Lipid membrane-assisted condensation and assembly of amphiphilic Janus particles

Abstract

Amphiphilic Janus particles self-assemble into complex metastructures, but little is known about how their assembly might be modified by weak interactions with a nearby biological membrane surface. Here, we report an integrated experimental and molecular dynamics simulation study to investigate the self-assembly of amphiphilic Janus particles on a lipid membrane. We created an experimental system in which Janus particles are allowed to self-assemble in the same medium where zwitterionic lipids form giant unilamellar vesicles (GUVs). Janus particles spontaneously concentrated on the inner leaflet of the GUVs. They exhibited biased orientation and heterogeneous rotational dynamics as revealed by single particle rotational tracking. The combined experimental and simulation results show that Janus particles concentrate on the lipid membranes due to weak particle-lipid attraction, whereas the biased orientation of particles is driven predominantly by inter-particle interactions. This study demonstrates the potential of using lipid membranes to influence the self-assembly of Janus particles.

Janus Nanoparticles: Recent Advances in Their Interfacial and Biomedical Applications

“…In this regard, it is very important to understand the biological interaction of Janus nanoparticles to ensure their successful clinical trial. Several simulation and experimental studies reported in the literature exhibit that Janus particles show different biological interactions as compared to homogeneous particles owing to their surface anisotropy. ,− These studies help us to rationally design Janus particles, with the desired biological properties and use them to understand and manipulate different cellular functions as required.…”

Curvature-Mediated Assembly of Janus Nanoparticles on Membrane Vesicles

“…21,22 Current synthesis methods of Janus particles allow to adjust surface properties such as hydrophobicity, hydrophilicity, and charge 23,24 that affect the adhesiveness to vesicle membranes. 25 The simulation data of Figure 1 show repulsive curvature-mediated interactions of two Janus particles that are adsorbed at the inside of a vesicle. In our simulated annealing Monte Carlo (MC) simulations, the bending energy of the vesicle is minimized at different, fixed distances of the two particles (see Supporting Information for further information).…”

“…The strongly adhesive cap of adsorbed Janus particles is fully covered by the vesicle membrane. In experiments, Janus particles with strongly adhesive and nonadhesive surface areas have been realized by partial coating with ligands that bind to receptors anchored in cell membranes. , Current synthesis methods of Janus particles allow to adjust surface properties such as hydrophobicity, hydrophilicity, and charge , that affect the adhesiveness to vesicle membranes …”

Interrogating Cellular Functions with Designer Janus Particles

“…Yet we currently have little knowledge about how the surface or structural anisotropy of Janus particles might affect their interaction with biological systems. Simulation studies have predicted that when Janus particles interact with biological systems, their behavior deviates from that of uniform particles due to their surface anisotropy. − We and other groups have also demonstrated this experimentally in a few recent studies. ,,− However, more studies from both theoretical and experimental perspectives are necessary to fully elucidate the role the anisotropy of Janus particles plays in their biological behavior. With such fundamental knowledge, we may then be able to rationally design Janus particle-based materials with desirable biological properties.…”