npj Microgravity最新文献

Prolonged space missions expose astronauts to microgravity and cosmic radiation, leading to persistent vascular dysfunction driven by oxidative stress, cardiac deconditioning, and reduced physical activity. Current therapies are limited by adverse effects such as hypertension, hyperkalemia, and poor bioavailability, with no effective countermeasures targeting oxidative and endothelial-specific damage. Here, we present a multifunctional zein nanocage-based therapeutic formulation (ZNT) that encapsulates a remedial cocktail designed to mitigate oxidative stress and protect cardiovascular health under simulated microgravity conditions. In vitro studies on endothelial cells have revealed that microgravity induces reactive oxygen species generation, mitochondrial membrane depolarization, oxidative DNA damage, and apoptosis. These changes were accompanied by elevated nitric oxide production and aberrant expression of angiogenesis-related genes, including VEGFA, HIF-1α, eNOS, iNOS, FGF-2, and ANG1. Treatment with ZNT restored redox balance, preserved mitochondrial integrity, prevented DNA damage and apoptosis, and normalized angiogenic gene expression. These protective effects were further validated in vivo using zebrafish larvae and chick embryo models. By addressing both oxidative stress and pathological angiogenesis, ZNT emerges as a promising nanotherapeutic strategy to safeguard cardiovascular function during and after spaceflight, potentially filling a critical gap in astronaut healthcare.

Expanding human space exploration necessitates technologies for sustainable local resource acquisition, to overcome unviable resupply missions. Asteroids, some of which rich in metals like platinum group elements, are promising targets. The BioAsteroid experiment aboard the International Space Station tested the use of microorganisms (bacteria and fungi) to extract 44 elements from L-chondrite asteroidal material under microgravity. Penicillium simplicissimum enhanced the release of palladium, platinum and other elements in microgravity, compared to non-biological leaching. For many elements, non-biological leaching was more effective in microgravity than on Earth, while bioleaching remained stable. Metabolomic analysis revealed distinct changes in microbial metabolism in space, particularly for P. simplicissimum, with increased production of carboxylic acids, and molecules of potential biomining or pharmaceutical interest in microgravity. These results demonstrate the impact of microgravity on bioleaching, highlighting the need for optimal combination of microorganisms, rock substrate, and conditions for successful biomining, in space and Earth.

Long-duration spaceflight presents similar medical challenges to submarine deployment, including limited surgical capabilities and the psychological strain from isolation. This review synthesizes submarine medical literature to highlight parallels and divergences with space medicine, focusing on acute conditions. By comparing incidence data on acute medical diagnoses and examining case studies of these conditions, we propose countermeasures such as expanded surgical training and increased mental engagement. These analogies provide a blueprint for autonomous medical care on missions to the Moon and Mars.

We demonstrate a novel biomedical application of a commercial spiral microfluidic chip (Fluidic 382), originally developed for particle sorting, by repurposing it for label-free, size-based isolation of pathological blood cells, including leukemic blasts from acute myeloid leukemia (AML) samples. For the first time, we establish and validate a streamlined protocol for cell separation using Dean-driven hydrodynamic forces in a chip not originally designed for blood analysis. Using a 9-turn, 6-outlet spiral channel configuration, we achieved high-efficiency sorting of red and white blood cells from healthy donors and selectively enriched pathological blasts from AML patient blood. The device's performance was validated through flow cytometry and numerical simulations, demonstrating strong agreement between experimental and computational results with less than 1% relative error. With its compact footprint, reagent-free operation, and automation potential, this method represents a significant advance toward point-of-care blood diagnostics in extreme environments, particularly space missions. The chip's ability to separate pathological cells in microgravity-compatible conditions offers a promising route for real-time astronaut health monitoring, supporting early detection and mitigation of radiation-induced haematological disorders such as AML.

Understanding the shear and intrusion rheological behavior of granular materials under reduced gravitational conditions is crucial for applications in planetary exploration and submarine earthquake engineering. To this end, it is important to understand whether gravity affects the drag forces on objects intruding granular media and, if so, quantify these effects. We have studied this issue experimentally in 1 g and 0 g conditions, the latter using the Beijing Drop Tower. Measuring the resistive forces on a cylinder moving at a constant speed through a granular bed, we find that gravity plays a significant role - the resistive forces increase significantly with cylinder speed in 0 g, while increasing much more slowly in 1 g. We use Coupled Eulerian-Lagrangian (CEL) simulations that support our results. We attribute this behavior to the increasingly dominant effect of pressure-sensitive frictional forces in microgravity with increasing fluidity in these conditions. Other than the significant implications for extraterrestrial exploration, our findings suggest that constitutive modeling of flow in microgravity should differ significantly from that in 1 g.

Space biomanufacturing using engineered microbes offers a sustainable approach for producing biomaterials, pharmaceuticals, and essential metabolites, critical for long-duration space missions. However, microgravity-induced physiological changes can alter microbial metabolism and biosynthetic efficiency. This study investigated the effects of microgravity on melanin biosynthesis in non-motile Escherichia coli aboard the International Space Station (ISS). Despite expressing functional tyrosinase, ISS-grown E. coli exhibited significantly lower melanin production than ground controls. Differential pulse voltammetry revealed high extracellular tyrosine in ISS samples, indicating inefficient substrate catalysis. Low Shear Modeled Microgravity (LSMMG) experiments in the Rotating Wall Vessel bioreactor confirmed reduced melanin production and bacterial viability. Proteomic profiling identified increased expression of membrane, transport, and stress-related proteins, while metabolomic analysis showed elevated trehalose and decreased glutathione, indicating oxidative stress and perturbed redox homeostasis. These findings highlight the impact of microgravity on microbial metabolism and provide insights for optimizing microbial biomanufacturing in extraterrestrial environments.

Lunar surface operations conducted by the United States and the Soviet Union confirmed that penetration resistance is a key indicator for evaluating the engineering properties of lunar regolith. To quantitatively assess the influence of reduced gravity on penetration resistance, this study employed a newly developed Geotechnical Magnetic-gravity Modeling Test (GMMT) system to perform cone penetration tests under controlled gravitational acceleration levels of 1/6 g, 1 g, and 2 g. The results indicated that the normalized penetration resistance increased as gravity decreased, and this effect was amplified at higher relative densities. To investigate the underlying mechanisms, discrete element method (DEM) simulations were conducted. The findings revealed that, in addition to gravity, in situ factors such as high relative density and irregular particle morphology also significantly enhanced penetration resistance by strengthening interparticle contact and friction. These non-gravitational effects partially offset the expected reduction in resistance under lower gravity, leading to a smaller-than-anticipated decline. This study provides new insights into the gravity-dependent penetration behavior of lunar regolith.

The accelerated pace of commercial spaceflight is rapidly increasing the number of civilian spaceflight participants (SFP). In this study, SFPs were shown to be older with a broader age range than NASA astronauts, and have more diverse educational backgrounds and occupations. K-means clustering using demographic data showed that NASA astronauts fall broadly into categories reflecting military pilot training versus non-pilots, often scientists and engineers. Conversely, SFPs fall into five categories we label as Professional Astronauts, Veteran Adventurers, Young Adventurers, Celebrities, and Science Tourists. Overall, these SFPs are a more diverse and globally representative population than traditional governmental astronauts, and the demographics of each cohort directly reflect the mission objectives of their respective agencies and companies. Demographics provide insight into the goals and priorities of both governmental and commercial spaceflight organizations, and further investigation of these trends will be important as human spaceflight continues to change in the decades to come.

Bone density loss is a major concern for astronauts in space, largely due to altered mechanical stimuli in microgravity. These changes are thought to impact bone cells by directly affecting musculoskeletal cell physiology and disrupting mechanosensing and mechanotransduction pathways. This review focuses on the role of the primary cilium, a small, non-motile cellular structure, involved in these processes. Previously underestimated, the primary cilium is now known to act as a mechano- and chemo-sensor on the surface of most vertebrate cells, transmitting signals via multiple intracellular pathways. The primary cilium senses the extracellular fluid flow and its dynamic changes in physiological and pathological conditions, which may include exposure to microgravity, connecting its inactivation to bone density loss. This systematic review will compile and analyze current data on how weightlessness affects the mechanosensing functions of the primary cilium and its role in bone homeostasis disruption.

Age-related skeletal muscle deterioration, referred to as sarcopenia, poses significant risks to astronaut health and mission success during spaceflight, yet its multisystem drivers remain poorly understood. While terrestrial sarcopenia manifests gradually through aging, spaceflight induces analogous musculoskeletal decline within weeks, providing an accelerated model to study conserved atrophy mechanisms. Here, we introduced an integrative framework combining cross-species genetic analysis with physiological modeling to understand mechanistic pathways in space-induced sarcopenia. By analyzing rodent and human datasets, we identified conserved molecular pathways underlying spaceflight-induced muscle atrophy, revealing shared regulators of neuromuscular signaling including pathways related to neurotransmitter release and regulation, mitochondrial function, and synaptic integration. Building upon these molecular insights, we developed a physiologically grounded central pattern generator model that reproduced spaceflight-induced locomotion deficits in mice. This multi-scale approach established mechanistic connections between transcriptional changes and impaired movement kinetics while identifying potential therapeutic targets applicable to both spaceflight and terrestrial aging-related muscle loss.