Size-Dependent Interaction of Nanoparticles with Non-ionic Bilayers

Understanding the mechanism of transit of a nanoparticle (NP) through a biomimetic bilayer has been at the forfront of research for the design of efficient drug-delivery mechanisms, nanotechnology and biomedicine. Establishing a consistent picture of how the transit mechanism depends on the physiochemical property of a NP is critical to understanding what approach may be the most effective for nanomedicine design. In this study, using molecular simulation techniques, we have analyzed the key properties of a NP that may affect the mechanism of transit - the effect of size and hydrophobicity. By using a continuum model of a NP based on the Hamaker potential, we have created NP of tunable hydrophobic properties. The effect of hydrophilic, hydrophobic, and mixed properties of the NP is analyzed against a biomimetic bilayer - we show that this model can illustrate three distinct properties - where the hydrophilic type shows rupture of the bilayer, the hydrophobic type showing a entrapment of the NP around the hydrophobic tailgroups of the bilayer, and the mixed type showing a distinct, direct translocation type mechanism. Increasing the NP size shows different effects for each type of NP, and hence, may provide insight into the design of NPs with these types of mechanisms involved.