Stimuli-responsive polymersomes as nanocarriers for drug and gene delivery

Polymeric formulations (micelles, vesicles etc.) have emerged as versatile drug carriers due to their increased stability, site specificity, blood circulation resistance and thus overall potential therapeutic effects compared to liposomes. Furthermore, stimuli-responsive systems have been developed whose properties change after applying certain external triggers. Polymersomes are mainly composed of amphiphilic block copolymers that are held together in water due to strong physical interactions between the insoluble hydrophobic blocks, thus forming a bilayer morphology or, in the case of triblock copolymers, a bilayer-like morphology. Formation and destabilization of these assemblies is a consequence of external stimuli (temperature, pH, oxidation/reduction conditions etc.). This review focuses on recent developments concerning stimuli- responsive polymersomes made of amphiphilic block copolymers and their potential applications within the biomedical field.