In the present work, we aimed at evaluating the magnetofection properties of two types of polycationic core-shell nanoparticles (~200nm), wherein the magnetite core

and functional siloxane shell covalently linked to PHMBG or PEI. Synthesis, magnetic properties, and bactericidal action of such NPs have been previously reported [29, 50–52]. The NPs transfection efficiency was evaluated by conducting a knockdown efficiency study using a dual luciferase reporter assay, and toxicity was studied by the cell proliferation (MTS) and by the lactate dehydrogenase assay (LDH) in HeLa and CHO-K1 #mean keyword# cells lines. We found that PEI’s toxicity was reduced and its transfection efficiency (in one cell line) improved when attached to the surface of the superparamagnetic Inhibitors,research,lifescience,medical nanoparticles. Magnetofection increased

the efficiency of these transfection vehicles even further. 2. Materials and Methods 2.1. Materials Branched polyethyleneimine (PEI, nominal average molecular weight, 25kDa) with a molar ratio of primary to secondary to tertiary amino groups of 1:2:1 was obtained from Sigma-Aldrich Chemical Co. (St. Louis, MO). After dialysis in water (MWCO 12–14kDa) and removal of lower molecular weight fractions, the Mw was 38kDa and Mw/Mn = 1.55. Poly(hexamethylene biguanide) (PHMBG) was from Arch UK Biocides Ltd. (Manchester, UK) supplied as a Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical 20wt% aqueous solution (Cosmocil CQ) with a reported Mw of 2674Da and a polydispersity of 1.89. FeCl3·6H2O (98%), FeCl2·4H2O (99%), aqueous 25wt% glutaraldehyde, tetraethyl orthosilicate (99%, TEOS), 3-glycidoxypropyl trimethoxysilane (97%, GPTMS), and Triton X-100 solution, were all purchased from Sigma-Aldrich Chemical Co. (St.Louis, MO). Fetal bovine serum (FBS) was obtained from Thermo Scientific Hyclone (Logan, Ut). Ethidium bromide was purchased from Bio-Rad (Hercules, CA). CHO-K1 and HeLa cell lines were obtained from ATCC (www.selleckchem.com/products/Imatinib-Mesylate.html Manassas, VA). Dual reporter luciferase assay and cell titer 96 aqueous solution were purchased from Inhibitors,research,lifescience,medical Promega (Madison, Wisconsin). Cell culture media, penicillin, streptomycin, optiMEM buffer,

phosphate buffered saline (PBS), trypsin and trypan blue, were all purchased from Invitrogen (Frederick, MD). The Firefly siRNA sequence and negative control siRNA are commercially available from Applied Biosystems (catalog#AM4629). LDH Cytotoxicity Detection Kit was purchased from Clontech (Mountain Brefeldin_A View, CA). Magnets (NeFeB, magnetic strength of 0.3 Tesla) were purchased from Chemicell, “MagnetoFACTOR-96 plate.” 2.2. Magnetic Particle Synthesis Magnetite-silica core-shell particles functionalized with epoxy groups were synthesized as described in our previous work [29]. First, magnetite particles were prepared, which were well-dispersed in water with the aid of tetramethylammonium hydroxide (TMAOH).