Disclosed herein is a glucose-responsive insulin delivery system based on the interaction between the glucose-modified insulin and glucose transporters (GLUTs) on erythrocytes (or red blood cells, RBCs). After being conjugated with a competitive inhibitor of a glucose transporter, insulin can efficiently bind to RBC membranes. The binding is reversible in the setting of hyperglycemia, resulting in fast release of insulin and subsequent drop of blood glucose (BG) level in vivo.