermore, current photoresin formulations do not allow long-term cell encapsulation and are difficult to perform in microgravity. In this study, we demonstrate a new gravity-independent filamented light (G-FLight) biofabrication system with in-built refrigeration and heating units, which can create viable muscle constructs within seconds. We developed new photoresin formulations based on gelatin methacrylate (GelMA) for encapsulation of primary cells (murine myoblasts) and storage in printing cuvettes for at least a week at 4{degrees}C or -80{degrees}C. The tissues printed in microgravity based on the new formulations exhibited higher cell viability, number of proliferating cells and after maturation higher numbers of myotubes and fusion index compared to control formulations (i.e., GelMA dissolved in phosphate buffered saline). The microgravity-printed tissues also featured similar myotube density and fusion index to those printed using the same resins on-ground. The G-Flight printing concept, together with the new resins enabling refrigeration or cryopreservation with encapsulated cells, offers a promising solution for biofabrication in space.

bioengineering↗

Local erythropoiesis directs oxygen availability in bone fracture repair

Oxygen tension dynamically regulates stem cell fate and tissue regeneration, yet how local oxygen availability is controlled within the bone marrow niche remains poorly understood. While bone marrow injury, such as by bone fracture, disrupts marrow vasculature, the consequences on local oxygen tension remain unclear. Here, we show in mice that while the tissue oxygen tension in bone marrow is low (25 mmHg, [~]4% O2), intracellular oxygenation is heterogeneous and erythroid cells are high in oxygen. Bone fracture elevates oxygen tension in the injured bone marrow (>55 mmHg, [~]8%), which persists for over a week post-injury. This oxygen elevation results not from angiogenesis, but rather from localized expansion of erythroid precursor cells in the injured bone marrow. The activated erythroid precursors synthesize hemoglobin and accumulate oxygen, acting as local modulators of oxygen tension. Blocking transferrin receptor 1 (CD71)-mediated iron uptake impairs hemoglobin synthesis, reduces local oxygen levels, and enhances bone regeneration through increased angiogenesis and osteogenesis. These findings identify erythroid precursors as active regulators of local oxygen availability in the bone marrow niche, which may be targetable to enhance tissue regeneration.

cell biology↗