Scheme 1.

Schematic illustration of PTAO‐PCL micelles for cancer drug delivery. a) The encapsulation of DOX into PTAO micelles self‐assembled from PTAO‐PCL block copolymers. b) After intravenous injection, PTAO micelles (i) circulate long in blood via red blood cell (RBC) hitchhiking and (ii) attach on cell membranes to trigger transcytosis‐mediated extravasation and (iii) subsequent active tumor penetration. Inside tumor cells, a portion of PTAO micelles (iv) target mitochondria and induce cell death.