A targeted phototheranostic agent with strong AIE effect and boosted type I ROS generation

Hypoxia and nonspecific killing always hinder the photodynamic therapy of malignant tumors and infectious diseases that both severely threatening human health. Herein, we report a type I photosensitizer (MTOTPy) with aggregation-induced near-infrared (NIR) emission feature and specific identification ability by rational molecular design. Enhanced electron-donating effect and electron-rich anion-x+ structure endow MTOTPy with strong NIR fluorescence and intensive type I reactive oxygen species generation in aggregation. It is demonstrated that MTOTPy can achieve fast identification of tumor cells by targeting mitochondria and specific recognition of Staphylococcus aureus (S. aureus) among other kinds of microbes. Moreover, MTOTPy can kill more than 90% tumor cells and S. aureus upon visible light irradiation at low concentration of 5.0 & mu;M and 0.5 & mu;M, respectively. The work provides a feasible idea for designing photosensitizers to overcome the hypoxic limitation of photodynamic therapy and advance the development of image-guided therapy with high efficiency.

Automated summary

In this study, a type I photosensitizer called MTOTPy was developed by rational molecular design, which exhibited aggregation-induced near-infrared emission and specific identification ability. MTOTPy showed strong near-infrared fluorescence and efficient type I reactive oxygen species generation in an aggregated state due to enhanced electron-donating effect and electron-rich anion structure. It was demonstrated that MTOTPy could selectively identify tumor cells by targeting mitochondria and specifically recognize Staphylococcus aureus among other microbes. Moreover, under visible light irradiation at low concentrations of 5.0 μM and 0.5 μM, MTOTPy killed more than 90% of tumor cells and S. aureus, respectively. This work provides a feasible approach for designing photosensitizers to overcome hypoxia in photodynamic therapy and advance the development of efficient image-guided therapy.