pH-Induced　charge-reversal　nanoparticles　incorporating　microRNA　(miRNA)　were　engineered　through　a　single-step　self-assembly　of　polyelectrolyte　complexes.　We　found　that　the　endosomal/lysosomal　acidic　environment　could　trigger　the　charge　reversal　of　the　nanoparticles　from　negative　charge　to　positive　charge　and　induce　the　structure　alteration　of　the　nanoparticles,　which　in　turn　led　to　accelerated　endosomal　escape　and　enhanced　miRNA　modulation　in　esophageal　cancer　cells.