A DNA/Upconversion Nanoparticle Complex Enables Controlled Co-Delivery of CRISPR-Cas9 and Photodynamic Agents for Synergistic Cancer Therapy.

Photodynamic therapy (PDT) is a noninvasive therapeutic strategy that depends on the light-irradiated exciting of photosensitizer (PS) to generate reactive oxygen species (ROS), which faces challenges and limitations in hypoxia and antioxidant response of cancer cells, and limited tissue-penetration of light. Herein, we develop a multi-functional DNA/upconversion nanoparticles (UCNPs) complex that enables controlled co-delivery of CRISPR-Cas9, hemin, and protoporphyrin (PP) for synergistic PDT activated by near-infrared (NIR) light. An ultra-long ssDNA is prepared via rolling circle amplification (RCA), which contains recognition sequences of sgRNA for loading Cas9 ribonucleoprotein (RNP), G-quadruplex sequences for loading hemin and PP, and linker sequences for combining UCNP. Cas9 RNP precisely cleaves the antioxidant regulator nuclear factor E2-related factor 2 (Nrf2) gene, improving the sensitivity of cancer cells to ROS, and enhancing the synergistic PDT effect. The G-quadruplex/hemin DNAzyme mimicks horseradish peroxidase (HRP) to catalyze the endogenous H 2 O 2 to O 2 , overcoming the hypoxia condition in tumors. The introduced UCNP converts NIR irradiation with deep tissue penetration to light with shorter wavelength, exciting PP to transform the abundant O 2 to 1 O 2 . The integration of gene editing and PDT allows substantial accumulation of 1 O 2 in cancer cells for enhanced cell apoptosis, and this synergistic PDT has shown remarkable therapeutic efficacy in a breast cancer mouse model. This article is protected by copyright. All rights reserved.