NIR-II Absorbed Dithienopyrrole-Benzobisthiadiazole Based Nanosystems for Autophagy Inhibition and Calcium Overload Enhanced Photothermal Therapy

Small. 2024 Sep;20(37):e2309891. doi: 10.1002/smll.202309891. Epub 2024 May 9.

Abstract

Although the current cancer photothermal therapy (PTT) can produce a powerful therapeutic effect, tumor cells have been proved a protective mechanism through autophagy. In this study, a novel hybrid theranostic nanoparticle (CaCO3@CQ@pDB NPs, CCD NPs) is designed and prepared by integrating a second near-infrared (NIR-II) absorbed conjugated polymer DTP-BBT (pDB), CaCO3, and autophagy inhibitor (chloroquine, CQ) into one nanosystem. The conjugated polymer pDB with asymmetric donor-acceptor structure shows strong NIR-II absorbing capacity, of which the optical properties and photothermal generation mechanism of pDB are systematically analyzed via molecular theoretical calculation. Under NIR-II laser irradiation, pDB-mediated PTT can produce powerful killing ability to tumor cells. At the same time, heat stimulates a large amount of Ca2+ inflow, causing calcium overload induced mitochondrial damage and enhancing the apoptosis of tumor cells. Besides, the released CQ blocks the self-protection mechanism of tumor cells and greatly enhances the attack of PTT and calcium overload therapy. Both in vitro and in vivo experiments confirm that CCD NPs possess excellent NIR-II theranostic capacity, which provides a new nanoplatform for anti-tumor therapy and builds great potential for future clinical research.

Keywords: NIR‐II absorption; autophagy; calcium overload therapy; photothermal therapy; theranostics.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Autophagy* / drug effects
  • Calcium* / chemistry
  • Calcium* / metabolism
  • Cell Line, Tumor
  • Humans
  • Infrared Rays*
  • Mice
  • Nanoparticles / chemistry
  • Photothermal Therapy*
  • Thiadiazoles / chemistry
  • Thiadiazoles / pharmacology

Substances

  • Calcium
  • Thiadiazoles