Hybrid nano‐ and microgels doped with photoacoustic contrast agents for cancer theranostics

Abstract Photoacoustic imaging (PAI) is an emerging noninvasive and inexpensive bioimaging modality, which has stimulated a wide interest in recent years for cancer theranostics. Hybrid nano‐ and microgels have been designed as protective carriers to incorporate PAI contrast agents due to their biocompatibility and biodegradability, high loading capacity, versatile surface chemistry, and stimuli‐responsive properties. These key features offer unprecedented opportunities for the design of innovative multifunctional cancer theranostic agents. This review focuses on the recent development of photoacoustic active nano‐ and microgels for biomedical applications in cancer theranostics and cancer hallmark imaging. The various chemical natures of gels and PAI contrast agents and the elaboration methods of hybrid matrices are summarized and discussed. Their applications in multimodal cancer theranostics and cancer hallmark imaging are presented, highlighting their merits and potential in treatment and diagnosis.