Fig. 4.

Schematic illustration of phospholipase A2 (PLA2)-triggered antibiotic release from liposomes stabilized by chitosan-modified gold nanoparticles (AuChiliposome) to treat bacteria (e.g., H. pylori) that secrete the enzyme. Antibiotic (e.g. doxycycline)-loaded liposomes are prohibited from fusion by adsorbing AuChi nanoparticles onto their surface. Once the AuChi-liposomes encounter bacteria-secreted PLA2, the enzyme cleaves the phospholipids that form the liposome membranes and thus releases the encapsulated antibiotics, which subsequently kill or inhibit the growth of the bacteria. Reproduced with permission from ref. 38. Copyright © 2014, The Royal Society of Chemistry.