Covalent immobilization of trypsin onto thermo‐sensitive poly(N‐isopropylacrylamide‐co‐acrylic acid) microspheres with high activity and stability

Poly(N‐isopropylacrylamide‐co‐acrylic acid) (P(NIPAM‐co‐AA)) microspheres with a high copolymerized AA content were fabricated using rapid membrane emulsification technique. The uniform size, good hydrophilicity, and thermo sensitivity of the microspheres were favorable for trypsin immobilization. Trypsin molecules were immobilized onto the microspheres surfaces by covalent attachment. The effects of various parameters such as immobilization pH value, enzyme concentration, concentration of buffer solution, and immobilization time on protein loading amount and enzyme activity were systematically investigated. Under the optimum conditions, the protein loading was 493 ± 20 mg g^?1 and the activity yield of immobilized trypsin was 155% ± 3%. The maximum activity (V_max) and Michaelis constant (K_m) of immobilized enzyme were found to be 0.74 μM s^?1 and 0.54 mM, respectively. The immobilized trypsin showed better thermal and storage stability than the free trypsin. The enzyme‐immobilized microspheres with high protein loading amount still can show a thermo reversible phase transition behavior. The research could provide a strategy to immobilize enzyme for application in proteomics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43343.     

Production of the Quorum-Sensing Molecules N-Acylhomoserine Lactones by Endobacteria Associated with Mortierella alpina A-178

Gram‐negative bacteria communicate with one another using N‐acylhomoserine lactones (AHLs) as signaling molecules. This mechanism, known as quorum sensing (QS), is needed to develop pathogenicity, as well as symbiotic interactions with eukaryotic hosts, such as animals and plants. Increasing evidence indicates that certain bacteria, namely endobacteria, also inhabit fungal cells and establish symbiotic relationships with their hosts. However, it has not been clear whether bacterial QS acts in developing the relationships. Here we describe the isolation and identification of N‐heptanoylhomoserine lactone and N‐octanoylhomoserine lactone from the culture broth of the zygomycete fungus Mortierella alpina A‐178. This suggested the presence of endobacteria in the fungus, as was confirmed by PCR, fluorescence in situ hybridization, and transmission electron microscopy. Two major bands obtained by PCR‐denaturing gradient gel electrophoresis showed sequence identity to genes in the β‐proteobacterium Castellaniella defragrans (100 %) and the Gram‐positive bacterium Cryobacterium sp. (99.8 %). The production of AHLs depended on the presence of endobacteria and was induced in response to the increase in the concentration of AHLs, suggesting that the bacterium conducts AHL‐mediated QS in the fungus. This paper is the first to report the production of AHLs by endofungal bacteria and raises the possibility that QS plays roles in the development of fungus–endobacterium symbiosis.     

Efficient wound odor removal by β‐cyclodextrin functionalized poly (ε‐caprolactone) nanofibers

Polymer‐cyclodextrin (CD) composite nanofibers, by virtue of the hollow cavities and abundant hydroxyl groups present in CDs, have tremendous potential in a variety of biomedical applications. However, in most cases, especially in aliphatic polyesters, polymer chains thread readily into CD cavities, therefore its potential has not yet been fully realized. Herein, we report the formation of poly(ε‐caprolactone) (PCL)/β‐CD functional nanofibers by electrospinning their mixture from chloroform/N,N‐dimethylformamide (60 : 40). The fiber diameters of the neat PCL and β‐CD functionalized fibers were measured from the images obtained from a scanning electron microscope and were found to be about 500 nm. The efficiency of wound odor absorbance by these composite fibers was studied using a simulated wound odor solution, consisting of butyric and propionic acids in ethanol. Immersion tests indicated that even under less than ideal test conditions, the nanofibers containing β‐CDs were very efficient in masking the odor. The odor masking capability of the β‐CD functionalized PCL nanofibers were further confirmed by thermogravimetric analyses and GC observations, with the former method showing unique degradation patterns. The PCL/β‐CD nanocomposites, by virtue of having their β‐CD cavities free and unthreaded by PCL, could potentially be an ideal substrate for removing wound odors through formation of inclusion compounds with odorants, while providing an ideal environment for the wound to heal. These results suggest tailoring polymer‐CD nanostructures for specific applications in wound odor absorbance, surface grafting of chemical moieties, and vehicles for drug delivery, as examples. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42782.     

A novel insulin oral delivery system assisted by cationic β‐cyclodextrin polymers

This work describes a new oral pharmaceutical formulation of insulin that is complexed with cationic β‐cyclodextrin polymers (CPβCDs), and then encapsulated into alginate/chitosan microspheres, which are prepared by ionotropic pregelation/polyelectrolyte method. CPβCDs were synthesized through a one‐step polymerization of β‐cyclodextrin (βCD), epichlorohydrin, and choline chloride. CPβCDs have enhanced ability to complex with insulin due to the assistance of their polymeric chains, as well as the electrostatic interactions between insulin (negatively charged while pH>5.3) and quaternary ammonium groups of CPβCDs. The noncovalent inclusion complex formed between CPβCDs and insulin was analyzed by Fourier transform infrared and fluorescence emission spectra. With the increase of zeta potential of CPβCDs from 1.8 to 14.2 mV, the insulin association efficiency (AE) of current system was increased from 55.2 to 71.8%, whereas the AE of insulin‐loaded microspheres at the same condition was only 50.7%. The cumulative insulin release in simulated intestinal fluid was also higher than that of the insulin‐loaded microspheres and βCD‐insulin encapsulated microspheres. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

α‐Amylase immobilized by Fe3O4/poly(styrene‐co‐maleic anhydride) magnetic composite microspheres: Preparation and characterization

Fe₃O₄/poly(styrene‐co‐maleic anhydride) core–shell composite microspheres, suitable for binding enzymes, were prepared using magnetite particles as seeds by copolymerization of styrene and maleic anhydride. The magnetite particles were encapsulated by polyethylene glycol, which improved the affinity between the magnetite particles and the monomers, thus showing that the size of the microspheres, the amount of the surface anhydrides, and the magnetite content in the composite are highly dependent on magnetite particles, comonomer ratio, and dispersion medium used in the polymerization. The composite microspheres, having 0.08–0.8 μm diameter and containing 100–800 μg magnetite/g microspheres and 0–18 mmol surface‐anhydride groups/g microsphere, were obtained. Free α‐amylase was immobilized on the microspheres containing reactive surface‐anhydride groups by covalent binding. The effects of immobilization on the properties of the immobilized α‐amylase [magnetic immobilized enzyme (MIE)] were studied. The activity of MIE and protein binding capacity reached 113,800 U and 544.3 mg/g dry microspheres, respectively. The activity recovery was 47.2%. The MIE had higher optimum temperature and pH compared with those of free α‐amylase and showed excellent thermal, storage, pH, and operational stability. Furthermore, it can be easily separated in a magnetic field and reused repeatedly. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 328–335, 2005     

Stability of β‐galactosidase immobilized on composite microspheres of artemisia seed gum and chitosan

In this work, composite microspheres were prepared by using artemisia seed gum and chitosan as a source. The composite microspheres have activated aldehyde groups by using glutaraldehyde. β‐Galactosidase was covalently bound on these activated microspheres. The properties of the immobilized enzyme were investigated and compared with those of the free enzyme, for which o‐nitrophenol β‐D ‐galactopyranoside (ONPG) was chosen as a substrate. The results showed that the pH and thermal stability of the immobilized β‐galactosidase were higher than those of the soluble one. Apart from these, the Michaelis constant K_m was evaluated for the immobilized β‐galactosidase and the soluble enzyme. The immobilized β‐galactosidase exhibited better environmental adaptability and reusability than the soluble one. POLYM. COMPOS., 29:9–14, 2008. © 2007 Society of Plastics Engineers     

Altering associations of doxorubicin‐loaded alginate esters micelles in presence of β‐cyclodextrin

The aim of this article was to evaluate the effects of β‐cyclodextrin (β‐CD) on doxorubicin (DOX)‐loaded alginate esters (SA‐C₁₆) micelles (DOX/SA‐C₁₆) in aqueous solution. DOX was physically loaded into SA‐C₁₆ micelles by an o/w emulsion method with a substantial encapsulation efficiency (EE) level (36.12%), and DOX/SA‐C₁₆ was distributed in size diameters of approximately 254 nm. SA‐C₁₆ as carriers for the DOX can lead to the formation of associative networks in aqueous solutions between the hydrophobic tails of SA‐C₁₆ and DOX, and the dried morphology of DOX/SA‐C₁₆ aggregate was spherical shape. Addition of β‐CD to the system of DOX/SA‐C₁₆ facilitated decoupling of these associations via inclusion complex formation between β‐CD cavities and the polymer hydrophobic tails that produced the release of DOX immediately, and the EE level was dropped to 0.08%, and at the same time the size distribution of aggregate was increased to about 413 nm, moreover, the aggregate was relatively large and becoming irregular spherical shape. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40702.     

Immobilization of glucoamylase on the plain and on the spacer arm‐attached poly(HEMA‐EGDMA) microspheres

Immobilization glucoamylase onto plain and a six‐carbon spacer arm (i.e., hexamethylene diamine, HMDA) attached poly(2‐hydroxyethylmethacrylate‐ethyleneglycol dimethacrylate) [poly(HEMA‐EGDMA] microspheres was studied. The microspheres were prepared by suspension polymerization and the spacer arm was attached covalently by the reaction of carbonyl groups of poly(HEMA‐EGDMA). Glucoamylase was then covalently immobilized either on the plain of microspheres via CNBr activation or on the spacer arm‐attached microspheres via CNBr activation and/or using carbodiimide (CDI) as a coupling agent. Incorporation of the spacer arm resulted an increase in the apparent activity of the immobilized enzyme with respect to enzyme immobilized on the plain of the microspheres. The activity yield of the immobilized glucoamylase on the spacer arm‐attached poly(HEMA‐EGDMA) microspheres was 63% for CDI coupling and 82% for CNBr coupling. This was 44% for the enzyme, which was immobilized on the plain of the unmodified poly(HEMA‐EGDMA) microspheres via CNBr coupling. The K_m values for the immobilized glucoamylase preparations (on the spacer arm‐attached microspheres) via CDI coupling 0.9% dextrin (w/v) and CNBr coupling 0.6% dextrin (w/v) were higher than that of the free enzyme 0.2% dextrin (w/v).The temperature profiles were broader for both immobilized preparations than that of the free enzyme. The operational inactivation rate constants (k_iop) of immobilized enzymes were found to be 1.42 × 10^?5 min^?1 for CNBr coupled and 3.23 × 10^?5 min^?1 for CDI coupled glucoamylase. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2702–2710, 2001     

Maximum volumetric production of β‐galactosidase by Kluyveromyces fragilis in fed‐batch culture with automatic control

The production of β‐galactosidase by Kluyveromyces fragilis was studied in different culture systems, with dissolved oxygen concentration control and using defined media. An operating strategy of fed‐batch culture with automatic control of substrate addition regulated by dissolved oxygen concentration, consisting of the replacement of variable volumes of broth by fresh medium (once the fed‐batch culture has finished), was designed. The volumetric enzyme productivity (Q_p, 13 600 UI dm^?3 h^?1) obtained was 38% higher than that reached in continuous culture of K fragilis with dissolved oxygen concentration control and far higher than that obtained by batch culture of K fragilis under the same aeration conditions. © 2002 Society of Chemical Industry     

Grafting of titanium dioxide microspheres with a temperature‐responsive polymer via surface‐initiated atom transfer radical polymerization without the use of silane coupling agents

Titania microspheres with narrow size distribution and diameters of about 1 µm were prepared and subsequently functionalized using surface‐initiated atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide. The ATRP initiator was immobilized on the particle surface via acylation of surface hydroxyl groups with α‐bromoisobutyryl bromide. Subsequently, an established ATRP reaction system was used for the preparation of titania surface‐grafted poly(N‐isopropylacrylamide) (PNiPAAm). Characterization was performed with electron microscopies, X‐ray diffraction, infrared spectroscopy and dynamic light scattering. It was found that the particle size in aqueous dispersions changed reversibly with temperature as expected for a shell of PNiPAAm, a polymer with a lower critical solution temperature at 32 °C. This confirmed the successful preparation of functional, stimuli‐responsive TiO₂ microparticles via a straightforward controlled surface‐initiated polymerization method.     

Preparation of novel amphiphilic copolymer microspheres and their drug‐release and glucose‐sensitive properties

A novel amphiphilic copolymer was prepared by the copolymerization of N‐acryloyl‐3‐aminophenylboronic acid with β‐cyclodextrin containing maleic anhydride. The copolymer was fully characterized with ¹³C‐NMR, ¹H‐NMR, IR, and scanning electron microscopy. The self‐assembling mechanism of the copolymer in H₂O–CH₃OH cosolvents was studied. Gliclazide as a model drug was loaded inside the copolymer microspheres, and the drug‐release behavior of the microspheres was studied. The results of in vitro oscillating release tests indicated that the microspheres responded to glucose rapidly in 30 min, and the microspheres exhibited self‐regulated on–off release behavior four to six times in 6 h between the solution with 3 g/L glucose and the medium without glucose; this met the clinical requirements of multidrug delivery. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Heparin‐immobilized poly(2‐hydroxyethylmethacrylate)‐based microspheres

Poly(2‐hydroxyethylmethacrylate) (PHEMA)‐based microspheres (150–200 µm in diameter) were produced by a modified suspension polymerization of different type of comonomers—namely, acrylic acid, dimethylaminoethyl‐methacrylate, and methylmethacrylate. These microspheres were activated with cyanogen bromide (CNBr) at pH 11.5, and heparin molecules were then immobilized through covalent bonds. The amount of immobilized heparin was controlled by changing the initial concentration of CNBr and heparin. The increase in the initial concentrations of both CNBr and heparin caused an increase in the amount of heparin immobilized onto microspheres for all polymer surfaces. The maximum heparin immobilization was observed on the PHEMA homopolymer microspheres (180 mg/g). The plain and heparin‐immobilized microspheres were contacted with blood in in vitro systems and in ex vivo animal experiments. Loss of the blood cells and clotting times were followed. Anticoagulant effect of the immobilized heparin was clearly observed with blood coagulation experiments. Loss of cells in the blood contacting with heparin‐immobilized microspheres was significantly lower than those observed with the plain microspheres. Bovine serum albumin adsorption onto the microspheres containing heparin on their surfaces was also studied. High albumin adsorption values (up to 127 mg/g) were observed in which the heparin‐immobilized PHEMA microspheres were used. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 655–662, 1999     

Covalent immobilization of β‐galactosidase onto electrospun nanofibers of poly (AN‐co‐MMA) copolymer

Immobilization of β‐galactosidase in poly (acrylonitrile‐co‐methyl methacrylate) poly (AN‐co‐MMA) Nanofibers was studied by electrospinning, and a spacer‐arm i.e., (Polyethyleneimine (PEI)) was covalently attached by the reaction of carbonyl groups of Poly (AN‐co‐MMA) nanofibers. β‐galactosidase was then covalently immobilized through the spacer‐arm of the Poly (AN‐co‐MMA) nanofibers by using glutaraldehyde (GA) as a coupling agent. Nanofibers mode of interaction was proven by FTIR and thermal gravimetric analysis and supported by morphological changes recognized through SEM examination. Factors affecting the modification process such as PEI concentration, reaction time, and reaction temperature have been studied. Its influence on the amount of coupled PEI was consequently correlated to the changes of the catalytic activity and the retained activity of immobilized enzyme, the main parameters judging the success of the immobilization process. Evidences of Poly (AN‐co‐MMA) nanofibers modification were extracted from morphological changes recognized through SEM examination. The maximum activity (V_max) and michaelis constant (K_m) of immobilized enzyme were found to be 8.8 μmole/min mg protein and 236.7 mM, respectively. Stabilities of the immobilized β‐galactosidase were obviously improved. The optimum temperature for β‐galactosidase immobilized on the spacer‐arm attached nanofiber was 5°C higher than that of the free enzyme and was also significantly broader. The immobilized β‐galactosidase had better resistance to temperature inactivation than did the free form. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of the Human Milk Oligosaccharide Lacto‐N‐Tetraose in Metabolically Engineered,Plasmid‐Free E. coli

Human milk oligosaccharides (HMOs) constitute the third most abundant solid component of human milk. HMOs have been demonstrated to show positive effects on the infant’s well‐being. Despite numerous studies, more physiological analyses of single compounds are needed to fully elucidate these effects. Although being one of the most abundant core structures in human milk, the HMO lacto‐N‐tetraose (LNT) is not available at reasonable prices. In this study, we demonstrate the construction of the first E. coli strain capable of producing LNT in vivo. The strain was constructed by chromosomally integrating the genes lgtA and wbgO, encoding β‐1,3‐N‐acetylglucosaminyltransferase and β‐1,3‐galactosyltransferase. In shake‐flask cultivations, the strain yielded a total concentration of 219.1±3.5 mg L^?1 LNT (LNT in culture broth and the cell pellet). After recovery of LNT, structural analysis by NMR spectroscopy confirmed the molecule structure.     

Preparation and characterization of a temperature‐sensitive nonwoven poly(propylene) with increased affinity for guest molecules

A temperature‐sensitive hydrogel with the capability of inclusion complex formation with guest molecules was successfully grafted onto the surface of nonwoven polypropylene (nonwoven PP). This was carried out by the use of N‐isopropylacrylamide monomer and a modified cyclodextrin (acrylamidomethyl‐β‐cyclodextrin (β‐CD‐NMA)). Fourier‐transform infra red (FT‐IR) and elemental analyses confirmed the presence of poly(N‐isopropylacrylamide) (PNIPAAm) and β‐CD‐NMA components on the surface of the textile. Equilibrium swelling ratio measurements showed that the grafted hydrogel maintained its temperature‐sensitive property compared to a nongrafted hydrogel. The effect of β‐CD‐NMA and crosslink agent concentrations on the grafting yield was studied. The β‐CD‐NMA content into the PNIPPAM‐ β‐CD‐NMA grafted nonwoven PP (PNIPAAm‐β‐CD‐NMA‐PP) was estimated by FT‐IR through a new procedure. The estimated amounts of β‐CD‐NMA in PNIPAAm‐β‐CD‐NMA‐PP were determined to be 0.9, 1.9 mg g^?1 for 0.019M and 0.049M concentrations of β‐CD‐NMA in monomer solution, respectively. The PNIPAAm‐β‐CD‐NMA‐PP showed a remarkable increase in absorbance affinity of 8‐anilino‐1‐naphthalenesulfonic acid ammonium salt at 20°C from 0.93 to 3.33 µmol g^?1 compared to PNIPAAm‐PP. Furthermore, the results showed a temperature‐sensitive loading affinity for PNIPAAm‐β‐CD‐NMA‐PP in absorbance of guest molecules due to the presence of β‐CD‐NMA. The use of hydrophobic guest molecules such as fragrance oils and antibiotics in modified fabrics can provide new applications in textile and pharmaceutical industry. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40497.     

A Genetic Circuit System Based on Quorum Sensing Signaling for Directed Evolution of Quorum‐Quenching Enzymes

Quorum sensing is a cell–cell communication mechanism that is involved in the regulation of biological functions such as luminescence, virulence, and biofilm formation. Quorum‐quenching enzymes, which interrupt quorum‐sensing signaling through degradation of quorum‐sensing molecules, have emerged as a new approach to controlling and preventing bacterial virulence and pathogenesis. In an effort to develop quorum‐quenching enzymes with improved catalytic activities, a genetic circuit system based on acylhomoserine‐lactone (AHL)‐mediated quorum‐sensing signaling was constructed. The genetic circuit system was composed of lux‐R, lux‐I promoter, β‐lactamase, and β‐lactamase inhibitor, and designed to confer antibiotic resistance on host cells expressing an AHL‐degrading enzyme, thereby enabling rapid screening of quorum‐quenching enzymes. To demonstrate the utility of the genetic circuit system, we attempted the directed evolution of the AHL hydrolase from Bacillus sp. The genetic circuit system was shown to be effective in screening of quorum‐quenching enzymes with high catalytic efficiency. From these results it is expected that the genetic circuit system can be widely used for the isolation and directed evolution of quorum‐quenching enzymes with greater potential.     

Chitosan and chitosan/β‐cyclodextrin microspheres as sustained‐release drug carriers

The main aim of this study was to compare two microspheres, chitosan (CTS) and CTS/β‐cyclodextrin (β‐CD), made by spray‐drying, as pulmonary sustained drug‐delivery carriers. Theophylline (TH) was used as a model drug. The characteristics of the microspheres and in vitro release were studied. The yield of CTS/β‐CD microspheres was 46.1%, which was higher than that of the CTS microspheres (36.5%). The drug loads of the CTS and CTS/β‐CD microspheres were 22.7 and 21.1%, respectively, whereas the encapsulation efficiencies were 90.7 and 91.4%, respectively. The distribution of 50% [(diameter) d (0.5)] of the CTS microspheres was below 6.49 μm and that of the CTS/β‐CD microspheres was below 4.90 μm. Scanning electron microscopy showed that both microspheres yielded a spherical shape with smooth or wrinkled surfaces. Fourier transform infrared spectroscopy demonstrated that the carbonyl group of TH formed hydrogen bonds with the amide group of CTS and the hydroxyl group of β‐CD. The swelling ability of the two microspheres was more than three times their weight, and their humidity rates attained equilibrium within 24 h. The ciliary beat movement times of CTS and CTS/β‐CD microspheres were 493.00 and 512.33 min, respectively, which indicated that the two microspheres effectively reduced the ciliotoxicity and possessed better adaptability. In vitro release of TH from CTS/β‐CD microspheres was slower than that from CTS microspheres at pH 6.8 and provided a sustained release of 72.0% within 12 h. The results suggest that CTS/β‐CD microspheres are a promising carrier for sustained release for pulmonary delivery. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1183–1190, 2007     

Biodegradation of chlorophenols using the cell‐free culture broth of Phanerochaete chrysosporium immobilized in polyurethane foam

A cell‐free culture broth of Phanerochaete chrysosporium immobilized in polyurethane foam has been evaluated for the biodegradation of chlorophenols. Lignin peroxidase, manganese peroxidase, and oxalate concentrations in cell‐free culture broth were measured and compared to find the optimum combination of secondary metabolites for the highest biodegradation of chlorophenols. The isozyme distributions and their expression levels were significantly different and changed with increases in the culture time. The oxalate concentration was also found to vary, depending on culture time. Cell‐free broth containing an optimal combination of secondary metabolites showed the greatest biodegradation of 2,4,5‐chlorophenol in the presence of veratryl alcohol and H₂O₂. Phenols with greater numbers of chlorines were degraded more efficiently by this cell‐free culture broth according to the results of biodegradation experiments for five chlorophenols, including 2‐, 4‐, 2,4‐, 2,4,5‐, and pentachlorophenol, as well as phenol. This degradation efficiency correlated well with remaining lignin peroxidase activity during degradation. Cell‐free culture broths may readily be used for biodegradation of highly recalcitrant chemicals since the system would not be affected by the toxicity of the chemicals nor would the adsorption characteristics of the cells be of concern. © 2002 Society of Chemical Industry     

Synthesis of β‐cyclodextrin‐based dendrimer as a novel encapsulation agent

The aim was the fabrication of glycodendrimer encapsulation agents with high proportions of cyclodextrins (CDs) to maintain the biocompatibility properties, as well as to notably improve their ability to load various suitably sized drugs. The novel glycodendrimers contained β‐CD in both core and branches, namely β‐cyclodextrin‐based dendrimer (CD‐dendrimer) prepared through a straightforward procedure using S_N2 displacement to attach multivalent β‐CDs together. The desired CD‐dendrimer was synthesized in three steps: (i) reaction of β‐CD with p‐toluenesulfonyl chloride and/or iodine to afford C‐6 mono‐ and/or per‐β‐CD derivative; (ii) reaction of the β‐CD precursors with ethylenediamine to give C‐6 mono‐ and/or per‐amino‐β‐CD derivative; and (iii) S_N2 displacement of β‐CD electrophilic derivative with β‐CD nucleophilic derivative in dimethylsulfoxide to provide the CD‐dendrimer. Then, the encapsulation behaviour of the CD‐dendrimer was examined using naproxen and naltrexone as the guest molecules. The structure of the designed CD‐dendrimer allowed two types of possible sites for encapsulation of the guest: in cavities of the dendritic structure and in hydrophobic cavities of CDs. © 2013 Society of Chemical Industry     

Influence of polymer morphology on the adsorption behaviors of molecularly imprinted polymer‐methacrylic acid functionalized β‐cyclodextrin

The influence of molecularly imprinted polymer‐methacrylic acid functionalized β‐cyclodextrin (MIP(MAA‐β‐CD)) morphology on the adsorption behavior studies towards benzylparaben (BzP) was explored. The effects of time, concentration, and temperature towards BzP uptake were extensively evaluated. The adsorption performance of MIP(MAA‐β‐CD) was compared with that on the molecularly imprinted polymer‐methacrylic acid (MIP(MAA)) synthesized without β‐CD. The MIP(MAA‐β‐CD) was synthesized to obtain a spherical and spongy‐porous texture with a broad pore size distribution. The MIP(MAA‐β‐CD) showed fast kinetic and the intra‐particle diffusion model demonstrated a three step (surface and pore) adsorption process. The Koble‐Corrigan isotherm was the most suitable model for data fitting, which indicated that MIP(MAA‐β‐CD) had homogeneous and heterogeneous surfaces. This finding clearly demonstrated that the large uptake and strong affinity of MIP(MAA‐β‐CD) did not only probably result from the monomer‐template interactions, but also due to the morphological MIP(MAA‐β‐CD) structure. In contrary to MIP(MAA‐β‐CD), MIP(MAA) synthesized with uniform morphology and narrow pore size distribution had lower adsorption capacities and its kinetic data fitted the pseudo‐second order diffusion model, indicating a two‐step (surface only) adsorption process. The MIP(MAA) adsorption process followed the Langmuir isotherm model referred to solely homogeneous uptake. The calculated thermodynamic parameters showed that the BzP uptake was exothermic, spontaneous, and physisorption process onto MIPs, which supported the results of kinetics and isotherm adsorption data. This study clearly revealed that the presence of β‐CD improved the morphology of synthesized MIP, and automatically enhanced the adsorption behavior of MIP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42720.