Photothermal Conjugated Polymers and Their Biological Applications in Imaging and Therapy

Conjugated polymers have been developed as candidates with great potential for biological and biomedical applications due to the excellent properties, including strong light absorption, high photostability, good biocompatibility, and tunable spectra. By design of the backbone structure, photothermal polymers can be obtained with narrow band gaps and high photothermal conversion efficiencies. As promising photothermal agents, photothermal conjugated polymers have been synthesized to be water-soluble or in the form of nanoparticles for biological applications of imaging, phototherapy, and photoactivation. This review summarizes the recent (2018–2020) progress on photothermal conjugated polymers with regard to molecular design, preparation, and photothermal biological applications, especially NIR imaging (fluorescence and photoacoustic)-guided photothermal therapy and combined therapy for cancer and antibacterial photothermal therapy. Further challenges and the outlook for photothermal conjugated polymers in biological applications are also discussed at the end.