Supporting Information
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Supporting Information Siegwart et al. 10.1073/pnas.1106379108 Additional Experimental Details TDA 305-040 triple detector, VE 7510 degasser, VE 1122 pump, Materials. Oligo(ethylene glycol) methacrylate 300 (OEOMA300, and VE 5200 autosampler. In the case of homo- and diblock poly(ethylene glycol) methyl ether methacrylate, Mn ¼ 300 g∕ copolymers, samples were eluted though three GPMWxL col- mol), oligo(ethylene glycol) methacrylate 475 (OEOMA475, poly umns (Viscotek) in series at a flow rate of 1 mL∕ min in 0.05M (ethylene glycol) methyl ether methacrylate, Mn ¼ 475 g∕mol), gly- sodium nitrate (aq.). The columns and detectors were both cidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA), thermostated at 40 °C. For the HT analysis of core-shell nano- 2-carboxyethyl acrylate (CEA), methacrylic acid (MAA), 2-(di- particles, the flow injection polymer analysis (FIPA) technique methylamino)ethyl methacrylate (DMAEMA), and methyl metha- was utilized, eluting polymers through a W-100-1078 ViscoGEL crylate (MMA) were purchased from Aldrich and passed through a FIPA (Viscotek) column. A single PEO standard with known short column containing basic aluminum oxide to remove the MW, concentration, intrinsic viscosity, and dn/dc was used for inhibitor before use. Oligo(ethylene glycol) methacrylate 1100 triple detection calibration in both cases. Block copolymers K (OEOMA1100, poly(ethylene glycol) methyl ether methacrylate, and L were analyzed using two A-MBHMW-3078 columns for Mn ¼ 1100 g∕mol) (Aldrich) was slightly heated to melt and then anionic polymers (Viscotek) under normal mode with linear passed through a short column containing basic alumina to remove poly(acrylic acid) standards and RI detection at 30 °C. The flow the inhibitor before use. 2,2′-Azobis(2-methylpropionitrile) (AIBN) rate was 1 mL∕ min and the mobile phase was 5% ammonium (Aldrich, 98%) and 4,4′-azobis(4-cyanovaleric acid) (V-501) (Wako hydroxide (aq.). Block copolymer M was analyzed using two Pure Chemical Industries) were recrystallized from methanol before C-MBHMW-3078 columns for cationic polymers (Viscotek) use. N,N-Dimethylformamide (DMF) (Aldrich, 99.8%, anhydrous), under normal mode with linear poly(2-vinylpyridine) standards diethyl ether (Aldrich, 99%), toluene (Aldrich, 99.8%, anhydrous), and RI detection at 30 °C. The flow rate was 1 mL∕ min and the S-(thiobenzoyl)thioglycolic acid (Aldrich, 99%), ethanol (Pharma- mobile phase was 3% acetic acid (aq.). For organic soluble homo- Aaper, 100%), [3-(methacryloylamino)propyl]dimethyl(3-sulfopro- and diblock copolymers, GPC was performed using a Waters pyl)ammonium hydroxide inner salt) (Zwit) (Aldrich), dimethyl system equipped with a 2400 differential refractometer, 515 sulfoxide (DMSO) (Aldrich, anhydrous), tetrahydrofuran (THF) pump, and 717-plus autosampler. The flow rate was 1 mL∕ min (Aldrich, anhydrous), dichloromethane (DCM) (Aldrich), trifluor- and the mobile phase was tetrahydrofuran (THF). The Styragel oacetic acid (TFA) (Aldrich), cholesteryl chloroformate (Aldrich), columns (Waters) and detector were thermostated at 35 °C. N-boc-ethylene diamine (Aldrich), and fluorescein isothiocyanate Linear polystyrene standards were used for calibration. (FITC) (Aldrich) were used as received. Unless labeled as anhy- drous, all solvents used for polymerizations were bubbled with argon Chemical Structure Drawing and Physical Property Modeling. Chemi- for at least 5 hr before use. Unless otherwise noted, all numbered cal structures were drawn using ChemDraw and ChemAxon amines and other chemicals were obtained from commercial MarvinSketch. HT reactions with the library of amines were sources (Aldrich, Alfa Aesar, TCI-America, and Fluka) and used modeled using ChemAxon Reactor. A single nucleophilic nitro- without further purification. Cumyl dithiobenzoate was synthesized gen from each amine was reacted in silico with one equivalent following a procedure from the literature.(1) of GMA. JChem for Excel (version 5.3.1) enabled rapid modeling of microspecies pKas. 1 Instrumentation. H NMR was performed on a Bruker Avance- 400 spectrometer. Transmission electron microscopy (TEM) was In Vitro siRNA Transfection Assay. HeLa cells, stably expressing performed using a JEOL JEM200CX TEM operated at an accel- both firefly (Photinus pyralis) and Renilla (Renilla reniformis) erated voltage of 200 kV. For sample preparation, a droplet of luciferase were seeded (15;000 cells∕well) into each well of an nanoparticle solution was placed on a carbon film covered TEM opaque white 96-well plate (Corning) and allowed to attach over- grid. The filter paper that was placed underneath the grid wicked night in growth medium composed of 90% phenol red-free the water and allowed the particles to be deposited on the grid. DMEM and 10% FBS. Cells were transfected with 50 ng of fire- Because the density of the cross-linked core was generally much fly-specific siLuc complexed with nanoparticle at a nanoparticle/ higher than the uncross-linked shell, sufficient contrast was ob- siRNA ratio of 50∶1 (wt∕wt). Transfections were performed in tained without any staining. AFM was performed using a Veeco triplicate. Working dilutions of each nanoparticle were prepared Nanoscope IV scanning probe microscope (SPM) controller with in 25 mM sodium acetate buffer (pH 5.2). The diluted nano- a Dimension 3100 SPM. Samples were prepared by dropping particle was added to diluted siRNA in a well of a 96-well plate 30 μLofa5 mg∕mL nanoparticle suspension in purified water and vigorously mixed using a pipette tip. The mixtures were onto mica. Excess solvent was removed by wicking using a piece incubated at room temperature for 20 min to allow for complex of filter paper. The surface was washed several times with water formation. The growth medium was removed from the cells and and then allowed to dry before imaging. Particle size (diameter, fresh media was added. Nanoparticle/siRNA complexes (contain- nm) and surface charge (zeta potential) measurements were ing 50 ng siRNA and 2.5 μg nanoparticle) were applied, followed made using a ZetaPALS dynamic light scattering (DLS) instru- by gentle pipette mixing. Cells were incubated for 24 h at 37 °C, ment (Brookhaven Instruments). Experiments were performed 5% CO2 and then firefly and Renilla luciferase activity was ana- in PBS, and viscosity and refraction indices were set equal to lyzed using Dual-Glo assay kits (Promega). those specific to water. Average electrophoretic mobilities were measured at 25 °C using PALS zeta potential analysis software In Vivo Factor VII Silencing in Mice. All procedures used in animal and the Smoluchowsky model for aqueous suspensions. Zeta studies were approved by the Institutional Animal Care and Use potential (mV) is expressed as an average of 9 runs Æ standard Committee and were consistent with local, state, and federal deviation. regulations as applicable. C57BL/6 mice (Charles River Labs) were used for siRNA silencing experiments. 2′-O-methyl sugar Gel Permeation Chromatography (GPC). For water soluble polymers, modified siRNAs (Alnylam) were used to prevent activation of GPC was performed using a Viscotek system equipped with a the Toll-like receptor 7 immune response and confer enzymatic Siegwart et al. www.pnas.org/cgi/doi/10.1073/pnas.1106379108 1of9 resistance. Nanoparticles were purified by dialysis into sterile The contents were stirred to dissolve the macroCTA and initiator. PBS. Prior to injection, complexes were diluted in PBS at siRNA The solution was bubbled with argon for 30 min to deoxygenate concentrations such that each mouse was administered a dose the reaction. The flask was lowered into a preheated oil bath set of 0.01 mL∕g body weight. Formulations were administered in- at 65 °C. The reaction was stopped after 15 min by exposure to travenously via tail vein injection. After 48 h, body weight gain/ air. The polymer was isolated by dialysis using a MWCO 3500 loss was measured and mice were anaesthetized by isofluorane membrane for 24 hr, changing the water three times. The dried inhalation for blood sample collection by retro-orbital eye bleed. block copolymer was obtained by lyphilization. Mn ¼ 15200, Serum was isolated with serum separation tubes (Becton Dickin- PDI ¼ 1.31 (THF GPC). son) and Factor VII protein levels were analyzed by chromogenic assay (Biophen FVII, Aniara Corporation). A standard curve Synthesis of Precursor Block Copolymer B, polyððoligoðethylene Þ Þ b ð Þ Þ Pðð Þ b was constructed using samples from PBS-injected mice and rela- oxide 5methacrylate 56- - glycidyl methacrylate 8 OEO5MA 56- - Þ tive Factor VII activity was determined by comparing treated GMA8 . 152.3 mg cumyl dithiobenzoate (0.56 mmol), 20 mL OEO- groups to an untreated PBS control. MA300 (70 mmol), 18.4 mg AIBN (0.112 mmol), and 30 mL toluene were added to a 100 mL Schlenk flask equipped with a stir In Vitro pDNA Transfection Assay. HeLa cells (ATTC) were seeded bar. The contents were stirred to dissolve the CTA and initiator. (15;000 cells∕well) into each well of an opaque white 96-well The solution was bubbled with argon for 30 min to deoxygenate plate and allowed to attach overnight in growth medium com- the reaction. The flask was lowered into a preheated oil bath set posed of 90% phenol red-free DMEM and 10% FBS. Cells were at 65 °C. The reaction was stopped after 3 hr by exposure to air. transfected with 150 ng of Gwiz (luciferase) pDNA (Aldevron) The polymer was isolated by dialysis using a MWCO 3500 mem- complexed with nanoparticle at a nanoparticle/pDNA ratio of brane for 24 hr, changing the water three times. The dried macro- 50∶1 (wt∕wt). Transfections were performed in triplicate. Work- CTA was obtained by lyphilization (yield ¼ 1.72 g). Mn ¼ 17100, ing dilutions of each nanoparticle were prepared in 25 mM PDI ¼ 1.32 (THF GPC). sodium acetate buffer (pH 5.2). The diluted nanoparticle was 897 mg PððOEO5MAÞ56 macroCTA (52.4 μmol), 1.73 mg added to diluted pDNA in a well of a 96-well plate and vigorously AIBN (10.5 μmol), 720 μL GMA (5.27 mmol), and 1.2 mL DMF mixed using a pipette tip.