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Enzyme hydrogel

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https://www.readbyqxmd.com/read/28087273/chitosan-cross-linked-with-poly-ethylene-glycol-dialdehyde-via-reductive-amination-as-effective-controlled-release-carriers-for-oral-protein-drug-delivery
#1
Zi-Wei Jing, Zhi-Wei Ma, Chen Li, Yi-Yang Jia, Min Luo, Xi-Xi Ma, Si-Yuan Zhou, Bang-Le Zhang
The covalently cross-linked chitosan-poly(ethylene glycol)1540 derivatives have been developed as a controlled release system with potential for the delivery of protein drug. The swelling characteristics of the hydrogels based on these derivatives as the function of different PEG content and the release profiles of a model protein (bovine serum albumin, BSA) from the hydrogels were evaluated in simulated gastric fluid with or without enzyme in order to simulate the gastrointestinal tract conditions. The derivatives cross-linked with difunctional PEG1540-dialdehyde via reductive amination can swell in alkaline pH and remain insoluble in acidic medium...
December 31, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28074904/gd-iii-induced-supramolecular-hydrogelation-with-enhanced-magnetic-resonance-performance-for-enzyme-detection
#2
Yongquan Hua, Guojuan Pu, Caiwen Ou, Xiaoli Zhang, Ling Wang, Jiangtao Sun, Zhimou Yang, Minsheng Chen
Here we report a supramolecular hydrogel based on Gd(III)-peptide complexes with dramatically enhanced magnetic resonance (MR) performance. The hydrogelations were formed by adding Gd(III) ion to the nanofiber dispersion of self-assembling peptides naphthalene-Gly-Phe-Phe-Tyr-Gly-Arg-Gly-Asp (Nap-GFFYGRGD) or naphthalene-Gly-Phe-Phe-Tyr-Gly-Arg-Gly-Glu (Nap-GFFYGRGE). We further showed that, by adjusting the molar ratio between Gd(III) and the corresponding peptide, the mechanical property of resulting gels could be fine-tuned...
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28071851/preprogramming-complex-hydrogel-responses-using-enzymatic-reaction-networks
#3
Sjoerd G J Postma, Ilia N Vialshin, Casper Y Gerritsen, Min Bao, Wilhelm T S Huck
The creation of adaptive matter is heavily inspired by biological systems. However, it remains challenging to design complex material responses that are governed by reaction networks, which lie at the heart of cellular complexity. The main reason for this slow progress is the lack of a general strategy to integrate reaction networks with materials. Herein we use a systematic approach to preprogram the response of a hydrogel to a trigger, in this case the enzyme trypsin, which activates a reaction network embedded within the hydrogel...
January 10, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28064496/alkaline-phosphatase-triggered-simultaneous-hydrogelation-and-chemiluminescence
#4
Zijuan Hai, Jindan Li, Jingjing Wu, Jiacheng Xu, Gaolin Liang
Chemiluminescence (CL) has a higher signal-to-noise ratio than fluorescence, but the use of CL to track an enzyme-instructed self-assembly (EISA) process has not been reported. In this work, by coincubation of the hydrogelator precursor Fmoc-Phe-Phe-Tyr(H2PO3)-OH (1P) and the CL agent AMPPD (2) with alkaline phosphatase (ALP), we employed CL to directly characterize and image the simultaneous EISA process of 1P. Hydrogelation processes of 1P with and without 2 and the CL properties of 2 with and without 1P under ALP catalysis were systematically studied...
January 11, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28064043/conductive-hydrogel-composed-of-1-3-5-benzenetricarboxylic-acid-and-fe-3-used-as-enhanced-electrochemical-immunosensing-substrate-for-tumor-biomarker
#5
Huiqiang Wang, Hongliang Han, Zhanfang Ma
In this work, a new conductive hydrogel was prepared by a simple cross-linking coordination method using 1,3,5-benzenetricarboxylic acid as the ligand and Fe(3+) as the metal ion. The hydrogel film was formed on a glassy carbon electrode (GCE) by a drop coating method, which can dramatically facilitate the transport of electrons. A sensitive label-free electrochemical immunosensor was fabricated following electrodeposition of gold nanoparticles (AuNPs) on a hydrogel film and immobilization of an antibody. Neuron-specific enolase (NSE), a lung cancer biomarker, was used as the model analyte to be detected...
December 30, 2016: Bioelectrochemistry
https://www.readbyqxmd.com/read/28063388/nanostructured-biosensor-for-detecting-glucose-in-tear-by-applying-fluorescence-resonance-energy-transfer-quenching-mechanism
#6
Longyi Chen, Wai Hei Tse, Yi Chen, Matthew W McDonald, James Melling, Jin Zhang
In this paper, a nanostructured biosensor is developed to detect glucose in tear by using fluorescence resonance energy transfer (FRET) quenching mechanism. The designed FRET pair, including the donor, CdSe/ZnS quantum dots (QDs), and the acceptor, dextran-binding malachite green (MG-dextran), was conjugated to concanavalin A (Con A), an enzyme with specific affinity to glucose. In the presence of glucose, the quenched emission of QDs through the FRET mechanism is restored by displacing the dextran from Con A...
December 23, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28054768/remote-controlling-dna-hydrogel-by-magnetic-field
#7
Xiaozhou Ma, Zhongqiang Yang, Yijie Wang, Guoliang Zhang, Yu Shao, Haoyang Jia, Tianyang Cao, Rui Wang, Dongsheng Liu
DNA hydrogel has aroused widespread attentions due to its unique properties. In this work, the DNA modified magnetic nanoparticles were integrated into the mainframe of DNA hydrogel, resulting in DNA-MNP hydrogel. Under the magnetic field, this hydrogel can be remotely deformed into various shapes, driven to jump between two planes and even climb the hill. By applying various triggers, such as temperature, enzyme and magnetic field, DNA-MNP hydrogel can specifically undergo sol-gel transition. This work not only imparts DNA hydrogel with a new fold of property but also opens a unique platform of such smart materials for its further applications...
January 5, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28040649/acetyl-coa-production-by-encapsulated-pyruvate-ferredoxin-oxidoreductase-in-alginate-hydrogels
#8
Makoto Takenaka, Ki-Seok Yoon, Takahiro Matsumoto, Seiji Ogo
Pyruvate ferredoxin oxidoreductase from Citrobacter sp. S-77 (PFORS77) was purified in order to develop a method for acetyl-CoA production. Although the purified PFORS77 showed high O2-sensitivity, the activity could be remarkably stabilized in anaerobic conditions. PFORS77 was effectively immobilized on ceramic hydroxyapatite (PFORS77-HA) with an efficiency of more than 96%, however, after encapsulation of PFORS77-HA in alginate, the rate of catalytic acetyl-CoA production was highly reduced to 36% when compared to that of the free enzyme...
March 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28034309/designing-biopolymer-microgels-to-encapsulate-protect-and-deliver-bioactive-components-physicochemical-aspects
#9
REVIEW
David Julian McClements
Biopolymer microgels have considerable potential for their ability to encapsulate, protect, and release bioactive components. Biopolymer microgels are small particles (typically 100nm to 1000μm) whose interior consists of a three-dimensional network of cross-linked biopolymer molecules that traps a considerable amount of solvent. This type of particle is also sometimes referred to as a nanogel, hydrogel bead, biopolymer particles, or microsphere. Biopolymer microgels are typically prepared using a two-step process involving particle formation and particle gelation...
December 16, 2016: Advances in Colloid and Interface Science
https://www.readbyqxmd.com/read/28024532/-aerogels-of-enzymatically-oxidized-galactomannans-from-leguminous-plants-versatile-delivery-systems-of-antimicrobial-peptides-and-enzymes
#10
Paola Campia, Erika Ponzini, Bianca Rossi, Stefano Farris, Tiziana Silvetti, Luca Merlini, Milena Brasca, Rita Grandori, Yves M Galante
We describe aerogels obtained by laccase/TEMPO-oxidation and lyophilization of galactomannans (GM) from fenugreek, sesbania and guar. Enzymatic oxidation of GM in aqueous solution caused viscosity increase up to fifteen-fold, generating structured, elastic, stable hydrogels, presumably due to establishment of hemiacetalic bonds between newly formed carbonyl groups and free hydroxyl groups. Upon lyophilization, water-insoluble aerogels were obtained, whose mechanical properties and porosity were investigated...
February 20, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/27997114/low-molecular-weight-hydrogels-as-new-supramolecular-materials-for-bioelectrochemical-interfaces
#11
Deepak Jain, Aleksandar Karajic, Magdalena Murawska, Bertrand Goudeau, Sabrina Bichon, Sébastien Gounel, Nicolas Mano, Alexander Kuhn, Philippe Barthélémy
Controlling the interface between biological tissues and electrodes remains an important challenge for the development of implantable devices in terms of electroactivity, biocompatibility, and long-term stability. To engineer such a biocompatible interface a low molecular weight gel (LMWG) based on a glycosylated nucleoside fluorocarbon amphiphile (GNF) was employed for the first time to wrap gold electrodes via a noncovalent anchoring strategy, that is, self-assembly of GNF at the electrode surface. Scanning electron microscopy (SEM) studies indicate that the gold surface is coated with the GNF hydrogels...
December 20, 2016: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/27960405/improving-antiadhesion-effect-of-thermosensitive-hydrogel-with-sustained-release-of-tissue-type-plasminogen-activator-in-a-rat-repeated-injury-model
#12
Tao He, Chang Zou, Linjiang Song, Ning Wang, Suleixin Yang, Yan Zeng, Qinjie Wu, Wenli Zhang, Yingtai Chen, Changyang Gong
Intraperitoneal adhesion occurs frequently after pelvic and abdominal surgery, which plays an enormous burden on patients. Various drugs and barrier agents were studied and used to prevent adhesions, but few of them were satisfactory. A thermosensitive hydrogel was developed in our previous work and was effective in preventing adhesions. But in our preliminary experiment, it showed limited activity in a more rigorous rat repeated-injury adhesion model, which was much closer to clinical. In this study, tissue-type plasminogen activator (tPA) loaded thermosensitive hydrogel (tPA-hydrogel) was prepared, which combined barrier functions with sustained release of antiadhesion drug...
December 14, 2016: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/27960396/neovascularization-induced-by-the-hyaluronic-acid-based-spongy-like-hydrogels-degradation-products
#13
Lucília P da Silva, Rogério P Pirraco, Tírcia C Santos, Ramon Novoa-Carballal, Mariana T Cerqueira, Rui L Reis, Vitor M Correlo, Alexandra P Marques
Neovascularization has been a major challenge in many tissue regeneration strategies. Hyaluronic acid (HA) of 3-25 disaccharides is known to be angiogenic due to its interaction with endothelial cell receptors. This effect has been explored with HA-based structures but a transitory response is observed due to HA burst biodegradation. Herein we developed gellan gum (GG)-HA spongy-like hydrogels from semi-interpenetrating network hydrogels with different HA amounts. Enzymatic degradation was more evident in the GG-HA with high HA amount due to their lower mechanical stability, also resulting from the degradation itself, which facilitated the access of the enzyme to the HA in the bulk...
December 14, 2016: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/27942755/tyramine-modified-pectins-via-periodate-oxidation-for-soybean-hull-peroxidase-induced-hydrogel-formation-and-immobilization
#14
Milos Prokopijevic, Olivera Prodanovic, Dragica Spasojevic, Gordana Kovacevic, Natalija Polovic, Ksenija Radotic, Radivoje Prodanovic
Pectin was modified by oxidation with sodium periodate at molar ratios of 2.5, 5, 10, 15 and 20 mol% and reductive amination with tyramine and sodium cyanoborohydride afterwards. Concentration of tyramine groups within modified pectin ranged from 54.5 to 538 μmol/g of dry pectin while concentration of ionizable groups ranged from 3.0 to 4.0 mmol/g of dry polymer compared to 1.5 mmol/g before modification due to the introduction of amino group. All tyramine-pectins showed exceptional gelling properties and could form hydrogel both by cross-linking of carboxyl groups with calcium or by cross-linking phenol groups with peroxidase in the presence of hydrogen peroxide...
December 9, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27936722/modular-and-adaptable-tumor-niche-prepared-from-visible-light-initiated-thiol-norbornene-photopolymerization
#15
Han Shih, Tanja Greene, Murray Korc, Chien-Chi Lin
Photopolymerized biomimetic hydrogels with adaptable properties have been widely used for cell and tissue engineering applications. As a widely adopted gel cross-linking method, photopolymerization provides experimenters on-demand and spatial-temporal controls in gelation kinetics. Long wavelength ultraviolet (UV) light initiated photopolymerization is among the most popular methods in the fabrication of cell-laden hydrogels owing to its rapid and relatively mild gelation conditions. The use of UV light, however, still causes concerns regarding its potential negative impacts on cells...
December 12, 2016: Biomacromolecules
https://www.readbyqxmd.com/read/27933762/nanocomputed-tomography-imaging-of-bacterial-alkaline-phosphatase-activity-with-an-iodinated-hydrogelator
#16
Zhen Zheng, Anming Tang, Yong Guan, Liang Chen, Fuqiang Wang, Peiyao Chen, Weijuan Wang, Yufeng Luo, Yangchao Tian, Gaolin Liang
Alkaline phosphatase (ALP) is an important enzyme, but direct imaging of ALP activity with high spatiotemporal resolution remains challenging. In this work, we rationally designed an iodinated hydrogelator precursor Nap-Phe-Phe(I)-Tyr(H2PO3)-OH (1P) which self-assembles into nanofibers to form hydrogel under the catalysis of ALP. With this property of concentrating iodine atoms at the locations of ALP, 1P was successfully applied for direct nanocomputed tomography (nano-CT) imaging of ALP activity in bacteria for the first time...
December 9, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27924631/cardioprotective-effects-of-curcumin-loaded-magnetic-hydrogel-nanocomposite-nanocurcumin-against-doxorubicin-induced-cardiac-toxicity-in-rat-cardiomyocyte-cell-lines
#17
Mehrdad Namdari, Ali Eatemadi
Curcumin, is a yellow substance extracted from Curcuma longa rhizomes, it is a crystalline compound that has been traditionally applied in culinary practices and medicines in India. The aim of our study is to demonstrate the efficacy of curcumin-loaded magnetic hydrogel nanocomposite in the treatment of heart hypertrophy. 10 rats weighing 150-200 g each were induced with heart failure using 2.5 mg/kg doxorubicin for 2 weeks. The test groups were treated with curcumin-loaded magnetic hydrogel nanocomposite while the control was treated with curcumin alone...
December 7, 2016: Artificial Cells, Nanomedicine, and Biotechnology
https://www.readbyqxmd.com/read/27919839/heparin-hyaluronic-acid-hydrogel-for-efficient-cellular-activities-of-3d-encapsulated-adipose-derived-stem-cells
#18
Kihak Gwon, Eunsol Kim, Giyoong Tae
: We have developed stem cell-responsive, heparin-hyaluronic acid (Hep-HA) hydrogel, crosslinked by thiolated heparin (Hep-SH) and methacrylated hyaluronic acid (HA-MA) via visible light mediated, thiol-ene reaction. Physical properties of the hydrogel (gelation time, storage modulus, and swelling ratio) were tunable by adjusting light intensity, initiator/polymer concentration, and precursor pH. Culture of human adipose derived mesenchymal stem cells (ADSCs) using this hydrogel was characterized and compared with the control hydrogels including Hep-PEG hydrogel, PEG-HA hydrogel...
December 5, 2016: Acta Biomaterialia
https://www.readbyqxmd.com/read/27904965/chitosan-hydrogel-microspheres-an-effective-covalent-matrix-for-crosslinking-of-soluble-dextranase-to-increase-stability-and-recycling-efficiency
#19
Faiza Shahid, Afsheen Aman, Muhammad Asif Nawaz, Asad Karim, Shah Ali Ul Qader
Dextranase is a unique biocatalyst that has high specificity and stereo-selectivity towards a complex biopolymer known as dextran. Dextranase has wide industrial application, but most of the time harsh environmental conditions adversely affect the functionality and stability of the enzyme. To overcome this issue, a covalent cross-linking immobilization method was adapted in the current study utilizing a nontoxic and biocompatible matrix known as chitosan. Chitosan hydrogel microspheres were synthesized using chitosan which exhibited noteworthy physical and mechanical strength...
November 30, 2016: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/27863665/biodegradable-hydrophilic-carriers-for-the-oral-delivery-of-hematological-factor-ix-for-hemophilia-b-treatment
#20
Sarena D Horava, Katie J Moy, Nicholas A Peppas
Current protein replacement therapies for hemophilia B, a genetic bleeding disorder caused by a deficiency in coagulation factor IX, rely on IV injections and infusions. Oral delivery of factor IX is a desirable needle-free option, especially for prophylaxis. We have developed a biodegradable, pH-responsive hydrogel microcarrier system based on the poly(methacrylic acid)-grafted-poly(ethylene glycol) [P(MAA-g-EG)]. Incorporation of an enzymatically degradable peptide crosslinking agent allows for site-specific degradation by trypsin in the small intestine...
November 30, 2016: International Journal of Pharmaceutics
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