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Enzyme hydrogel

Dong Wang, Yue Hu, Peifeng Liu, Dan Luo
Bioresponsive hydrogels can respond to various biological stimuli by a macroscopic change of physical state or by converting biochemical inputs into biological or mechanical outputs. These materials are playing an increasingly important role in a wide variety of applications, especially in the biological and biomedical fields. However, the design and engineering of intriguing bioresponsive materials with adequate biocompatibility and biodegradability have proven to be a great challenge. DNA, on the other hand, possesses many unique and fascinating properties, including its indispensable genetic function, broad biocompatibility, precise molecular recognition capability, tunable multifunctionality, and convenient programmability...
February 10, 2017: Accounts of Chemical Research
Heidi R Culver, John R Clegg, Nicholas A Peppas
Nature has mastered the art of molecular recognition. For example, using synergistic non-covalent interactions, proteins can distinguish between molecules and bind a partner with incredible affinity and specificity. Scientists have developed, and continue to develop, techniques to investigate and better understand molecular recognition. As a consequence, analyte-responsive hydrogels that mimic these recognitive processes have emerged as a class of intelligent materials. These materials are unique not only in the type of analyte to which they respond but also in how molecular recognition is achieved and how the hydrogel responds to the analyte...
February 7, 2017: Accounts of Chemical Research
Gang Yang, Zhenghua Xiao, Xiaomei Ren, Haiyan Long, Kunlong Ma, Hong Qian, Yingqiang Guo
Heart failure often develops after acute myocardial infarction because the injured myocardial tissue fails to recover or regenerate. Stem cell transplantation using adult cell sources, such as adipose-derived stromal vascular fraction (SVF), draws extensive attention. In this study, SVF cells were isolated from rat adipose tissue and cultivated on enzyme-crosslinked gelatin hydrogels. Morphological features of cell development and spontaneous beating behavior from these cells were observed and recorded. Cardiac phenotypes were characterized via immunofluorescence staining, and the expression of cardiac-specific genes was measured via RT-PCR...
February 3, 2017: Scientific Reports
Rui Qu, Hejin Shi, Ruolin Wang, Tangjian Cheng, Rujiang Ma, Yingli An, Linqi Shi
Artificial enzymes are widely investigated to mimic the active center and the recognition center of natural enzymes. The active center is responsible for the catalytic activity of enzymes, and the recognition center provides enzymes with specificity. Most of the previous studies on artificial enzymes preferred to solve the problem of activity rather than specificity due to the complexity of the enzyme structures related to substrate recognition. Inspired by the multilevel structures of enzymes and the unique net-structures of hydrogels, hemin-micelles immobilized in alginate hydrogels (HM-AH) were constructed by multistep self-assembly...
January 31, 2017: Biomaterials Science
Chunfang Li, Shuhui Jiang, Xinying Zhao, Hao Liang
In this paper we report a facile method for preparing co-immobilized enzyme and magnetic nanoparticles (MNPs) using metal coordinated hydrogel nanofibers. Candida rugosa lipase (CRL) was selected as guest protein. For good aqueous dispersity, low price and other unique properties, citric acid-modified magnetic iron oxide nanoparticles (CA-Fe₃O₄ NPs) have been widely used for immobilizing enzymes. As a result, the relative activity of CA-Fe₃O₄@Zn/AMP nanofiber-immobilized CRL increased by 8-fold at pH 10...
January 23, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Lindsey R Bornhoeft, Aniket Biswas, Michael J McShane
There is a growing need for advanced tools that enable frequent monitoring of biomarkers for precision medicine. In this work, we present a composite hydrogel-based system providing real-time optical bioanalyte monitoring. The responsive material, alginate-in-alginate (AnA), is comprised of an alginate hydrogel with embedded bioactive, nanofilm-coated phosphorescent microdomains; palladium tetracarboxyphenylporphyrin serves as an optical indicator, glucose oxidase as a model enzyme, and layer-by-layer deposited polyelectrolyte multilayers (PEMs) as the diffusion barrier...
January 22, 2017: Biosensors
K B Goh, Hua Li, K Y Lam
A remarkable feature of biomaterials is their ability to deform in response to certain external bio-stimuli. Here, a novel biochemo-electro-mechanical model is developed for the numerical characterization of the urea-sensitive hydrogel in response to the external stimulus of urea. The urea sensitivity of the hydrogel is usually characterized by the states of ionization and denaturation of the immobilized urease, as such the model includes the effect of the fixed charge groups and temperature coupled with pH on the activity of the urease...
January 12, 2017: Biosensors & Bioelectronics
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
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
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
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
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...
April 2017: Bioelectrochemistry
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
Xiaozhou Ma, Zhongqiang Yang, Yijie Wang, Guoliang Zhang, Yu Shao, Haoyang Jia, Tianyang Cao, Rui Wang, Dongsheng Liu
DNA hydrogel has aroused widespread attention because of 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 11, 2017: ACS Applied Materials & Interfaces
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
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...
February 2017: Advances in Colloid and Interface Science
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
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
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
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
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