HDL Coupled Multimeric Micelles Co-delivery of siRNA and Doxorubicin for Cell Uptake and Reversal of Multidrug Resistance / 中国药学杂志

ABSTRACT

OBJECTIVE: To prepare siRNA/HDL modified Dox/micelle multimeric polymer(siRNA/HDL-Dox/micelle) by using HDL as a siRNA carrier and a targeting ligand and to realize the effective co-delivery of siRNA and antitumor drug. METHODS: HDL was incubated with chol-siRNA to prepare siRNA/LDL complex, then coupled with Dox/micelle to form siRNA/HDL modified Dox/micelle multimeric polymer (siRNA/HDL-Dox/micelle). The particle size and stability were investigated in different medium. HepG2/ADM with P-glycoprotein(P-gp) over-expressed were used to study the cell uptake, sub-cellular localization and anti-tumor efficacy in vitro. The ability of siRNA to silence target genes at mRNA and protein level was examined by RT-PCR and Western blot. RESULTS: HDL exhibited an efficient binding ability for siRNA and protected siRNA from RNase. The size and surface morphology of siRNA/HDL-Dox/micelle confirmed by TEM showed that most of the micelles were compact and spherical, exhibited a narrow size distribution and good dispersion. The particle size and Zeta potential increased with increasing incubation time in pH 5.3 PBS. The siRNA was efficiently delivered into the cells by encapsulation into HDL, and the expression of P-gp is effectively down-regulated at the mRNA level and the protein level, thereby increasing the accumulation of intracellular Dox and enhancing the antitumor activity. CONCLUSION: siRNA/HDL-Dox/micelle could effectively deliver siRNA and Dox into tumor cells, thereby exerting gene silencing, reversing tumor drug resistance and enhancing anti-tumor effect.