Small size mesoporous organosilica nanorods with different aspect ratios: Synthesis and cellular uptake

Abstract In the work, small size thioether-bridged mesoporous organosilica nanorod (MONRs) are successfully synthesized using cetyltrimethylammonium bromide (CTAB) as structure-directing agent and bis[3-(triethoxysilyl)propyl]tetrasulfide (TETS) and tetraethoxysilane (TEOS) as co-precursors. The MONRs have tunable aspect ratios of 2, 3, and 4 (denoted as MONRs-2, MONRs-3, and MONRs-4), small and controllable lengths (75–310 nm), high surface area (570–870 cm 2  g −1 ), uniform mesopores (2.4–2.6 nm), large pore volume (0.34 cm 3  g −1 ), and excellent biocompatibility. The uptake of the MONRs by multidrug resistant human breast cancer MDR-MCF-7 cells is related to their aspect ratios. The MONRs-3 shows a faster and higher cellular internalization compared to the MONRs-4 and MONRs-2, respectively. Thanks to the high cellular uptake, doxorubicin (DOX) loaded MONRs-3 show obviously improved chemotherapeutic effect on MDR-MCF-7 cancer cells. It is expected that the MONRs provide a useful platform for drug delivery and therapeutics.