Translating therapeutic microgels into clinical applications.

Microgels are crosslinked polymer networks of finite dimensions in the range of 10 nm to 100 μm. Water-swollen microgels are inherently biocompatible and therefore of interest for biomedical applications. They can be modified chemically or biologically, priming microgels also for advanced clinical applications. Depending on their intended use, microgels require different mechanical and structural properties, which can be engineered and tuned on demand by altering the biochemical composition, crosslink density of the polymer network, and the fabrication method. Here, we discuss the fundamental aspects of microgel research and development as well as their specific applications for theranostics and therapy in the clinic. We present a detailed overview of microgel fabrication techniques with regards to their intended clinical application, while focussing on how microgels can be employed as local drug delivery materials, scavengers, and contrast agents. Moreover, we discuss how microgels can act as scaffolds for tissue engineering and regeneration application. Finally, we give an overview of microgels, which already made it into pre-clinical and clinical trials and discuss future challenges and chances. This review presents an instructive guideline for chemists, material scientists, and researchers in the biomedical field to introduce them to the fundamental physicochemical properties of microgels and guide them from fabrication methods via characterization techniques and functionalization of microgels towards specific applications in the clinic. This article is protected by copyright. All rights reserved.