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Enzyme hydrogel

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https://www.readbyqxmd.com/read/28742363/improved-performance-of-glucose-bioanodes-using-composites-of-7-6-single-walled-carbon-nanotubes-and-a-ferrocene-lpei-redox-polymer
#1
Jie Chen, Rujuta Munje, Nicholas P Godman, Shalini Prasad, Daniel T Glatzhofer, David W Schmidtke
The effect of incorporating different types of carbon nanotubes into composite films of a redox polymer (FcMe2-C3-LPEI) and glucose oxidase (GOX) was investigated. The composite films were constructed by first forming a high-surface area network film of either single-walled carbon nanotubes (SWNTs) or multiwalled carbon nanotubes (MWNTs) on a glassy carbon electrode (GCE) by solution casting of a suspension of Triton-X-100 dispersed SWNTs. Next a glucose responsive redox hydrogel was formed on top of the nanotube-modified electrode by cross-linking FcMe2-C3-LPEI with glucose oxidase via ethylene glycol diglycidyl ether (EGDGE)...
July 25, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28738228/streptavidin-hydrogel-prepared-by-sortase-a-assisted-click-chemistry-for-enzyme-immobilization-on-an-electrode
#2
Takuya Matsumoto, Yuki Isogawa, Tsutomu Tanaka, Akihiko Kondo
A tetrameric streptavidin (SA)-appended LPETG tag was site-specifically linked to azido-containing tri-glycine via sortase A catalysis and the resulting azido-modified SA (SA-N3) was retained in the biotin-binding pocket. SA-N3 was polymerized with dibenzylcyclooctyne-modified branched poly(ethyleneglycol) (DBCO-PEG) using azido-modified branched PEG (N3-PEG) as a spacer via copper-free click chemistry. The resulting SA-based hydrogel exhibited gel-like mechanical properties and could immobilize biotin-modified molecules through biotin-SA affinity...
July 19, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28736041/construction-of-multilayer-alginate-hydrogel-beads-for-oral-delivery-of-probiotics-cells
#3
Yang Li, Chao Feng, Jing Li, Yuzhi Mu, Ya Liu, Ming Kong, Xiaojie Cheng, Xiguang Chen
Multilayer alginate hydrogel beads (MAHBs), which were prepared by emulsion method, had been fabricated via the ionic crosslinking between calcium ion (Ca(2+)) and carboxylic group of alginate and utilized as encapsulating material for oral delivery of a model probiotic bacteria Bifidobacterium breve. Optical and fluorescence microscopy obviously showed the microorganism cells were encapsulated in the core beads. The viability of B. breve cells encapsulated in MAHBs was significantly enhanced compared with ordinary free cultured ones, the top CFU per mL were (3...
July 20, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28729217/preventing-postoperative-tissue-adhesion-using-injectable-carboxymethyl-cellulose-pullulan-hydrogels
#4
Sumi Bang, Young-Gwang Ko, Won Il Kim, Donghwan Cho, Won Ho Park, Oh Hyeong Kwon
An injectable adhesive hydrogel composed of carboxymethyl cellulose (CMC) and pullulan is developed and evaluated as a postoperative anti-adhesion barrier. CMC was modified with tyramine to introduce crosslinking via an EDC-NHS reaction. The in situ hydrogel was developed by an enzyme-mediated reaction of tyramine-immobilized CMC with horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). Pullulan was added to the hydrogel solution to improve adhesiveness to the wound area and accelerate biodegradation...
July 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28722424/metabolic-study-of-cancer-cells-using-a-ph-sensitive-hydrogel-nanofiber-light-addressable-potentiometric-sensor
#5
Parmiss Mojir Shaibani, Hashem Etayash, Selvaraj Naicker, Kamaljit Kaur, Thomas Thundat
We report a simple, fast, and cost-effective approach that measures cancer cell metabolism and their response to anticancer drugs in real time. Using a Light Addressable Potentiometric Sensor integrated with pH sensitive hydrogel nanofibers (NF-LAPS), we detect localized changes in pH of the media as cancer cells consume glucose and release lactate. NF-LAPS shows a sensitivity response of 74 mV/pH for cancer cells. Cancer cells (MDA MB231) showed a response of ∼0.4 unit change in pH compared to virtually no change observed for normal cells (MCF10A)...
January 27, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28714570/human-osteoarthritic-chondrons-outnumber-patient-and-joint-matched-chondrocytes-in-hydrogel-culture-future-application-in-autologous-cell-based-oa-cartilage-repair
#6
Miriam Rothdiener, Tatiana Uynuk-Ool, Norbert Südkamp, Matthias Aurich, Alan J Grodzinsky, Bodo Kurz, Bernd Rolauffs
Autologous chondrocyte implantation (ACI) is used in 34-60% for osteoarthritic (OA) cartilage defects, although ACI is neither recommended nor designed for OA. Envisioning a hydrogel-based ACI for OA that uses chondrons instead of classically used chondrocytes, we hypothesized that human OA-chondrons may outperform OA-chondrocytes. We compared patient- and joint surface-matched human OA-chondrons vs. OA-chondrocytes cultured for the first time in a hydrogel, using a self-assembling peptide system. We determined yield, viability, cell numbers, mRNA expression, GAPDH mRNA enzyme activity, collagen II synthesis (CPII) and degradation (C2C), and sGAG...
July 17, 2017: Journal of Tissue Engineering and Regenerative Medicine
https://www.readbyqxmd.com/read/28707693/single-step-fabrication-of-multi-compartmentalized-biphasic-proteinosomes
#7
Lei Wang, Ping Wen, Xiaoman Liu, Yuting Zhou, Mei Li, Yudong Huang, Lin Geng, Stephen Mann, Xin Huang
Multi-compartmentalized biphasic proteinosomes were self-assembled using a single-step double Pickering emulsion procedure, and exploited for enzyme-mediated interfacial catalysis, polysaccharide shell templating, and hydrogel functionalization.
July 27, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28692282/design-and-applications-of-metastable-state-photoacids
#8
Yi Liao
Proton transfer is one of the most common processes in nature, and many chemical, material, and biological processes are sensitive to proton concentration, from acid-catalyzed reactions to the activities of many enzymes. Photoacids that reversibly undergo proton dissociation upon irradiation promise remote spatial and temporal control over proton-sensitive processes and could provide a way to convert photoenergy into other types of energy. The recently discovered metastable-state photoacids can produce a large proton concentration with high efficiency and good reversibility...
July 10, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28675212/enzymatic-self-assembly-of-an-immunoreceptor-tyrosine-based-inhibitory-motif-itim
#9
Natsuko Yamagata, Xiaoyi Chen, Jie Zhou, Jie Li, Xuewen Du, Bing Xu
Here we show the first example of an immunoreceptor tyrosine-based inhibitory motif (ITIM), LYYYYL, as well as its enantiomeric or retro-inverso peptide, to self-assemble in water via enzyme-instructed self-assembly. Upon enzymatic dephosphorylation, the phosphohexapeptides become hexapeptides, which self-assemble in water to result in supramolecular hydrogels. This work illustrates a new approach to design bioinspired soft materials from a less explored, but important pool of immunomodulatory peptides.
July 4, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28662470/multiple-functional-strategies-for-amplifying-sensitivity-of-amperometric-immunoassay-for-tumor-markers-a-review
#10
REVIEW
Zhongxue Tang, Zhanfang Ma
Multiple functional strategies have shown great potential in ultrasensitive amperometric immunoassays for tumor markers, which promote conductivity and signal multiple amplification. The sensitivity of amperometric immunoassays is significantly affected by the conductivity and specific area of the sensing interface as well as the electrochemical activity of redox species. Thus, these strategies are generally based on integrating various materials together and endowing immunosensing systems with many advantages, such as large specific area, high electrochemical activity, good conductivity, biocompatibility, and catalytic performance...
June 21, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28661119/versatile-dual-photoresponsive-system-for-precise-control-of-chemical-reactions
#11
Can Xu, Wei Bing, Faming Wang, Jinsong Ren, Xiaogang Qu
A versatile method for photoregulation of chemical reactions was developed through a combination of near-infrared (NIR) and ultraviolet (UV) light sensitive materials. This regulatory effect was achieved through photoresponsive modulation of reaction temperature and pH values, two prominent factors influencing reaction kinetics. Photothermal nanomaterial graphene oxide (GO) and photobase reagent malachite green carbinol base (MGCB) were selected for temperature and pH regulation, respectively. Using nanocatalyst- and enzyme-mediated chemical reactions as model systems, we demonstrated the feasibility and high efficiency of this method...
July 3, 2017: ACS Nano
https://www.readbyqxmd.com/read/28660091/can-a-biodegradable-implanted-bilayered-drug-delivery-system-loaded-with-bmp-2-bmp-12-take-an-effective-role-in-the-biological-repair-process-of-bone-tendon-injuries-a-preliminary-report
#12
Baran Komur, Yener Akyuva, Numan Karaslan, Mehmet Isyar, Seyit Ali Gumustas, Ibrahim Yilmaz, Semih Akkaya, Duygu Yasar Sirin, Cagri Ata Mutlu, Ahmet Guray Batmaz, Olcay Guler, Mahir Mahirogullari
BACKGROUND: Use of biodegradable and biocompatible materials in the orthopedic surgery is gaining popularity. In this research, the rate of controlled release of a bilayered prototype biomaterial designed to promote osteoblastic and tenoblastic activity was calculated using pharmacochemical methods. METHODS: The first part of the design, composed of a sodium tetraborate, polyvinyl alcohol, and starch based hydrogel, was loaded with bone morphogenic protein-2. The second part which was composed of a sodium tetraborate, polyvinyl alcohol, and chitosan based hydrogel was loaded with bone morphogenic protein-12...
2017: Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28656771/antagonistic-enzymes-in-a-biocatalytic-ph-feedback-system-program-autonomous-dna-hydrogel-life-cycles
#13
Laura Heinen, Thomas Heuser, Alexander A Steinschulte, Andreas Walther
Enzymes regulate complex functions and active behavior in natural systems and have shown increasing prospect for developing self-regulating soft matter systems. Striving for advanced autonomous hydrogel materials with fully programmable, self-regulated life cycles, we combine two enzymes with an antagonistic pH-modulating effect in a feedback-controlled biocatalytic reaction network (BRN) and couple it to pH-responsive DNA hydrogels to realize hydrogel systems with distinct preprogrammable lag times and lifetimes in closed systems...
June 28, 2017: Nano Letters
https://www.readbyqxmd.com/read/28627868/alkaline-phosphatase-instructed-self-assembly-of-gadolinium-nanofibers-for-enhanced-t2-weighted-magnetic-resonance-imaging-of-tumor
#14
Ling Dong, Junchao Qian, Zijuan Hai, Jinyong Xu, Wei Du, Kai Zhong, Gaolin Liang
Alkaline phosphatase (ALP) is an important enzyme but using ALP-instructed self-assembly of gadolinium nanofibers for enhanced T2-weighted magnetic resonance imaging (MRI) of tumor has not been reported. In this work, we rationally designed a hydrogelator Nap-FFFYp-EDA-DOTA(Gd) (1P) which, under the catalysis of ALP, was able to self-assemble into gadolinium nanofibers to form hydrogel Gel I for enhanced T2-weighted MR imaging of ALP activity in vitro and in tumor. T2 phantom MR imaging indicated that the transverse relaxivity (r2) value of Gel I was 33...
June 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28603958/novel-biocompatible-thermoresponsive-poly-n-vinyl-caprolactam-clay-nanocomposite-hydrogels-with-macroporous-structure-and-improved-mechanical-characteristics
#15
Kun Shi, Zhuang Liu, Chao Yang, Xiao-Ying Li, Yi-Min Sun, Yi Deng, Wei Wang, Xiao-Jie Ju, Rui Xie, Liang-Yin Chu
Poly(N-vinyl caprolactam) (PVCL) hydrogels usually suffer from the imporous structure and poor mechanical characteristics as well as the toxicity of cross-linkers, although PVCL itself is biocompatible. In this paper, novel biocompatible thermoresponsive poly(N-vinyl caprolactam)/clay nanocomposite (PVCL-Clay) hydrogels with macroporous structure and improved mechanical characteristics are developed for the first time. The macroporosity in the hydrogel is introduced by using Pickering emulsions as templates, which contain N-vinyl caprolactam (VCL) monomer as dispersed phase and clay sheets as stabilizers at the interface...
June 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28595135/soft-nanocomposites-of-gelatin-and-poly-3-hydroxybutyrate-nanoparticles-for-dual-drug-release
#16
Rafael A Bini, Mônica F Silva, Laudemir C Varanda, Marcelo A da Silva, Cécile A Dreiss
We developed a nanocomposite gel composed of gelatin and poly(3-hydroxybutyrate) polymeric nanoparticles (PNP) to be used as an injectable gel for the contemporaneous, dual sustained release of bioactive molecules. The hydrogel matrix was formed by a very simple process, using either the physical gelation of gelatin or the natural enzyme transglutaminase to covalently cross-link the gelatin chains in the presence of embedded PNP. Oscillatory rheological measurements showed that the addition of the PNP induced an increase in the storage modulus compared to pure gelatin gels, for both physical and chemical gels...
May 22, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28582709/electrodepositable-alginate-membranes-for-enzymatic-sensors-an-amperometric-glucose-biosensor-for-whole-blood-analysis
#17
A Márquez, C Jiménez-Jorquera, C Domínguez, X Muñoz-Berbel
Simple and disposable point of care systems are usually the best solution for chronic patients to get a rapid diagnosis in home care context. However, their main drawback relies on the poor reliability derived from the low stability of the bio-recognition elements and low quality of the transducers. In the current work, we study the use of electrodeposited calcium alginate hydrogels as a biocompatible matrix in the development of enzymatic amperometric biosensors for whole blood analysis, to enhance the enzymes stability and to protect the transducer from biofouling...
May 30, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28581831/development-and-characterization-of-new-and-scalable-topical-formulations-containing-n-acetyl-d-glucosamine-loaded-solid-lipid-nanoparticles
#18
Joana Marto, Cecilia Sangalli, Priscilla Capra, Paola Perugini, Andreia Ascenso, Lídia Gonçalves, Helena Ribeiro
N-Acetyl-d-glucosamine (NAG) has been recently considered for topical treatment of hyperpigmentation disorders due to its inhibitory effect on thyrosinase enzymes in melanocytes. NAG is a precursor of hyaluronic acid, increasing its amount in skin, and consequently, preserving the skin hydration and elasticity. It may also act as an emulsion stabilizer. Solid lipid nanoparticles (SLN) are advanced delivery systems successfully used in pharmaceutical and cosmetic formulations for the improvement of active molecules penetration into the skin...
June 21, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/28574067/multi-responsive-polypeptide-hydrogels-derived-from-n-carboxyanhydride-terpolymerizations-for-delivery-of-nonsteroidal-anti-inflammatory-drugs
#19
Jingwei Fan, Richen Li, Hai Wang, Xun He, Tan P Nguyen, Rachel A Letteri, Jiong Zou, Karen L Wooley
A polypeptide-based hydrogel system, when prepared from a diblock polymer with a ternary copolypeptide as one block, exhibited thermo-, mechano- and enzyme-responsive properties, which enabled the encapsulation of naproxen (Npx) during the sol-gel transition and its release in the gel state. Statistical terpolymerizations of l-alanine (Ala), glycine (Gly) and l-isoleucine (Ile) NCAs at a 1 : 1 : 1 feed ratio initiated by monomethoxy monoamino-terminated poly(ethylene glycol) afforded a series of methoxy poly(ethylene glycol)-block-poly(l-alanine-co-glycine-co-l-isoleucine) (mPEG-b-P(A-G-I)) block polymers...
June 28, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28569438/enzymatic-urease-mediated-mineralization-of-gellan-gum-hydrogel-with-calcium-carbonate-magnesium-enriched-calcium-carbonate-and-magnesium-carbonate-for-bone-regeneration-applications
#20
Timothy E L Douglas, Agata Łapa, Sangram Keshari Samal, Heidi A Declercq, David Schaubroeck, Ana C Mendes, Pascal Van der Voort, Agnieszka Dokupil, Agnieszka Plis, Karel De Schamphelaere, Ioannis S Chronakis, Elżbieta Pamuła, Andre G Skirtach
Mineralization of hydrogel biomaterials is considered desirable to improve their suitability as materials for bone regeneration. Calcium carbonate (CaCO3 ) has been successfully applied as a bone regeneration material, but hydrogel-CaCO3 composites have received less attention. Magnesium (Mg) has been used as a component of calcium phosphate biomaterials to stimulate bone-forming cell adhesion and proliferation and bone regeneration in vivo, but its effect as a component of carbonate-based biomaterials remains uninvestigated...
June 1, 2017: Journal of Tissue Engineering and Regenerative Medicine
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