Candida antarctica lipase B chemically immobilized on epoxy-activated micro- and nanobeads: catalysts for polyester synthesis.


:Candida antarctica Lipase B (CALB) was covalently immobilized onto epoxy-activated macroporous poly(methyl methacrylate) Amberzyme beads (235 microm particle size, 220 A pore size) and nanoparticles (nanoPSG, diameter 68 nm) with a poly(glycidyl methacrylate) outer region. Amberzyme beads allowed CALB loading up to 0.16 g of enzyme per gram of support. IR microspectroscopy generated images of Amberzyme-CALB beads showed CALB is localized within a 50 microm thick loading front. IR microspectroscopy images, recorded prior to and after treatment of Amberzyme-CALB with DMSO/aqueous Triton X-100, are similar, confirming that CALB is largely chemically linked to Amberzyme. The activity of CALB immobilized on Amberzyme, Lewatit (i.e., Novozym 435 catalyst), and nanoPSG was assessed for lactone ring-opening and step-condensation polymerizations. For example, the percent conversion of -caprolactone using the same amount of enzyme catalyzed by Amberzym-CALB, Novozym 435, and nanoPSG-CALB for 20 min was 7.0, 16, and 65%, respectively. Differences in CALB reactivity were discussed based on resin physical parameters and availability of active sites determined by active site titrations. Regardless of the matrix used and chemical versus physical immobilization, -CL ring-opening polymerizations occur by a chain growth mechanism without chain termination. To test Amberzyme-CALB stability, the catalyst was reused over three reaction cycles for -CL ring-opening polymerization (70 degrees C, 70 min reactions) and glycerol/1,8-octanediol/adipic acid polycondensation reactions (90 degrees C, 64 h). Amberzyme-CALB was found to have far better stability for reuse relative to Novozym 435 for the polycondensation reaction.






Chen B,Hu J,Miller EM,Xie W,Cai M,Gross RA




Has Abstract


2008-02-01 00:00:00












  • Solid-state NMR analysis of a peptide (Gly-Pro-Gly-Gly-Ala)6-Gly derived from a flagelliform silk sequence of Nephila clavipes.

    abstract::Solid-state NMR is especially useful when the structures of peptides and proteins should be analyzed by taking into account the structural distribution, that is, the distribution of the torsion angle of the individual residue. In this study, two-dimensional spin-diffusion solid-state NMR spectra of 13C-double-labeled ...


    pub_type: 杂志文章


    authors: Ohgo K,Kawase T,Ashida J,Asakura T

    更新日期:2006-04-01 00:00:00

  • Langmuir and Langmuir-Blodgett films of organophosphorus acid anhydrolase.

    abstract::In this paper, we describe the preparation and characterization of Langmuir and Langmuir-Blodgett (LB) monolayers of the enzyme organophosphorus acid anhydrolase (OPAA). Langmuir films of OPAA were characterized on different subphases, such as phosphate, ammonium carbonate, and bis-tris-propane buffers. Monolayers at ...


    pub_type: 杂志文章


    authors: Mello SV,Mabrouki M,Cao X,Leblanc RM,Cheng TC,DeFrank JJ

    更新日期:2003-07-01 00:00:00

  • Antibiofilm Synergy of β-Lactams and Branched Polyethylenimine against Methicillin-Resistant Staphylococcus epidermidis.

    abstract::Microbial biofilms are ubiquitous in nature, and they pose a serious threat to public health. Staphylococcus epidermidis is the most common clinical isolate from healthcare- and medical device-related biofilm infections. No antibiotic currently on the market can eradicate pathogenic biofilms, which contain complex def...


    pub_type: 杂志文章


    authors: Lam AK,Wouters CL,Moen EL,Pusavat J,Rice CV

    更新日期:2019-10-14 00:00:00

  • Highly filled bionanocomposites from functionalized polysaccharide nanocrystals.

    abstract::Cellulose and starch nanocrystals obtained from the acid hydrolysis of ramie fibers and waxy maize starch granules, respectively, were subjected to isocyanate-mediated reaction to graft polycaprolactone (PCL) chains with various molecular weights on their surface. Grafted nanoparticles were characterized by X-ray diff...


    pub_type: 杂志文章


    authors: Habibi Y,Dufresne A

    更新日期:2008-07-01 00:00:00

  • Bioinspired pH- and Temperature-Responsive Injectable Adhesive Hydrogels with Polyplexes Promotes Skin Wound Healing.

    abstract::Despite great potential, the delivery of genetic materials into cells or tissues of interest remains challenging owing to their susceptibility to nuclease degradation, lack of permeability to the cell membrane, and short in vivo half-life, which severely restrict their widespread use in therapeutics. To surmount these...


    pub_type: 杂志文章


    authors: Le TMD,Duong HTT,Thambi T,Giang Phan VH,Jeong JH,Lee DS

    更新日期:2018-08-13 00:00:00

  • Altering peptide fibrillization by polymer conjugation.

    abstract::A strategy is presented that exploits the ability of synthetic polymers of different nature to disturb the strong self-assembly capabilities of amyloid based β-sheet forming peptides. Following a convergent approach, the peptides of interest were synthesized via solid-phase peptide synthesis (SPPS) and the polymers vi...


    pub_type: 杂志文章


    authors: Dehn S,Castelletto V,Hamley IW,Perrier S

    更新日期:2012-09-10 00:00:00

  • Metastability of nematic gels made of aqueous chitin nanocrystal dispersions.

    abstract::Chitin nanocrystal aqueous dispersions were prepared by acid hydrolysis of crude chitin from crab shells. The resulting dispersions were studied with small deformation oscillatory experiments and polarized optical microscopy under different conditions of nanocrystal concentration, ionic strength, pH, and temperature. ...


    pub_type: 杂志文章


    authors: Tzoumaki MV,Moschakis T,Biliaderis CG

    更新日期:2010-01-11 00:00:00

  • pH-responsive polymeric micelle carriers for siRNA drugs.

    abstract::The ability of small interfering RNA (siRNA) to efficiently silence the expression of specific genes provides the basis for exciting new therapies based on RNA interference (RNAi). The efficient intracellular delivery of siRNA from cell uptake through the endosomal trafficking pathways into the cytoplasm remains a sig...


    pub_type: 杂志文章


    authors: Convertine AJ,Diab C,Prieve M,Paschal A,Hoffman AS,Johnson PH,Stayton PS

    更新日期:2010-11-08 00:00:00

  • Polymeric surfactants based on inulin, a polysaccharide extracted from chicory. 1. Synthesis and interfacial properties.

    abstract::Inulin, the polydisperse reserve polysaccharide from chicory, has been modified by carbamoylation in organic solvents. The reaction of inulin with a range of alkyl isocyanates resulted, after crystalization, in a variety of carbamoylated inulins from which the interfacial properties were determined. The medium and lon...


    pub_type: 杂志文章


    authors: Stevens CV,Meriggi A,Peristeropoulou M,Christov PP,Booten K,Levecke B,Vandamme A,Pittevils N,Tadros TF

    更新日期:2001-01-01 00:00:00

  • Nature of Amorphous Hydrophilic Block Affects Self-Assembly of an Artificial Viral Coat Polypeptide.

    abstract::Consensus motifs for sequences of both crystallizable and amorphous blocks in silks and natural structural analogues of silks vary widely. To design novel silklike polypeptides, an important question is therefore how the nature of either the crystallizable or the amorphous block affects the self-assembly and resulting...


    pub_type: 杂志文章


    authors: Willems L,van Westerveld L,Roberts S,Weitzhandler I,Calcines Cruz C,Hernandez-Garcia A,Chilkoti A,Mastrobattista E,van der Oost J,de Vries R

    更新日期:2019-10-14 00:00:00

  • Readily controllable step-growth polymerization method for poly(lactic acid) copolymers having a high glass transition temperature.

    abstract::Poly(lactic acid) (PLA) copolymers having a significantly higher glass transition temperature (T(g)) than that of high molar mass PLA homopolymers (typically 60 +/- 5 degrees C) were prepared. Lactic acid was copolymerized with 1,4:3,6-dianhydro-D-glucitol (isosorbide, ISB) and succinic acid (SA-2), 1,2,3,4-butanetetr...


    pub_type: 杂志文章


    authors: Inkinen S,Stolt M,Södergård A

    更新日期:2010-05-10 00:00:00

  • Structure analysis of an amyloid-forming model peptide by a systematic glycine and proline scan.

    abstract::The ability to adopt at least two different stable conformations is a common feature of proteins involved in many neurodegenerative diseases. The involved molecules undergo a conformational transition from native, mainly helical states to insoluble amyloid structures that have high β-sheet content. A detailed characte...


    pub_type: 杂志文章


    authors: Gerling UI,Brandenburg E,von Berlepsch H,Pagel K,Koksch B

    更新日期:2011-08-08 00:00:00

  • Structure-activity relationships of antibacterial and biocompatible copolymers.

    abstract::The development of polymers that are both bactericidal and biocompatible would have many applications and are currently of research interest. Following the development of strongly bactericidal copolymers of 4-vinylpyridine and poly(ethylene glycol) methyl ether methacrylate, biocompatibility assays have been completed...


    pub_type: 杂志文章


    authors: Stratton TR,Howarter JA,Allison BC,Applegate BM,Youngblood JP

    更新日期:2010-05-10 00:00:00

  • Ferulic Acid-Based Polymers with Glycol Functionality as a Versatile Platform for Topical Applications.

    abstract::Ferulic acid-based polymers with aliphatic linkages have been previously synthesized via solution polymerization methods, yet they feature relatively slow ferulic acid release rates (∼11 months to 100% completion). To achieve a more rapid release rate as required in skin care formulations, ferulic acid-based polymers ...


    pub_type: 杂志文章


    authors: Ouimet MA,Faig JJ,Yu W,Uhrich KE

    更新日期:2015-09-14 00:00:00

  • Porosity-Tuned Chitosan-Polyacrylamide Hydrogel Microspheres for Improved Protein Conjugation.

    abstract::We report a robust method to manufacture polyacrylamide-based functional hydrogel microspheres with readily tunable macroporous structures by utilizing a simple micromolding-based technique. Specifically, surface tension-induced droplet formation of aqueous solutions of chitosan and acrylamide in 2D-shaped micromolds ...


    pub_type: 杂志文章


    authors: Jung S,Abel JH,Starger JL,Yi H

    更新日期:2016-07-11 00:00:00

  • Hydrogels for osteochondral repair based on photocrosslinkable carbamate dendrimers.

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    pub_type: 杂志文章


    authors: Degoricija L,Bansal PN,Söntjens SH,Joshi NS,Takahashi M,Snyder B,Grinstaff MW

    更新日期:2008-10-01 00:00:00

  • Pectic polysaccharides from Panax ginseng as the antirotavirus principals in ginseng.

    abstract::To evaluate the antidiarrheal effect of ginseng, the active principals of ginseng were studied in vitro model of rotavirus infection, the leading cause of severe diarrhea. Two pectic polysaccharides, named as GP50-dHR (56.0 kDa) and GP50-eHR (77.0 kDa), were purified from hot water extract of ginseng by bioassay-linke...


    pub_type: 杂志文章


    authors: Baek SH,Lee JG,Park SY,Bae ON,Kim DH,Park JH

    更新日期:2010-08-09 00:00:00

  • A Universal Approach to Render Nanomedicine with Biological Identity Derived from Cell Membranes.

    abstract::Biomimetic nanoengineering built through integrating the specific cell membrane with artificially synthetic nanomedicines represents one of the most promising directions for the actualization of personalized therapy. For addressing the technical hurdle against the development of this biomimetic technology, the present...


    pub_type: 杂志文章


    authors: Zhu J,Zhang M,Zheng D,Hong S,Feng J,Zhang XZ

    更新日期:2018-06-11 00:00:00

  • Characterization of the rheological, mucoadhesive, and drug release properties of highly structured gel platforms for intravaginal drug delivery.

    abstract::This investigation describes the formulation and characterization of rheologically structured vehicles (RSVs) designed for improved drug delivery to the vagina. Interactive, multicomponent, polymeric platforms were manufactured containing hydroxyethylcellulose (HEC, 5% w/w) polyvinylpyrrolidone (PVP, 4% w/w), Pluronic...


    pub_type: 杂志文章


    authors: Andrews GP,Donnelly L,Jones DS,Curran RM,Morrow RJ,Woolfson AD,Malcolm RK

    更新日期:2009-09-14 00:00:00

  • Conformational preferences of the O-antigen polysaccharides of Escherichia coli O5ac and O5ab using NMR spectroscopy and molecular modeling.

    abstract::Escherichia coli serogroup O5 comprises two different subgroups (O5ab and O5ac), which are indiscernible from the point of view of standard immunological serotyping. The structural similarities between the O-antigen polysaccharides (PSs) of these two strains are remarkable, with the only difference being the glycosidi...


    pub_type: 杂志文章


    authors: Sarkar A,Fontana C,Imberty A,Pérez S,Widmalm G

    更新日期:2013-07-08 00:00:00

  • Bottom-up synthesis of hyaluronan and its derivatives via enzymatic polymerization: direct incorporation of an amido functional group.

    abstract::This paper reports the synthesis of hyaluronan (HA) and its derivatives via the hyaluronidase-catalyzed polymerization of 2-substituted oxazoline derivative monomers designed as "transition-state analogue substrates". Polymerization of 2-methyl oxazoline monomer from N-acetylhyalobiuronate (GlcAbeta(1-->3)GlcNAc) effe...


    pub_type: 杂志文章


    authors: Ochiai H,Ohmae M,Mori T,Kobayashi S

    更新日期:2005-03-01 00:00:00

  • Structural studies of an exopolysaccharide produced by Streptococcus thermophilus THS.

    abstract::The structure of an extracellular polysaccharide (EPS) from Streptococcus thermophilus THS has been determined. A combination of component analysis, methylation analysis and NMR spectroscopy shows that the polysaccharide is composed of pentasaccharide repeating units. Sequential information was obtained by two-dimensi...


    pub_type: 杂志文章


    authors: Nordmark EL,Yang Z,Huttunen E,Widmalm G

    更新日期:2005-01-01 00:00:00

  • Grafting of oligosaccharides onto synthetic polymer colloids.

    abstract::A new method to form colloidally stable oligosaccharide-grafted synthetic polymer particles has been developed. The oligosaccharides, of weight-average degree of polymerization approximately 38, were obtained by enzymatic debranching of amylopectin. Through the use of a cerium(IV)-based redox initiation process, oligo...


    pub_type: 杂志文章


    authors: Mange S,Dever C,De Bruyn H,Gaborieau M,Castignolles P,Gilbert RG

    更新日期:2007-06-01 00:00:00

  • Effect of the head-group geometry of amino acid-based cationic surfactants on interaction with plasmid DNA.

    abstract::The interaction between DNA and different types of amino acid-based cationic surfactants was investigated. Particular attention was directed to determine the extent of influence of surfactant head-group geometry toward tuning the interaction behavior of these surfactants with DNA. An overview is obtained by gel retard...


    pub_type: 杂志文章


    authors: Jadhav V,Maiti S,Dasgupta A,Das PK,Dias RS,Miguel MG,Lindman B

    更新日期:2008-07-01 00:00:00

  • Copolymerization of 2-carboxyisopropylacrylamide with N-isopropylacrylamide accelerates cell detachment from grafted surfaces by reducing temperature.

    abstract::Acrylic acid (AAc) has been utilized to introduce reactive carboxyl groups to a temperature-responsive polymer, poly(N-isopropylacrylamide) (PIPAAm). However, AAc introduction shifts the copolymer phase transition temperatures higher and dampens the steep homopolymer phase transition with increasing AAc content. We pr...


    pub_type: 杂志文章


    authors: Ebara M,Yamato M,Hirose M,Aoyagi T,Kikuchi A,Sakai K,Okano T

    更新日期:2003-03-01 00:00:00

  • Type, density, and presentation of grafted adhesion peptides on polysaccharide-based hydrogels control preosteoblast behavior and differentiation.

    abstract::In this work, cell-responsive polysaccharide hydrogels were prepared by a simple procedure based on the sequential bioconjugation and cross-linking of the polysaccharide backbone with bioactive peptides and poly(ethylene glycol)-bis(thiol) (PEG-(SH)2), respectively. Using thiol-ene reactions, we successfully functiona...


    pub_type: 杂志文章


    authors: Jing J,Fournier A,Szarpak-Jankowska A,Block MR,Auzély-Velty R

    更新日期:2015-03-09 00:00:00

  • Contrasting biofunctionalization strategies for the enhanced endothelialization of biodegradable vascular grafts.

    abstract::Surface modification of biodegradable vascular grafts is an important strategy to improve the in situ endothelialization of tissue engineered vascular grafts (TEVGs) and prevent major complications associated with current synthetic grafts. Important strategies for improving endothelialization include increasing endoth...


    pub_type: 杂志文章


    authors: Melchiorri AJ,Hibino N,Yi T,Lee YU,Sugiura T,Tara S,Shinoka T,Breuer C,Fisher JP

    更新日期:2015-02-09 00:00:00

  • Multiblock copolymers of L-lactide and trimethylene carbonate.

    abstract::Sequential copolymerizations of trimethylene carbonate (TMC) and l-lactide (LLA) were performed with 2,2-dibutyl-2-stanna-1,3-oxepane as a bifunctional cyclic initiator. The block lengths were varied via the monomer/initiator and via the TMC/l-lactide ratio. The cyclic triblock copolymers were transformed in situ into...


    pub_type: 杂志文章


    authors: Pospiech D,Komber H,Jehnichen D,Häussler L,Eckstein K,Scheibner H,Janke A,Kricheldorf HR,Petermann O

    更新日期:2005-01-01 00:00:00

  • Polygalactose containing nanocages: the RAFT process for the synthesis of hollow sugar balls.

    abstract::Hollow poly(6-O-acryloyl-alpha-D-galactopyranose) (PAGP) nanospheres were prepared in a facile manner using the RAFT (reversible addition fragmentation chain transfer) process. Initially, an amphiphilic block copolymer, poly(lactide)-block-poly(6-O-acryloyl-alpha-D-galactopyranose) (PLA-b-PAGP), was synthesized using ...


    pub_type: 杂志文章


    authors: Ting SR,Gregory AM,Stenzel MH

    更新日期:2009-02-09 00:00:00

  • Double-Network Hydrogels Including Enzymatically Crosslinked Poly-(2-alkyl-2-oxazoline)s for 3D Bioprinting of Cartilage-Engineering Constructs.

    abstract::Double-network (DN) hydrogels are fabricated from poly(2-ethyl-2-oxazoline) (PEOXA)-peptide conjugates, which can be enzymatically crosslinked in the presence of Sortase A (SA), and physical networks of alginate (Alg), yielding matrices with improved mechanical properties with respect to the corresponding PEOXA and Al...


    pub_type: 杂志文章


    authors: Trachsel L,Johnbosco C,Lang T,Benetti EM,Zenobi-Wong M

    更新日期:2019-12-09 00:00:00