The document discusses modified red blood cells (RBCs) as a potential drug delivery platform. RBCs naturally interact with many drugs and affect their pharmacokinetics. Researchers are looking to engineer RBCs to optimize therapeutic delivery through the cardiovascular system. One method is to couple therapeutics to RBC surfaces, which avoids extracting, treating, and reintroducing modified RBCs. However, this provides little therapeutic isolation and could cause immune responses. Encapsulating therapeutics inside RBCs protects the drug but risks damaging the cells during encapsulation. Overall, modified RBCs show promise for improving drug safety, efficacy, and targeting, but challenges remain regarding immune responses and potential cell damage.