摘要To achieve highly selective synergistic chemotherapy attractive for clinical translation,the precise polymeric nano-prodrugs(PPD-NPs)were successfully constructed via the facile crosslinking reaction between pH-sensitive poly(ortho ester)s and reduction-sensitive small molecule synergistic prodrug(Pt(Ⅳ)-1).PPD-NPs endowed the defined structure and high drug loading of cisplatin and demethylcantharidin(DMC).Moreover,PPD-NPs exhibited steady long-term storage and circulation via the crosslinked structure,suitable negative potentials and low critical micelle concentration(CMC),improved selective tumour accumulation and cellular internalization via dynamic size transition and surficial amino protonation at tumoural extracellular pH,promoted efficient disintegration and drug release at tumoural intracellular pH/glutathione,and enhanced cytotoxicity via the synergistic effect between cisplatin and DMC with the feed ratio of 1:2,achieving significant tumour suppression while decreasing the side effects.Thus,the dynamic crosslinked polymeric nano-prodrugs exhibit tremendous potential for clinically targeted synergistic cancer therapy.