Theranostics 2017; 7(10):2746-2756. doi:10.7150/thno.18861

Research Paper

A Tumor-pH-Responsive Supramolecular Photosensitizer for Activatable Photodynamic Therapy with Minimal In Vivo Skin Phototoxicity

Xingshu Li1,2, Bi-Yuan Zheng1, Mei-Rong Ke1, Yongfan Zhang1, Jian-Dong Huang1✉, Juyoung Yoon2✉

1. College of Chemistry, State Key Laboratory of Photocatalysis on Energy and Environment, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Fuzhou University, Fuzhou 350108, China;
2. Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea.

Abstract

A major challenge in photodynamic therapy (PDT) is the development of new tumor-targeting photosensitizers. The tumor-specific activation is considered to be an effective strategy for designing these photosensitizers. Herein, we describe a novel tumor-pH-responsive supramolecular photosensitizer, LDH-ZnPcS8, which is not photoactive under neutral conditions but is precisely and efficiently activated in a slightly acidic environment (pH 6.5). LDH-ZnPcS8 is prepared by using a simple coprecipitation method based on the electrostatic interaction between negatively charged octasulfonate-modified zinc(II) phthalocyanine (ZnPcS8) and cationic hydroxide layers of layered double hydroxide (LDH). The in vitro photodynamic activities of LDH-ZnPcS8 in cancer cells are dramatically enhanced relative to those of ZnPcS8 alone. The results of in vivo fluorescence imaging demonstrate that the nanohybrid is activated in tumor tissues, where it displays an excellent PDT effect resulting in 95.3% tumor growth inhibition. Furthermore, the minimal skin phototoxicity of LDH-ZnPcS8 highlights its high potential as a novel photosensitizer for activatable PDT.

Keywords: photodynamic therapy, activatable photosensitizer, skin phototoxicity, layered double hydroxide, phthalocyanine.

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How to cite this article:
Li X, Zheng BY, Ke MR, Zhang Y, Huang JD, Yoon J. A Tumor-pH-Responsive Supramolecular Photosensitizer for Activatable Photodynamic Therapy with Minimal In Vivo Skin Phototoxicity. Theranostics 2017; 7(10):2746-2756. doi:10.7150/thno.18861. Available from http://www.thno.org/v07p2746.htm