Polypeptide cationic micelles mediated co-delivery of docetaxel and siRNA for synergistic tumor therapy

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cancer Therapy

Background:

• Combined therapeutic strategies with distinct mechanisms can enhance anti-tumor efficacy.
• Co-delivery of chemotherapeutics and small interfering RNA (siRNA) via nanoparticles offers a promising approach for synergistic cancer treatment.

Purpose of the Study:

• To develop and evaluate polypeptide micelle nanoparticles (NPs) for the co-delivery of docetaxel (DTX) and siRNA targeting Bcl-2 (siRNA-Bcl-2).
• To assess the synergistic anti-tumor activity and therapeutic potential of this combined drug/gene delivery system.

Main Methods:

• Fabrication of triblock copolymer (poly(ethylene glycol)-b-poly(l-lysine)-b-poly(l-leucine)) into polypeptide micelle nanoparticles.
• Encapsulation of docetaxel within the hydrophobic core and complexation of siRNA-Bcl-2 with the cationic backbone.
• In vitro assessment of Bcl-2 mRNA and protein knockdown and in vivo evaluation of anti-tumor efficacy in a MCF-7 xenograft murine model.

Main Results:

• The prepared polypeptide micelle NPs demonstrated stability, biocompatibility, and passive targeting capabilities.
• Co-delivery of DTX and siRNA-Bcl-2 effectively reduced Bcl-2 expression and exhibited enhanced anti-tumor activity compared to individual treatments.
• Significant inhibition of tumor growth was observed in the murine model treated with the DTX-siRNA-NPs, indicating a synergistic effect.

Conclusions:

• Well-defined PEG-PLL-PLLeu polypeptide cationic micelles enable effective co-delivery of DTX and siRNA-Bcl-2.
• This dual-delivery system exhibits a significant synergistic effect, enhancing anti-tumor efficacy and warranting further investigation for combined cancer therapy.