Scratching the Surface of Unventured Possibilities with In Situ Self-Assembly: Protease-Activated Developments for Imaging and Therapy

In situ self-assembly has attracted increasing research interest for applications in imaging and therapy in recent years. Particularly for protease-activated developments, inspiration is drawn from the innate specificity of their catalytic activities, rapid discovery of the various roles they play in the proliferation of certain diseases, and inherent susceptibility of small molecule peptide conjugates to proteolytic digestion in vivo. The overexpression of a disease-related protease of interest can be exploited as an endogenous stimulus for site-specific self-assembly to largely amplify a molecular event happening at the cellular level. This holds great potential for applications in early stage disease detection, long-term disease monitoring, and sustained therapeutic effects. This review summarizes the recent developments in protease-activated self-assemblies for imaging and therapeutic applications toward the manifestation of tumors, bacterial infections, neurodegenerative disorders, and wound recovery.