Advances in atom-transfer radical polymerization for drug delivery applications

The availability of appropriate materials is the main requisite for the design of controlled-release drug delivery systems (DDS), such as nanoparticles, micelles, microparticles, hydrogels and bioconjugates. These delivery platforms must be biocompatible and present appropriate mechanical, physical, chemical and biological properties, allowing the desired control over drug loading and release and granting the benefits of this therapeutic administration route. Atom transfer radical polymerization (ATRP) is presently one of the most used methods of controlled polymerization, applied to synthesize well-defined functional materials and complex polymeric architectures with programmed molecular weights and low dispersity. This review features recent advances in the synthesis of DDS by ATRP, their preparation methods, characteristics and toxicity challenges due to residual metal catalysts. A brief description of controlled polymer architectures, drug loading and release mechanisms, and ATRP techniques is presented to contextualize the readers. It is noted that precise engineering of polymeric materials over molecular architecture, granted by ARTP, is being translated to customized physical properties, allowing fine control over fundamental parameters for the design of DDS. (AU)