Nitric oxide activatable photosensitizer accompanying extremely elevated two-photon absorption for efficient fluorescence imaging and photodynamic therapy

Wenbo Hu; Meng Xie; Hui Zhao; Yufu Tang; Song Yao; Tingchao He; Chuanxiang Ye; Qi Wang; Xiaomei Lu; Wei Huang; Quli Fan

doi:10.1039/c7sc04044j

Nitric oxide activatable photosensitizer accompanying extremely elevated two-photon absorption for efficient fluorescence imaging and photodynamic therapy

Chem Sci. 2017 Nov 27;9(4):999-1005. doi: 10.1039/c7sc04044j. eCollection 2018 Jan 28.

Authors

Wenbo Hu^{1

2}, Meng Xie¹, Hui Zhao¹, Yufu Tang¹, Song Yao³, Tingchao He³, Chuanxiang Ye³, Qi Wang², Xiaomei Lu², Wei Huang^{2

4}, Quli Fan¹

Affiliations

¹ Key Laboratory for Organic Electronics and Information Displays , Institute of Advanced Materials (IAM) , Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing University of Posts & Telecommunications , Nanjing 210023 , China . Email: iamqlfan@njupt.edu.cn.
² Key Laboratory of Flexible Electronics (KLOFE) , Institute of Advanced Materials (IAM) , Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University (NanjingTech) , Nanjing 211816 , China . Email: wei-huang@njtech.edu.cn.
³ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province , College of Physics Science & Technology , Shenzhen University , Shenzhen 518060 , China.
⁴ Shaanxi Institute of Flexible Electronics (SIFE) , Northwestern Polytechnical University (NPU) , Xi'an 710072 , China.

Abstract

Elevated nitric oxide (NO) levels perform an important pathological role in various inflammatory diseases. Developing NO-activatable theranostic materials with a two-photon excitation (TPE) feature is highly promising for precision imaging and therapy, but constructing such materials is still a tremendous challenge. Here, we present the first example of a NO-activatable fluorescent photosensitizer (DBB-NO) accompanying extremely NO-elevated two-photon absorption (TPA) for efficient fluorescence imaging and photodynamic therapy (PDT). Upon responding to NO, DBB-NO shows not only a remarkably enhanced fluorescence quantum yield (Φ_F, 0.17% vs. 9.3%) and singlet oxygen quantum yield (Φ_Δ, 1.2% vs. 82%) but also an extremely elevated TPA cross-section (δ, 270 vs. 2800 GM). Simultaneous enhancement of Φ_Δ, Φ_F and δ allows unprecedented two-photon fluorescence brightness (δ × Φ_F = 260.4 GM) and two-photon PDT (TP-PDT) efficiency (δ × Φ_Δ = 2296 GM) which precedes the value for a commercial two-photon photosensitizer by two orders of magnitude. With these merits, the proof-of-concept applications of NO-activatable two-photon fluorescence imaging and TP-PDT in activated macrophages (in which NO is overproduced) were readily realized. This work may open up many opportunities for constructing two-photon theranostic materials with other pathological condition-activatable features for precise theranostics.