Depletion effect and biomembrane budding
Depletion effects are well known to lead to phase separation in microsystems consisting of large and small particles with short-range repulsive interactions that act over macromolecular length scales. The equilibrium mechanics between an enveloped colloidal particle and a biomembrane caused by entropy is investigated by using a continuum model. We show that the favorable contact energy stems from entropy, which is sufficient to drive engulfment of the colloidal particle, and deformation of the biomembrane determines the resistance to the engulfment of the colloidal particle. The engulfment process depends on the ratio of the radii of the larger particle and smaller particles and the bending rigidity. The results show insights into the effects of depletion on biomembrane budding and nanoparticle transportation by a vesicle.
KeywordsDepletion effects Cell adhesion and cell mechanics Biomembrane and vesicles Elasticity theory
Acknowledgements are made to the National Natural Science Foundation of China under Grants NO.11047022, NO.11164004, NO.41061039 and NO.30770529. We are also grateful to the Guizhou provincial tracking key program of social development under Grants NO.SZ20113069 and SY20093086 and the Grant for Visiting Scholar of the Key Laboratory of Biorheological Science and Technology of Ministry of Education (Chongqing University).
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