Amplifying Free Radical Generation of AIE Photosensitizer with Small Singlet-Triplet Splitting for Hypoxia-Overcoming Photodynamic Therapy

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)5112–5121
Journal / PublicationACS Applied Materials and Interfaces
Volume14
Issue number4
Online published20 Jan 2022
Publication statusPublished - 2 Feb 2022

Abstract

Type-I photodynamic therapy (PDT) with less oxygen consumption shows great potential for overcoming the vicious hypoxia typically observed in solid tumors. However, the development of type-I PDT is hindered by insufficient radical generation and the ambiguous design strategy of type-I photosensitizers (PSs). Therefore, developing highly efficient type-I PSs and unveiling their structure-function relationship are still urgent and challenging. Herein, we develop two phenanthro[9,10-d]imidazole derivatives (AQPO and AQPI) with aggregation-induced emission (AIE) characteristics and boost their reactive oxygen species (ROS) generation efficiency by reducing singlet-triplet splitting (ΔEST). Both AQPO and AQPI show ultrasmall ΔEST values of 0.09 and 0.12 eV, respectively. By incorporating electron-rich anisole, the categories of generated ROS by AIE PSs are changed from type-II (singlet oxygen, 1O2) to type-I (superoxide anion radical, O2•- and hydroxyl radical, •OH). We demonstrate that the assembled AQPO nanoparticles (NPs) achieve a 3.2- and 2.9-fold increase in the O2•- and •OH generation efficiencies, respectively, compared to those of AQPI NPs (without anisole) in water, whereas the 1O2 generation efficiency of AQPO NPs is lower (0.4-fold) than that of AQPI NPs. The small ΔEST and anisole group endow AQPO with an excellent capacity for type-I ROS generation. In vitro and in vivo experiments show that AQPO NPs achieve an excellent hypoxia-overcoming PDT effect by efficiently eliminating tumor cells upon white light irradiation with good biosafety.

Research Area(s)

  • aggregate-induced emission, electron-rich group, hypoxia, singlet-triplet splitting, type-I photodynamic therapy

Citation Format(s)

Amplifying Free Radical Generation of AIE Photosensitizer with Small Singlet-Triplet Splitting for Hypoxia-Overcoming Photodynamic Therapy. / Xiao, Ya-Fang; Chen, Wen-Cheng; Chen, Jia-Xiong et al.

In: ACS Applied Materials and Interfaces, Vol. 14, No. 4, 02.02.2022, p. 5112–5121.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review