Stimulus-responsive drug/gene delivery system based on polyethylenimine cyclodextrin nanoparticles for potential cancer therapy.

Combination therapy through simultaneous delivery of anti-cancer drugs and genes with nano-assembled structure has been proved to be a simple and effective approach for treating breast cancer. In this study, redox-sensitive folate-appended-polyethylenimine-β-cyclodextrin (roFPC) host-guest supramolecular nanoparticles (HGSNPs) were developed as a targeted co-delivery system of doxorubicin (Dox) and Human telomerase reverse transcriptase-small interfering RNA) hTERT siRNA) for potential cancer therapy. The nanotherapeutic system was prepared by loading adamantane-conjugated doxorubicin (Ad-Dox) into roFPC through the supramolecular assembly, followed by electrostatically-driven self-assembly between hTERT siRNA and roFPC/Ad-Dox. The roFPC' host-guest structures allow pH-dependent intracellular drug release in a sustained manner, as well as simultaneous and effective gene transfection. This co-delivery vector displayed combined anti-tumor properties of the Dox-enhanced gene transfection, good water-solubility, and biocompatibility, possesses considerably enhanced hemocompatibility, and especially targets folate receptor-positive cells only at low N/P levels to prompt effective cell apoptosis for cancer treatment.