2-aminoethyl Methacrylate Hydrochloride Research Articles

Fabrication of antimicrobial cationic hydrogels driven by physically and chemically crosslinking for wound healing

The wound therapy based on antibiotic delivery inevitably leads to the emergence of drug resistance. Hydrogel biomaterials with inherent antibacterial activities have emerged as promising candidates for addressing this issue. However, developing an inherently antibacterial hydrogel through simple and facile strategies to promote localized wound infection healing remains a challenge. In this study, we successfully constructed antimicrobial cationic hydrogels with self-healing and injectable properties through physically and chemically dual-crosslinked networks. The networks were formed by the copolymers poly[(di(ethylene glycol) methyl ether methacrylate)-co-(4-formylphenyl methacrylate)-co-(2-(methacryloyloxy)ethyl]trimethylammonium chloride solution)] (PDFM) and poly[(di(ethylene glycol) methyl ether methacrylate)-co-(2-aminoethyl methacrylate hydrochloride)-co-(2-(((6-(6-methyl-4[1H]pyrimidionylureido) hexyl)carbamoyl)oxy)ethyl methacrylate)] (PDAU). The hydrogel systems effectively facilitate the regeneration and healing of infected wounds through the contact bactericidal feature of quaternary ammonium cations. The presence of Schiff base bonds in the injectable hydrogels imparts remarkable pH responsiveness and self-healing properties. In vitro experiments verified their intrinsic antibacterial activities along with their favorable cytocompatibility and hemocompatibility in both in vitro and in vivo. In addition, the hydrogel significantly accelerated the healing of bacterially infected in a full-thickness skin wound. This facilely prepared dual-crosslinked hydrogel, without antibiotics loading, holds significant prospects for treating infected wounds.

Targeted downregulation of MYC mediated by a highly efficient lactobionic acid-based glycoplex to enhance chemosensitivity in human hepatocellular carcinoma cells

The chemosensitization of tumor cells by gene therapy represents a promising strategy for hepatocellular carcinoma (HCC) treatment. In this regard, HCC-specific and highly efficient gene delivery nanocarriers are urgently needed. For this purpose, novel lactobionic acid-based gene delivery nanosystems were developed to downregulate c-MYC expression and sensitize tumor cells to low concentration of sorafenib (SF). A library of tailor-made cationic glycopolymers, based on poly(2-aminoethyl methacrylate hydrochloride) (PAMA) and poly(2-lactobionamidoethyl methacrylate) (PLAMA) were synthesized by a straightforward activators regenerated by electron transfer atom transfer radical polymerization. The nanocarriers prepared with PAMA114-co-PLAMA20 glycopolymer were the most efficient for gene delivery. These glycoplexes specifically bound to the asialoglycoprotein receptor and were internalized through the clathrin-coated pit endocytic pathway. c-MYC expression was significantly downregulated by MYC short-hairpin RNA (MYC shRNA), resulting in efficient inhibition of tumor cells proliferation and a high levels apoptosis in 2D and 3D HCC-tumor models. Moreover, c-MYC silencing increased the sensitivity of HCC cells to SF (IC50 for MYC shRNA + SF 1.9 μM compared to 6.9 μM for control shRNA + SF). Overall, the data obtained demonstrated the great potential of PAMA114-co-PLAMA20/MYC shRNA nanosystems combined with low doses of SF for the treatment of HCC.

In Situ Chemical Modification with Zwitterionic Copolymers of Nanofiltration Membranes: Cure for the Trade-Off between Filtration and Antifouling Performance.

Breaking the trade-off between filtration performance and antifouling property is critical to enabling a thin-film nanocomposite (TFC) nanofiltration (NF) membrane for a wide range of feed streams. We proposed a novel design route for TFC NF membranes by grafting well-defined zwitterionic copolymers of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) and 2-aminoethyl methacrylate hydrochloride (AEMA) on the polyamide surfaces via an in situ surface chemical modification process. The successful grafting of a zwitterionic copolymer imparted the modified NF membranes with better surface hydrophilicity, a larger actual surface area (i.e., nodular structures), and a thinner polyamide layer. As a result, the water permeability of the modified membrane (i.e., TFC-10) was triple that of the pristine TFC membrane while maintaining high Na2SO4 rejection. We further demonstrated that the TFC-10 membrane possessed exceptional antifouling properties in both static adsorption tests and three cycles of dynamic protein and humic acid fouling tests. To recap, this work provides valuable insights and strategies for the fabrication of TFC NF membranes with simultaneously enhanced filtration performance and antifouling property.

Engineering silica-polymer hybrid nanosystems for dual drug and gene delivery.

In recent years, it has been shown that a combination of different antitumour strategies involving distinct therapeutic agents, such as chemical compounds and genetic material, could result in an effective therapeutic activity that is much higher than that obtained by conventionally used individual approaches. Therefore, the main goal of this work was to develop a new hybrid nanosystem based on mesoporous silica nanoparticles and polymers to efficiently transport and deliver drug and plasmid DNA into cancer cells. Moreover, its potential to mediate a combinatorial antitumour strategy involving epirubicin and herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) gene therapy was evaluated. For this purpose, various cationic polymers were assessed, including poly(β-amino ester) homopolymer, gelatine type A, gelatine type B, and poly(ethylene glycol)-b-poly(2-aminoethyl methacrylate hydrochloride) block copolymer. The obtained results show that using different polymers leads to nanosystems with different physicochemical properties and, consequently, different biological activities. The best formulation was obtained for hybrid nanosystems coated with PEG-b-PAMA. They demonstrated the ability to cotransport and codeliver an anticancer drug and plasmid DNA and effectively mediate the combined antitumour strategy in 2D and 3D tumour cell culture models. In summary, we developed a novel silica- and polymer-based nanosystem able to mediate a dual chemotherapeutic and suicide gene therapy strategy with a much higher therapeutic effect than that obtained through the use of individual approaches, showing its potential for cancer treatment.

Facile Synthesis of Hydrogel-Based Ion-Exchange Resins for Nitrite/Nitrate Removal and Studies of Adsorption Behavior.

This research aimed to create facile, reusable, hydrogel-based anion exchange resins that have been modified with two different amines to test their ability to adsorb nitrate and nitrite in water using batch and continuous systems. In the batch experiment, maximum adsorption capacities of nitrate and nitrite onto poly (ethylene glycol) diacrylate methacryloxyethyltrimethyl ammonium chloride (PEGDA-MTAC) and poly (ethylene glycol) diacrylate 2-aminoethyl methacrylate hydrochloride (PEGDA-AMHC) adsorbents can be obtained as 13.51 and 13.16 mg NO3−-N/g sorbent; and 12.36 and 10.99 mg NO2−-N/g sorbent respectively through the Langmuir isotherm model. After 15 adsorption/desorption cycles, PEGDA-MTAC and PEGDA-AMHC retained nitrate adsorption efficiencies of 94.71% and 83.02% and nitrite adsorption efficiencies of 97.38% and 81.15% respectively. In a column experiment, modified adsorbents demonstrated adsorption efficiencies greater than 45% after being recycled five times. Proposed hydrogel-based adsorbents can be more effective than several types of carbon-based sorbents for nitrate and nitrite removal in water and have benefits such as reduced waste generation, cost-effectiveness, and a facile synthesis method.

In Vivo Evaluation of Gamma-Irradiated and Heparin-Immobilized Small-Diameter Polycaprolactone Vascular Grafts with VEGF in Aged Rats.

The effectiveness of small-diameter vascular grafts depends on their antithrombogenic properties and ability to undergo accelerated endothelialization. The extreme hydrophobic nature of poly(ε-caprolactone) (PCL) hinders vascular tissue integration, limiting its use in medical implants. To enhance the antithrombogenicity of PCL as a biomaterial, we grafted 2-aminoethyl methacrylate (AEMA) hydrochloride onto the PCL surface using gamma irradiation; developed a biodegradable heparin-immobilized PCL nanofibrous scaffold using gamma irradiation and N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide reaction chemistry; and incorporated vascular endothelial growth factor (VEGF) into the scaffold to promote vascular endothelial cell proliferation and prevent thrombosis on the vascular grafts. We assessed the physicochemical properties of PCL, heparin-AEMA-PCL (H-PCL), and VEGF-loaded heparin-AEMA-PCL (VH-PCL) vascular grafts using scanning electron microscopy, attenuated total reflection–Fourier transform infrared spectroscopy, toluidine blue O staining, and fibrinogen adsorption and surface wettability measurement. In addition, we implanted the vascular grafts into 24-month-old Sprague Dawley rats and evaluated them for 3 months. The H-PCL and VH-PCL vascular grafts improved the recovery of blood vessel function by promoting the proliferation of endothelial cells and preventing thrombosis in clinical and histological evaluation, indicating their potential to serve as functional vascular grafts in vascular tissue engineering.

Catalytic Activity Comparison of Gold Nanoparticles in Annealed and Quenched Spherical Polyelectrolyte Brushes

Abstract Two kinds of cationic spherical polyelectrolyte brushes (SPB), quenched poly(methacryloxyethyltrimethyl ammonium chloride) brush and annealed poly(2-aminoethyl methacrylate hydrochloride) brush with polystyrene cores (PS-PMETAC and PS-PAEMH), were synthesized by photo-emulsion polymerization. The small and uniform gold nanoparticles (AuNPs) were successfully immobilized in these two SPBs. The chain layer extension of the quenched SPB loaded with AuNPs (SPB-Au) was more complete than that of the annealed SPB-Au in alkaline system. Compared the catalysis of the prepared AuNPs onto the two SPBs, it was found that the catalytic activity of AuNPs in quenched SPB is higher than that in annealed SPB.

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.

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.

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.

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.

Influence of the Structure of a Surface Layer of Methyl Methacrylate-Based Cationic Particles on Adsorption of Biomolecules

Crosslinked cationic particles 200–600 nm in diameter have been synthesized via emulsifier-free copolymerization of methyl methacrylate and 2-aminoethyl methacrylate hydrochloride in the presence of cross-linking agents (N,N'-methylenebisacrylamide, triethylene glycol dimethacrylate, and diethylene glycol dimethacrylate). It has been shown that polymer particles with a maximum concentration of surface functional groups (1.42 µmol/m2) and a stable structure of a surface layer are formed only in the presence of ethanol (20 vol %). The synthesized particles efficiently adsorb biologically active substances, and their dispersions are stable against aggregation in buffer solutions at pH 7.0.

Imine bonding self-repair hydrogels after periodate-triggered breakage of their cross-links

The development of new materials with smart properties is currently expanding the development of new technologies. Therefore, the design of materials with novel sensitivities and smart behavior is important for the development of smart systems with automated responsivity. We have recently reported the synthesis of hydrogels, cross-linked by N,N'-diallyltartardiamide (DAT). The covalent DAT-crosslinking points have vicinal diols which can be easily cleaved with periodate, generating changes in the hydrogel properties, as well as generating valuable α-oxo-aldehyde functional groups useful for further chemical modification. Based on those findings, we envisioned that a self-healable hydrogel could be obtained by incorporation of primary amino functional groups, from 2-aminoethyl methacrylate hydrochloride (AEMA), coexisting with DAT into the same network. Herein, α-oxo-aldehyde groups generated after the reaction with periodate would arise in the immediate environment of amine groups to form imine cross-links. For this purpose, DAT-crosslinked hydrogels were synthesized and carefully characterized. The cleavage of DAT-crosslinks with periodate promoted changes in the mechanical and swelling properties of the materials. As expected, a self-healing behavior was observed, based on the spontaneous formation of imine covalent bonds. In addition, we surprisingly found a combination of fast vicinal diols cleavage and a low speed self-crosslinking reaction by imine formation. Consequently, it was found a time-window in which a periodate-treated polymer was obtained in a transient liquid state, which can be exploited to choose the final shape of the material, before automated gelling. The singular properties attained on these hydrogels could be useful for developing sensors, actuators, among other smart systems.

Electrochemical sensing of methylmalonic acid based on molecularly imprinted polymer modified with graphene oxide and gold nanoparticles

Molecularly imprinted allyl trimethoxysilane –grafted- graphene oxide/gold nano particle co polymerised with -allyl amine (AA) /2-aminoethyl methacrylate hydrochloride (AEMA) polymer (GO/AuNP-g-ATMS-co-AEMA/AA) was synthesised by bulk imprinting method. The synthesised product was tested for sensing and quantifying methylmalonic acid (MMA) in blood samples in selective manner. Electrochemical studies performed with the developed sensor. The effective pH for the response of the sensor material was found to be 7.4. The response time, limit of detection (LOD) and limit of quantification (LOQ) of the electrode was found to be ~2 min, 0.2095 μM and 0.2935 μM respectively. The constructed sensor exhibits great selectivity and is useful for the rapid determination of MMA in human serum. The designed electrode is long lasting, reproducible and no pre-treatment of biological samples required during clinical analysis which makes it advantageous. The feasibility of the developed sensor was ensured by comparing it with the HP GC/MSD method practiced in diagnostic laboratory (correlation coefficient of 0.967). These results clearly indicate that the sensor developed through molecularly imprinting technique is valid for real sample analysis.

Preparation of hollow silica nanoparticles using cationic spherical polyelectrolyte brushes as catalytic template

This paper presents a facile procedure to fabricate uniform-sized hollow silica nanoparticles (SNP) under a mild condition by using cationic spherical polyelectrolyte brushes (SPB) with a polystyrene (PS) core and densely grafted poly(2-aminoethyl methacrylate hydrochloride) (PAEMH) brush shell as a catalytic template. By changing the brush layer thickness of SPB, hollow SNP with different silica shell thickness could be easily obtained. This method provides a new way for the preparation of hollow SNP without additional catalyst. The obtained hollow SNP exhibited a high-drug encapsulation efficiency (80%) for doxorubicin hydrochloride (DOX), should be of significance in the fields of drug delivery, cancer therapy, and bioimaging.

Preparation, stability and film properties of cationic polyacrylate latex particles with various substituents on the nitrogen atom

Cationic latexes have received wide attention due to their special properties and potential applications in wood coatings, fabric treatment, etc. However, the practical application of cationic latexes was hindered due to their poor stability, especially the alkali resistance stability. In this work, various stable cationic polyacrylate latexes were prepared by an efficient route. Three cationic comonomers, i.e., methacrylatoethyl trimethyl ammonium chloride (DMC), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and 2-aminoethyl methacrylate hydrochloride (AEMH), were used in the aqueous semi-continuous seeded emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) using cetyl trimethyl ammonium bromide (CTAB) and 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIBI) as the cationic emulsifier and initiator, respectively. The alkali resistance of the latex could be significantly improved by the addition of cationic monomer DMC and be simply tuned by adjusting DMC dosage. The improved stability of the latex might originate from the higher charge density on the surface of the latex by the introduction of DMC. Moreover, the effects of initiator dosage, emulsifier dosage and different cationic comonomers on the latex preparation and the film properties were also systematically investigated. This work not only introduces an efficient route to prepare cationic latexes with superior stability, but also paves the way for latexes to be used in applications such as textile finishing, paper industry, and biomedical field, etc.

Emulsifier-Free Emulsion Copolymerization of Methyl Methacrylate As a Method of Obtaining Cationic Particles for Diagnostics of Tick-Borne Encephalitis Virus

Cross-linked cationic particles 150–300 nm in diameter have been synthesized via single-stage emulsifier-free copolymerization of methyl methacrylate and 2-aminoethyl methacrylate hydrochloride in the presence of cross-linking agents (ethylene glycol dimethacrylate and N,N'-methylenebisacrylamide). Factors that enable one to control the morphology and polydispersity of the resulting particles have been determined. It has been shown that the dispersions of the particles are aggregatively stable in physiological solutions and after the sorption of biologically active molecules. The synthesized particles can be used for efficient revealing tick-borne encephalitis virus via latex agglutination reaction, with the analysis time being no longer than 10 min.

Brushing the surface: cascade reactions between immobilized nanoreactors.

Functionalization of hard or soft surfaces with, for example, ligands, enzymes or proteins, is an effective and practical methodology for the development of new applications. We report the assembly of two types of nanoreactors based upon poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (PDMS-b-PMOXA) diblock copolymers as scaffold, uricase and lactoperoxidase as bio-catalysts located within the nanoreactors, and melittin as the biopores inserted into the hydrophobic shell. The nanoreactors were immobilized on poly(2-hydroxyethyl methacrylate)-co-poly(2-aminoethyl methacrylate hydrochloride) (PHEMA-co-P(2-AEMA·HCl) brushes-grafted wafer surfaces by utilizing the strong supramolecular interactions between biotin and streptavidin. The (PHEMA-co-P(2-AEMA·HCl) brushes on silicon surfaces were prepared by a surface initiating atom transfer radical polymerization (ATRP) "graft-from" technique. Cascade reactions between different surface-anchored nanoreactors were demonstrated by converting Amplex® Red to the fluorescent probe resorufin by using the H2O2 produced from uric acid and H2O. The detailed properties of the nanoreactors on the functionalized surface including the binding behaviours and cascade reactions were investigated using emission spectroscopy, transmission electron microscopy (TEM), light scattering (LS), atomic force microscopy (AFM) and a quartz crystal microbalance (QCM-D). The results are proof-of-principle for the preparation of catalytically functional engineered surface materials and lay the foundation for applying this advanced functional surface material in biosensing, implanting and antimicrobial materials preparation.

Construction of a stable zwitterionic layer on negatively-charged membrane via surface adsorption and cross-linking

In this study, a stable zwitterionic layer on the surface of a membrane was developed to improve antifouling properties of the membrane, whereby negatively-charged membranes were modified by a positively-charged zwitterionic copolymer via surface adsorption and a cross-linking reaction. Here, 2-methacryloyloxyethyl phosphorylcholine and 2-aminoethyl methacrylate hydrochloride copolymer (P(MPC-co-AEMA)) was used as a model zwitterionic copolymer that can be adsorbed onto negatively-charged surfaces, and cross-linked by glutaraldehyde. The surface chemical compositions, morphology, hydrophilicity, charge, and antifouling properties of the membranes were characterized. Furthermore, the stability of the coating layer was evaluated. The results indicated that the surface hydrophilicity and antifouling properties of the membrane were clearly improved after surface modification. In addition, the stability of the coating layer was significantly increased after cross-linking compared to that after only surface adsorption. This is likely due to the cross-linking of the interpenetrating polymer networks inside the porous structure on the surface. Our findings provide a simple and effective method for surface modification via surface adsorption for use in practical applications.