Enzyme-powered Janus platelet cell robots for active and targeted drug delivery

Summary

This study transforms living platelets into self-propelled micromotors without attaching them to a rigid engine or requiring harsh fuel conditions. Urease was immobilized asymmetrically on the platelet surface, creating a Janus distribution that decomposed urea unevenly and generated chemophoretic motion in biological fluids. The modification had little apparent effect on key platelet surface proteins, so the engineered cells retained their natural ability to recognize cancer cells and bacteria. When urea fuel was present, active movement increased contact and binding with both target types. Loading the platelet motors with model anticancer or antibiotic drugs then improved therapeutic efficacy relative to the corresponding nonpropelled context. The principal finding is that an endogenous enzyme and a common biological substrate can provide autonomous propulsion while preserving useful cellular recognition functions. Motion therefore augments, rather than replaces, the platelet's intrinsic targeting. Its significance is a biogenic microrobot architecture that could combine cell-derived affinity, active transport, and diverse cargos in one platform without external actuation equipment. The abstract does not specify in vivo models, propulsion distances, drug identities, comparative toxicity, or whether urease modification affects platelet behavior over longer periods.