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Published on: October 28, 2015
A Selenium-Substituted Heptamethine Cyanine Photosensitizer for Near-Infrared Photodynamic Therapy
Jinghan Sun1, Erting Feng1, Yutong Shao2
1State Key Laboratory of Fine Chemicals, Dalian University of Technology, 2 Ling gong Road, Hi-techZone, Dalian, 116024, P. R. China.
Abstract:
Photodynamic therapy (PDT) is a relatively safe approach to cancer treatment without significant systemic side effects or drug resistance. However, the current PDT efficiency is unsatisfactory due to the lack of near-infrared (NIR) photosensitizers. Heptamethine cyanine (Cy7) dyes are well-known NIR fluorophores and are also used as photosensitizers. But their singlet oxygen quantum yields (ΦΔ ) are not ideal. Herein, we developed an NIR photosensitizer with a long-lived excited triplet state (τ=4.3 μs) by introducing a selenium atom into the structure of a Cy7 dye. The new NIR photosensitizer exhibits a significantly high singlet oxygen quantum yield (ΦΔ =0.11). Its good PDT effect was demonstrated in the living cells. Considering that the selenium-substituted photosensitizer has a very low dark cytotoxicity and good chemical stability, we conclude that it will have a promising future in biomedical and clinical applications.
Insights
Researchers developed a novel near-infrared (NIR) photosensitizer by adding selenium to cyanine 7 (Cy7) dyes. This enhanced photosensitizer shows improved singlet oxygen production for more effective photodynamic therapy (PDT) cancer treatment.
Area of Science:
- Biomedical Engineering
- Photochemistry
- Materials Science
Background:
- Photodynamic therapy (PDT) offers a safe cancer treatment modality with minimal systemic toxicity and drug resistance.
- Current PDT efficacy is limited by the scarcity of efficient near-infrared (NIR) photosensitizers.
- Existing heptamethine cyanine (Cy7) dyes, while NIR fluorophores, possess suboptimal singlet oxygen quantum yields.
Purpose of the Study:
- To develop a novel NIR photosensitizer with enhanced singlet oxygen generation for improved PDT.
- To investigate the impact of selenium incorporation into Cy7 dye structures on photosensitizing properties.
- To evaluate the efficacy and safety of the new photosensitizer in preclinical models.
Main Methods:
- Synthesis of a selenium-substituted heptamethine cyanine (Cy7) dye.
- Characterization of the photosensitizer's photophysical properties, including excited triplet state lifetime and singlet oxygen quantum yield (ΦΔ).
- In vitro evaluation of the photosensitizer's photodynamic effect in living cells, assessing cytotoxicity and therapeutic potential.
Main Results:
- The selenium-substituted Cy7 dye exhibited a prolonged excited triplet state lifetime (τ=4.3 μs).
- The novel photosensitizer demonstrated a significantly high singlet oxygen quantum yield (ΦΔ=0.11).
- Effective photodynamic therapy effects were observed in living cells, with low dark cytotoxicity and good chemical stability.
Conclusions:
- Selenium incorporation into Cy7 dyes yields a potent NIR photosensitizer for photodynamic therapy.
- The developed photosensitizer offers a promising alternative for enhancing PDT efficacy in cancer treatment.
- This advancement holds significant potential for future biomedical and clinical applications in oncology.
