Aminoethyl Methacrylate Research Articles

Influence of hydrophilic and hydrophobic functional monomers on the performance of magnetic molecularly imprinted polymers for selective recognition of human insulin

Magnetic molecularly imprinted polymers (MMIPs) were used to detect and bioseparation of insulin. Because of the significant role of electrostatic interactions, the effects of hydrophilic/hydrophobic interactions were investigated in non-covalent molecular imprinting. The imprinting polymer was synthesized using different type and molar ratios of functional monomers containing acrylamide (AAm) as the neutral-hydrophilic monomer alongside methacrylic acid (MAA) and 2-dimethyl aminoethyl methacrylate (DMA) in the two cases: hydrophilic-hydrophobic-neutral (MMIP3) and hydrophobic-neutral (MMIP2), respectively. The MMIPs adsorption results showed high capacity, good selectivity, and high rapidness to insulin adsorption in both cases. The maximum adsorption (Q) and imprinting factor (IF) of MMIP2 and MMIP3 obtained 54 mg.g−1 and 4.4, and 67 mg.g−1 and 3.2, respectively. In addition, dynamic light scattering results revealed that the average particle size of the surface-modified magnetic nanoparticles (Fe3O4@SiO2@MPS), MMIP2, and MMIP3 were equal to 135 ± 8, 360 ± 21, and 275 ± 28 nm, respectively. The thermogravimetric analysis demonstrated that MNIP2 has almost 25% more polymer layer than MNIP3. VSM analysis was also carried out showed the magnetic power of 21.88, 7.74, and 19.93 emu/g for MNPs, MMIP2, and MMIP3, respectively.

Expanding the use of affordable CuSO4·5H2O in ATRP techniques in homogeneous media

Advances in atom transfer radical polymerization (ATRP) are usually focused on reducing the metal catalyst concentration, using low toxicity metals or even metal-free catalysts, to minimize or avoid the contamination of polymers. In this work, the less toxic and inexpensive CuSO4·5H2O was used to replace CuBr2, the most employed metal source for ATRP, to control polymerizations under homogeneous conditions. Well-defined (Đ ≤ 1.3) hydrophobic homopolymers of poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polystyrene (PS) and poly(butyl acrylate) (PBA) were obtained in various organic solvent/water mixtures with similar control as when CuBr2 was used. The main limitation is the lower solubility of the CuSO4/L complex in pure organic solvents compared with CuBr2/L. The preparation of several hydrophilic polymers, namely poly(2-hydroxyethyl acrylate) (PHEA), poly((3-acrylamidopropyl)trimethylammonium chloride) (PAMPTMA), poly(2-hydroxyethyl acrylamide) (PHEAA), polyacrylamide (PAAm), poly(N,N-dimethylacrylamide) (PDMAA), poly(2-aminoethyl methacrylate hydrochloride) (PAMA), poly[oligo(ethylene oxide) methyl ether acrylate] (POEOA) and biorelevant block copolymers (PHEA-b-PAMPTMA and PAMPTMA-b-PHEAA) was successfully carried out in aqueous medium using different ATRP techniques. Future studies on this system will include the use of CuSO4/L complexes in several organic solvents and in heterogeneous ATRP.

CO2 Capture and Low-Temperature Release by Poly(aminoethyl methacrylate) and Derivatives.

Poly(aminoethyl methacrylate) (PAEMA), poly(ethylene oxide)-block-(aminoethyl methacrylate) (PEO–PAEMA), and their guanidinylated derivates, poly(guanidine ethyl methacrylate) (PGEMA) and poly(ethylene oxide)-block-(guanidine ethyl methacrylate) (PEO–PGEMA), were prepared to study their capabilities for CO2 adsorption and release. The polymers of different forms or degree of guanidinylation were thoroughly characterized, and their interaction with CO2 was studied by NMR and calorimetry. The extent and kinetics of adsorption and desorption of N2 and CO2 were investigated by thermogravimetry under controlled gas atmospheres. The materials did not adsorb N2, whereas CO2 could be reversibly adsorbed at room temperature and released by an elevated temperature. The most promising polymer was PGEMA with a guanidinylation degree of 7% showing a CO2 adsorption capacity of 2.4 mmol/g at room temperature and a desorption temperature of 72 °C. The study also revealed relations between the polymer chemical composition and CO2 adsorption and release characteristics that are useful in future formulations for CO2 adsorbent polymer materials.

Surface charge control of poly(methyl methacrylate-co-dimethyl aminoethyl methacrylate)-based membrane for improved fouling resistance

• P(MMA-co-DMAEMA) was synthesized and blended with polysulfone UF membrane. • Blend PSF-PMD membrane was quaternized to increase surface positive charge. • Membrane was grafted with 2-carboxyethyl acrylate for surface neutralization. • Neutralization resulted in comprehensive anti-fouling smooth membrane surface. • Surface charge control is simple and effective to mitigate membrane fouling. In this study, a new poly(methyl methacrylate-co-dimethyl aminoethyl methacrylate) (P(MMA-co-DMAEMA))-based membrane was fabricated and modified to control surface charge in order to improve fouling resistance. The positively-charged P(MMA-co-DMAEMA) copolymer was first synthesized from the free radical polymerization of methyl methacrylate (MMA) and dimethylamino-2-ethyl methacrylate (DMAEMA). The copolymer was blended with polysulfone and cast into a membrane via nonsolvent-induced phase separation. The membrane was then quaternized using iodomethane and neutralized by grafting 2-carboxylethyl acrylate via UV irradiation. The membrane surface charge, composition, morphology, hydrophilicity, and anti-fouling properties were evaluated. Surface charge control of the membrane resulted in outstanding antibacterial activity and fouling resistance against model protein foulants. While the incorporation of P(MMA-co-DMAEMA) in the membrane and its quaternization greatly improved the surface hydrophilicity of the membrane and endowed positive surface charge as well. Neutralization of the blend membrane endowed a smooth and electroneutral surface layer on the membrane surface, which led to not only excellent anti-bacterial activity and comprehensive resistance against charged foulants, but also high flux retention after simple membrane washing. Dynamic filtration using protein and bacterial foulants revealed the ability of the membrane with almost zero net surface charge to regulate fouling even in practical filtration applications. The results in this study exhibit a simple and effective method for mitigation of membrane fouling propensity for practical application.

Quaternization of Poly(2-diethyl aminoethyl methacrylate) Brush-Grafted Magnetic Mesoporous Nanoparticles Using 2-Iodoethanol for Removing Anionic Dyes

Magnetic mesoporous silica nanoparticles (Fe3O4-MSNs) were successfully synthesized with a relatively high surface area of 568 m2g−1. Fe3O4-MSNs were then modified with poly(2-diethyl aminoethyl methacrylate) (PDEAEMA) brushes using surface-initiated ARGET atom transfer radical polymerization (ATRP) (Fe3O4@MSN-PDMAEMA). Since the charge of PDEAEMA is externally regulated by solution pH, tertiary amines in the polymer chains were quaternized using 2-iodoethanol to obtain cationic polymer chains with a permanent positive charge (Fe3O4@MSN-QPDMAEMA). The intensity of the C−O peak in the C1s X-ray photoelectron spectrum increased after reaction with 2-iodoethanol, suggesting that the quaternization process was successful. The applicability of the synthesized materials on the removal of methyl orange (MO), and sunset yellow (E110) dyes from an aqueous solution was examined. The effects of pH, contact time, and initial dyes concentrations on the removal performance were investigated by batch experiments. The results showed that the Fe3O4@MSN-PDMAEMA sample exhibited a weak adsorption performance toward both MO and E110, compared with Fe3O4@MSN-QPDMAEMA at a pH level above 5. The maximum adsorption capacities of MO and E110 using Fe3O4@MSN-QPDMAEMA were 294 mg g−1 and 194.8 mg g−1, respectively.

Preparation of poly(DMA-co-DBA) and its application in gene delivery

(2-dimethyl amino)ethyl methacrylate (DMA) was co-polymerized with (2-dibutyl amino)ethyl methacrylate (DBA) to form random copolymer P(DMA-co-DBA) with DMA/DBA molar ratios in the range of 9:1 to 1:9 by Atom Transfer Radical Polymerization (ATRP). The (co)polymers were characterized with techniques such as GPC, 1HNMR and acid-base titration. The cytotoxicity of the polymers was assessed by MTT. Size and zeta potential of P(DMA-co-DBA)/DNA polyplex were analyzed by dynamic light scattering. In vitro gene transfection was performed for P(DMA-co-DBA)/DNA polyplex in the medium with and without serum. In comparison with PDMA/DNA and PEI/DNA, P(DMA-co-DBA) 8:2/DNA showed much higher transfection efficiency than those of PDMA/DNA and PEI/DNA within the range of 0.125 − 1.25 μg·mL−1 of DNA concentrations in the medium with 10% FBS. Confocal images showed that P(DMA-co-DBA) 8:2/DNA was superior to PDMA/DNA and PEI/DNA in the speed and capacity for endosomal release, which might be the main cause of its higher transfection efficiency.

Regulated Polyelectrolyte Nanogels for Enzyme Encapsulation and Activation.

Polyelectrolyte (PE) nanogels consisting of cross-linked PE networks integrate the advanced features of both nanogels and PEs. The soft environment and abundant intrinsic charges are of special interest for enzyme immobilization. However, the crucial factors that regulate enzyme encapsulation and activation remain obscure to date. Herein, we synthesized cationic poly (dimethyl aminoethyl methacrylate), PDMAEMA, nanogels with well-defined size and cross-link degrees and fully investigated the effects of different control factors on lipase immobilization. We demonstrate that the cationic PDMAEMA nanogels indeed enable efficient and safe loading of anionic lipase without disturbing their structures. Strong charge interaction achieved by tuning pH and larger particle size are favorable for lipase loading, while the enhanced enzymatic activity demands nanogels with smaller size and a moderate cross-link degree. As such, PDMAEMA nanogels with a hydrodynamic radius of 35 nm and 30% cross-linker fraction display the optimal catalytic efficiency, which is fourfold of that of free lipase. Moreover, the immobilization endows enhanced enzymatic activity in a broad scope of pH, ionic strength, and temperature, demonstrating effective protection and activation of lipase by the designed nanogels. Our study validates the crucial controls of the size and structure of PE nanogels on enzyme encapsulation and activation, and the revealed findings shall be helpful for designing functional PE nanogels and boosting their applications for enzyme immobilization.

High Adsorption of α-Glucosidase on Polymer Brush-Modified Anisotropic Particles Acquired by Electrospraying-A Combined Experimental and Simulation Study.

In this particular contribution, we aim to immobilize a model enzyme such as α-glucosidase onto poly(DMAEMA) [poly(2-dimethyl amino ethyl methacrylate)] brush-modified anisotropic (cup- and disc-shaped) biocompatible polymeric particles. The anisotropic particles comprising a blend of PLA [poly(lactide)] and poly(MMA-co-BEMA) [poly((methyl methacrylate)-co-(2-(2-bromopropionyloxy) ethyl methacrylate)] were acquired by electrospraying, a scalable and convenient technique. We have also demonstrated the role of a swollen polymer brush grafted on the surface of cup-/disc-shaped particles via surface-initiated atom transfer radical polymerization in immobilizing an unprecedentedly high loading of enzyme [441 mg/g (cup)-589 mg/g (disc) of particles, 15-20 times higher than that of the literature-reported system] as compared to non-brush-modified particles. Circular dichroism spectroscopy was used to predict the structural changes of the enzyme upon immobilization onto the carrier particles. An enormously high amount of enzymes with preserved activity (∼85 ± 13% for cups and ∼78 ± 15% for discs) was found to adhere onto brush-modified particles at pH 7 via electrostatic adsorption. These findings were further explored at the atomistic level using a coarse-grained dissipative particle dynamics simulation approach, which exhibited excellent correlation with experimental results. In addition, accelerated particle separation was also achieved via magnetic force-induced aggregation within 20 min (without a centrifuge) by incorporating magnetic nanoparticles into disc-shaped particles while electrojetting. This further strengthens the technical feasibility of the process, which holds immense potential to be applied for various enzymes intended for several applications.

Amphiphilic copolymers of dimethyl aminoethyl methacrylate and methyl methacrylate with controlled hydrophilicity for antialgal activity

AbstractBiofouling due to algae mass attachment has detrimental effects on the performance and economy of many manufacturing processes. In consideration of this, present research is focused to mitigate such effect through the development of environmentally benign active antialgal cationic amphiphilic copolymers of poly(2‐(dimethylamino)ethyl methacrylate) (PDMAEMA) and methyl methacrylate (MMA). The copolymers compositions were synthesized to tailor various characteristics to control surface biofilm formation and antialgal activities were determined through suspension assay. Biofilm formation of Dictyosphaerium sp. algae on the synthesized copolymers of different surface energies was ascertained by measuring chlorophyll A content and percent adhesion of algae. The copolymers antialgal performance enhanced with increase in PDMAEMA concentration as it exhibited the lowest contact angle as well as adhesion and minimum chlorophyll A contents. Algal adhesion on the surface of materials was also observed by optical microscopy. The copolymers with higher concentration of DMAEMA resulted in greater hydrophilicity which exhibited low adhesion of Dictyosphaerium algae due to possibility of stronger hydration effect and wettability as evident from their lower water contact angle. The developed benign cationic polymers of PDMAEMA and PMMA with varying compositions can lead to important breakthrough in the subject area of antialgal research in several manufacturing processes.

Preparation and characterization of a new family of bio-interpenetrating network hydrogel based on a green method

In this work, semi-interpenetrating polymer network hydrogels with and without castor oil (S-2IPN, S-3IPN, S-4IPN, S-2IPNC, S-3IPNC and S-4IPNC) are synthesized using a free-radical solution polymerization in presence of acrylic acid as a pH-responsive monomer and dimethyl aminoethyl methacrylate as a thermoresponsive monomer with carboxymethyl cellulose (CMC) as a cellulose derivative, potassium persulphate and N, N'-methylene bisacrylamide. Castor oil, as a green chemical material, is incorporated with a ratio (1:2) to CMC. The semi-interpenetrating network structures are formed and justifications are done by ATR-FTIR and Raman spectroscopy to assure their chemical composition. TGA, SEM, XRD and AFM approve thermogravimetric analysis, phase morphology, crystallinity and surface topography, respectively. The results show that the addition of castor oil enhances the texture and stability of hydrogels. It is concluded that S-IPNC hydrogels show higher swelling capacity than S-IPN hydrogels at lower NaCl concentration and pH range (5-7), due to increasing the osmotic pressure.Therefore, castor oil could be used as a green material in interpenetrating network hydrogels for water-saving applications.According to the principle of sustainable growth, environmentally biopolymer hydrogels pose a significant potential for using as water storage in the agricultural sector.

Mechanistic Study of Membrane Disruption by Antimicrobial Methacrylate Random Copolymers by the Single Giant Vesicle Method.

Cationic amphiphilic polymers have been a platform to create new antimicrobial materials that act by disrupting bacterial cell membranes. While activity characterization and chemical optimization have been done in numerous studies, there remains a gap in our knowledge on the antimicrobial mechanisms of the polymers, which is needed to connect their chemical structures and biological activities. To that end, we used a single giant unilamellar vesicle (GUV) method to identify the membrane-disrupting mechanism of methacrylate random copolymers. The copolymers consist of random sequences of aminoethyl methacrylate and methyl (MMA) or butyl (BMA) methacrylate, with low molecular weights of 1600-2100 g·mol-1. GUVs consisting of an 8:2 mixture of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol), sodium salt (POPG) and those with only 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were prepared to mimic the bacterial (Escherichia coli) or mammalian membranes, respectively. The disruption of bacteria and mammalian cell membrane-mimetic lipid bilayers in GUVs reflected the antimicrobial and hemolytic activities of the copolymers, suggesting that the copolymers act by disrupting cell membranes. The copolymer with BMA formed pores in the lipid bilayer, while that with MMA caused GUVs to burst. Therefore, we propose that the mechanism is inherent to the chemical identity or properties of hydrophobic groups. The copolymer with MMA showed characteristic sigmoid curves of the time course of GUV burst. We propose a new kinetic model with a positive feedback loop in the insertion of the polymer chains in the lipid bilayer. The novel finding of alkyl-dependent membrane-disrupting mechanisms will provide a new insight into the role of hydrophobic groups in the optimization strategy for antimicrobial activity and selectivity.

Zwitterionic Copolymer-Regulated Interfacial Polymerization for Highly Permselective Nanofiltration Membrane.

A highly permselective nanofiltration membrane was engineered via zwitterionic copolymer assembly regulated interfacial polymerization (IP). The copolymer was molecularly synthesized using single-step free-radical polymerization between 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-aminoethyl methacrylate hydrochloride (AEMA) (P[MPC-co-AEMA]). The dynamic network of P[MPC-co-AEMA] served as a regulator to precisely control the kinetics of the reaction by decelerating the transport of piperazine toward the water/hexane interface, forming a polyamide (PA) membrane with ultralow thickness of 70 nm, compared to that of the pristine PA (230 nm). Concomitantly, manipulating the phosphate moieties of P[MPC-co-AEMA] integrated into the PA matrix enabled the formation of ridge-shaped nanofilms with loose internal architecture exhibiting enhanced inner-pore interconnectivity. The resultant P[MPC-co-AEMA]-incorporated PA membrane exhibited a high water permeance of 15.7 L·m-2·h-1·bar-1 (more than 3-fold higher than that of the pristine PA [4.4 L·m-2·h-1·bar-1]), high divalent salt rejection of 98.3%, and competitive mono-/divalent ion selectivity of 52.9 among the state-of-the-art desalination membranes.

Initial Characterization of PDMAEMA: Styrene Porous Polymer Monolithic Morphologies

This research aimed to investigate a new fabrication of poly-(2-dimethyl(aminoethyl) methacrylate)-co-styrene in a porous polymer monolithic morphology. Poly-(2-dimethyl(aminoethyl) methacrylate) (PDMAEMA) is responsive to changes in pH while styrene remains unresponsive to external stimuli. IR, UV/Vis, and SEM were employed to determine that the proposed porous polymer (PPM) monolith can present pH-initiated stimuli response while remaining intact. The copolymerization of PDMAEMA with styrene has not been previously documented in a PPM morphology. It is important to demonstrate that the PPM retains tunable capabilities without destruction to the material. The utility of PDMAEMA copolymers is wide-reaching and this new adaptation of its tunability in a resilient PPM can serve as a distinct preface to original applications in fields such as surface modification, membrane technologies and stationary phases. To further the groundwork of this communication, dynamic studies on the interactions of small molecules with the pores of the monolith will be essential and accomplished via capillary electrochromatography.

Effect of an elastomeric urethane monomer on BisGMA-free resin composites containing different co-initiators.

The aim of this study was to investigate the mechanical, chemical, optical, and adhesive properties of BisGMA-free experimental resin composites containing Exothane-24-an elastomeric urethane monomer-and different co-initiators. A blend of urethane dimethacrylate (UDMA), extended dimethacrylate urethane (PEG 400), triethylene glycol dimethacrylate (TEGDMA), and camphorquinone was prepared. Two different co-initiators-dimethyl aminoethyl methacrylate (DMAEMA) or 4-N alcohol, N-dimethylamine phenylethyl (DMPOH)-were added to the blend. Exothane-24 monomer was added to the blend for each co-initiator and four groups were established as follows: DMAEMA; DMAEMA + Exothane; DMPOH; and DMPOH + Exothane. Specimens were photo-activated using a multi-wave LED light-curing unit (VALO; 954 mW/cm2 of irradiance). Mechanical (ultimate tensile strength, flexural strength, flexural modulus and hardness), chemical (degree of conversion, hardness reduction, water sorption and solubility), optical (color change), and adhesive (microtensile bond strength) properties were analyzed. Data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The resin composite containing DMPOH and Exothane-24 showed similar or superior performance to those of the other experimental composites for mechanical and chemical properties, except for flexural strength. It also showed less color change and greater micro-tensile bond strength. Among the combinations tested, the BisGMA-free resin composite containing Exothane-24 combined with the DMPOH co-initiator showed the best mechanical, chemical, optical, and adhesive properties. Clinical relevance Exothane-24 monomer and DMPOH co-initiator could be useful in the formulation of BisGMA-free resin composites in order to minimize exposure to BPA.

Quantum dot assisted luminescent hexarhenium cluster dye for a transparent luminescent solar concentrator

A luminescent solar concentrator (LSC) is a solar-light harvesting device that concentrates light on a photovoltaic cell placed at the edge of an LSC panel to convert it into electricity. The nano-sized inorganic–organic cluster complex (dMDAEMA)4[Re6S8(NCS)6] (this refers to RMC where dMDAEMA is 2-dimethyl amino ethyl methacrylate) is a promising candidate for LSC luminophores due to its downshifted broad photoluminescence suitable for photovoltaic cells. However, the low quantum yield (QY) of RMC limits the performance. Here, zinc-doped CuGaS/ZnS core/shell quantum dots (ZQD) were used as energy transferring donor with high QY to improve the performance of the LSC. The two metal chalcogenide luminophores, RMC and ZQD, are chemically suitable for dispersion in an amphiphilic polymer matrix, producing a transparent waveguide with suppressed reabsorption and extended harvesting coverage of the solar spectrum. We achieved an ηopt of 3.47% and a PCE of 1.23% while maintaining greater than 80% transparency in the visible range. The high performance of this dual-dye LSC with suppressed reabsorption, and scattering losses is not only due to uniform dispersion of dyes in a polymer matrix, but also energy transfer from ZQD to RMC. This report suggests a new possibility for promising various multi-dye LSCs for use in building-integrated photovoltaic windows.

Improving Resistance to Fouling of Aromatic Polyamide Thin-Film Composite Reverse Osmosis Membrane by Surface Grafting of N,N'-Dimethyl Aminoethyl Methacrylate (DMAEMA)

Improving Resistance to Fouling of Aromatic Polyamide Thin-Film Composite Reverse Osmosis Membrane by Surface Grafting of N,N'-Dimethyl Aminoethyl Methacrylate (DMAEMA)

Active-Targeting Polymeric Dual Nanosensor for Ratiometrically Measuring Proton and Oxygen Concentrations in Mitochondria

Dysfunction of mitochondria is closely related to neurodegenerative diseases, heart diseases, cancers, and so on. Because both proton and oxygen participate in vital biochemical reactions occurring in mitochondria such as adenosine triphosphate (ATP) generation, measuring proton and oxygen concentrations in mitochondria is therefore crucial for monitoring mitochondria activities and understanding cellular behavior. For this purpose, we developed a ratiometric fluorescent nanosensor for simultaneously sensing and imaging O2 and pH in mitochondria. The steps are as follows: (1) Styrene was copolymerized with 2-aminoethyl methacrylate hydrochloride to produce amino-functionalized polymer nanoparticles. (2) The reference dye rhodamine B isothiocyanate (RBITC) and oxygen-sensitive dye platinum(II) octaethylporphyrin (PtOEP) were encapsulated into a polymer sphere during polymerization, while the pH indicator fluorescein isothiocyanate (FITC) and mitochondrial-targeting molecule (3-carboxypropyl)triphenylphosphonium bromide (TPP) were further modified on the surface of the nanoparticles. The developed nanosensor shows a narrow distribution of particle size, high sensitivity toward O2 and pH, excellent stability, and low cytotoxicity. These remarkable features of the dual nanosensor render them capable of real-time sensing and imaging of O2 and pH in mitochondria with high spatial resolution. Applying the mitochondrial-targeted dual nanosensor in HeLa cells, we quantitatively measured and imaged mitochondrial proton and oxygen concentration variations after carbonyl cyanide m-chlorophenylhydrazone (CCCP) treatment.

Synthesis of thermosensitive copolymers of N-isopropylacrylamide with 2-aminoethylmethacrylate hydrochloride

Objectives. Due to the increasing number of oncological diseases, active research into developing new radiopharmaceuticals is underway. Thermosensitive copolymers have valuable physicochemical properties that can be harnessed to develop therapeutic radiopharmaceuticals for treating solid tumors. The aim of this study was to develop a method for producing thermosensitive copolymers that can find use as radionuclide carriers to create therapeutic radiopharmaceuticals for treating solid tumors.Methods. Using radical copolymerization in polar solvents, we synthesized water-soluble copolymers based on N-isopropyl acrylamide and 2-aminoethyl methacrylate hydrochloride. The resulting copolymers were characterized in terms of molecular composition and hydrodynamic properties using gel permeation chromatography, IR spectroscopy, potentiometry, and viscometry. Changes in optical density during temperature scanning helped determine the phase transition temperature (PTT) of aqueous copolymer solutions.Results. We developed a method for preparing copolymers of N-isopropylacrylamide with 2-aminoethyl methacrylate using radical copolymerization in water and isopropanol with a content of 2-aminoethyl methacrylate hydrochloride in a copolymer up to 23 mol %. We studied how the second comonomer affected the PTT of the aqueous copolymer solutions. An increase in the content of 2-aminoethyl methacrylate in the copolymer caused the PTT to increase. We found that the change in the PTT depending on the content of 2-aminoethyl methacrylate units in the copolymer had a straightforward relationship with its content up to 17 mol %. The use of physiological saline as a solvent led to a temperature decrease of the phase transition by two degrees.Conclusions. The method of producing thermosensitive copolymers by radical copolymerization in isopropanol does not allow creating a radionuclide carrier. Solutions of the obtained lowmolecular weight oligomers form coacervate solutions, which will inevitably cause the radionuclide to spread throughout the body. The copolymers obtained by radical copolymerization in water with the content of the second comonomer 2-aminoethyl methacrylate from 10–17 mol % can be used as a radionuclides carrier provided that a physiological solution of sodium chloride is used as a solvent.

Utilization of a novel polymer–clay material for high elimination of hazardous radioactive contamination uranium(VI) from aqueous environments

In the current work, the effect of the poly(2-aminoethyl methacrylate)-grafted kaolin ([email protected]) was investigated for the potential removal of U(VI) from aqueous samples. This novel adsorbent prepared for U(VI) removal was characterized by various techniques (Fourier transform infrared spectrometry (FTIR), energy-dispersive x-ray analysis (EDX), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS)). Response surface methodology (RSM) was utilized to optimize and model the removal of U(VI) by [email protected] from aqueous environments. The effects of different parameters such as pH, U(VI) concentration (Co), [email protected] dosage, and shaking time were optimized by central composite design (CCD) combined with RSM. The optimum points were numerically determined as 5.07 for pH, 35.16 mg/L for Co, 13.73 mg for [email protected] dosage, and 92.09 min for the shaking time. The maximum removal was obtained at 96.03% under the optimum conditions. The kinetic data was better described by the pseudo-second-order and Weber–Morris models. U(VI) removal onto [email protected] follows the Langmuir isotherm model. Thermodynamic studies showed that U(VI) removal by [email protected] was spontaneous and exothermic in nature. The results indicate that [email protected] is a promising adsorbent for the effective removal of radionuclides like U(VI) from aqueous media.

Atorvastatin-Eluting Contact Lenses: Effects of Molecular Imprinting and Sterilization on Drug Loading and Release.

Statins are receiving increasing attention in the ophthalmic field. Their activity as 3-hydroxy-3-methylglutaryl–CoA (HMG–CoA) reductase inhibitors is clinically used to regulate cholesterol levels and leads to pleiotropic effects, which may help in the management of diabetes-related ocular pathologies. This work aims to design bioinspired contact lenses (CLs) with an affinity for atorvastatin by mimicking the active site of HMG–CoA reductase. Sets of imprinted and nonimprinted 2-hydroxyethyl methacrylate (HEMA) hydrogels were synthesized, varying the contents in functional monomers that bear chemical groups that resemble those present in HMG–CoA reductase, namely, ethylene glycol phenyl ether methacrylate (EGPEM), 2-aminoethyl methacrylate hydrochloride (AEMA), and N-(3-aminopropyl) methacrylamide hydrochloride (APMA). The hydrogels were characterized in terms of suitability as CLs (solvent uptake, light transmission, mechanical properties, and biocompatibility) and capability to load and release atorvastatin. Three sterilization protocols (steam heat, gamma radiation, and high hydrostatic pressure) were implemented and their effects on hydrogel properties were evaluated. Copolymerization of AEMA and, particularly, APMA endowed the hydrogels with a high affinity for atorvastatin (up to 11 mg/g; KN/W > 200). Only high hydrostatic pressure sterilization preserved atorvastatin stability and hydrogel performance. Permeability studies through the porcine cornea and sclera tissues revealed that the amount of atorvastatin accumulated in the cornea and sclera could be effective to treat ocular surface diseases.