The epidemiological statistics reveals the striking patterns of cancer in women and highlights the need for novel therapeutic strategies. In this work, mesoporous silica nanoparticles（MSNs） as representative of inorganic nanoparticles were prepared for loading si RNA that plays a role of gene silencing to treat breast carcinoma（MCF-7） cells. The critical processes of synthesis were optimized for the nanoparticles with desired quality attributes that have the enlarged pores for elevated loading capacity. After si RNA loading into mesoporous, crosslinked-polyethylenimine was employed as the cap to coat the enlarged MSN pores and protect the cargo from leakage. The elevated quantity of si RNA（35 μg si RNA/mg MSNs） were loaded in the MSNs. The as-synthesized MSNs were further evaluated on MCF-7 cells in vitro and shown negligible cytotoxicity. As expected, the si RNA loaded in the as-synthesized MSNs was readily internalized into MCF-7 cells and displayed 420 times higher intake than that of naked si RNA. The MSNs may be exploited to become an effective si RNA cell delivery strategy and further studied for the anti-tumor efficacy.
