Surface Engineering of g-maghemite (Fe 2 O 3 ) Nanoparticles Process Optimization Using Design Of Experiments (DoE) for sirna-mediated Gene Silencing Prof. J.-P. Lellouche (Dpt of Chem. BIU & BINA) Profs. S. Michaeli & Ron S. Kenett (BINA & KPA Ltd. on-going cooperation) Liron L. Israel & Emmanuel Lellouche (PhD students) $$$$ VII th European Project SaveMe (grant agreement n 263307) (FP7-NMP-2010- LARGE-4 area - Large Collaborative Projects) & Israeli Ministry of Trade & Industry KAMIN/RIMONIM (Magnet project) funding Bar-Ilan University, Dpt of Chemistry, Nanomaterials Research Center, Institute of Nanotechnology & Advanced Materials (BINA) 5290002 Ramat Gan, Israel Phone: 972-3-531 83 24, Fax: 972-3-738 40 53, Email: lellouj@biu.ac.il & jp.m.lellouche@gmail.com
# Ultra-small [CeL n ] 3/4+ cation/complex-doped g-fe 2 O 3 NPs (fabrication & selected characterization features) # Anti-aggregation & [CeL n ] 3/4+ cation/complex-mediated properties of corresponding ultra-small hydrophilic NPs Coordinative attachment chemistry of organic species (25kDa b-pei polymer) # Global DoE-driven optimization of the [CeL n ] 3/4+ cation/complex doping step # Gene silencing experiments (sirna delivery) & selected NP/composite toxicity
Ultra-Small CAN-maghemite (CAN- -Fe 2 O 3 ) NPs - Fabrication Process Data New nanofabrication conditions = Hydrophilic ultra-small maghemite ( -Fe 2 O 3 ) NPs (mono-electronic CAN oxidant-mediated ultrasound-assisted processing) Absolute NP aggregation control (charge control): Neither use of any surfacepassivating bifunctional ligand nor physically adsorbed natural/non-natural polymer Pre-formed Massart magnetite (Fe 3 O 4 ) nanoparticles (NPs) CAN [Ce(IV)(NH 4 ) 2 (NO 3 ) 6 ], MeCOMe/EtOH, 20-55 C, 0.5-1h, high power ultrasonication Ce 3/4+ cation doping of the NP surface = Inorganic method for NP aggregation control Ce 3/4+ cation-stabilized maghemite NPs (CAN- g-fe 2 O 3 NPs) Fe(III) atom Fe Fe Fe O(H) NP Fe core Fe Fe Fe O(H) Fe [CeL n ] 3/4+ Doping Ce 3/4+ metal cation/complex L L L Ce L L L 3/4 + [CeL n [ 3/4+ -based coordination chemistry L: Coordinating monodentate/ polydentate ligand (OH, H 2 O, O-N(=O)-O, R-NH 2 and/or R-NH-linker-NH-R' (PEI) ligands) CAN
Ultra-Small CAN-maghemite (CAN- -Fe 2 O 3 ) NPs Selected Characterization Data Ce element/[celn] 3/4+ complexes: Very low level of Ce (NP surface - ICP-AES: Ce/Fe wt/wt ratio = 0.029, Ce/Fe molar ratio = 0.0204) XRD & XPS features Compatible with a crystalline -Fe 2 O 3 phase Ultra-small 6.0-7.0 nm-sized (TEM) positively charged (z potential: +40-50 mv) NPs: Ce 3d 5/2 - BE = 890.47 ev)
HR-TEM/Compositional EDAX Analysis = Presence of the Ce element (0.24% weight/0.02% atom)
Super-paramagnetic NPs Saturation Ms: 75.2 emu/g & blocking T C: 109-110 C
Ultra-Small CAN-maghemite (CAN- -Fe 2 O 3 ) NPs MRI Relaxivity Data (Bioimage Ltd. MRI Research & Consulting) Clinically approved SPIONs: Ferumoxides (Feridex/Endorem, r 1 /r 2 relaxivites: 23.9 & 98.3 mm - 1 sec -1 ) at a particle size of 120-180 nm, & Ferucarbotran (Resovist, r 1 /r 2 relaxivites: 25.4 & 151.0 mm -1 sec -1 respectively) at a particle size 60 nm Main effect of SPION particles on T 2 * relaxation = MRI usually performed using T 2 /T2*-weighted sequences Wang YX. Superparamagnetic iron oxide based MRI contrast agents: Current status of clinical application. Quant Imaging Med Surg 2011;1:35-40. DOI: 10.3978/j.issn.2223-4292.2011.08.03 Bioimage Ltd. MRI Research & Consulting CAN- -Fe 2 O 3 NPs: r 1 : 0.015 & r 2 : 189 mm -1 sec -1
Ultra-Small CAN-maghemite (CAN- -Fe 2 O 3 ) NPs [CeL n ] 3/4+ cation/complex-mediated NP functionalization/significance = Design of Experiment - Driven Global Doping Process Optimization Fe FeO(H) Fe CAN-g-Fe 2 O 3 NPs [CeL n ] 3/4+ L L L Ce L L L 3/4+ L: Coordinating ligand (OH, H 2 O, O-N(=O)-O, R- NH 2 and/or R-NH-linker-NH-R' (PEI) ligands) 1. 25 kda PEI 25 2. Aq. H 2 O 2, 10 C, overnight 3. RNA complexation NP RNA-loaded PEI 25-ox -CAN-g-Fe 2 O 3 NPs CAN oxidant = Dual role: Fe 3 O 4 phase oxidant & elemental Ce donor Unusual highly positive NP z potential/surface charge due to [CeL n ] 3/4+ cation/cpx doping even at a so low level - Ce/Fe wt/wt ratio = 0.029, Ce/Fe molar ratio = 0.0204 Innovative way of NP decoration chemistry: [CeL n ] 3/4+ cations/complexes acting as very strong Lewis Acid centers together with corresponding lanthanide coordination capability of any Lewis base N/O/S-containing organic species (ccordination attachment of polymers, small ligands, peptides, oligosaccharides, antibodies, & more Experimental Design of Experiments (DoE) for doping process global optimization (opti- Mization of selected NP physico-chemical features)
CAN DOE -maghemite (CAN DOE - -Fe 2 O 3 ) NPs: Design of Experiment (DoE) methodology for globally optimized USassisted doping process: 4 main factors set-up at both low & high value levels # Ageing time of starting Fe 3 O 4 (magnetite) NPs # CAN oxidant amount # MeCOMe solvent value (v/v 1/1mixture MeCOMe/ddH 2 O) # High-power US time (power modulator: 25%) = Four factor two-level full factorial design (MINITAB 16 DoE software - version 16.2.4, Minitab Inc.) with one factor replicate (corner points) & center points = Table of 17 experiments (2 4 + 1 center point 1 block) Ageing time [h] CAN oxidant [mg] MeCOMe volume [ml] Reaction time [h] DLS [nm] ξ Potential [mv] Wt Ce/Fe ratio NP Size [TEM, nm] 12 150 6 0.5 49.65 +33.0 0.00725 7.47 2 500 18 1.5 54.05 +40.5 0.01568 6.83 12 500 6 0.5 55.66 +52.1 0.07716 6.99 2 500 6 0.5 45.72 +47.2 0.0623 6.81 2 150 6 0.5 49.05 +37.6 0.00652 6.49 7 325 12 1 37.04 +37.1 0.02198 7.63 12 500 6 1.5 40.81 +33.6 0.0462 7.85 12 500 18 0.5 80.2 +47.3 0.02266 8.10 2 500 18 0.5 56.64 +30.9 0.03052 7.60 2 150 6 1.5 34.78 +26.3 0.0012 7.61 12 150 18 0.5 84.08 +34.9 0.00592 8.01 12 150 6 1.5 40.93 +35.4 0.00565 7.40 2 150 18 1.5 58.88 +39.9 0.00425 6.79 2 500 6 1.5 38.37 +46.4 0.04971 7.02 12 500 18 1.5 51.8 +50.4 0.05255 7.71 12 150 18 1.5 75.73 +35.0 0.00304 7.69 2 150 18 0.5 65.87 +23.2 0.00736 7.42
CAN DOE -maghemite (CAN DOE - -Fe 2 O 3 ) NPs Data analysis of critical factors influence Most influential factor: CAN amount Entry 3: Ce doping increase by a 266.1% factor!!! All other factors & 2 nd /3 rd order standardized effects found less influential/significant Highest w/w Ce/Fe ratios for 6.0 ml MeCOMe & CAN amount(s) >> 430.0 mg
CAN DOE - -Fe 2 O 3 NPs Data analysis of critical factors influence Smallest (TEM) NPs (7.0-7.25 nm) obtained for similarly high amounts/volume of CAN & MeCOMe components Same conditions also provided NP highest z potenvalues (+40.0 - +45.0 mv) & smallest hydrodynamic diameters (40-50 nm range) CAN oxidant [mg] Contour Plot of potential [mv] vs CAN oxidant [mg], acetone [ml] 500 450 400 350 300 250 200 potential [mv] < 25 25 30 30 35 35 40 40 45 45 50 50 55 > 55 CAN oxidant [mg] CAN oxidant [mg] 500 450 400 350 300 250 500 450 400 350 300 250 200 150 6 Contour Plot of Size/TEM vs CAN oxidant [mg], acetone [ml] 8 10 12 acetone [ml] Contour Plot of DLS [nm] vs CAN oxidant [mg], acetone [ml] 14 16 18 Size/TEM < 6.50 6.50 6.75 6.75 7.00 7.00 7.25 7.25 7.50 7.50 7.75 7.75 8.00 > 8.00 DLS [nm] < 40 40 50 50 60 60 70 70 80 > 80 150 6 8 10 12 acetone [ml] 14 16 18 200 150 6 8 10 12 acetone [ml] 14 16 18
CAN DOE - -Fe 2 O 3 NPs Data analysis of critical factors influence Two-way interaction plot graphs: analysis of the way the different factors interact & influence process response(s) Two-way Interaction plot graphs = Both US time & MeCOMe volume show significant intercations for z potential & NP (TEM) size responses
CAN DOE - -Fe 2 O 3 NPs Use of the MINITAB 16 software profile optimizer tool Software optimizer tool = takes under consideration differently important responses with predictive capabilities for given designed conditions # Proposed optimal conditions: 4.22h ageing time (Fe 3 O 4 NPs), 500.0 mg CAN, 6.0 ml MeCOMe, & 0.5 high-power US Blue values for calculated responses # Experimentally DoE Tool obtained values: 60.00 nm (DLS), z potential: +45.7 mv, w/w Ce/Fe ratio: 0.1000 (even higher than the Tool calculated value), & 6.61±2.04 nm NP diameter
CAN DOE - -Fe 2 O 3 NPs Use of the MINITAB 16 software profile optimizer tool (Selected Physico-Chemical Characterization Data) Hydrodynamic NP Ø: 60.00± 1.98 nm potential: +45.7±1.88 mv ICP-AES elemental analysis: wt/wt Ce/Fe ratio = 0.1000 (60.5% higher than software prediction) x 3.5 fold!! the value found for non-optimized conditions (0.029) (TEM) NP Ø: 6.61±2.04 nm (slightly lower than the software predicted value - 6.89 nm)
CAN DOE - -Fe 2 O 3 NPs Use of the MINITAB 16 software profile optimizer tool (Selected Physico-Chemical Characterization Data) Hydrodynamic NP Ø: 60.00± 1.98 nm XPS & EDAX/ICP analyses confirm elemental Ce presence (higher amounts) 60.0 nm Increased doping Ce amount: Presence of nitrate [CeL n ] 3/4+ complexing ligands on the NP surface N 1s peak: 407.39 ev BE
CAN DOE - -Fe 2 O 3 NPs: chemical modifications using 25kDa b-pei/modified b-pei polymers for gene silencing (sirna delivery) - Selected Physico- Chemical Characterization Data) [CeL n ] 3/4+ cation-stabilized maghemite NPs (CAN-g-Fe 2 O 3 NPs) Fe O(H) Fe [CeL n ] 3/4+ [CeL n [ 3/4+ -based coordination chemistry L L L Ce L L L 1. 25 KDa b-pei (coordination mode) 2. sirna/rna complexation 3/4 + L: Coordinating monodentate/ polydentate ligand (OH, H 2 O, O-N(=O)-O, R- NH 2 and/or R-NH-linker-NH-R' (PEI) ligands) HO O RNA-loaded b-pei 25 -CAN-g-Fe 2 O 3 NPs N O OH Dipicolinic acid (red: coordinating atoms) sirna/rna cell delivery & gene silencing or 1. 25 KDa b-pei (coordination mode) 2. Aq. H 2 O 2, 10 C 3. sirna/rna complexation NP NP RNA-loaded PEI 25-ox -CAN-g-Fe 2 O 3 NPs
b-pei 25 -CAN DOE -g-fe 2 O 3 NPs Selected characterization data # w/w b-pei/fe ratio: 5.25 6.86±1.55 (TEM) & 82.90±1.26 (DLS) nm # w/w Ce/Fe: 0.1000 # z Potential: +31.1 mv # Presence of both NO 3 (-) anions/b-pei phase (XPS N 1s peaks at BEs 406.0-407.0 & 398.0-402.0 ev) # TGA analysis: b-pei phase (73.62 w% at 200-410 C temperature range) # Strong T* 2 contrast NP agent: r 1 & r* 2 relaxivity values of 0.103 & 168.0 mmol -1 s -1 # Super-paramagnetic NPs # Effective gene silencing capabilities using a dual luciferase (Firefly & Renilla) system = Human osteosarcoma U2OS-Luc cells
b-pei 25 -CAN DOE -g-fe 2 O 3 NPs - Selected characterization data sirna capture at increasing Fe/siRNA w/w ratios sirna capture at increasing b-pei 25 /sirna w/w ratios
b-pei 25 -CAN DOE -g-fe 2 O 3 NPs Selected characterization data Gene silencing properties = quite high effectiveness (very low Fe/siRNA w/w ratios)
b-pei 25-ox -CAN DOE -g-fe 2 O 3 NPs Selected characterization data & gene silencing capability # 0.1, 0.5 & 5% molar oxidation of b-pei 25 amine groups (sreening experiments) # w/w b-pei/fe ratio: 5.25 6.36±2.65 (TEM) & 120.0 (DLS) nm # w/w Ce/Fe: 0.1000 # z Potential: +29.4 mv # Super-paramagnetic NPs # Effective gene silencing capabilities using a dual luciferase (Firefly & Renilla) system = Human osteosarcoma U2OS-Luc cells with total absence of in vivo toxicity Luciferase silencing in U2OS-Luc cells by CAN-g-Fe 2 O 3 NPs + PEI + 0.5% mass H 2 0 2 [contact process] PEI/Fe=5.25 Luciferase silencing in U2OS-Luc cells by CAN-g-Fe 2 O 3 NPs + PEI + 5% mass H 2 0 2 [contact process] PEI/Fe=5.25 % of control 220 200 180 160 140 120 100 80 60 40 20 0 control 0.063 0.126 0.157 0.315 0.4725 0.63 811 Firefly Renilla % of control 140 120 100 80 60 40 20 0 control 0.063 0.126 0.157 0.315 0.4725 0.63 813 Firefly Renilla Fe/siRNA mass ratio Fe/siRNA mass ratio
sirna capture by b-pei 25-ox -CAN DOE -g-fe 2 O 3 NPs at increasing Fe/siRNA w/w ratios 0.1% molar oxidation b-pei 25 # in vivo injection till 4.0 mg sirna/kg (24h: 2 mg/kg + 2 mg/kg) ------------ mice alive!
# Innovative ultra-small [CeL n ] 3/4+ cation/complex-doped g-fe 2 O 3 NPs = New type of non-toxic magnetic (MRI-enabling) nanoscale inorganic carriers # Effective use of statistically relevant Design of Experiments (DoE) methods for optimization of NP surface engineering (doping step by lanthanide [CeL n ] 3/4+ cations/complexes) # NP Aggregation control executed = new concept using positive metallic cation implantation/doping # Potential straight obtainment of dual / [CeL n ] 3/4+ cation/complex-doped g-fe 2 O 3 NPs On-going work focusing also on hard-totransfect cells 22