Manufacturing of Polymeric Nanomaterials for Biomedical applications Yvon Durant Advanced Polymer Laboratory Nanostructured Polymer Research Center Presented at the International Congress of Nanotechnology- October 31-November 3, 2005 San Francisco
Architecture - Size @ 100KD Random coil 24nm linear chain 700nm 10nm 7nm G5 dendrimer 2
Block copolymer architecture diblock-copolymers Star block copolymer Tri block-copolymers gradient-copolymers Block-gradient -copolymers Block pendant copolymer 3
Why are polymer well suited for nanoscale manufacturing ? • Assume a block copolymer PEG-PGLA 55K-b-45K – Random coil size = Rg= l(n a ) 0.5 with l=0.2nm – Density of PGLA = 1.1 g/cm 3 • PGLA assembled in a 10nm “dry” core • Number of chains/particle, n= π D 3 /6 * ρ /m.A • N= 3.14*(10E-7) 3 /6*1.1/45000*6.02E23=8 chains • Rg =l(n a ) 0.5 =0.2*((55000)/44) 0.5 =0.2*(1250) 0.5 =7nm • D=10+7*2=24nm O O O O x y OH n m O 4
• Polymeric Nanoparticles synthesis processes – Mini-emulsion Polymerization – Self assembly – Directed assembly • Application to biotechnologies – liposomes for transmembrane delivery – biosensors by molecularly imprinted polymers – Drug delivery 5
Emulsion Polymerization : soap opera Micelle:5nm Stabilized Polymeric Particle: 50-500nm Stabilized Monomer droplet:5-50 m ygd1 6
Slide 6 Yvon Durant, 1/28/2002 ygd1
Miniemulsion Polymerization • Create a meta-stable emulsion of the monomer(s). • Use 2 key elements : – High shear source to break large droplets • Sonicator • Microfluidizer • Homogeneizer – Use a water insoluble molecule to stabilize the particle • Sometimes called cosurfactant (missleading) • Hexadecane, Eicosane, polymer, macromonomer, macroinitiator, CTA, ... 7
Miniemulsion stability Water Surfactant(s) Monomer(s) Stabilizer No stabilizer With stabilizer 8
Particle size control K. Landfester, N. Bechthold, F. Tiarks, and M. Antonietti, Miniemulsion Polymerization with Cationic and Nonionic Surfactants: A Very Efficient Use of Surfactants for Heterophase Polymerization. Macromolecules 1999 , 32 , 2679. 9
Mini to micro emulsion K. Landfester, Recent Developments in Miniemulsions - Formation and Stability Mechanisms. Macromol. Symp. 2000 , 150 , 171. 10
Encapsulation of magnetite in polymer particles by miniemulsion 11
Magnetite encapsulation SEM TEM Magnetite PS-PMAA cNRG targeting peptide cNRG targets CD13 – PEG shell tracer of engiogenesis 50nm Magnetic nanoparticles functionalized with cNGR for atherosclerotic plaque diagnostic. 12
• Polymeric Nanoparticles synthesis processes – Emulsion Polymerization – Mini-emulsion Polymerization – Self assembly – Directed assembly • Application to biotechnologies – biosensors by molecularly imprinted polymers – liposomes for transmembrane delivery – Bypassing the BBB 13
Molecularly Imprinted Polymers 1. Selection of template molecule and functional monomers 2. Self-assembly of template molecule and functional monomers 3. Polymerization 4. Analyte Extraction 14
SINP : Surface Imprinted NanoParticle 1 st stage 2 nd stage Miniemulsion Emulsion Polymerization Polymerization MAA P(MMA-EGDMA) P(MMA-EGDMA) P(MMA-EGDMA) Core Core Core EGDMA Extraction by dialysis Caffeine Caffeine P(MAA-EGDMA) shell MJB-21: 2nd stage imprinting MJB-20: miniemulsion seed Water 57.74% Organic phase = 23% : MMA 85.5%, EGDMA 9.5%, Hexadecane 5%, MJB20 (wet) 33.44% NaHCO3 0.042% Water phase = 77% : Water 99%, SDS 0.6%, KPS 0.025%, NP-50 0.39% KPS 0.047% Prepare the two phases, mix them together, magnetically stir them for 15 Caffeine 5.78% minutes, then, sonicate the resulting emulsion for 2 minutes (90%, 9) in ice. EGDMA 2.63% MAA 0.31% SCexp = 22.25%, Conversion = 98.96%, Water, MJB-21, NaHCO3, were mixed and heated at 80C. Size = Malvern Nanosizer: Dz = 107.1 nm, Dv = 111.9 nm When at temperature, add caffeine and start degassing. After 15 minutes, add KPS and start feeding with egdma+maa. Dilute with 250g of hot water (336%) while stirring. SCexp = 2.635% (dilution) Conversion = 57.86% Size = Malvern nanosizer Dz= 108.4 nm, Dv = 114.2nm Brookhaven 90+: Dz = 104.9 nm, Effective Dv = 105.2 nm 15
SEM+DLS of SNIP MJB21 16
Adsorption studies by HPLC Caffeine adsorption isotherm 1.80E-02 1.60E-02 EGDMA-MA -caf imprint in ACN (bulk-1) Binding constant specific site 1027 l/mol 1.40E-02 Binding constant non-specific site 47 l/mol 1.20E-02 caffeine bound-g 1.00E-02 Nanoparticles EDGMA-MA in H2) caf(MJB40) 8.00E-03 Binding constant specific site 888 l/mol Binding constant non-specific site 51 l/mol 6.00E-03 4.00E-03 2.00E-03 0.00E+00 0.00E+00 5.00E-03 1.00E-02 1.50E-02 2.00E-02 2.50E-02 3.00E-02 3.50E-02 4.00E-02 caffeine free-gm. 17
Biomimetic electrochemical sensors based on molecular imprinting • A chemical sensor selectively recognizes a target analyte molecule in a complex matrix and gives an output signal which correlates with the concentration of the analyte. The transducer: When the analyte interacts with the recognition element of a sensor, there is a change in one or more physicochemical parameters associated with the interaction. Transducer convert these parameters into an electrical output signal than can be amplified, processed and displayed in a suitable form. Molecular imprinting use as sensing materials Advantage : cheap, stable and robust under a wide range of conditions including pH, humidity and temperature Problem: Signal transduction is so low that it seem to be environmental artifacts. Due to the insulating nature of the polymer constituting the MIP Biomimetic electrochemical sensors based on molecular imprinting / Chap.18 MIP – D. Kriz, R. J. Ansell- Vol 23 -Elsevier 18
QCM • A QCM consists of a thin quartz disc sandwiched between a pair of electrodes. Due to the piezoelectric properties of quartz, it is possible to excite the crystal to oscillation by applying an AC voltage across its electrodes. 19
Q-Sense D300 20
Coated QCM sensor Fracture SEM 21
Raw data 22
QCM results Adsorption of caffeine at different caffeine solution concentrations 1 caffeine 0.05g/L 0.9 caffeine 0.0005g/L caffeine 0.005 g/L 0.8 0.7 150Hz 0.6 F1/F1max 0.5 0.4 1.6Hz 0.3 0.2 0.1 12Hz 0 0 5 10 15 20 25 time in minutes With the Langmuir equation the quantity adsorbed can be calculated for the caffeine MIP at a concentration of 0.0005g/L. This value is found to be equal to 7.3×10-6g of caffeine per gram of MIP. The mass of MIP on the crystal is equal to 4×10- 5g. With these two values, the minimum amount detected in this experiment was equal to 0.3nanogram. 23
Guanosine Recognition • Perfect complement to imprint NH 2 Guanosine O Cytidine guanosine is cytidine N N N H N O O N O N H 2 N O O O O O O • Modified cytidine monomer O NH 2 NH 2 O O O N N OH H O O N N + O O H3PO4 1.3eq OH OH H O H O EDIC 1.5eq DMAP 2.5eq in water RT 12 hrs EDCI: 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride DAMP: 4-dimethylaminopyridine 24
LC/MS Base peak chromatogram m/z 112, NH 2 266 N RT: 0.05 - 29.98 NL: 13.10 100 N O 1.57E6 Base Peak 95 HO O Na+ F: MS marine_sampl 90 e_05042011 4728 85 HO OH 80 13.06 266 75 70 65 NH 2 60 Relative Abundance N 55 O 50 N O 45 O O Na+ 40 m/z 226, 174, etc 35 HO OH 334.1 30 m/z 334 24.94 25.06 25 25.13 24.89 20 Two different 15 Isomers apparently 1.93 12.61 1.87 10 1.81 11.14 10.64 20.72 20.64 20.80 2.12 5 28.04 28.64 1.65 3.74 5.04 9.66 5.51 6.22 23.13 24.53 20.43 13.68 15.72 17.72 19.78 7.02 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Time (min) 25
SINP : Guanosine detection 2 nd stage 1 st stage Emulsion Precipitation Polymerization Polymerization Cytidine-MA P(MMA-EGDMA) P(MMA-EGDMA) P(MMA-EGDMA) Core Core Core EGDMA Extraction by dialysis Guanosine Guanosine P(MAA-EGDMA) shell 26
Precipitation Polymerization in ACN 27
Precipitation polymerization • Smaller… • 20nm • Higher sensitivity 28
Low cost QCM 29
QCM200 0.6 0.6 -300 50 LAN28-a-6-6th Event MJB18-a-2 Event 40 -350 0.5 0.5 30 -400 0.4 0.4 Frequency (Hz) 20 Frequency (Hz) Caffeine (g/L) Caffeine (g/L) -450 0.3 0.3 10 -500 0 0.2 0.2 -550 -10 0.1 0.1 -600 -20 -650 0 0 -30 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Time (Hours) Time (Hours) 30
• Polymeric Nanoparticles synthesis processes – Emulsion Polymerization – Mini-emulsion Polymerization – Self assembly – Directed assembly • Application to biotechnologies – biosensors by molecularly imprinted polymers – liposomes for transmembrane delivery – Drug delivery 31
Self assembly (Claverie) insulin pH = 7.4 Spontaneous self association PGlu PLA PEG O NH 2 k HN O O CO 2 H O O NH Me O m n O CO 2 H O HN j + k + 1 = l H j 32
Parental delivery of insulin Small Intestine Nanoparticle protease dispersion Digestion of the PGlu hairy layer hydrophobic Enteric Coating particle is adsorbed microvilii endocytosis Acidic degradation of PLA Endosome (pH = 5) epithelial cell Insulin delivery 33
Recommend
More recommend
