2-isocyanatoethyl Methacrylate Research Articles

Facile Preparation of a Photo-Cross-Linked Silk Fibroin-Poly Ionic Liquid Hydrogel with Antifreezing and Ion Conductive Properties.

The silk fibroin (SF)/ionic liquid (IL) based hydrogel is a kind of remarkable substrate for flexible devices because of its subzero-temperature elasticity, electrical conductivity, and water retention, although the procedure of the gelation is considered complex and time-consuming. In this work, we introduced an approximate method for the development of novel photo-cross-linked SF/IL hydrogel, that is, SF-IMA/PIL hydrogel via the modification of silk fibroin chain with 2-isocyanatoethyl methacrylate (SF-IMA) in a certain ionic liquid with an unsaturated double bond. The chemical cross-linking between methacrylated SF and IL was triggered by UV light, while the physical cross-linking of the hydrogel was attributed to the β-sheet formation of SF in SF-IMA/IL mixed solution. In addition to being a UV-induced three-dimensional (3D) printable one, the SF-IMA/PIL hydrogel performed significant ionic conductivity between room temperature and -50 °C and water retention within a wide range of relative humidity, which were the featured advantages as the ionic liquid involved. Moreover, the static and dynamic mechanical tests demonstrated that the hydrogel reserved its great elasticity at -50 °C and displayed its stiffness transition temperatures between -100 and -70 °C.

Exploring SEI Characteristics in Propylene Carbonate-Based Electrolyte with 2-Isocyanatoethyl Methacrylate at Graphite Electrode

Propylene carbonate (PC) has the advantage of a much lower melting point than ethylene carbonate (EC), but it cannot suppress the exfoliation of graphite layers because of its cointercalation with Li+ before forming a stable solid electrolyte interface (SEI). This paper introduces 2−isocyanatoethyl methacrylate (ICEMA) as an additive in PC−based electrolytes. ICEMA is a bifunctional monomer in which the isocyanate group is linked by the ethyl group to the acrylate group, which reacts through thermal polymerization. The isocyanate moiety is initiated as a radical during the initial charging process to induce electropolymerization and reaction with the PC radical. Radicals propagate through the entire reaction at the electrode to form a stable SEI. The modified interface suppresses the cointercalation of Li+−PC to graphite electrode. In situ Fourier transform infrared effectively showed the polymerization of the isocyanate and active reaction with the PC radical. Consequently, the reaction mechanisms to form the stable SEI in PC−based electrolytes were determined.

Versatile Potential of Photo-Cross-Linkable Silk Fibroin: Roadmap from Chemical Processing Toward Regenerative Medicine and Biofabrication Applications.

Over the past two decades, hydrogels have come to the forefront of tissue engineering and regenerative medicine due to their biocompatibility, tunable degradation and low immunogenicity. Due to their porosity and polymeric network built up, it is possible to incorporate inside drugs, bioactive molecules, or other biochemically active monomers. Among biopolymers used for the fabrication of functional hydrogels, silk fibroin (SF) has received considerable research attention owing to its known biocompatibility and tunable range of mechanical properties. However, its relatively simple structure limits the potential usability. One of the emerging strategies is a chemical functionalization of SF, allowing for the introduction of methacrylate groups. This allows the versatile processing capability, including photo-cross-linking, which makes SF a useful polymer as a bioink for 3D printing. The methacrylation reaction has been done using numerous monomers such as methacrylic anhydride (MA), 2-isocyanatoethyl methacrylate (IEM), or glycidyl methacrylate (GMA). In this Review, we summarize the chemical functionalization strategies of SF materials and their resulting physicochemical properties. More specifically, a brief explanation of the different functionalization methods, the cross-linking principles, possibilities, and limitations of methacrylate compound functionalization are provided. In addition, we describe types of functional SF hydrogels and link their design principles to the performance in applications in the broad fields of biofabrication, tissue engineering, and regenerative medicine. We anticipate that the provided guidelines will contribute to the future development of SF hydrogels and their composites by providing the rational design of new mechanisms linked to the successful realization of targeted biomedical application.

A smart polymer electrolyte coordinates the trade-off between thermal safety and energy density of lithium batteries

In this article, we develop a smart polymer electrolyte through in-situ radical random polymerization of the cyclic carbonate urethane methacrylate monomer and the 2-isocyanatoethyl methacrylate monomer, which coordinates the trade-off between thermal safety and energy density of lithium batteries. It is demonstrated that the as-developed polymer electrolyte can incur the battery thermal shutdown before reaching the thermal runaway temperature. This originates from the highly crosslinking network caused by the nucleophilic addition of carbamate to isocyanate in the polymer matrix under the elevated temperature exceeding 170 °C. Besides, superior cycle performance of 4.5 V-class LiNi0.6Co0.2Mn0.2O2/Li batteries can be achieved, with a capacity retention of 80% after 200 cycles at 0.5 C and 30 °C, owing to enhanced interface compatibility of this polymer electrolyte. Noting that this polymer electrolyte possesses a superior water-scavenging ability, which helps improve the moisture resistance and battery cycle performance. Impressively, this polymer electrolyte can achieve improved energy density and superior safety characteristic of lithium batteries under high cut-off voltage.

Double bond crosslinked and phosphocholinated biological heart valve with robust antithrombogenicity, durability and anticalcification property

Glutaraldehyde crosslinked biological heart valves (BHVs) are increasingly implanted with development of transcatheter heart valve implantation. While poor cytocompatibility and calcification that are associated with glutaraldehyde crosslinking may further lead to degeneration of BHVs, and post-implantation thrombosis also induces dysfunction of BHVs. Herein, porcine pericardium (PP) was firstly methacrylated by 2-Isocyanatoethyl methacrylate (ICM) to graft CC (double bond) bonds and then copolymerized with phosphocholine-based monomer 2-methacryloyloxyethyl phosphorylcholine (MPC) to fabricate phosphocholinated BHVs (PICM-MPC-PP). PICM-MPC-PP exhibited improved stability, cytocompatibility. Mitigated immune response and reduced calcification were observed in PICM-MPC-PP, after subcutaneous implantation. Owing to the introduction of biomimetic fouling-resistant poly-MPC, the antithrombotic performance was improved for PICM-MPC-PP. Moreover, PICM-MPC-PP fabricated BHV prototype was demonstrated to exhibit satisfactory durability and hydrodynamics under wide range of simulated conditions. Altogether, the proposed double bond crosslinking strategy simultaneously accomplished crosslinking and antithrombotic modification of BHVs, and PICM-MPC-PP with improved biocompatibility, antithrombogenicity, anticalcification performance as well as appropriate hydrodynamics and durability would be a promising alternative for BHVs crosslinked by glutaraldehyde.

Constructing highly stable solid electrolyte interphase for Si@Graphene anodes by coupling 2-isocyanatoethyl methacrylate and fluoroethylene carbonate

Si-based anode materials have become the most popular candidate in next generation high-specific energy lithium-ions batteries owing to the advantages of high theoretical capacity, low operation potential, environmental friendliness, and low cost. However, the huge volume changes of Si-based anode during the charging and discharging process results in unstable solid electrolyte interphase (SEI) films and poor cycling performance. Here, 2-isocyanatoethyl methacrylate (IEM) and fluoroethylene carbonate (FEC) are used as functional electrolyte additives to constructing stable and durable inorganic-organic composite SEI films on the surface of Si@Graphene (Si/G) anode. The composite SEI film can tolerate the volume change of Si/G anode. As a result, the Si/G anode shows enhanced initial Coulombic efficiency (ICE), cycling stability and rate capability. Specifically, the ICE of Li||Si/G cell can reach 90%, and the specific capacity of Li||Si/G cell can maintain 1373 mAh g−1 after 100 cycles at the rate of 1 A g−1 by adding 1 vol% IEM and 9 vol% FEC.

Material Properties and Cell Compatibility of Photo-Crosslinked Sericin Urethane Methacryloyl Hydrogel.

There is a need to develop novel cytocompatible hydrogels for cell encapsulation and delivery in regenerative medicine. The objective of this work was to synthesize isocyanato ethyl methacryloyl-functionalized sericin and determine its material properties as a natural hydrogel for the encapsulation and delivery of human mesenchymal stem cells (MSCs) in regenerative medicine. Sericin extracted from silk cocoons was reacted with 2-isocyanatoethyl methacrylate (IEM) or methacrylic anhydride (MA) to produce sericin urethane methacryloyl (SerAte-UM) or sericin methacryloyl (SerAte-M, control) biopolymers, respectively. The hydrogels produced by photo-crosslinking of the biopolymers in an aqueous solution were characterized with respect to gelation kinetics, microstructure, compressive modulus, water content, degradation, permeability, and viability of encapsulated cells. The secondary structure of citric acid-extracted sericin was not affected by functionalization with IEM or MA. SerAte-UM hydrogel was slightly more hydrophilic than SerAte-M. The gelation time of SerAte-UM hydrogel decreased with an increasing degree of modification. The photo-polymerized SerAte-UM hydrogel had a highly porous, fibrous, honeycomb microstructure with an average pore size in the 40–50 µm range. The compressive modulus, swelling ratio, and permeability of SerAte-UM hydrogel depended on the degree of modification of sericin, and the mass loss after 21 days of incubation in aqueous solution was <25%. Both SerAte-UM and SerAte-M hydrogels supported viability and growth in encapsulated MSCs. The SerAte-UM hydrogel, with its higher hydrophilicity compared to SerAte-M, is promising as a matrix for encapsulation and delivery of stem cells in tissue engineering.

Isocyanate group containing reactive hydrogels: Facile synthesis and efficient biofunctionalization

Functionalizable hydrogels that are readily accessible and can undergo facile and specific conjugation with various functional molecules are attractive platforms for many biomedical applications. In this study, a series of isocyanate functional group bearing reactive hydrogels were synthesized using photopolymerization of 2-isocyanatoethyl methacrylate (ICEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) in the presence of pentaerythritol tetraacrylate (PETA) crosslinker. Bulk hydrogels were characterized using FTIR, TGA and SEM analyses. Hydrogels were also prepared as flat or micropatterned films covalently bonded onto glass surfaces. The reactive isocyanate groups embedded in the hydrogel undergo facile and efficient functionalization with amine- and thiol-containing molecules. The extent of functionalization of these hydrogels can be adapted by varying the amount of reactive monomer incorporated during the syntheses. Apart from several examples of functionalizations, it is demonstrated that these hydrogels can be easily functionalized with bioactive ligands to enable ligand-directed protein immobilization.

A bioprosthetic heart valve prepared by copolymerization of 2-isocyanatoethyl methacrylate modified pericardium and functional monomer

Bioprosthetic heart valves (BHVs), mostly fabricated from glutaraldehyde crosslinked porcine or bovine pericardium, have been increasingly used in clinic with the application of transcatheter aortic valve replacement surgery. However, several drawbacks of glutaraldehyde crosslinked BHVs including poor cytocompatibility, thrombosis and calcification might lead to dysfunction and structural valvular degeneration (SVD) of BHVs. Here, we developed a glutaraldehyde-free crosslinking method in which the porcine pericardium was treated with 2-isocyanatoethyl methacrylate (ICM) to introduce methacrylate groups and subsequently copolymerized with crosslinker, poly(ethylene glycol) dimethacrylate (PEGDA), to prepare a PEGDA polymer crosslinked porcine pericardium (PICM-PEGDA-PP). The PICM-PEGDA-PP exhibited improved cytocompatibility, stability, mechanical properties and anticalcification property compared with glutaraldehyde crosslinked porcine pericardium (GA-PP). Owing to the introduction of PEGDA polymers, PICM-PEGDA-PP exhibited lower adsorption of proteins, platelets and blood cells as well as significant antithrombotic performance. Furthermore, the hydrodynamic performance and durability of PICM-PEGDA-PP were proved to meet the requirements of ISO 5840–3 for BHVs. These results indicated that the component stabilization and antithrombic functionalization of BHVs can be achieved by the proposed glutaraldehyde-free crosslinking method and PICM-PEGDA-PP is expected to be developed into a potential alternative for glutaraldehyde crosslinked BHVs clinically in the future.

New Synthesis Routes toward Improvement of Natural Filler/Synthetic Polymer Interfacial Crosslinking.

Among the critical issues dictating bio-composite performance is the interfacial bonding between the natural fibers and polymer matrix. In this regard, this article presents new synthesis routes comprising the treatment and functionalization of both date palm powder (DPP) filler and a polypropylene (PP) matrix to enhance filler–polymer adhesion in the newly developed bio-composites. Specifically, four bio-composite forms are considered: untreated DPP filled PP (DPP-UT/PP), treated DPP filled PP (DPP-T/PP), treated DPP filled functionalized PP using 2-isocyanatoethyl methacrylate (DPP-T/PP-g-IEM), and treated and functionalized DPP using 4-toluenesulfonyl chloride filled functionalized PP using 2-acrylamide ((DPP-T)-g-TsCl/PP-g-AcAm). The functional groups created on the surface of synthesized PP-g-IEM react with activated hydroxyl groups attached to the filler, resulting in chemical crosslinking between both components. Similarly, the reaction of TsCl with NH2 chemical groups residing on the mating surfaces of the filler and polymer generates an amide bond in the interface region. Fourier transform infrared spectroscopy (FTIR) is used to confirm the successful coupling between the filler and polypropylene matrix after applying the treatment and functionalization schemes. Owing to the introduced crosslinking, the DPP-T/PP-g-IEM bio-composite exhibits the best mechanical properties as compared to the neat polymer, unfunctionalized polymer-based bio-composite, and (DPP-T)-g-TsCl/PP-g-AcAm counterpart. The applied compatibilizers assist in reducing the water uptake of the manufactured bio-composites, increasing their durability.

Nonglutaraldehyde crosslinked bioprosthetic heart valves based on 2-isocyanatoethyl methacrylate crosslinked porcine pericardium with improved properties of stability, cytocompatibility and anti-calcification

Valvular heart diseases (VHD) have a high incidence in the elderly, and the morbidity and fatality rate of VHD increase gradually. To save the lives of patients at the end stage of VHD, valve replacement is the most effective treatment. Owning to the good hydrodynamic performance and application of transcatheter aortic valve replacement (TAVR), bioprosthetic heart valves (BHVs) fabricated from glutaraldehyde crosslinked porcine or bovine pericardium have become a popular choice for patients. However, BHVs fail within 10–15 years of implantation due to the structural degradation and calcification which are greatly attributed to glutaraldehyde crosslinking. In this work, 2-isocyanatoethyl methacrylate (ICM) was used as crosslinking agent for the first time to stabilize porcine pericardium by radical polymerization crosslinking. The ICM-crosslinked pericardium (PICM10-PP) was demonstrated to exhibit better cytocompatibility, mechanical property, and milder immune responses compared with glutaraldehyde crosslinked porcine pericardium (GA-PP). In addition, the PICM10-PP was less calcific than GA-PP after 30 and 90 days of subcutaneous implantation. Following the guidance of ISO5840-3, the hydrodynamic performance and durability of PICM10-PP were evaluated and demonstrated to conform the requirements for BHVs. These results indicate that ICM is a potential alternative of glutaraldehyde in crosslinking BHVs. A nonglutaraldehyde crosslinked bioprosthetic heart valve based 2-isocyanatoethyl methacrylate (ICM) crosslinked porcine pericardium. Methacryloyl groups were introduced to the porcine pericardium through the reaction between collagen and ICM, and the crosslinking was achieved through subsequent radical polymerization. The crosslinked porcine pericardium exhibited enhanced stability, cytocompatibility, mechanical property, anti-calcification hemocompatibility, and its hydrodynamic performance and durability were met the requirements of ISO5840-3. • 2-isocyanatoethyl methacrylate (ICM) was used as nonglutaraldehyde crosslinking agent for the first time for porcine pericardium. • The ICM-crosslinked pericardium (PICM10-PP) exhibited improved cytocompatibility and mechanical property.. • PICM10-PP was shown to be dramatically less calcific than GA-PP. • The hydrodynamic performance and durability of PICM10-PP met the requirement of ISO5840-3 for BHVs.

Preparation of photo-crosslinkable acrylic copolymer and its debonding property on silicon wafer

As silicon wafers become thinner and easier to warp, it is important to improve production efficiency of dies. In the wafer grinding and dicing process, photo-crosslinkable pressure sensitive adhesive (PSA) tapes are applied to fix the silicon wafer and greatly increase die yield. The PSA tapes must be peeled easily without any residues after UV light irradiation. Herein, a hydroxyl group containing copolymer was first synthesized from 2-ethylhexyl acrylate, methyl methacrylate, acrylic acid and hydroxyethyl acrylate monomers via free radical polymerization, followed by the introduction of methacrylate groups through the addition reaction of 2-isocyanatoethyl methacrylate with hydroxyl groups on side chain of copolymers. The photo-crosslinkable adhesive was then prepared by the mixing the copolymers with photoinitiator and aziridine crosslinker. Glass transition temperature (Tg) and storage modulus of the photo-crosslinked adhesives increased with UV irradiation time, which benefited the picking-up process. A digital microscope was used to observe the surface morphology of the debonded silicon wafers and excellent debonding effect occurred after 40 s UV irradiation.

An analogue memristor made of silk fibroin polymer

A novel protein-based polymer memristor is synthesized by a polymerization reaction using silk fibroin protein (SFP) and 2-isocyanatoethyl methacrylate.

Acrylic Functionalization of Cellulose Nanocrystals with 2-Isocyanatoethyl Methacrylate and Formation of Composites with Poly(methyl methacrylate).

Cellulose nanocrystals (CNCs) derived from renewable plant-based materials exhibit strong potential for improving properties of polymers by their dispersal in the polymer matrix as a composite phase. However, the hydrophilicity and low thermal stability of CNCs lead to compromised particle dispersibility in common polymers and limit the processing conditions of polymer–CNC composites, respectively. One route that has been explored is the modification of CNCs to alter surface chemistry. Acrylic materials are used in a broad class of polymers and copolymers with wide commercial applications. Yet, the available methods for adding groups that react with acrylics to enhance dispersion are quite limited. In this work, a versatile chemical modification route is described that introduces acryloyl functional groups on CNCs that can in turn be polymerized in subsequent steps to create acrylic–CNC composites. The hydroxyl group on CNC surfaces was reacted with the isocyanate moiety on 2-isocyanatoethyl methacrylate (IEM), a bifunctional molecule possessing both the isocyanate group and acryloyl group. The resulting modified CNCs (mCNCs) showed enhanced hydrophobicity and dispersibility in organic solvent relative to unmodified CNCs. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis verified the surface modification and allowed an estimation of the degree of modification as high as 0.4 (26.7% surface hydroxyl substitution CNC). The modified CNCs were copolymerized with methyl methacrylate, and the composites had improved dispersion relative to composites with unmodified CNCs and enhanced (104%) tensile strength at 2 wt % CNC when compared to the neat poly(methyl methacrylate) (PMMA), indicating a benefit of the reactive acryloyl groups added to the CNC surface. Overall, the modification strategy was successful in functionalizing CNCs, opening possibilities for their use in organic media and matrices.

Boosting up printability of biomacromolecule based bio-ink by modulation of hydrogen bonding pairs

This study describes low dose UV curable and bioprintable new bioink made of hydrogen bond donor-acceptor adaptor molecule 2-isocyanatoethyl methacrylate (NCO)modified gelatin (NCO-Gel). Our theoretical calculations demonstrate that insertion of 2-isocyanatoethyl methacrylate doubles the interaction energy (500 meV) between gelatin chains providing significant contribution in interchain condensation and self-organization as compared to methacrylic anhydride modified gelatin (GelMA). The NCO-Gel exhibits peak around 1720 cm−1 referring to bidentate hydrogen bonding between H-NCO and its counterpart OCNH. These strong interchain interactions drive chains to be packed and thereby facilitating UV crosslinking. The NCO-Gel is exhibiting a rapid, 10 s gelation process by the exposure of laser (3 W, 365 nm). The dynamic light scattering characterization also reveals that NCO-Gel has faster sol to gel transition as compared to GelMA depending on the UV curing time. The NCO-Gel was found to be more firm and mechanically strong that provides advantages in molding as well as bioprinting processes. Bioprinted NCO-Gel has shown sharp borders and stable 3D geometry as compared to GelMA ink under 10 s UV curing time. The cell viability tests confirm that NCO-Gel facilitates cell proliferation and supports cell viability. We foresee that NCO-Gel bioink formulation provides a promising opportunity when low dose UV curing and rapid printing are required.

Wool Keratin Photolithography as an Eco-Friendly Route to Fabricate Protein Microarchitectures

Herein, we present an eco-friendly route to construct protein microarchitectures by using wool keratin (WK) as a green biophotoresist. The photoactive WK was extracted from wool with a method of alkaline hydrolysis and reacted with 2-isocyanatoethyl methacrylate (IEM). The whole process can avoid the use of surfactant and does not cause apparent changes in the structure and function of WK. With the aid of direct-write photolithography, "photoresist-like" WK can be further used for fabricating well-defined and high-performance patterns at a low micron-scale (μm) without high temperature, complicated process, long time, and high production cost.

Improvement of interfacial interaction in impregnated wood via grafting methyl methacrylate onto wood cell walls

Abstract Improving the interaction between the wood cell wall and a modifying agent is fundamental to enhancing the efficacy of wood modification. The extent of interaction is, nevertheless, difficult to evaluate due to the highly heterogeneous nature of the modified wood. In this study, methacryl groups were grafted onto the wood cell wall polymers, via the reaction between 2-isocyanatoethyl methacrylate (IEMA) and hydroxyl groups, to improve their compatibility and reactivity. Subsequently, methyl methacrylate (MMA) was introduced into methacrylated wood and copolymerized with the bonded methacryl groups. The distribution of IEMA and poly MMA (PMMA) in the wood cell walls was investigated by scanning electron microscopy (SEM) and confocal Raman microscopy. The results showed that MMA penetrated the wood cell walls and formed strong interfacial interaction, which was confirmed by confocal Raman microscopy combined with principal component analysis (PCA). With copolymerization, the highest anti-swelling efficiency (ASE) (57%) was achieved, because of the effect of methacrylation. Compared to the reference, the water resistance and hardness were significantly improved. In addition, the dynamic wettability was also altered largely due to copolymerization.

Dentin Bonding and SEM Analysis of a New Experimental Universal Adhesive System Containing a Dendrimer.

Due to their polymerization characteristics, hyper-branched dendrimers have lately shown to be promising candidates for use in dental materials. In this study, a new dental adhesive system was prepared, using a dendrimer derived from 2-isocyanatoethyl methacrylate (G-IEMA), and its adhesive properties were investigated. The exposed dentin was treated with four universal adhesives (UAs): SBU (Scotchbond Universal™), FUT (Futurabond M+™), AE1 (experimental adhesive with Bis-GMA) and AE2 (experimental adhesive with G-IEMA), using Etch & Rinse (ER) or Self Etch (SE) protocols. Composite build-ups were prepared and stored for 24 h at 37 °C in distilled water. Composite/dentin beams were prepared with cross-sectional areas of 1 ± 0.3 mm2 and µTBS (Micro-tensile bond strength) test was performed at 0.5 mm/min. Failures modes were evaluated by stereomicroscopy, and bonding interfaces were observed by scanning electron microscopy (SEM). Statistical analysis of µTBS data was performed using General Linear (GLM) and Linear Mixed Models (LMM). The effect of adhesive type on µTBS was significant (p = 0.010), with AE1 presenting significantly higher µTBS than SBU (p = 0.019). No other differences between adhesives were observed. ER showed significantly better results than SE (p = 0.019), and no significant interactions between the adhesives and protocols were determined. Results obtained so far pinpoint the emergence of a new paradigm in the dental materials field, as G-IEMA can be used successfully as an alternative to Bis-GMA.

Preparation and application of teicoplanin functionalized polymeric monolith for enantioseparation of chiral drugs

A novel chiral stationary phase (CSP), based on a monolithic organic polymer chemically modified with teicoplanin, was fabricated within a 100 μm I.D. fused silica capillary. The teicoplanin was firstly derivatized with 2-isocyanatoethyl methacrylate (ICNEML) and then thermally co-polymerized with the crosslinker ethylene dimethacrylate (EDMA) in presence of porogens (methanol and dimethylsulfoxide). The optimal experimental conditions (e.g., concentration and ratio of the reagents), considering enantioresolution and permeability, were systematically investigated. The prepared monolith was evaluated using scanning electron microscopy, and the column exhibited quite good morphology. In order to further evaluate the enantioresolving power of the poly(ICNEML-teicoplanin-co-EDMA) monolith, a series of basic and acidic chiral compounds were analyzed using an isocratic mode of polar organic solvents (methanol and acetonitrile) or the same solvents in combination with water (reversed-phase) by nano-liquid chromatography. Five mandelic acids and six derivatized amino acids were enantioresolved under reversed-phase mode (Rs = 1.22–3.47 and α = 1.43–6.33). This monolithic teicoplanin-CSP was also effective in the enantioseparations of 17 amino alcohol drugs employing polar-organic phase mode (MeOH/ACN/TEA/HOAc (80/20/0.03/0.055, v/v/v/v)). Ten of them were baseline enantioresolved (alprenolol, betaxolol, clenbuterol, isoproterenol, metoprolol, pindolol, propranolol, salbutamol, sotalol, tertatolol) (Rs = 1.55–2.48 and α = 1.21–1.55), while the others were partially enantioseparated (Rs = 1.14–1.48).

Preparation of degradable magnetic temperature- and redox-responsive polymeric/Fe3O4 nanocomposite nanogels in inverse miniemulsions for loading and release of 5-fluorouracil

This work reports the synthesis of novel degradable magnetic temperature- and redox-responsive polymer/Fe3O4 nanocomposite nanogels (NCGs) through inverse miniemulsion polymerization and their potential application as nanocarriers for controlled drug delivery. Surface of Fe3O4 magnetic nanoparticles (MNPs) were vinyl-modified with 2-isocyanatoethyl methacrylate. Poly(N-vinylcaprolactam) (PNVCL)/Fe3O4 NCGs were prepared via inverse miniemulsion polymerization by using a disulfide-containing cross-linker. The Fe3O4 MNPs were chemically attached to the polymer matrix of NCGs, offering a good structural integrity of NCGs in aqueous systems. The PNVCL/Fe3O4 NCGs not only inherited the good superparamagnetism of Fe3O4 MNPs, but also displayed a reversible temperature-responsiveness as well as marked redox-responsiveness. The release behavior of a model anticancer drug 5-fluorouracil from the PNVCL/Fe3O4 NCGs could be conveniently tuned by the external temperature, redox condition of media, or their combination. The prepared PNVCL/Fe3O4 NCGs displayed a low cytotoxicity, holding a great potential in functioning as magnetic guiding nanocarriers for controlled drug delivery.