Theranostics 2013; 3(5):317-330. doi:10.7150/thno.5284

Review

Upconversion Nanoparticles for Photodynamic Therapy and Other Cancer Therapeutics

Chao Wang, Liang Cheng, Zhuang Liu

Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China.

Abstract

Photodynamic therapy (PDT) is a non-invasive treatment modality for a variety of diseases including cancer. PDT based on upconversion nanoparticles (UCNPs) has received much attention in recent years. Under near-infrared (NIR) light excitation, UCNPs are able to emit high-energy visible light, which can activate surrounding photosensitizer (PS) molecules to produce singlet oxygen and kill cancer cells. Owing to the high tissue penetration ability of NIR light, NIR-excited UCNPs can be used to activate PS molecules in much deeper tissues compared to traditional PDT induced by visible or ultraviolet (UV) light. In addition to the application of UCNPs as an energy donor in PDT, via similar mechanisms, they could also be used for the NIR light-triggered drug release or activation of 'caged' imaging or therapeutic molecules. In this review, we will summarize the latest progresses regarding the applications of UCNPs for photodynamic therapy, NIR triggered drug and gene delivery, as well as several other UCNP-based cancer therapeutic approaches. The future prospects and challenges in this emerging field will be also discussed.

Keywords: Photodynamic therapy, Upconversion nanoparticles.

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How to cite this article:
Wang C, Cheng L, Liu Z. Upconversion Nanoparticles for Photodynamic Therapy and Other Cancer Therapeutics. Theranostics 2013; 3(5):317-330. doi:10.7150/thno.5284. Available from http://www.thno.org/v03p0317.htm