Modeling the internal structure of micelles in a delivery system based on 4-arm star shaped polymers

Abstract

A previously studied drug delivery systems based on 4-arm star shaped polyacids with pentaerythritol core have been proposed as excellent micellar nanocarriers with adjustable characteristics for drug loading and release, including anti-inflammatory drugs. A series of experiments to measure the release of drugs by micelles of various composition were conducted. Here we model this release process by mathematical methods and conclude about the structure and loading capability of the obtained micelles in relation to their composition. Our method is a random walk simulation in a potential field. The results predict a decreasing dependency of the micelle core size on hydrophobic content which relates to the loading capability and release kinetics. We link this phenomenon to the packing quality of the micelle’s core, which is reflected by the values of the drug’s binding energy to the core and the probability to incorporate the drug into the core.