Tuning loading and release by modification of micelle core crystallinity and preparation

Abstract

Controlling and tuning the loading and release of incorporated drugs are vital parts of the advancement of drug delivery systems. Micelle systems that use core crystallinity to tune the loaded amount of hydrophobic molecules as well as their released amount were therefore developed. The conductive and electroactive aniline pentamer was incorporated into poly(ethylene glycol)–poly(ε‐caprolactone) (PEG–PCL) micelles with semi‐crystalline cores and poly(ethylene glycol)–poly(ε‐decalactone) (PEG–PεDL) micelles with amorphous cores. The difference in core crystallinity of the two micelle systems gave rise to highly different loading capacities and release rates. The loading capacity was strongly dependent on the core crystallinity, and the amorphous PEG–PεDL micelles had almost twice as high loading capacity as the semi‐crystalline PEG–PCL micelles. In addition, the loading capacity was highly influenced by the loading procedure. The dependence on core crystallinity was also evident for the release of the aniline pentamer. The release occurred faster for the PEG–PεDL micelles with amorphous cores compared with the PEG–PCL micelles with semi‐crystalline cores. The use of just these two systems gave us the ability to tune the released amount and rate, and a combination of these systems can enable access to a wide range of release profiles, thereby being available to a variety of drug delivery applications. © 2015 The Authors. Polymers for Advanced Technologies Published by John Wiley & Sons Ltd.