Assembly of Janus Nanoparticles on Lipid Vesicles

Janus nanoparticles (JNPs), which integrates two different components into one structure to promote different functions, have a wide range of potential application, and have thus been the subject of many studies during the past few years. Here, we investigate the adhesion modes of two spherical JNPs on and inside lipid vesicles through large scale molecular dynamics simulations of a coarse-grained implicit-solvent model.  Compared to isotropic spherical nanoparticles, the wrapping of JNPs by the membrane is mainly controlled by their degree of Janusity and their diameter. A detailed phase diagram of the NPs arrangement on the vesicle is obtained from molecular dynamics simulations of coarse-grained implicit-solvent model in conjunction with the Weighted Histogram Analysis Method. In the case where the JNPs are inside the vesicle, they prefer to be apart at specific preferred locations relative to each other, regardless of the degree of Janusity. In the case where the JNPs are outside the vesicle, and for low degrees of Janusity, the JNPs again prefer to be apart from each other at specific locations. However, for relatively high values of the degree of Janusity, the JNPs dimerize. Overall, our results agree with those of Bahrami and Weikl [Nano Lett. 18, 1259 (2018)], which are based on a Monte Carlo Monte Carlo energy minimization of a dynamically triangulated vesicle. Interesting, however, the deformations caused by the JNPs on the vesicle are not always symmetric, when they adhere to the exterior.