In article number 1900720 by Mingxi Wan, Yujin Zong, and co-workers, reactive oxygen species (ROS)-responsive IR780/PTL-nanoparticles are developed using ROS-cleavable thioketal linkers (TL). Under ultrasound (US) stimulation, these nanoparticles produces high amounts of ROS, which can rapidly release the anti-tumor drug PTX and induce apoptosis in human glioma (U87) cells. In addition, the IR780/PTL-NPs release the drug at the target sites in a controlled manner upon US stimulation, which significantly inhibits tumor growth and induces apoptosis in the tumor tissues with no obvious toxicity. Cover design by Pengying Wu, Mingxi Wan, and Yujin Zong.