Metformin bicarbonate-mediated efficient RNAi for precise targeting of TP53 deficiency in colon and rectal cancers

•Metformin bicarbonate (MetC) is synthesized to produce gas under acidic condition.•MetC-based nanoparticle is synthesized to generate “bomb” effect in late endosome.•The “bomb” effect enables endosomal escape of siRNA for effective RNAi in cytosol.•MetC has a similar anticancer effect to the commonly used metformin hydrochloride.•Colon and rectal cancers may not be simply combined as colorectal cancer for study.