Development of novel nanoporphyrin biomaterials for NIR-II activated photothermal therapy against tumor in vivo

Photothermal therapy (PTT), a promising spatiotemporally controllable cancer treatment method, needs effective depth of laser irradiation to ensure the anticancer efficiency. Second near-infrared window (NIR-II) absorbing conjugated polymer (CP) nanomaterials are emerging candidates for a non-invasive treatment of cancer with considerations of safety. Herein, a new organic CP compound (Ppordpp) with the donor-acceptor structure of porphyrin and diketopyrrolopyrrole was synthesized, which showed efficient absorption extending in NIR-II and spontaneously self-assembled into NPs (similar to 190 nm), leading to emission quenching and facilitating nonradiative thermal generation. Photothermal conversion efficiency (PCE) of our Ppordpp NPs was up to 86.21 %, higher than most of reported PTT reagents. Under 940 nm (0.75 W/cm(2)) laser irradiation for 10 min, the Ppordpp NPs showed dramatical PTT effects in vitro to kill 78 % 4T1 cancer cells with 40 mu g/mL incubation, and in vivo to almost completely inhibition tumor growth by 200 mu g/mL injection without obvious side effects. Our CP nanomaterials Ppordpp NPs with a D-A structure provide new alternatives for precise cancer through photothermal therapy with high PCE. (C) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

A new organic CP compound (Ppordpp) with efficient absorption in the NIR-II region was synthesized and self-assembled into NPs, showing high photothermal conversion efficiency and effective cancer treatment through photothermal therapy.