Outside Front Cover: Lipid Modified with Pyridinium Betaine Manipulates Liposomal Membrane Fusion Behavior for Spatially Confined Cytoplasmic Delivery

In the Research Article (e22025), Chunxiong Zheng, Bingjia Xu, Mingqiang Li, Guang Shi, and co-workers designed a pyridinium-betaine-capped lipid to regulate membrane fusion behavior of liposome. Leveraging its protonation effect, the liposomal membrane fusion activity can be rapidly and reversibly switched responding to acidic tumor environment, thereby confining lysosome-bypassing cytosolic delivery of STING agonist in tumors for potent antitumor immunity and negligible toxicity.