Transmembrane transport of polymer brush-grafted nanoparticles into giant vesicles

TL;DR

This study uses Self-Consistent Field Theory to analyze how polymer brush-grafted nanoparticles cross cell-like membranes, revealing two mechanisms influenced by membrane thickness and grafting density, with entropy driving the process.

Contribution

It systematically elucidates the effects of key parameters on nanoparticle transmembrane transport mechanisms using theoretical modeling.

Findings

Two distinct transport mechanisms identified: direct translocation and endocytosis.

Transport behavior depends on membrane thickness and grafting density.

Entropy is the main driving force for nanoparticle translocation.

Abstract

Polymer brush-grafted nanoparticles have significant application value in fields such as gene therapy and targeted drug delivery. A profound understanding of the interaction mechanisms between these particles and cell membranes represents a critical scientific challenge in biophysics. Using the Self-Consistent Field Theory, this work systematically explores the transmembrane transport of polymer brush-grafted nanoparticles into giant vesicles. The impacts of critical parameters-polymer brush grafting density, nanoparticle size, and giant vesicle membrane thickness-on transport behavior are comprehensively elucidated. The findings reveal two distinct transmembrane transport mechanisms for polymer brush-grafted nanoparticles, which are governed by membrane thickness and grafting density. At high grafting density, the nanoparticles undergo direct transmembrane translocation; at low grafting density, transport occurs via endocytosis. Thermodynamic analysis identifies entropy as the dominant driving force for this process.