U L T I MULTIMOD ITN: M O Poly CyanoAcrylate-based...
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MULTIMOD is an Initial Training Network funded within the 7 th Framework Programme of the European Commission www.multimod.eu MULTIMOD ITN:Multi-Scale Computational Modeling of Chemical and Biochemical Systems ITN M U L T I M O D ITN M U L T I M O D Free Radical Polymerization Inhibition of Anionic Polymerization Batch Anionic Polymerization Reaction (0 ˚C) Solvent: Dichloromethane (DCM) Initiator: Triethylamine (TEA) (1% of monomer) Monomer concentration 0.03 mol/L The anionic polymerization was inhibited using a mixture of DCM with Dichloroacetic acid (DCAA) (50 ppm) Introduction Alkyl CyanoAcrylates are highly reactive acrylic functional monomers undergoing very fast anionic polymerization in the presence of weak bases. Poly-Alkyl Cyano Acrylates are FDA approved materials for biomedical applications such as tissue adhesives and raw material for the syntesis of nanoparticles (NPs) aiming to drug delivery. However, the high reactivity and the fast degradation rates limit their use. Recently, the possibility to copolymerize Alkyl CyanoAcrylates with MethAcrylates by free radical polymerization processes disclosed new opportunities towards the uses of such polymers. Aim of the work The first objective of this work was to control the anionic polymerization of Butyl CyanoAcrylate (BCA). The reactivity of the copolymerization system has been investigated through ab initio simulations in order to guide the further experiments. Free radical copolymerization of Butyl CyanoAcrylate with Methyl MethAcrylate (MMA) was carried out and the obtained co-polymers have been characterized. The produced co-polymers were used to prepare nanoparticles (NPs) through nanoprecipitation NPs characterization Finally, the biocompatibility of these NPs have been studied in in vitro experiments using human fetal amniotic fluid derived stem cells. Various mixtures of monomers without addition of initiator Inhibitor: mixture of DCM and DCAA (100:1) 5% v/v Temperature: 50 °C Residence time: 30 min Results for the conversion were obtained by gravimetric analysis using moisture analyzer at 120 °C NMR analysis of the sample with highest conversion Absence of polymer peak in the NMR spectrum Same NMR spectra for all the samples GPC and MALDI-TOF analysis confirm the absence of polymer Assumption that the solid residue is product of side reactions at 120 °C during the drying process DCAA can inhibit the anionic polymerization under conditions suitable for FRP GPC analysis Presence of monomer peak after monomer addition The area of monomer peak decreases progressively over time while the polymer peak increases its area and moves to higher molecular weights Gravimetric analysis Monomer Addition starts the polymerization (living process) Higher reaction rate after the monomer addition Poly CyanoAcrylate-based Biodegradable Copolymers Evangelos Mavroudakis 1 , Valentina Diana 2 , Giuseppe Storti 3 , Davide Moscatelli 1 1 Department of Chemistry, Materials and Chemical Engineering ‘‘Giulio Natta’’ Politecnico di Milano, via Mancinelli 7, 20131 Milan Italy 2 Istituto Auxologico Italiano, Milan Italy 3 Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland Conclusions Nanoprecipitation NPs prepared by using the copolymer obtained through FRP Biocompatibility test Human fetal amniotic fluid derived stem cells were cultured in stem cells culture medium supplemented with Poly Butyl CyanoAcrylate based nanoparticles at dilutions of 1:1 and 1:100 Computational study: Thermodynamic and kinetic parameters determined by a Density Functional Theory (B3LYP/6-31 G(d,p)) Calculations performed with Gaussian 03 Copolymer reactivity ratios determined according to the Terminal Model GPC analysis (sample 3) GPC analysis (sample 4) Monomer ratio MMA - BCA solvent Size (nm) PDI 1 10% - 90% THF 203,5 0,230 2 30% - 70% THF 202,7 0,194 3 50% - 50% THF 157,6 0,113 4 70% - 30% THF 204,3 0,242 5 90% - 10% THF 192,3 0,175 DCAA proved a good inhibiton of anionic polymerization even under conditions suitable for free radical polymerization (high temperature, bulk reactors) The anionic polymerization of BCA confirmed to be a living process Copolymers of BCA with MMA were synthesized through bulk free radical polymerization and then characterized NPs prepared through a nanoprecipitation process with size suitable for biological applications The biocompatibility of the nanoparticles has been proved in in vitro experiments on stem cell Copolymerization of BCA with MMA could lead to polymers with controlled degradation rates. The biocompatibility of these copolymers and the relative nanoparticles confirms their possible use in biomedical applications. NPs TEM picture (sample 4) All the experimental efforts sustain the possible use of BCA - MMA copolymers for stem cell housing/culture 1) 2) 3) 4) 5) MALDI TOF analysis (sample 4) Experiments : Butch reactors without strirring Initiator: AIBN (1% w/w) Temperature: 50 °C Inhibitor: DCAA (1% v/v) Copolymer composition according to the Terminal Model * Polymer characterization by GPC (standard styrene) ** Data for copolymer composition obtained by MALDI TOF Monomer ratios Mn* (100% conversion) (Da) PDI* Polymer composition for low conversion** (MMA%) 1 10MMA/90BCA 3,44 x 10 4 1,93 21 ± 10 2 30MMA/70BCA 1,44 x 10 5 1,97 23 ± 10 3 50MMA/50BCA 2,11 x 10 5 1,93 30 ± 10 4 70MMA/30BCA 2,41 x 10 5 1,99 36 ± 15 5 90MMA/10BCA 3,04 x 10 5 1,96 40 ± 15 Monomer units 4 MMA 5MMA FMMA Intensity FMMA Intensity 4BCA 50% 67 55% 21 5BCA 44% 86 50% 35 6BCA 40% 98 45% 42 7BCA 36% 100 42% 47 8BCA 33% 100 38% 53 9BCA 31% 96 35% 50 10BCA 29% 87 33% 41 The presence of the NPs does not significantly induce cell toxicity. High concentration of MMA (sample 5) reduces cell metabolism (long terms - 4 days). Conversion Time (s) The living characteristic of the anionic polymerization of BCA has been confirmed Conversion % BCA in monomer mixture
Transcript of U L T I MULTIMOD ITN: M O Poly CyanoAcrylate-based...
MULTIMOD is an Initial Training Network funded within the 7th Framework Programme of the European Commission
www.multimod.eu
MULTIMOD ITN:Multi-Scale Computational Modeling of Chemical and Biochemical Systems
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Free Radical Polymerization
Inhibition of Anionic PolymerizationBatch Anionic Polymerization Reaction (0 ˚C)Solvent: Dichloromethane (DCM)Initiator: Triethylamine (TEA) (1% of monomer)Monomer concentration 0.03 mol/LThe anionic polymerization was inhibited using amixture of DCM with Dichloroacetic acid (DCAA)(50 ppm)
IntroductionAlkyl CyanoAcrylates are highly reactive acrylic functional monomers undergoing very fast anionic polymerization inthe presence of weak bases.Poly-Alkyl Cyano Acrylates are FDA approved materials for biomedical applications such as tissue adhesives andraw material for the syntesis of nanoparticles (NPs) aiming to drug delivery. However, the high reactivity and the fastdegradation rates limit their use.Recently, the possibility to copolymerize Alkyl CyanoAcrylates with MethAcrylates by free radical polymerizationprocesses disclosed new opportunities towards the uses of such polymers.
Aim of the workThe first objective of this work was to control the anionic polymerization of Butyl CyanoAcrylate (BCA).The reactivity of the copolymerization system has been investigated through ab initio simulations in order to guide the further experiments.Free radical copolymerization of Butyl CyanoAcrylate with Methyl MethAcrylate (MMA) was carried out and the obtained co-polymers have beencharacterized.The produced co-polymers were used to prepare nanoparticles (NPs) through nanoprecipitation NPs characterizationFinally, the biocompatibility of these NPs have been studied in in vitro experiments using human fetal amniotic fluid derived stem cells.
Various mixtures of monomers without addition of initiatorInhibitor: mixture of DCM and DCAA (100:1) 5% v/vTemperature: 50 °CResidence time: 30 minResults for the conversion were obtained by gravimetric analysis using moisture analyzer at 120 °C
NMR analysis of the sample with highest conversion
Absence of polymer peak in the NMR spectrum Same NMR spectra for all the samples GPC and MALDI-TOF analysis confirm the absence of polymer Assumption that the solid residue is product of side reactions at
120 °C during the drying process DCAA can inhibit the anionic polymerization under conditions
suitable for FRP
GPC analysis Presence of monomer peak after monomer
addition The area of monomer peak decreases
progressively over time while the polymer peak increases its area and moves to higher molecular weights
Gravimetric analysis Monomer Addition starts the polymerization
(living process) Higher reaction rate after the monomer
addition
Poly CyanoAcrylate-based Biodegradable Copolymers
Evangelos Mavroudakis1, Valentina Diana2, Giuseppe Storti3, Davide Moscatelli11Department of Chemistry, Materials and Chemical Engineering ‘‘Giulio Natta’’ Politecnico di Milano, via Mancinelli 7, 20131 Milan Italy
2Istituto Auxologico Italiano, Milan Italy 3Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland
Conclusions
NanoprecipitationNPs prepared by using the copolymer obtained through FRP
Biocompatibility test Human fetal amniotic fluid derived stem cells were cultured in stem cells culture medium supplemented with Poly Butyl CyanoAcrylate based nanoparticles at dilutions of 1:1 and 1:100
Computational study: Thermodynamic and kinetic
parameters determined by a Density Functional Theory (B3LYP/6-31 G(d,p))
Calculations performed with Gaussian 03
Copolymer reactivity ratios determined according to the Terminal Model
GPC analysis (sample 3) GPC analysis (sample 4)
Monomer ratioMMA - BCA
solvent Size (nm) PDI
1 10% - 90% THF 203,5 0,230
2 30% - 70% THF 202,7 0,194
3 50% - 50% THF 157,6 0,113
4 70% - 30% THF 204,3 0,242
5 90% - 10% THF 192,3 0,175
DCAA proved a good inhibiton of anionic polymerization even under conditions suitable for free radical polymerization(high temperature, bulk reactors)
The anionic polymerization of BCA confirmed to be a living process Copolymers of BCA with MMA were synthesized through bulk free radical polymerization and then characterized NPs prepared through a nanoprecipitation process with size suitable for biological applications The biocompatibility of the nanoparticles has been proved in in vitro experiments on stem cell
Copolymerization of BCA with MMA could lead to polymers with controlled degradation rates. The biocompatibility of these copolymers and the relative nanoparticles confirms their possible use in biomedical applications.
NPs TEM picture(sample 4)
All the experimental efforts sustain the possible use of BCA - MMA copolymers for stem cell housing/culture
1) 2) 3) 4) 5)
MALDI TOF analysis (sample 4)
Experiments : Butch reactors without strirring Initiator: AIBN (1% w/w) Temperature: 50 °C Inhibitor: DCAA (1% v/v)
Copolymer composition according to the Terminal Model
* Polymer characterization by GPC (standard styrene)** Data for copolymer composition obtained by MALDI TOF
Monomer ratios Mn* (100% conversion)(Da)
PDI* Polymer compositionfor low conversion**
(MMA%)
1 10MMA/90BCA 3,44 x 104 1,93 21 ± 102 30MMA/70BCA 1,44 x 105 1,97 23 ± 103 50MMA/50BCA 2,11 x 105 1,93 30 ± 104 70MMA/30BCA 2,41 x 105 1,99 36 ± 155 90MMA/10BCA 3,04 x 105 1,96 40 ± 15
Monomer units 4 MMA 5MMAFMMA Intensity FMMA Intensity
4BCA 50% 67 55% 215BCA 44% 86 50% 356BCA 40% 98 45% 427BCA 36% 100 42% 478BCA 33% 100 38% 539BCA 31% 96 35% 5010BCA 29% 87 33% 41
The presence of the NPs does not significantly induce cell toxicity.
High concentration of MMA (sample 5) reduces cell metabolism (long terms - 4 days).
Con
vers
ion
Time (s)
The living characteristic of the anionic polymerization of BCA has been confirmed
Con
vers
ion
% BCA in monomer mixture
