Related Experiment Video
Updated: Sep 17, 2025
Anticancer Efficacy of Photodynamic Therapy with Lung Cancer-Targeted Nanoparticles
Published on: December 1, 2016
A Nitroreductase-Responsive Type I Photosensitizer with Aggregation-Induced Emission Characteristics for Precise
Kristy W K Lam1, Yaojia Zhang2, Wutong Du1
1Department of Chemistry, Department of Chemical and Biological Engineering, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and State Key Laboratory of Nervous System Disorders, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China.
Abstract:
Cancer remains a significant global health challenge, with early and accurate detection being key to improving treatment outcomes. Developing targeted photosensitizers (PS) that selectively image and treat cancer cells is critical for cancer diagnosis, staging, and treatment monitoring. Understanding the hypoxic nature of solid tumors is essential in cancer detection, as hypoxia is associated with tumor aggressiveness and therapy resistance. Nitroreductase (NTR), which is overexpressed in hypoxic tumors, offers a target for selective imaging and treatment. In this study, we developed a type-I PS called TPAPyN, which is responsive to NTR. TPAPyN facilitates the imaging of hypoxic cancer cells and facilitates image-guided photodynamic therapy (PDT). Because of photoinduced electron transfer, TPAPyN does not emit fluorescence in the aqueous environment. However, its fluorescence is restored when NTR cleaves the nitrofuran quencher, forming highly emissive TPAPy aggregates. This characteristic makes TPAPyN a valuable fluorescent probe for specific imaging of NTR-overexpressed cancer cells. Additionally, TPAPy exhibits high efficiency in generating reactive oxygen species, indicating its potential as a PS for cancer treatment via PDT.
Insights
This study introduces TPAPyN, a novel photosensitizer for cancer detection and treatment. It specifically targets hypoxic tumors by utilizing nitroreductase enzymes, enabling enhanced imaging and photodynamic therapy (PDT).
Area of Science:
- Biomedical Engineering
- Photochemistry
- Oncology
Background:
- Early cancer detection and targeted therapy are crucial for improving patient outcomes.
- Hypoxia in solid tumors is linked to increased aggressiveness and resistance to treatment.
- Nitroreductase (NTR) is overexpressed in hypoxic tumors, presenting a target for selective cancer interventions.
Purpose of the Study:
- To develop a novel type-I photosensitizer (PS) responsive to NTR for targeted cancer imaging and photodynamic therapy (PDT).
- To create a fluorescent probe for specific imaging of hypoxic cancer cells overexpressing NTR.
- To evaluate the potential of the developed PS for image-guided PDT.
Main Methods:
- Development of a nitroreductase-responsive photosensitizer, TPAPyN.
- Utilizing photoinduced electron transfer for fluorescence quenching in aqueous environments.
- Investigating NTR-mediated cleavage of a nitrofuran quencher to restore fluorescence.
- Assessing reactive oxygen species (ROS) generation efficiency for PDT efficacy.
Main Results:
- TPAPyN exhibits quenched fluorescence in aqueous environments due to photoinduced electron transfer.
- NTR-mediated cleavage of the nitrofuran quencher restores TPAPyN's fluorescence, enabling specific imaging of NTR-overexpressing cancer cells.
- TPAPyN demonstrates high efficiency in generating reactive oxygen species, crucial for photodynamic therapy.
Conclusions:
- TPAPyN serves as a valuable fluorescent probe for the specific imaging of hypoxic cancer cells.
- The developed photosensitizer shows significant potential for image-guided photodynamic therapy in cancer treatment.
- This NTR-responsive PS offers a promising strategy for targeted cancer diagnosis and therapy.
