Dual-Photosensitizer Nanoplatform Based on Near-Infrared Excitation Orthogonal Emission Nanomaterials for Enhanced Photodynamic Therapy of Tumors

Photodynamic therapy (PDT) is considered as a promisingtherapeuticapproach for clinical cancer treatment. However, the hypoxia of thetumor microenvironment leads to the low effect of single PDT. Here,a dual-photosensitizer nanoplatform based on near-infrared excitationorthogonal emission nanomaterials is constructed by introducing twokinds of photosensitizers into the nanosystem. Orthogonal emissionupconversion nanoparticles (OE-UCNPs) were used as light conversionreagents to generate red emission under 980 nm irradiation and greenemission under 808 nm irradiation. On the one hand, merocyanine 540(MC540) is introduced as a photosensitizer (PS), which can absorbgreen light to generate reactive oxygen species (ROS) and triggerPDT for tumor treatment. On the other hand, another photosensitizer,chlorophyll a (Chla), which can be excited by red light, has alsobeen introduced into the system to build a dual PDT nanotherapeuticplatform. The introduction of photosensitizer Chla can synergisticallyincrease ROS concentration to accelerate cancer cell apoptosis. Ourresearch shows that this dual PDT nanotherapeutic platform combinedwith Chla has better therapeutic effects and effectively destroyscancer.