Enzyme-powered janus upconversion nanomotors for deep tumor penetration and photodynamic therapy

Photodynamic therapy (PDT) utilizes photosensitizers to generate reactive oxygen species (ROS) for tumor treatment. However, its efficacy is often hindered by the limited tissue penetration and inefficient photosensitizer delivery. The development of upconversion nanoparticles (UCNPs) offers a promising solution to these challenges by converting near-infrared (NIR) light into visible emissions, thereby enabling deeper tissue activation. Herein, we present a urease-powered Janus UCNP nanomotor that combines active photosensitizer delivery with NIR-activated PDT. The nanomotors features a UCNP core and a Janus mesoporous silica shell loaded with chlorin e6 (Ce6), which is further activated by UCNP-emitted visible light under 980 nm NIR irradiation. Through urea decomposition catalyzed by urease, these Janus nanomotors gain self-propulsion capabilities, enhancing cellular uptake and facilitating deep tumor tissue penetration. This active motion markedly improves Ce6 delivery efficiency and promotes ROS generation, thereby enhancing the therapeutic efficacy of PDT. The enzyme-powered Janus UCNP nanomotors present a precise and minimally invasive platform for effective and targeted cancer therapy.