Engineering Biomimetic Platesomes for pH-Responsive Drug Delivery and Enhanced Antitumor Activity.

Biomimetic camouflage, i.e., using natural cell membranes for drug delivery, has demonstrated advantages over synthetic materials in both pharmacokinetics and biocompatibility, and so represents a promising solution for the development of safe nanomedicine. However, only limited efforts have been dedicated to engineering such camouflage to endow it with optimized or additional properties, in particular properties critical to a "smart" drug delivery system, such as stimuli-responsive drug release. A pH-responsive biomimetic "platesome" for specific drug delivery to tumors and tumor-triggered drug release is described. This platesome nanovehicle is constructed by merging platelet membranes with functionalized synthetic liposomes and exhibits enhanced tumor affinity, due to its platelet membrane-based camouflage, and selectively releases its cargo in response to the acidic microenvironment of lysosomal compartments. In mouse cancer models, it shows significantly better antitumor efficacy than nanoformulations based on a platesome without pH responsiveness or those based on traditional pH-sensitive liposomes. A convenient way to incorporate stimuli-responsive features into biomimetic nanoparticles is described, demonstrating the potential of engineered cell membranes as biomimetic camouflages for a new generation of biocompatible and efficient nanocarriers.