Diethylamino Ethyl Methacrylate Research Articles

Macroporous modified poly (vinyl alcohol) hydrogels with charged groups for tissue engineering: Preparation and in vitro evaluation

Poly(vinyl alcohol) (PVA) hydrogels are widely employed for various biomedical applications, including tissue engineering, due to their biocompatibility, high water solubility, low protein adsorption, and chemical stability. However, non-charged surface of PVA-based hydrogels is not optimal for cell adhesion and spreading. Here, cross-linked macroporous hydrogels based on low molecular weight acrylated PVA (Acr-PVA) was synthesized by modification of the pendant alcohol groups on the PVA with glycidyl methacrylate (GMA). To enhance cell affinity, charged groups were introduced to the hydrogel composition. For this purpose, Acr-PVA was copolymerized with either negatively charged acrylic acid (AA) or positively charged 2-(diethylamino) ethyl methacrylate (DEAEMA) monomers. A surface charge of the obtained hydrogels was found to be in function of the co-monomer type and content. Confocal microscopy observations confirmed that adhesion and spreading of both mouse fibroblasts (L929) and human mesenchymal stem cells (hMSC) on the modified Acr-PVA-AA and Acr-PVA-DEAEMA hydrogels were better than those on the non-modified Acr-PVA hydrogel. The increase of DEAEMA monomer content from 5 to 15mol% resulted in the enhancement of cell viability which was 1.5-fold higher for Acr-PVA-DEAEMA-15 hydrogel than that of the non-modified Acr-PVA hydrogel sample.

Adhesion between oppositely charged polyelectrolytes

ABSTRACTThe adhesion between a grafted polyelectrolyte layer (brush) and a gel of an oppositely charged polyelectrolyte has been measured as a function of applied pressure, and the interface has been traced using neutron reflectometry. The interface (in aqueous medium at pH 6) between the (polycationic) brush and the (polyanionic) gel has a limited pressure dependence, with a small amount of deformation of the interface at the brush–gel contact. Brushes with a dry thickness of up to 13 nm exhibit weak adhesion (measured using a mechanical force tester) with an adhesive failure when the gel is detached. Thicker brushes result in the gel exhibiting cohesive failure. Reversing the geometry, whereby a polycationic brush is replaced with a polyanion and the polyanionic gel is replaced with a polycation, reveals that the pH dependence of the adhesion is moderately symmetric about pH 6, but that the maximum force required to separate the polycation gel from the polyanion brush over the range of pH is greater than that for the polycation brush and polyanion gel. The polyanion used is poly(methacrylic acid) (PMAA) and polycations of poly[2-(diethylamino)ethyl methacrylate] (PDEAEMA) and poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) were used.

Computer simulations on the pH-sensitive tri-block copolymer containing zwitterionic sulfobetaine as a novel anti-cancer drug carrier

In this work, dissipative particle dynamics (DPD) simulations were performed to study the self-assembled microstructures and doxorubicin (DOX) loading/release properties of pH-sensitive amphiphilic triblock copolymer: poly(ε-caprolactone)-b-poly(diethylaminoethyl methacrylate)-b-poly(sulfobetaine methacrylate) or poly (ethylene glycol methacrylate) (PCL-PDEA-PSBMA/PEGMA). Our results show that both copolymers can self-assemble into core-shell-corona micelles in aqueous environment. However, the corona structures are quite different for the two copolymer micelles. The shell layers formed by PEGMA have heterogeneous sizes while the shell layers in PCL-PDEA-PSBMA micelles are homogenous. This is mainly attributed to the stronger hydrophilicity of PSBMA than PEGMA. As the mole concentration of copolymer is increased from 10% to 50%, the microstructures formed by PCL-PDEA-PSBMA and DOX remains spherical micelles whereas PCL-PDEA-PEGMA undergoes structural transition from spherical to cylindrical and finally to lamellar micelles. Interestingly, the studied micelles have a pH-responsive drug release property, owing to the protonation of the PDEA block. The drug release process follows a “swelling-demicellization-release” mode. The multi-scale simulations demonstrate an avenue to the optimal design of nanomaterials for drug delivery with desired properties.

Synthesis of gold nanoparticles using poly(ethyleneglycol)-b-poly(N,N-diethylaminoethylmethacrylate) as nanoreactors

Polyethyleneglycol-block-poly(N,N′-diethylaminoethyl methacrylate) (PEG-b-PDEAEM) copolymers were used as nanoreactors for the preparation of gold nanoparticles (AuNPs) in aqueous and alcoholic medium. These copolymers were synthesized changing the size of the PDEAEM block by using reversible addition–fragmentation chain transfer (RAFT) polymerization as demonstrated by nuclear magnetic resonance and gel permeation chromatography measurements. The PEG-b-PDEAEM block copolymers were dispersed in water to form aggregates with sizes around 100 nm, depending on the lengths of the PDEAEM segment as well as the pH of the solution. The corresponding unimers were evident when these same copolymers were dissolved in alcohol or tetrahydrofuran medium showing hydrodynamic diameters (D h) between 4 and 10 nm. The aggregates and unimers were used as nanoreactors for the synthesis of AuNPs and were characterized using UV–Vis spectroscopy, dynamic light scattering and transmission electron microscopy. The AuNPs had a sphere-like shape with a diameter from 7 ± 1.7 to 34 ± 6 nm depending on the type of aggregate/unimer used in the synthesis. Nevertheless, when very large aggregates were used, AuNPs with different morphologies were observed.

Water Soluble Dual Responsive Star Copolymer for Encapsulation of Hydrophobic Dye Molecules

SummarySynthesis of water soluble thermo and pH responsive 3‐arm star shaped random copolymer of diethylene glycol methyl ether methacrylate (DEGMEM) and N, N diethylaminoethyl methacrylate (DEAEMA) is carried out by ATRP technique. The synthesized copolymer is characterized by 1H NMR spectroscopy and gel permeation chromatography (GPC). The dual stimuli responsive behavior of the synthesized block copolymers is demonstrated using dynamic light scattering (DLS) and fluorescence spectroscopy. The copolymer is insoluble in water at pH 9.2 which is attributed to the hydrophobicity of −NEt2 groups but at lower pH (pH 4 & 7) water solubility is observed due to protonation. Aggregation and dissociation behavior is only observed at pH 7 when the temperature is increased over 35 °C. Heating of the aqueous solution of the copolymer in presence of hydrophobic fluorescent molecule ‘Nile red’ over 35 °C shows a sharp increase in fluorescence intensity which again decreases with lowering of pH indicating temperature triggered encapsulation and pH triggered release of it. The increased hydrophobicity of −NEt2 groups ensure aggregated structure at pH 7 over 35 °C. This is very much important in view of loading of hydrophobic molecules within the polymer scaffold in the pH range that remains in blood stream at physiological conditions.

PH and Salt Effects on Surface Activity and Self-Assembly of Copolymers Containing a Weak Polybase.

Copolymers with well-defined architectures, controlled molecular weights, and narrow molar mass dispersities (Đ) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The resultant polymers contain different combinations of the pH-responsive monomer 2-(diethylaminoethyl) methacrylate (DEAEMA), the hydrophobic comonomer butyl methacrylate (BMA), and a neutral hydrophilic stabilizing monomer polyethylene glycol monomethyl ether methacrylate (designated O950). Surface tension and cryo-TEM measurements of native and heavy-atom stained samples were used to characterize the pH and salt responsiveness of the different polymers as a function of their composition. These studies indicate that while the polymers predominately self-assemble to form spherical micelles, a narrow size distribution is observed in aqueous solutions of poly(O950)-b-(BMA) and poly(O950)-b-(DEAEMA-co-BMA), whereas a broad size distribution characterizes the assemblies of poly(O950)-b-(DEAEMA) and poly(DEAEMA-co-BMA). In the latter case, micelles having diameters around 15-25 nm are found along with smaller aggregates (about 10 nm) mostly arranged in elongated necklace-like structures. The pH and salt-responsiveness of the DEAEMA residue, as indicated by the surface activity of the copolymers, was found to depend on the nature of the additional components: covalently linked hydrophobic groups (BMA) moderated the pH response of the copolymer as compared to nonionic and hydrophilic groups as in poly(O950)-b-(DEAEMA). These results suggest that mutual interactions among the building blocks of self-assembling copolymers should be taken into account when designing responsive copolymers.

Synthesis and biomedical application of polymer vesicles composite hydrogels

Nanocomposite hydrogel attracts increasing interest in drug delivery field on account of combining advantages of nanocomponents and hydrogels on the controlled drug release and biocompatibility. Polymer vesicle composite hydrogels were designed for ophthalmic drug delivery in the work. Polymer vesicle was fabricated by polymerization in situ and assembling of macromolecule (heparin/chondroitin sulphate)-monomer (diethylaminoethyl methacrylate) system. Vesicle size and zeta potential could be adjusted by many factors such as the property of macromolecule and cross-linking of vesicle. Vesicle was further characterized and confirmed by transmission electron microscopy. Polymer vesicle laden hydrogels were obtained by photopolymerization in situ. The transparency of composite hydrogel declined with increase in vesicle concentration. The equilibrium water content and water loss showed that polymer vesicle composite hydrogel with higher vesicle concentration was in a higher swollen state. The dynamic viscoelastic properties showed that all polymer vesicle composite hydrogels had some characteristics of cross-linked elastomers. After freeze-dried, polymer vesicle composite hydrogels had a coarser surface with scattered small particles. The drug loading and releasing behaviours as a function of initial drug immersing concentration were detected to evaluate the drug loading and releasing capacity of hydrogels using orfloxacin as a model drug. The results indicated that polymer vesicles in hydrogels could hold or help to hold drug molecules and slow down orfloxacin release speed or keep orfloxacin stably remain for a certain period of time in hydrogels.

Controlled release behavior of pH-sensitive poly(2-(diethylamino)ethyl methacrylate)/palygorskite composite microspheres prepared via pickering emulsion polymerization

(11.64 mM s) and GON-AN-FA (10.83 mM s) is much larger than that of the traditional positive MRI contrast agents, such as Magnevist (4.7 mM s). The results of cell viability assays indicate that the GON-AN and GON-AN-FA are almost non-cytotoxic. Furthermore, the specificities of GON-AN and GON-AN-FA were evaluated with two kinds of cancer cells that overexpress folate receptor alpha (FRα). The results reinforce that the GON-AN-FA is high-specifically-targetable to cancer cells via recognition of ligand FA and receptor FRα. In addition, the TEM and DLS results indicate that the SPION-AN-FA has a spherical shape, a uniform size and an excellent water-dispersibility (PDI b 0.05). The results of LSCM and flow cytometry demonstrate that the SPION-AN-FA is highly specific to MCF-7 and SPC-A1 cells due to the recognition of ligand FA and receptor FRα. The r1/r2 value of SPION-AN-FA is around 40, which is much higher than that of Resovist® indicating that our SPION-AN-FA has a stronger T2 shortening effect. The T2weighted images of MCF-7 cells incubated with SPION-AN-FA are significantly darker than those of MCF-7 cells incubated with AN, indicating that our SPION-AN-FA has a strong MR imaging efficacy.

One-pot synthesis of pH-responsive hybrid nanogel particles for the intracellular delivery of small interfering RNA

This report describes a novel, one-pot synthesis of hybrid nanoparticles formed by a nanostructured inorganic silica core and an organic pH-responsive hydrogel shell. This easy-to-perform, oil-in-water emulsion process synthesizes fluorescently-doped silica nanoparticles wrapped within a tunable coating of cationic poly(2-diethylaminoethyl methacrylate) hydrogel in one step. Transmission electron microscopy and dynamic light scattering analysis demonstrated that the hydrogel-coated nanoparticles are uniformly dispersed in the aqueous phase. The formation of covalent chemical bonds between the silica and the polymer increases the stability of the organic phase around the inorganic core as demonstrated by thermogravimetric analysis. The cationic nature of the hydrogel is responsible for the pH buffering properties of the nanostructured system and was evaluated by titration experiments. Zeta-potential analysis demonstrated that the charge of the system was reversed when transitioned from acidic to basic pH and vice versa. Consequently, small interfering RNA (siRNA) can be loaded and released in an acidic pH environment thereby enabling the hybrid particles and their payload to avoid endosomal sequestration and enzymatic degradation. These nanoparticles, loaded with specific siRNA molecules directed towards the transcript of the membrane receptor CXCR4, significantly decreased the expression of this protein in a human breast cancer cell line (i.e., MDA-MB-231). Moreover, intravenous administration of siRNA-loaded nanoparticles demonstrated a preferential accumulation at the tumor site that resulted in a reduction of CXCR4 expression.

Synthesis of Temperature- and pH-Sensitive Graft Copolymer Containing 2-(Diethylamino)ethyl Methacrylate and N-Vinylcaprolactam onto Silicone Rubber

Silicone rubber films were modified by the consecutive grafting of 2-(diethylamino)ethyl methacrylate (DEAEMA) and N-vinylcaprolactam (NVCL) using direct method on two steps with gamma-rays. The effect of absorbed dose and monomer concentration on grafting degree was determined. The grafted samples were verified by FTIR-ATR spectroscopy and swelling; thermal properties were analyzed by DSC and TGA. The stimuli-responsive behavior was studied by swelling and/or DSC. Thermo- and pH-sensitive films of (PP-g-DEAEMA)-g-NVCL presented a pH critical at 3.2 and LCST around 63.5℃.

Electrical conduction mechanism in plasma polymerized 2‐(diethylamino)ethyl methacrylate thin films

Thin films of different thicknesses were prepared through glow discharge of 2‐(diethylamino)ethyl methacrylate (DEAEMA) using a capacitively coupled reactor. Current density–voltage (J–V) characteristics for plasma polymerized (PP) DEAEMA thin films of thicknesses 100, 200, 250, and 300 nm in aluminum/PPDEAEMA/aluminum sandwich configuration were studied over the temperature range from 298 to 423 K. J–V curves reveal that in the low‐voltage region, the conduction current obeys Ohm's law while in the high‐voltage region the behavior attributed to be space charge‐limited conduction in PPDEAEMA thin films. The carrier mobility was calculated to be about 6.80 × 10−19 to 2.38 × 10−18 m−2 V−1s−1 for various thicknesses. The free carrier density was found to be about 1.78 × 1023 to 2.04 × 1023 m−3, and the trap density was found to be about 6.93 × 1023 to 15.9 × 1023 m−3 for different thicknesses. The activation energies were estimated to be about 0.005–0.016 eV for 2 and 30 V of PPDEAEMA thin films of different thicknesses. The low‐activation energies indicate that the thermally activated hopping conduction is operative in PPDEAEMA thin films. POLYM. ENG. SCI., 55:2729–2734, 2015. © 2015 Society of Plastics Engineers

Polyurethane/Poly(2-(Diethyl Amino)Ethyl Methacrylate) blend for drug delivery applications

A pH-sensitive blend of polyurethane (PU) and poly(2-(diethyl amino)ethyl methacrylate (PDEA) with good film-forming capacity was prepared from the corresponding aqueous dispersions. The polymer matrix was first characterized by using FTIR, DSC, water vapor transmission and water swelling capacity at different pHs. The drug release profile of films was evaluated using a vertical Franz Cell and theophylline as model drug. The water swelling degree increases from 54 to 180% when the pH of the medium is changed from 6 to 2, demonstrating the pH-responsive behavior of the film. The in-vitro release studies indicate that an anomalous transport mechanism governs the theophylline release.

Development of MIP sensor for monitoring propofol in clinical procedures

Propofol is a widely used intravenous anaesthetic which requires close patient monitoring that involves blood extraction methods. Polymers with high affinity for propofol were computationally designed and their binding affinity tested. A diethylaminoethyl methacrylate based molecularly imprinted polymer was optimised in solid-phase extraction experiments showing no cross-reactivity to injections of urea, glucose, alfentanil and morphine. These polymers were initially integrated with screen-printed electrodes by photopolymerisation and used to detect propofol amperometrically, before modification to include conductive carbon to create better communication between the recognition sites of the polymer and the electrode. The sensors exhibited excellent linearity across the relevant clinical range with a detection limit of 4.19 µM measured in the presence of highly electroactive interferents such as uric acid and ascorbic acid. The mode of operation of the sensor reported herein differs significantly from the current state of the art and opens new opportunity towards the integration of synthetic receptors as electrochemical biosensors for point-of-care applications.

A New Hyaluronic Acid Derivative Obtained from Atom Transfer Radical Polymerization as a siRNA Vector for CD44 Receptor Tumor Targeting.

Two derivatives of hyaluronic acid (HA) have been synthesized by atom transfer radical polymerization (ATRP), starting from an ethylenediamino HA derivative (HA-EDA) and by using diethylaminoethyl methacrylate (DEAEMA) as a monomer for polymerization. Both samples, indicated as HA-EDA-pDEAEMA a and b, are able to condense siRNA, as determined by gel retardation assay and resulting complexes show a size and a zeta potential value dependent on polymerization number, as determined by dynamic light scattering measurements. In vitro studies performed on HCT 116 cell line, that over express CD44 receptor, demonstrate a receptor mediated uptake of complexes, regardless of their surface charge.

Functionalized Emulsion Styrene-Butadiene Rubber Containing Diethylaminoethyl Methacrylate for Silica Filled Compounds

In this study, diethylaminoethyl methacrylate-styrene-butadiene terpolymer (DEAEMA-SBR), in which diethyl- aminoethyl methacrylate (DEAEMA) was introduced to the SBR molecule as a third monomer, was synthesized by cold emulsion polymerization. It is expected that amine group introduced to a rubber molecule would improve dispersion of silica by the formation of hydrogen bond (or ionic coupling) between the amine group and silanol groups of silica surface. The chemical structure of DEAEMA-SBR was analyzed using proton nuclear magnetic resonance spectroscopy (H-NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and differential scanning calorime- try (DSC). Then, various properties of DEAEMA-SBR/silica composite such as crosslink density, bound rubber content, abrasion resistance, and mechanical properties were evaluated. As a result, bound rubber content and crosslink density of DEAEMA-SBR/silica compound were higher than those of the SBR 1721 composite. Abrasion resistance and moduli at 300% elongation of the DEAEMA-SBR/silica composite were better than those of SBR 1721 composite due to the high bound rubber content and crosslink density. These results are attributed to high affinity between DEAEMA-SBR and silica. The proposed study suggests that DEAEMA-SBR can help to improve mechanical properties and abrasion resistance of the tire tread part.

Self-assembled and Nanostructured Copolymer Aggregations of the Tertiary Amine Methacrylate Based Triblock Copolymers

The micellization behavior of novel tertiary amine methacrylate-based ABA type triblock copolymers formed by poly[2-(dimethylamino)ethyl methacrylate] [PDMA] middle block and poly[2-(diethylamino)ethyl methacrylate] [PDEA] or poly[2-(diisopropylamino)ethyl methacrylate] [PDPA] side blocks, PDPAm-b-PDMAn-b-PDPAl, and PDEAm-b-PDMAn-b-PDEAl was investigated. Both types of triblock copolymers were water-soluble and had potential for various applications due to their self-assembled and the bottom-up nanoscale micellar construction. The micellar aggregations of the triblock copolymers in aqueous solutions with varying comonomer ratios, molecular weights, temperatures, and pH values were investigated by small-angle X-ray scattering and dynamic light scattering. Compact micellar aggregations were obtained as 0.5 weight percent solutions at 20–21°C and pH 8.67 to 9.05, and characterized as polydispersed spherical core-shells. One group of triblock copolymer micelles had PDPA-cores with radii from 18 to 21 Å and PDMA-shell thicknesses of 89–105 Å, whereas the other group had PDEA-core spherical micelles with core radii of 60–62 Å and a PDMA-shell thicknesses of 64–66 Å.

Preparation and aqueous solution behavior of a ph‐responsive branched copolymer based on 2‐(diethylamino)ethyl methacrylate

ABSTRACTpH‐Responsive amphiphilic branched copolymers were prepared from poly(ethylene glycol) methyl ether methacrylate (PEGMA), 2‐(diethylamino)ethyl methacrylate (DEAEMA), 2‐(tert‐butylamino)ethyl methacrylate (tBAEMA), and ethylene glycol dimethacrylate (EGDMA) utilizing a thiol‐modified free radical polymerization. The molecular structures of copolymers were confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR) and triple‐detection gel permeation chromatography (tri‐GPC). The aqueous solution behaviors of the obtained copolymers were investigated by dynamic light scattering (DLS). The DLS data showed that about 16 nm polymer particles comprising of hydrophobic poly(tert‐butylamino)ethyl methacrylate (PtBAEMA) and poly(diethylaminoethyl methacrylate (PDEAEMA) core, hydrophilic PEGMA corona were formed above pH 8. With the decrease of pH from 8 to 6, a dramatic increase in the hydrodynamic radius of polymer particles from 16 nm to 130 nm was observed resulting from the protonation of the PDEAEMA segment. Moreover, in vitro drug release behaviors of the resulting polymer assemblies at different pH values were also investigated to evaluate their potential as sustained release drug carriers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42183.

Synthesis and Antifungal Activity of Complexes of Cu(II), Co(II) and Fe(III) with Quaternary Ammonium Salts Derivatives of Diethylaminoethyl Methacrylate Containing Acetic Acid Group

In the present paper the synthesis and characterization of three new metal complexes of Cu(II), Fe(III) and Co(II), with quaternary ammonium salts used as ligand derived from 2-(diethylamino)ethylmethacylate (DEAEMA) have been successfully prepared in alcoholic medium. The ligand has got -COOH moiety which is capable of chelation. The ligand and its metal complexes were characterized by conductivity measurements, FTIR spectroscopy, electronic spectroscopy, 1 H and 13 C NMR spectroscopies and have been screened for their antifungal activities

Grafting pH‐sensitive poly[2‐(diethylamino)ethyl methacrylate] modification of vesicular silica with activator regenerated by electron transfer atom transfer radical polymerisation for controlled drug release

pH-sensitive poly[2-(diethylamino)ethyl methacrylate]-modified vesicular silica (VS-PDEAEMA) is prepared in different amounts of 2-(diethylamino)ethyl methacrylate via activators regenerated by electron transfer for atom transfer radical polymerisation. The pH-responsive polymer is successfully grafted onto the shell of vesicular silica (VS) and then characterised. The inner PDEAEMA layer became thick, while the outmost polymer thickness did not change as the monomer amount was increased. Pure VS and VS-PDEAEMA are employed as supports for the loading and release of captopril. The release profiles of the captopril-loaded samples are studied in phosphate buffer solution with different pH values (4.0, 6.0 and 7.4). The captopril release rate can be controlled by PDEAEMA-functionalised carriers. Moreover, 31.5 and 70.0 wt% of captopril is released from the grafted polymer at pH 7.4 and 4.0, respectively. The modified VS can have potential applications in targeted drug delivery systems.

One-Pot Synthesis of Poly((diethylamino)ethyl methacrylate-co-styrene)-b-poly(methyl methacrylate-co-styrene) Nanoparticles via Nitroxide-Mediated Polymerization

Poly((diethylamino)ethyl methacrylate-co-styrene)-b-poly(methyl methacrylate-co-styrene) nanoparticles were prepared by one-pot process via nitroxide-mediated polymerization (NMP). For synthesizing the first block, the SG1-mediated copolymerization of 2-(diethylamino)ethyl methacrylate (DEAEMA), a pH-sensitive monomer, and a small percentage of styrene (S) was performed in water at 90 °C using 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VA-044) as a positively charged stabilizer and initiator. The resultant macroalkoxyamine was then employed without any purification in the protonated form as both macroinitiator and stabilizer in the same pot for the surfactant-free emulsion copolymerization of methyl methacrylate (MMA) and styrene at 90 °C, which proceeded via polymerization-induced self-assembly (PISA). Latex particles had monomodal size distribution, narrow size polydispersity, and small average size. The polymerization kinetics, the control over molar mass and molar mass distribution, the effect of the charge density on the particles size and latex stability, and the colloidal characteristics of the in situ formed block copolymer micelles were studied in detail.