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Enzyme hydrogel

Yuuki Hata, Toshiki Sawada, Takamasa Sakai, Takeshi Serizawa
The dispersion stabilization of colloidal particles and subsequent construction of functional materials are of great interest in areas ranging from colloid chemistry to materials science. A promising strategy is the spatial immobilization of colloidal particles within gel scaffolds. However, conventional gels readily deform and even collapse when changes in environmental conditions occur. Herein, we describe the enzyme-catalyzed bottom-up synthesis of mechanically and physicochemically stable nanoribbon network hydrogels composed of crystalline cellulose oligomers in which cellulose nanocrystals (CNCs) as model colloidal particles are immobilized spatially...
March 19, 2018: Biomacromolecules
Bing Hu, Yang Shen, Jozef Adamcik, Peter Fischer, Mirjam Schneider, Martin J Loessner, Raffaele Mezzenga
Adaptable hydrogel networks with reversible connectivity have emerged as a promising platform for biomedical applications. Synthetic copolymers and Low-Molecular Weight Gelators (LMWG) have been shown to form reversible hydrogels through self-assembly of the molecules driven by self complementary hydrophobic interaction and hydrogen bonding. Here, inspired by the adhesive proteins secreted by mussels, we found that simply adding natural polyphenols, such as epigallocatechin gallate (EGCG) to amyloid fibrils present in the nematic phase, successfully drives the formation of hydrogels through self-assembly of the hybrid supramolecules...
March 19, 2018: ACS Nano
Haeree Park, Yeongkyu Choi, M T Jeena, Eungjin Ahn, Yuri Choi, Myeong-Gyun Kang, Chae Gyu Lee, Tae-Hyuk Kwon, Hyun-Woo Rhee, Ja-Hyoung Ryu, Byeong-Su Kim
Owing to the unique advantages of combining the characteristics of hydrogels and nanoparticles, nanogels are actively investigated as a promising platform for advanced biomedical applications. In this work, a self-cross-linked hyperbranched polyglycerol nanogel is synthesized using the thiol-disulfide exchange reaction based on a novel disulfide-containing polymer. A series of structural analyses confirm the tunable size and cross-linking density depending on the type of polymer (homo- or copolymer) and the amount of reducing agent, dithiothreitol, used in the preparation of the nanogels...
March 15, 2018: Macromolecular Bioscience
Jie Li, Domenico Bullara, Xuewen Du, Hongjian He, Stavroula Sofou, Ioannis G Kevrekidis, Irving R Epstein, Bing Xu
Recent studies have demonstrated that enzyme-instructed self-assembly (EISA) in extra- or intracellular environments can serve as a multistep process for controlling cell fate. There is little knowledge, however, about the kinetics of EISA in the complex environments in or around cells. Here we design and synthesize three dipeptidic precursors (LD-1-SO3, DL-1-SO3, DD-1-SO3), consisting of diphenylalanine (L-Phe-D-Phe, D-Phe-L-Phe, D-Phe-D-Phe, respectively) as the backbone, which are capped by 2-(naphthalen-2-yl)acetic acid at the N-terminal and by 2-(4-(2-aminoethoxy)-4-oxobutanamido)ethane-1-sulfonic acid at the C- 2 terminal...
March 14, 2018: ACS Nano
Xia Wang, Shuangshuang Chen, Dongbei Wu, Qing Wu, Qingcong Wei, Bin He, Qinghua Lu, Qigang Wang
Due to their 3D cross-linked networks and tunable physicochemical properties, polymer hydrogels with different sizes are applied widely in tissue engineering, drug-delivery systems, pollution regulation, ionic conducting electrolytes, agricultural drought-resistance, cosmetics, and the food industry. Novel, environmentally friendly, and efficient oxidoreductase-initiated radical polymerizations to design hydrogels and micro/nanogels have gained increasing attention. Herein, the recent advances on the use of novel enzyme-initiated systems for hydrogel polymerization, including the mechanisms, and molding of polymeric and hybrid-polymeric networks are reviewed...
March 5, 2018: Advanced Materials
Zhaowei Chen, Zhenzhen Wang, Jinsong Ren, Xiaogang Qu
Bacterial infection continues to be a growing global health problem with the most widely accepted treatment paradigms restricted to antibiotics. However, antibiotics overuse and misuse have triggered increased multidrug resistance, frustrating the therapeutic outcomes and leading to higher mortalities. Even worse, the tendency of bacteria to form biofilms on living and nonliving surfaces further increases the difficulty in confronting bacteria because the extracellular matrix can act as a robust barrier to prevent the penetration of antibiotics and resist environmental stress...
February 28, 2018: Accounts of Chemical Research
Danya Lyu, Shanshan Chen, Weiwei Guo
A novel stimuli-responsive hydrogel system with liposomes serving as both noncovalent crosslinkers and functional small molecules carriers for controlled-release is developed. Liposomes can crosslink polyacrylamide copolymers functionalized with cholesterol-modified DNA motifs to yield a DNA hydrogel system, due to the hydrophobic interaction between cholesteryl groups and the lipid bilayer of liposomes. Functional information encoded DNA motifs on the polymer backbones endow the hydrogel with programmable smart responsive properties...
February 26, 2018: Small
Zhongyan Wang, Chunhui Liang, Yuna Shang, Shuangshuang He, Ling Wang, Zhimou Yang
We designed and synthesized three phosphorylated peptides as precursors of the same peptide Nap-YYY. We found that different precursors led to different materials with almost identical chemical compositions at the final stages. Only Nap-YpYY could form very uniform nanofibers in a stable supramolecular hydrogel by enzyme-instructed self-assembly (EISA) at the physiological temperature (37 °C). In contrast, de-phosphorylation of the other two precursors (Nap-pYYY and Nap-YYpY) resulted in diverse nanostructures in metastable hydrogels with precipitates...
February 26, 2018: Chemical Communications: Chem Comm
Hyosook Hwang, Hyeon-Soo Kim, JeongIl Kwon, Phil-Sun Oh, Ho Sung Park, Seok Tae Lim, Myung-Hee Sohn, Hwan-Jeong Jeong
PURPOSE: To investigate potential of chitosan hydrogel microparticles (CHI) for treatment of VX2 carcinoma. MATERIALS AND METHODS: Two weeks after liver VX2 implantation, contrast-enhanced computerized tomographic scanning was conducted. Rabbits (n = 2) with successful tumor growth were treated with different sizes of99m Tc-labeled CHI (60-80 μm and 100-120 μm) via intra-arterial hepatic catheterization. Liver distribution of99m Tc-labeled CHI was determined by means of autoradiography, a radiation-based photographic technique...
February 22, 2018: Journal of Vascular and Interventional Radiology: JVIR
Gregor Fuhrmann, Rona Chandrawati, Paresh A Parmar, Timothy J Keane, Stephanie A Maynard, Sergio Bertazzo, Molly M Stevens
Extracellular vesicles (EVs) have recently gained significant attention as important mediators of intercellular communication, potential drug carriers, and disease biomarkers. These natural cell-derived nanoparticles are postulated to be biocompatible, stable under physiological conditions, and to show reduced immunogenicity as compared to other synthetic nanoparticles. Although initial clinical trials are ongoing, the use of EVs for therapeutic applications may be limited due to undesired off-target activity and potential "dilution effects" upon systemic administration which may affect their ability to reach their target tissues...
February 23, 2018: Advanced Materials
Jiqing Yang, Xiaotong Hu, Jia Xu, Xin Liu, Li Yang
A novel capillary electrophoresis-integrated immobilized enzyme reactor (CE-integrated IMER) is developed using single-step in-situ acetylcholinesterase (AChE)-mediated alginate hydrogelation and enzyme encapsulation. Alginate hydrogelation with "egg-box" structure is triggered inside a capillary with releasing of Ca2+ by changing the pH of the sol solution, which is accomplished in-situ by AChE-catalyzed hydrolysis reaction of acetylthiocholine to produce acetic acid. AChE and any other enzyme initially contained in the sol solution [e...
February 22, 2018: Analytical Chemistry
Barry A Badeau, Michael P Comerford, Christopher K Arakawa, Jared A Shadish, Cole A DeForest
The successful transport of drug- and cell-based therapeutics to diseased sites represents a major barrier in the development of clinical therapies. Targeted delivery can be mediated through degradable biomaterial vehicles that utilize disease biomarkers to trigger payload release. Here, we report a modular chemical framework for imparting hydrogels with precise degradative responsiveness by using multiple environmental cues to trigger reactions that operate user-programmable Boolean logic. By specifying the molecular architecture and connectivity of orthogonal stimuli-labile moieties within material cross-linkers, we show selective control over gel dissolution and therapeutic delivery...
March 2018: Nature Chemistry
Minsu Kim, Kangwon Lee, Ji Eon Kwon, Won Gun Koh
In this study, we developed an enzyme-based miniaturized fluorescence biosensor to detect paraoxon, one of the most well-known neurotoxic organophosphorus compounds (OPs). The biosensor was fabricated with poly(ethylene glycol) (PEG) hydrogel microarrays that entrapped acetylcholinesterase (AChE) and quantum dots (QDs) as fluorescence reporters. Metal-enhanced fluorescence (MEF) was utilized to amplify the fluorescence signal, which was achieved by decorating QDs on the surface of silica-coated silver nanoparticles (Ag@Silica)...
February 16, 2018: Biofabrication
Rabia Mateen, M Monsur Ali, Todd Hoare
A significant problem in high-throughput drug screening is the disproportionate number of false hits associated with drug candidates that form colloidal aggregates. Such molecules, referred to as promiscuous inhibitors, nonspecifically inhibit multiple enzymes and are thus not useful as potential drugs. Here, we report a printable hydrogel-based drug-screening platform capable of non-ambiguously differentiating true enzyme inhibitors from promiscuous aggregating inhibitors, critical for accelerating the drug discovery process...
February 9, 2018: Nature Communications
Lanlan Li, Lijia Pan, Zhong Ma, Ke Yan, Wen Cheng, Yi Shi, Guihua Yu
Multiplexing, one of the main trends in biosensors, aims to detect several analytes simultaneously by integrating miniature sensors on a chip. However, precisely depositing electrode materials and selective enzymes on distinct microelectrode arrays remains an obstacle to massively produced multiplexed sensors. Here, we report on a "drop-on-demand" inkjet printing process to fabricate multiplexed biosensors based on nanostructured conductive hydrogels in which the electrode material and several kinds of enzymes were printed on the electrode arrays one by one by employing a multinozzle inkjet system...
February 12, 2018: Nano Letters
Maria-Eleni K Stathopoulou, Christina N Banti, Nikolaos Kourkoumelis, Antonios G Hatzidimitriou, Angelos G Kalampounias, Sotiris K Hadjikakou
The known metallotherapeutic [Ag(salH)]2 (AGSAL-1) of salicylic acid (salH2), was used for the development of new efficient silver based material for wounds healing. AGSAL-1 was characterized by spectroscopic techniques and X-ray crystallography. The wound healing epithelialization of AGSAL-1 was investigated by the means of scratch assay against immortalized human keratinocytes (HaCaT) cells. The anti-inflammatory activity of AGSAL-1 was evaluated by monitoring the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX)...
February 1, 2018: Journal of Inorganic Biochemistry
Jie Zhou, Xuewen Du, Jiaqing Wang, Natsuko Yamagata, Bing Xu
Enzyme-instructed self-assembly (EISA) offers a facile approach to explore the supramolecular assemblies of small molecules in cellular milieu for a variety of biomedical applications. One of the commonly used enzymes is phosphatase, but the study of the substrates of phosphatases mainly focuses on the phosphotyrosine containing peptides. In this work, we examine the EISA of phosphoserine containing small peptides for the first time by designing and synthesizing a series of precursors containing only phosphoserine or both phosphoserine and phosphotyrosine...
December 2017: Frontiers of Chemical Science and Engineering
Balaji V Sridhar, John R Janczy, Øyvind Hatlevik, Gabriel Wolfson, Kristi S Anseth, Mark W Tibbitt
Modern medicine, biological research, and clinical diagnostics depend on the reli- able supply and storage of complex biomolecules. However, biomolecules are inherently susceptible to thermal stress and the global distribution of value-added biologics, including vaccines, biotherapeutics, and Research Use Only (RUO) proteins, requires an integrated cold chain from point of manufacture to point of use. To mitigate reliance on the cold chain, formulations have been engineered to protect biologics from thermal stress, including materials-based strategies that impart thermal stability via direct encapsulation of the molecule...
February 2, 2018: Biomacromolecules
Lucília P da Silva, Amit K Jha, Vitor M Correlo, Alexandra P Marques, Rui L Reis, Kevin E Healy
The survival of a biomaterial or tissue engineered construct is mainly hampered by the deficient microcirculation in its core, and limited nutrients and oxygen availability to the implanted or colonizing host cells. Aiming to address these issues, we herein propose bioresponsive gellan gum (GG) hydrogels that are biodegradable by metalloproteinase 1 (MMP-1) and enable endothelial cells adhesion and proliferation. GG is chemically functionalized with divinyl sulfone (DVS) and then biofunctionalized with thiol cell-adhesive peptides (T1 or C16) to confer GG endothelial cell biorecognition cues...
February 1, 2018: Advanced Healthcare Materials
Ruibo Zhong, Qian Tang, Shaopeng Wang, Hongbo Zhang, Feng Zhang, Mingshu Xiao, Tiantian Man, Xiangmeng Qu, Li Li, Weijia Zhang, Hao Pei
Conducting hydrogels provide great potential for creating designer shape-morphing architectures for biomedical applications owing to their unique solid-liquid interface and ease of processability. Here, a novel nanofibrous hydrogel with significant enzyme-like activity that can be used as "ink" to print flexible electrochemical devices is developed. The nanofibrous hydrogel is self-assembled from guanosine (G) and KB(OH)4 with simultaneous incorporation of hemin into the G-quartet scaffold, giving rise to significant enzyme-like activity...
February 1, 2018: Advanced Materials
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