Recent advances and perspectives of multifunctional nanogels in biomedical applications

Nanogels (NGs) are considered as a kind of nanoscale hydrogels (<200 nm) endowing with the functions of both nanomaterials and hydrogels. In the last 20 years, NGs have garnered significant attention due to their versatility and adaptability. Herein, a comprehensive overview of the latest advancements and current research status of NGs is provided, with a particular focus on the synthesis strategies involving physical and chemical cross-linking methods, as well as the advantages of NGs in drug loading and responsive release. Based on the diverse design strategies of NGs, four key biomedical applications, including inflammation therapy, regenerative medicine, bioimaging and tumor therapy are further summarized and discussed. Moreover, the existed inherent challenges facing NGs are proposed, while highlighting their potential to revolutionize therapeutic and diagnostic approaches. Finally, we look forward to the further development and promising potentials of NGs in biomedical applications. This review aims to serve as a valuable reference for researchers, providing some insights into the evolving landscape of NGs and their potential in advanced biomedical applications.