Free Energy Simulations of Cargo-Carrier Interactions for Core-Multishell Nanotransporters

Abstract

Dendritic core-multishell (CMS) nanotransporters are composed of three parts: a polyglycerol amine core covalently linked to an inner alkyl shell and an outer polyethylene glycol shell. Aiming to unravel the preferred localization of the guest molecule within the locally well-tolerated delivery system, we transferred molecular dynamics simulations to CMS nanotransporters and verified the results with experimental data. Differences in free energy of the planar, nonpolar, and lipophilic Nile red (log P 3.4) indicated a preferential location within the inner CMS nanotransporter shell. Differences in free energy of the globular, polar and hydrophilic morphine (log P ≤ 0.8) predicted poor loading which has been verified. Replacing the outer CMS nanotransporter shell by glutamate or aspartate results in electrostatic forcemediated morphine attachment. Thus, the investigation of larger molecular systems consisting of many similar building blocks becomes feasible with our approach. In conclusion, the computational approach based on differences in free energy may improve the design of tailor-made CMS nanotransporters and enhance drug development.