Harnessing steric hindrance to control interfacial adsorption of patchy nanoparticles onto hairy vesicles

Adsorption on Ligand-Tethered Nanoparticles

We use coarse-grained molecular dynamics simulations to study adsorption on ligand-tethered particles. Nanoparticles with attached flexible and stiff ligands are considered. We discuss how the excess adsorption isotherm, the thickness of the polymer corona, and its morphology depend on the number of ligands, their length, the size of the core, and the interaction parameters. We investigate the adsorption-induced structural transitions of polymer coatings. The behavior of systems involving curved and flat "brushes" is compared.

Adsorption-induced co-assembly of hairy and isotropic particles

We use coarse-grained molecular dynamics simulations to study the behavior of polymer-tethered particles immersed in fluids of isotropic particles. Particles modified with weakly anchored, mobile ligands are considered. We discuss how the concentration of fluid particles affects the morphology of an isolated hairy particle. It is shown that hairy particles present different morphologies including typical core-shell, octopus-like and corn-like, depending on fluid-segment interactions and the fluid density. The mechanism of changes in the shape of hairy particles is explained. The reconfiguration of the polymer corona arises from adsorption of fluid particles "on chains". The adsorbed fluid particles form bridges between the chains. This causes the mobile ligands to merge into clusters on the core surface. A part of the core remains empty so the hairy particle becomes a Janus-like object. We also study co-assembly in mixtures of hairy and isotropic particles. Depending on the strength of fluid-segment interactions, hairy particles with fluid particles trapped inside their coronas remain isolated or form mixed clusters of different structures. The aggregation of hairy particles results from the formation of bridges between chains belonging to different cores by fluid particles.

Flow-Induced Shape Reconfiguration, Phase Separation, and Rupture of Bio-Inspired Vesicles

The structural integrity of red blood cells and drug delivery carriers through blood vessels is dependent upon their ability to adapt their shape during their transportation. Our goal is to examine the role of the composition of bio-inspired multicomponent and hairy vesicles on their shape during their transport through in a channel. Through the dissipative particle dynamics simulation technique, we apply Poiseuille flow in a cylindrical channel. We investigate the effect of flow conditions and concentration of key molecular components on the shape, phase separation, and structural integrity of the bio-inspired multicomponent and hairy vesicles. Our results show the Reynolds number and molecular composition of the vesicles impact their flow-induced deformation, phase separation on the outer monolayer due to the Marangoni effect, and rupture. The findings from this study could be used to enhance the design of drug delivery and tissue engineering systems.