Softness and Hydrodynamic Interactions Regulate Lipoprotein Transport in Crowded Yolk Environments

Nimmi Das Anthuparambil; Michelle Dargasz; Sonja Timmermann; Anita Girelli; Sebastian Retzbach; Johannes Möller; Wonhyuk Jo; Agha Mohammad Raza; Aliaksandr Leonau; James Wrigley; Frederik Unger; Maddalena Bin; Prince Prabhu Rajaiah; Iason Andronis; William Chèvremont; Jörg Hallmann; Angel Rodriguez-Fernandez; Jan-Etienne Pudell; Felix Brausse; Ulrike Boesenberg; Mohamed Youssef; Roman Shayduk; Rustam Rysov; Anders Madsen; Felix Lehmkühler; Michael Paulus; Fajun Zhang; Fivos Perakis; Frank Schreiber; Christian Gutt

arXiv · 2505.22520

Softness and Hydrodynamic Interactions Regulate Lipoprotein Transport in Crowded Yolk Environments

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Abstract

Low-density lipoproteins (LDLs) serve as nutrient reservoirs in egg yolk for embryonic development and as promising drug carriers. Both roles critically depend on their mobility in densely crowded biological environments. Under these crowded conditions, diffusion is hindered by transient confinement within dynamic cages formed by neighboring particles, driven by solvent-mediated hydrodynamic interactions and memory effects -- phenomena that have remained challenging to characterize computationally and experimentally. Here, we employ megahertz X-ray photon correlation spectroscopy to directly probe the cage dynamics of LDLs in yolk-plasma across various concentrations. We find that LDLs undergo anomalous diffusion, experiencing $\approx$ 100-fold reduction in self-diffusion at high concentrations compared to dilute solutions. This drastic slowing-down is attributed to a combination of hydrodynamic interactions, direct particle-particle interactions, and the inherent softness of LDL particles. Despite reduced dynamics, yolk-plasma remains as a liquid, yet sluggish, balancing dense packing, structural stability, and fluidity essential for controlled lipid release during embryogenesis.

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Nimmi Das Anthuparambil, Michelle Dargasz, Sonja Timmermann, Anita Girelli, Sebastian Retzbach, Johannes Möller, Wonhyuk Jo, Agha Mohammad Raza, Aliaksandr Leonau, James Wrigley, Frederik Unger, Maddalena Bin, Prince Prabhu Rajaiah, Iason Andronis, William Chèvremont, Jörg Hallmann, Angel Rodriguez-Fernandez, Jan-Etienne Pudell, Felix Brausse, Ulrike Boesenberg, Mohamed Youssef, Roman Shayduk, Rustam Rysov, Anders Madsen, Felix Lehmkühler, Michael Paulus, Fajun Zhang, Fivos Perakis, Frank Schreiber, Christian Gutt. 2025-05-28. Softness and Hydrodynamic Interactions Regulate Lipoprotein Transport in Crowded Yolk Environments. https://arxiv.org/abs/2505.22520

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