The tissue penetration limitation of excitation light and the absorption wavelength of the photosensitizer hinder the effective treatment of traditional photodynamic therapy (PDT) in deep-seated tumors. Recently, X-ray excited photodynamic therapy (XE-PDT) based on excitation or indirect excitation of photosensitizers via energy transfer by X-ray has attracted a great deal of attention. In this review, recent progress of nanoscintillators, including their rational designs, strategies of photosensitizer loading as well as effects of energy transfer and PDT are summarized. The main problems, challenges and future development in deep-seated tumor PDT are also discussed.
Contents
1 Introduction
2 Principle of X-ray excited photodynamic therapy
3 General photosensitizer loading strategies
3.1 Sol-gel method
3.2 Direct surface coating by polymer
4 X-ray excited phosphors
4.1 Rare-earth-element-based nanoparticles
4.2 Metal oxide (or sulfide) nanoparticles
4.3 Transition metal cluster compounds
5 Conclusion and outlook
Contents
1 Introduction
2 Principle of X-ray excited photodynamic therapy
3 General photosensitizer loading strategies
3.1 Sol-gel method
3.2 Direct surface coating by polymer
4 X-ray excited phosphors
4.1 Rare-earth-element-based nanoparticles
4.2 Metal oxide (or sulfide) nanoparticles
4.3 Transition metal cluster compounds
5 Conclusion and outlook