Abstract
The development of photothermal therapy (PTT) as a cancer therapy has been hampered by low photothermal conversion efficiency (PTCE), which reduces its efficacy for this application. Herein, we report the investigation of the photothermal properties of ICG-II, the dimer of indocyanine green (ICG), and show it to have an unexpectedly high PTCE of 95.6%. Based on density functional theory calculations, we attribute the high PTCE of ICG-II to changes in the relative energy levels of the occupied orbitals and a constrained “butterfly” oscillation around the dimer bond that facilitates nonradiative deexcitation. Through in vitro study, we demonstrate ICG-II to be highly biocompatible and stable to irradiation and temperatures needed for photothermal therapy. In vivo experiments show that direct injection of ICG-II followed by 2 min near-infrared (NIR) irradiation can completely eliminate xenograft tumors in mice. This work demonstrates that ICG-II is an attractive candidate for further preclinical development of photothermal agents and serves as a prototype for a class of rotationally constrained molecular rotors for PTT and other photochemical applications.
Original language | English (US) |
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Article number | 101748 |
Journal | Cell Reports Physical Science |
Volume | 5 |
Issue number | 1 |
DOIs | |
State | Published - Jan 17 2024 |
Keywords
- ICG dimer
- butterfly vibration
- cancer treatment
- dye dimer
- indocyanine green
- molecular rotor design
- non-radiative decay
- photothermal agents
- photothermal conversion efficiency
- photothermal therapy
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- General Engineering
- General Energy
- General Physics and Astronomy