Near‐Infrared Thermally Activated Delayed Fluorescence Nanoparticle: A Metal‐Free Photosensitizer for Two‐Photon‐Activated Photodynamic Therapy at the Cell and Small Animal Levels

Abstract

Thermally activated delayed fluorescence (TADF) materials with extremely small singlet‐triplet energy offsets have opened new horizons for the development of metal‐free photosensitizers for photodynamic therapy (PDT) in recent years. However, the exploration of near‐infrared (NIR) TADF emitters for efficient two‐photon‐excited (TPE) PDT is still a formidable challenge, thus it has not been reported yet. In this study, purely organic photosensitizers (PSs) based on the TADF nanoparticles (NIR‐TADF NPs) are designed for efficient TPE‐PDT, which show excellent singlet oxygen generation ability. Thanks to the intrinsic two‐photon excitation and NIR emission characteristics, the NIR‐TADF NPs demonstrate promising potential in both single‐photon‐excited (SPE) and TPE NIR imaging. More importantly, the anti‐tumor efficiency and biosafety of TADF‐based PSs at the small animal level are confirmed in A549 tumor xenograft models under TPE laser irradiance, which will facilitate the practical biomedical applications of TADF materials. This work not only provides a promising strategy to develop metal‐free PSs, but also expands the applied scope of TADF‐based nanotherapeutics and advances their possible clinical translation in cancer therapy.

Phototherapeutic Induction of Immunogenic Cell Death and CD8+ T Cell-Granzyme B Mediated Cytolysis in Human Lung Cancer Cells and Organoids

“…The development of self-exciting “auto-PDT” nanoplatforms for example, where activation is driven by chemiluminescence from compounds co-loaded with the photosensitizer, extends the range of PDT and can begin to overcome barriers associated with low light penetrance into tissues [ 54 ]. The application of Near-Infrared thermally activated delayed fluorescence materials with increased efficiency of singlet oxygen generation also extends the range of PDT and is showing promise in preclinical cancer models [ 55 ]. Capitalising on the neutrophil influx in response to PDT to target delivery of nano-particles to the tumour illustrates how nanoplatforms can be rationally and effectively combined with knowledge of the biological response to PDT in order to increase its efficiency [ 56 ].…”

Extracellular vesicles as bioactive nanotherapeutics: An emerging paradigm for regenerative medicine

“…In addition to the above-mentioned potential therapeutic mechanisms related to native EVs as regenerative entities, EVs can also affect oxidative stress. Overproduction of reactive oxygen species (ROS) and resultant oxidative stress are closely associated with the pathogenesis of various diseases by breaking the redox homeostasis 88 - 94 , which will be an effective target to restore the repair and regeneration capacities. Indeed, a rich variety of research has demonstrated the ROS-scavenging and antioxidative capabilities of EVs 95 , 96 .…”

A Perspective on Perovskite Solar Cells: Emergence, Progress, and Commercialization

“…Now, MHPs have developed into a broad range of materials with the general formula ABX 3 , where A and B are monovalent and divalent cations, respectively and X stands for anions. Besides, MHPs have been widely used as active materials in various optical and electronic applications, such as photovoltaic devices (PV) ( Kojima et al, 2009 ; Kim et al, 2012 ; Lee et al, 2012 ; Jeong et al, 2021 ), light-emitting diode ( Cho et al, 2015 ; Cao et al, 2018 ; Lin et al, 2018 ), photodetector ( Li et al, 2020a ; Li et al, 2020b ), laser ( Sutherland and Sargent, 2016 ; Wei et al, 2019 ), sensor ( Zaza et al, 2019 ; George et al, 2020 ), biomedicine ( Fang et al, 2021 ; Zhang et al, 2021 ; Fang et al, 2022 ) etc.…”