Multifunctional upconversion–nanoparticles–trismethylpyridylporphyrin–fullerene nanocomposite: a near-infrared light-triggered theranostic platform for imaging-guided photodynamic therapy

摘要

A multifunctional near-infrared-triggered nanocomposite has been demonstrated that is promising for diagnosing and treating tumours. Photodynamic therapy agents destroy cancer cells by generating reactive oxygen species when excited by light but suffer from limited penetration depths and reduced performance in the low-oxygen microenvironments near tumours. Now, scientists in China have developed a three-component nanocomposite consisting of upconversion nanoparticles, trismethylpyridylporphyrin and fullerene that has the potential to overcome both shortcomings. When excited by near-infrared radiation, the upconversion nanoparticles generate ultraviolet and visible light that induces trismethylpyridylporphyrin-fullerene to produce reactive oxygen species for killing tumours. Furthermore, the composite permits three imaging modalities for diagnosis and guiding therapy: fluorescence, upconversion luminescence and magnetic resonance imaging. Finally, folate-mediated active targeting combined with the enhanced permeability and retention effect enhances accumulation of the nanoparticles in tumours.