Efficient delivery of BRD4 inhibitor by glutathione-sensitive nanoparticle to suppress gallbladder cancer through inhibiting NF-κB signaling

•A redox-responsive nanoparticle system based on L-cysteine-based poly(disulfide amide) (Cys-8E Polymer) was implemented to achieve targeted delivery of therapeutic agents into gallbladder tumor.•BRD4 Inhibitor (JQ1) was effectively encapsulated by Cys-8E Polymer at a high drug loading for anti-cancer therapy.•JQ1-loaded Cys-8E nanoparticles (JQ1@Cys-8E NPs) significantly suppressed gallbladder tumor growth in vitro and in a PDX model of early recurrence with negligible systemic toxicity.•JQ1@Cys-8E NPs enhanced the therapeutic effect of JQ1 through inhibiting NF-κB pathway.