Filling core–shell microneedles with pressurized oxygen-embedded particles (POPs) to improve photodynamic therapy

experiments demonstrate that these particles could effectively accelerate the release and diffusion of MB. The released oxygen could relieve hypoxia and increase the generation of reactive oxygen species (ROS) of PDT. In a mouse melanoma model, the MN system enhances tumor growth inhibition induced by PDT and mitigates tumor metastasis. This innovative system offers an autonomous, safe, and convenient approach for localized gas delivery and drug diffusion, potentially creating new avenues for efficiently combining gas and other therapies for superficial diseases.