๐ฐ "Orientational frustration drives enhanced diffusion of anisotropic particles in a liquid labyrinth"
https://arxiv.org/abs/2605.23340 #Physics.Bio-Ph
#Extracellular #Cond-Mat.Soft
#Dynamics
Orientational frustration drives enhanced diffusion of anisotropic particles in a liquid labyrinth
Transport of nanoscale objects in complex, structured environments plays a key role in a wide range of processes, from biomolecular dynamics in extracellular spaces to transport in porous materials such as filters and catalysts. While anomalous diffusion is well established, how particle anisotropy governs transport under geometric constraints remains unclear. Here we use 3D single-particle tracking to investigate the diffusion of stiff one-dimensional carbon nanotubes in a continuous soft matter network of interconnected chambers and constrictions. Transport is anomalous and antipersistent, with strong length dependent confinement and trapping, consistent with obstructed diffusion. Unexpectedly, however, escape from confinement is poorly sensitive to nanotube length as opposed to what would be expected of pore mediated transport. Despite a tenfold length increase and significantly enhanced trapping, escape time increased by only ~1.4. Single-particle orientational tracking reveals the origin of this weak scaling. Indeed, long nanotube, i.e. those with length comparable to the chamber dimensions, dynamically align with constrictions enabling efficient, geometry-assisted escape that offsets increased confinement while shorter nanotubes need to screen the volume to find their escape path. These results uncover an alignment-mediated transport mechanism that decouples confinement strength from escape kinetics, distinct from pore-mediated transport mechanisms, establishing a quantitative framework for anisotropic diffusion in complex environments.
๐ฐ "A membrane-permeable small molecule biosensor accesses intractable cells and animals without genetic manipulation"
https://www.biorxiv.org/content/10.64898/2026.05.22.727289v1?rss=1 #Extracellular #Dynamics๐ฐ "3D bioprinting of engineered living materials in support slurries for complex free-standing structures"
https://www.biorxiv.org/content/10.64898/2026.05.20.726626v1?rss=1 #Extracellular #Mechanical๐ฐ "SurpHer: a genetically encoded ratiometric sensor for dynamic extracellular pH imaging"
https://www.biorxiv.org/content/10.64898/2026.05.18.725923v1?rss=1 #Extracellular #Dynamics๐ฐ "Compartmental-reaction diffusion framework for microscale dynamics of extracellular serotonin in brain tissue"
https://arxiv.org/abs/2512.10983 #Extracellular #Q-Bio.To
#Q-Bio.Nc
#Q-Bio.Cb
#Dynamics
Compartmental-reaction diffusion framework for microscale dynamics of extracellular serotonin in brain tissue
Serotonin (5-hydroxytryptamine) is a major neurotransmitter whose release from densely distributed serotonergic varicosities shapes plasticity and network integration throughout the brain, yet its extracellular dynamics remain poorly understood due to the sub-micrometer and millisecond scales involved. We develop a mathematical framework that captures the coupled reaction-diffusion processes governing serotonin signaling in realistic tissue microenvironments. Formulating a two-dimensional compartmental-reaction diffusion system, we use strong localized perturbation theory to derive an asymptotically equivalent set of nonlinear integro-ODEs that preserve diffusive coupling while enabling efficient computation. We analyze period-averaged steady states, establish bounds using Jensen's inequality, obtain closed-form spike maxima and minima, and implement a fast marching-scheme solver based on sum-of-exponentials kernels. These mathematical results provide quantitative insight into how firing frequency, varicosity geometry, and uptake kinetics shape extracellular serotonin. The model reveals that varicosities form diffusively coupled microdomains capable of generating spatial "serotonin reservoirs," clarifies aspects of local versus volume transmission, and yields predictions relevant to interpreting high-resolution serotonin imaging and the actions of selective serotonin-reuptake inhibitors.
๐ฐ "C. albicans ergosterol modulates the antifungal response of human neutrophils by masking ฮฒ-glucan"
https://www.biorxiv.org/content/10.64898/2026.05.18.721578v1?rss=1 #Extracellular #Morphogenesis๐ฐ "Differential collagen crosslinking and network organization creates distinct tissue remodeling patterns in fibrosis and COPD"
https://www.biorxiv.org/content/10.64898/2026.05.13.724372v1?rss=1 #Extracellular #Mechanical๐ฐ "Emerging Mechanobiological Roles of LIM-Only Proteins: Distinct Pathways of CRP and LMO in Cytoskeleton Regulation and Disease"
https://doi.org/doi:10.1002/cm.70151https://pubmed.ncbi.nlm.nih.gov/42129964/ #Mechanotransduction #Extracellular #Cytoskeleton
Rxiv mechanobio