A Critical Look at Multilayered Polymer Capsules in Biomedicine: Drug Carriers, Artificial Organelles, and Cell Mimics

This Feature Article discusses utility of multilayered polymer capsules in biomedicine, specifically in drug delivery and in design of artificial organelles and cells. We provide a critical view on recent successes and identified shortcomings of these capsules in delivery of therapeutic cargo and outline plausible further developments of capsules as candidate drug carriers. A special emphasis is placed on poly(methacrylic acid) hydrogel capsules as successful carriers used in delivery of anticancer drugs and protein and peptide vaccines. We further present a novel biomedical approach whereby the same vessel acts first as a microreactor and then as a carrier for de novo synthesized therapeutic cargo. Finally, utility of polymer capsules in design of cell mimics is discussed with an emphasis on assembly and performance of capsosomes, polymer capsules with liposomal subcompartments. This presentation of capsules in biomedicine aims to provide an overview of past achievements and existing challenges associated with these candidate vessels and to stimulate further research interest from a broad scientific audience.