Organic molecule-based photothermal agents: an expanding photothermal therapy universe

Abstract

Over the last decade, organic photothermal therapy (PTT) agents have attracted increasing attention as a potential complement for, or alternative to, classical drugs and sensitizers involving inorganic nanomaterials. In this tutorial review, we provide a structured description of the main classes of organic photothermal agents and their characteristics. Representative agents that have been studied in the context of photothermal therapy since 2000 are summarized and recent advances in using PTT agents to address various cancers indications are highlighted.

Boron Dipyrromethene Nano‐Photosensitizers for Anticancer Phototherapies

“…PTT also requires PSs with high NIR absorption for deep‐tissue penetration, a large absorption coefficient for superior photoactivity with sufficient heat, and good photostability to allow efficient treatment without photobleaching . Through chemical modification with a conjugated system, BODIPY‐based nano‐photosensitizers have a high absorption coefficient in the NIR region, which is favorable for deep‐tissue applications.…”

“…Typically, PSs generate heat through nonradiative relaxation pathways from excited states to the ground state by absorbing photons produced by light irradiation, eventually leading to cancer cell death . Additionally, PTT requires PSs that exhibit low fluorescence and 1 O 2 quantum yield to ensure a high nonradiative relaxation probability …”

Advanced Nanotechnology Leading the Way to Multimodal Imaging‐Guided Precision Surgical Therapy

“…PDT consists of three main components: oxygen, light, and photosensitizer (PS). [83,301,302] The emerging ablation techniques can be used as a complementary strategy in resection for synergy. [298][299][300] The cancer-killing mechanism of PTT is based on the photothermal effects that occur when tumor-accumulated photothermal transduction agents (PTAs) absorb light energy and transfer it into heat, thereby leading to microscopic temperature increment.…”

Two‐Dimensional Nanomaterials for Photothermal Therapy

“…Conventional cancer therapies, including surgery, chemotherapy, and radiotherapy, still have limitations, such as severe side effects and low efficiency. Photothermal therapy (PTT) is a spatiotemporally controllable cancer treatment method, which has attracted wide attention for its low cost, good specificity, and slight side effects to normal tissues . In 2003, plasmonic PTT was first developed by Halas and co‐workers .…”