Co-delivery of doxorubicin and CRISPR/Cas9 or RNAi-expressing plasmid by chitosan-based nanoparticle for cancer therapy

Folic acid (FA) and 2-(Diisopropylamino) ethyl methacrylate (DPA) double grafted trimethyl chitosan (TMC) nanoparticles (FTD NPs) were synthesized for the co-delivery of doxorubicin (DOX) and Survivin CRISPR/Cas9-expressing plasmid (sgSurvivin pDNA) or Survivin shRNA-expressing plasmid (iSur pDNA). FA modification enhanced the uptake of DOX and pDNA loaded into FTD NPs in tumor cells. A rapid release of DOX was triggered under acidic conditions due to pH-sensitiveness of FTD NPs arising from DPA conjugation. Negligible differences between FTD/sgSurvivin pDNA NPs and FTD/iSur pDNA NPs demonstrated that RNA interference (RNAi) and CRISPR/Cas9 technologies possessed comparable antitumor efficiency. Notably, the in vitro and in vivo antitumor efficacies of FTD/DOX/sgSurvivin pDNA NPs were superior to those of single delivery of DOX or sgSurvivin pDNA, while were comparable to those of FTD/DOX/iSur pDNA NPs. These results suggested that the combination of chemotherapeutics and CRISPR/Cas9 systems would provide a potential modality for cancer therapy.