Fundamental mechanism of translocation across liquidlike membranes: toward control over nanoparticle behavior

We envision and theoretically investigate a novel behavior of a functionalized nanoparticle designed to translocate through a liquidlike membrane. We develop a statistical-mechanical approach to such a system. We predict a new mechanism for the opening of a circular energy-dominated pore on the membrane by a nanoparticle functionalized with a peptide aggregate. Following fluctuations in the position and orientation of the nanoparticle, the peptide aggregate incorporates into the membrane and locally destabilizes it. The nucleation of a pore centered at the peptide aggregate attached to the particle is a precursor to particle translocation. The subsequent opening of the pore is assisted by adhesion of the membrane to the particle. We determine the conditions in which thermal fluctuations in the membrane shape and the pore size can induce translocation of the particle. For different system parameters quantities such as the free energy, entropy, pore size, degree of particle wrapping, and the probability of spontaneous translocation are obtained.