PGP and neoplasm: The comprehensive in vitro and in vivo results revealed that the PPDC@β‐Lap not only effectively enhanced cell uptake and drug delivery via tumor acidity‐activating charge conversion and ROS‐response drug release, but also efficiently replenished the intratumoral ROS, reduced MDR via blocking APT supply, downregulated the expression of P‐gp to achieve complete drug release and suppressed drug efflux.