Tailored Engineering of Novel Xanthonium Polymethine Dyes for Synergetic PDT and PTT Triggered by 1064 nm Laser toward Deep‐Seated Tumors

Abstract

Small molecular dye that simultaneously exerts dual PDT/PTT effects as well as florescence imaging triggered by a single NIR‐II light has never been reported to date. Apart from the huge challenge in pushing absorption profile into NIR‐II region, fine‐tuning dyes’ excited state via rational structure design to meet all three functions, especially oxygen photosensitization, remains the most prominent throttle. Herein, five novel NIR‐II dyes (BHs) are productively developed by strategically conjugating dyad innovative xanthonium with sequentially extended polymethine bridges, enabling intense absorption from 890 to 1206 nm, significantly 400 nm longer than conventional cyanine dyes with same polymethines. More importantly, owning to high resonance and favorable excited state energy population induced by greater rigidity via ring‐fused amino, BH 1024 exhibits best singlet oxygen generation capability, moderate photothermal heating, and considerable fluorescence under 1064 nm laser irradiation. Furthermore, BH 1024 is encapsulated into folate‐functionalized polymer, which demonstrated a synergetic PDT/PTT effect in vitro and in vivo, eventually achieving solid tumors elimination under NIR‐II fluorescence guide. As far as it is known, this is the first time small molecular dyes for NIR‐II PDT or NIR‐II PDT/PTT are explored and designed.

Achieving Efficient NIR‐II Type‐I Photosensitizers for Photodynamic/Photothermal Therapy upon Regulating Chalcogen Elements

“…Thus, no NIRII typeI PDT/PTT organic/polymeric photosensitizers have been reported, although a few NIRII typeII PDT/PTT ones have been used for cancer treatment. [14,15] Herein, three narrowbandgap SPs, poly[2,2″((E)4,4″bis(2 octyldodecyl) [6,6″bithieno[3,2b]pyrrolylidene]5,5″(4H,4″H) dione)alt2,5(thiophene)] (PTS), poly[2,2″((E)4,4″bis(2 octyldodecyl) [6,6″bithieno[3,2b]pyrrolylidene]5,5″(4H,4″H) dione)alt2,5(selenophene)] (PTSe), and poly[2,2″((E) 4,4″bis(2octyldodecyl) [6,6″bithieno[3,2b]pyrrolylidene] 5,5″(4H,4′H)dione)alt2,5(tellurophene)] (PTTe) were con structed with donor-acceptor (D-A) strategy, using thienoisoin digo (T) as a strong electronwithdrawing unit, and thiophene (S), selenophene (Se), or tellurophene (Te) as an electron donating unit, respectively (Scheme 1). The intense ICT feature enabled by D-A strategy not only extended the light absorption range to NIRII region, but the k ISC was significantly enhanced to generate triplet excitons by incorporating the heavy atoms (selenium and tellurium).…”

AIE-active luminogens as highly efficient free-radical ROS photogenerator for image-guided photodynamic therapy

“…Photosensitizers with "off-on" uorescence for image-guided PDT could realize high signal-to-noise ratio (S/N) imaging, and long absorption and emission wavelengths for photosensitizers could improve the quality of imaging and therapy in deep tissue. [38][39][40][41] The photophysical properties of TCM-CP and TCM-CPS were examined using their absorption and emission spectra. The absorption peak of TCM-CP in 99% water was located at 518 nm, and the absorption peak of TCM-CPS (512 nm) was slightly blue-shied compared to that of TCM-CP (Fig.…”

Semiconducting polymer nanoparticles for NIR-II fluorescence imaging-guided photothermal/thermodynamic combination therapy

“…1,2 As one of the phototherapeutic modalities, photothermal therapy (PTT), which uses heat to ablate tumor tissue, has been demonstrated to have good therapeutic efficacy. 3 Different kinds of materials with good photothermal efficiency have been designed for PTT, such as inorganic nanoparticles, 4,5 small molecular dyes 6 and organic nanomaterials. 7,8 Although PTT has been widely applied in cancer therapy, several disadvantages of PTT still need to be overcome.…”