01397nas a2200217 4500008004100000022001400041245003900055210003800094260000800132300001000140490000700150520080000157653002800957653001800985653002301003653002401026653001701050100002001067700002101087856007101108 2023 eng d a2214-552400aMechano-immunology in microgravity0 aMechanoimmunology in microgravity cMAY a50-640 v373 a

Life on Earth has evolved to thrive in the Earth's natural gravitational field; however, as space technology advances, we must revisit and investigate the effects of unnatural conditions on human health, such as gravitational change. Studies have shown that microgravity has a negative impact on various systemic parts of humans, with the effects being more severe in the human immune system. Increasing costs, limited experimental time, and sample handling issues hampered our understanding of this field. To address the existing knowledge gap and provide confidence in modelling the phenomena, in this review, we highlight experimental works in mechanoimmunology under microgravity and different computational modelling approaches that can be used to address the existing problems.

10aComputational modelling10aImmune system10aMechano-immunology10aMechanotransduction10aMicrogravity1 aMurali, Anirudh1 aSarkar, Ram, Rup uhttps://library.ncl.res.in/content/mechano-immunology-microgravity02366nas a2200145 4500008004100000245010000041210006900141260000800210300001100218490000700229520182100236100002002057700002102077856012202098 2024 eng d00aDynamic cellular responses to gravitational forces: exploring the impact on white blood cell(s)0 aDynamic cellular responses to gravitational forces exploring the cSEP a0541120 v183 a

In recent years, the allure of space exploration and human spaceflight has surged, yet the effects of microgravity on the human body remain a significant concern. Immune and red blood cells rely on hematic or lymphatic streams as their primary means of transportation, posing notable challenges under microgravity conditions. This study sheds light on the intricate dynamics of cell behavior when suspended in bio-fluid under varying gravitational forces. Utilizing the dissipative particle dynamics approach, blood and white blood cells were modeled, with gravity applied as an external force along the vertical axis, ranging from 0 to 2 g in parameter sweeps. The results revealed discernible alterations in the cell shape and spatial alignment in response to gravity, quantified through metrics such as elongation and deformation indices, pitch angle, and normalized center of mass. Statistical analysis using the Mann-Whitney U test underscored clear distinctions between microgravity (<1 g) and hypergravity (>1 g) samples compared to normal gravity (1 g). Furthermore, the examination of forces exerted on the solid, including drag, shear stress, and solid forces, unveiled a reduction in the magnitude as the gravitational force increased. Additional analysis through dimensionless numbers unveiled the dominance of capillary and gravitational forces, which impacted cell velocity, leading to closer proximity to the wall and heightened viscous interaction with surrounding fluid particles. These interactions prompted shape alterations and reduced white blood cell area while increasing red blood cells. This study represents an effort in comprehending the effects of gravity on blood cells, offering insights into the intricate interplay between cellular dynamics and gravitational forces.

1 aMurali, Anirudh1 aSarkar, Ram, Rup uhttps://library.ncl.res.in/content/dynamic-cellular-responses-gravitational-forces-exploring-impact-white-blood-cells02500nas a2200217 4500008004100000022001400041245008500055210006900140260000800209300001200217490000700229520177900236653002002015653002702035653003402062653001502096653001902111100002002130700002102150856011102171 2025 eng d a2214-552400aImpact of gravitational forces on Red Blood Cell dynamics in biofluid suspension0 aImpact of gravitational forces on Red Blood Cell dynamics in bio cNOV a197-2100 v473 a

The growing interest in space exploration and human spaceflight has highlighted the critical challenges posed by microgravity on human physiology. Among these, a significant issue is space anemia, which adversely affects Red Blood Cells (RBC) and alters its behavior. RBC depends on biofluids, for their systemic transport, a process that experiences disruption in the microgravity environment. This study aims to quantitatively address the puzzle of how red blood cells are influenced by gravity when they are suspended in bio-fluid. Dissipative Particle Dynamics (DPD) approach was used to model blood and the cell by applying gravity as an external force along the vertical axis and varied from 0g to 2g during parameter sweeps. Key metrics, including Elongation and Deformation indices, pitch angle, and normalized center of mass, were utilized to assess cellular behavior. Results revealed that gravity induces shape changes and spatial alignment in red blood cells. The Elongation Index and the normalized center of mass declined linearly with the applied gravity. Correlation analysis showed a strong correlation between applied gravity and the aforementioned variables. Additionally, forces acting on the cell, such as drag, shear stress, and solid forces, diminished as gravitational force increased. Further analysis indicates that increasing gravity affected the cell's velocity, resulting in prolonged proximity to vessel walls and intensified viscous interactions with surrounding fluid particles, thereby triggering morphological changes. This study provides crucial insights into the biophysical effects of gravity on the red blood cell and presents a significant step toward understanding cellular dynamics under altered gravitational conditions.

10aAltered gravity10aComputational modeling10aDissipative Particle dynamics10aFluid flow10aRed Blood Cell1 aMurali, Anirudh1 aSarkar, Ram, Rup uhttps://library.ncl.res.in/content/impact-gravitational-forces-red-blood-cell-dynamics-biofluid-suspension