Photothermal therapy (PTT) is performed using near-infrared-responsive agents, which is proven to be an effective therapeutic strategy against cancer with several advantages including minimal invasion, high effectiveness, and easy implementation.

Recently, photothermal therapy (PTT) has emerged as one of the most promising biomedical strategies for different areas in the biomedical field owing to its superior advantages, such as being noninvasive, target-specific and having fewer side effects. Graphene-based hydrogels (GGels), which have excellent mechanical and optical properties, high light-to-heat conversion efficiency and good biocompatibility, have been intensively exploited as potential photothermal conversion materials. This comprehensive review summarizes the current development of graphene-integrated hydrogel composites and their application in photothermal biomedicine. The latest advances in the synthesis strategies, unique properties and potential applications of photothermal-responsive GGel nanocomposites in biomedical fields are introduced in detail. This review aims to provide a better understanding of the current progress in GGel material fabrication, photothermal properties and potential PTT-based biomedical applications, thereby aiding in more research efforts to facilitate the further advancement of photothermal biomedicine.

Conjugated polymer (CP)-based photothermal materials have been widely acknowledged as a promising class of photothermal agents for biomedical applications. This is because of their light-harvesting ability, photothermal conversion efficiency, photostability, and favorable biocompatibility. Donor–acceptor (D–A) CPs, which are based on the evolution of CPs, have attracted considerable interest in this field because of their tunable absorption in the near-infrared biological window. This property enables their deep penetration into cancer sites, improving the efficiency of anti-cancer treatment. This review mainly focuses on the potential of D–A CP to achieve improved and efficient photothermal conversion, exploring its optimized advantages for photothermal therapy applications. Based on the general insight provided by the Jablonski diagram, the mechanism and related principles for activating photothermal conversion in CPs and D–A CP are proposed and discussed. This provides an overall understanding of the correlation between molecular CP nanomaterials and heat generation. This review presents the details of methodologies for the rational design of CP nanoparticles with efficient photothermal conversion ability, thus facilitating the use of CPs in biomedical diagnostic and therapeutic applications. Graphical Abstract