Fig. 1.

Schematic illustration for the simultaneous delivery of an anti-inflammatory agent and an antibiotic to the infectious site in the lung. (A) Activated neutrophils (HL-60 cells) are subjected to a cavitation force to produce cell membrane-derived nanovesicles. The nanovesicle membrane is infilled with cholesterol to maintain the pH gradient between intra-vesicles and outer-vesicles, so MPS and AZ can penetrate the membrane when D-COOH (D represents MPS or AZ) is neutral. After D-COOH is inside vesicles, DCOOH is deprotonated to become D-COO^- and then it is entrapped inside vesicles. (B) In a lung infection mouse model, neutrophil nanovesicles will home to infectious sites when they are intravenously administered to the mice because the nanovesicles inherit the targeting adhesion molecules of neutrophils. Therefore, effectively delivering MPS and AZ to the lung mitigates inflammation responses and clears bacteria. NV denotes neutrophil membrane-formed vesicle. Chol denotes cholesterol.