Polydots, Soft Nanoparticles, at Membrane Interfaces

Luminescent polymers confined into long lived polydots form a new class of soft nanoparticles whose emission characteristics are tunable. These polydots are candidates for new classes of targeted drug delivering agents and bio imaging markers. One critical step in the use of any nanoparticle (NP) for medicine is their transport across membranes. Their ability to penetrate cells depends on the NPs’ surface structure, their size, shape and charge as well as membrane characteristics. The soft nature of the polydots provides an edge in comparison to hard NPs; it allows modifications of their interfaces without losing their optical characterizes and the degree of confinement offers a response to changing environments, expressed in shift of emission wave lengths. Here we report the results of an all-atom molecular dynamics simulation of a polydot that consists of a collapsed model polymer, dinonyl poly para phenylene ethynylene (PPE), at the interface of a bilayer composed 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). We find that the initial membrane deformation formed following the introduction of the polydot relaxes over time. Methods of impregnating the membranes with polydots will be discussed following by effects of the soft NP on the structure and dynamics of the membranes. In parallel, the effects of the membrane on the polydot will be introduced.