Two-photon excited
photodynamic therapy (2PE-PDT) has attracted
great attention in recent years due to its great potential for deep-tissue
and highly spatiotemporally precise cancer therapy. Photosensitizers
(PSs) with high singlet oxygen (1O2) generation
efficiency and large two-photon absorption (2PA) cross-sections are
highly desirable, but the availability of such PSs is limited by challenges
in molecular design. In this work, we report that the polymerization
of small-molecule PSs with aggregation-induced emission (AIE) could
yield conjugated polymer PSs with good brightness, high 1O2 generation efficiency, and large 2PA cross-sections.
A pair of conjugated polymer PSs were designed and synthesized, and
the corresponding AIE PS dots were prepared by nanoprecipitation,
which exhibited outstanding 2PE-PDT performance in in vitro cancer cell ablation and in vivo zebrafish liver
tumor treatment. Our work highlights a strategy to design highly efficient
PSs for 2PE-PDT.