Stimuli-Responsive Organic Agents for Photoacoustic Imaging and Photothermal Therapy

Owing to their inherent biocompatibility, organic agents (OAs) have been extensively exploited for phototheranostics, such as photoacoustic imaging (PAI) and photothermal therapy (PTT). However, most existing OAs are inert to the surrounding microenvironment with limited phototheranostic outcomes. Emerging smart OAs that are stimuli-responsive can readily amplify phototheranostic effects under a variety of physiological and pathological stimuli, such as hypoxia, pH, reactive oxygen species, and ions. In this review, we summarize the recent advances in stimuli-responsive OAs for enhanced PAI and PTT and discuss the future challenges and prospects of this research area. We anticipate that this contribution will provide readers with greater insight into stimuli-responsive OAs and guide the design and synthesis of new high-performance OAs for stimuli-responsive disease diagnosis and treatment.