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Enzyme hydrogel

Christopher T Johnson, James A Wroe, Rachit Agarwal, Karen E Martin, Robert E Guldberg, Rodney M Donlan, Lars F Westblade, Andrés J García
Orthopedic implant infections are a significant clinical problem, with current therapies limited to surgical debridement and systemic antibiotic regimens. Lysostaphin is a bacteriolytic enzyme with high antistaphylococcal activity. We engineered a lysostaphin-delivering injectable PEG hydrogel to treat Staphylococcus aureus infections in bone fractures. The injectable hydrogel formulation adheres to exposed tissue and fracture surfaces, ensuring efficient, local delivery of lysostaphin. Lysostaphin encapsulation within this synthetic hydrogel maintained enzyme stability and activity...
May 14, 2018: Proceedings of the National Academy of Sciences of the United States of America
Su-Hwan Kim, Sang-Hyuk Lee, Ju-Eun Lee, Sung Jun Park, Kyungmin Kim, In Seon Kim, Yoon-Sik Lee, Nathaniel S Hwang, Byung-Gee Kim
We report on a tissue adhesive hydrogel based on novel recombinant tyrosinase mediated crosslinking. The adhesive hydrogels were fabricated by the site-directed coupling of tyramine-conjugated hyaluronic acid (HA_t, 1% w/v) and gelatin (3% w/v) (HG_gel) with novel tyrosinase derived from Streptomyces avermitilis (SA_Ty). The enzyme-based crosslinking by SA_Ty was fast, with less than 50 s for complete gelation, and the SA_Ty based crosslinking enhanced the physical properties and adhesive strength of the hydrogel significantly with the native tissue samples...
May 3, 2018: Biomaterials
Misha Ali, Qayyum Husain
Ginger peroxidase (GP) was entrapped into the hydrogels of guar gum (GG)-alginate/agarose and these immobilized GP preparations were employed for the treatment of textile effluent. GG is a natural hydrophilic polysaccharide which may form complex with enzyme increasing its molecular dimension that can be easily retained inside the entrapping support. Therefore, the activity retention by alginate-guar gum (ANGG) and agarose-guar gum (AGG) was higher than that of alginate and agarose alone. Scanning electron microscopy (SEM) analysis also revealed that GG-GP complex was successfully entrapped inside the alginate/agarose gels...
May 8, 2018: International Journal of Biological Macromolecules
Katrin-Stephanie Tücking, Roshan B Vasani, Alex A Cavallaro, Nicolas H Voelcker, Holger Schönherr, Beatriz Prieto-Simon
The development of enzyme-responsive hyaluronic acid methacrylate (HYAMA)-coated porous silicon (pSi) films and their application in electrochemical diagnostic devices for the in situ detection of the enzyme hyaluronidase (hyal), which is secreted by Staphylococcus aureus (S. aureus) bacteria, are reported. The approach relies on a HYAMA-pSi electrode made of thermally hydrocarbonized pSi (pSi-THC) that is impregnated with crosslinked HYAMA/polyethylene glycol diacrylate (PEGDA) hydrogels. The enzymatic degradation of HYAMA by bacterial hyal is monitored by differential pulse voltammetry (DPV) utilizing pSi-THC as a working electrode and ferro/ferricyanide (FF) as external redox probe...
May 11, 2018: Macromolecular Rapid Communications
Yunki Lee, Joo Young Son, Jeon Il Kang, Kyung Min Park, Ki Dong Park
Reactive oxygen species (ROS) have been implicated as a critical modulator for various therapeutic applications such as treatment of vascular disorders, wound healing, and cancer treatment. Specifically, growing evidence has recently demonstrated that transient or low levels of hydrogen peroxide (H2 O2 ) facilitate tissue regeneration and wound repair through acute oxidative stress that can evaluate intracellular ROS levels in cells or tissues. Herein, we report a gelatin-based H2O2-releasing hydrogel formed by dual enzyme-mediated reaction using horseradish peroxidase (HRP) and glucose oxidase (GOx)...
May 3, 2018: ACS Applied Materials & Interfaces
Yu Fukuoka, El-Sayed Khafagy, Takahiro Goto, Noriyasu Kamei, Kozo Takayama, Nicholas A Peppas, Mariko Takeda-Morishita
In previous studies we showed that the complexation hydrogels based in poly(methacrylic acid-g-ethylene glycol) [P(MAA-g-EG)] rapidly release insulin in the intestine owing to their pH-dependent complexation properties; they also exhibit a high insulin-loading efficiency, enzyme-inhibiting properties, and mucoadhesive characteristics. Cell-penetrating peptides (CPPs), such as oligoarginines [hexa-arginine (R6), comprising six arginine residues], have been employed as useful tools for the oral delivery of therapeutic macromolecules...
2018: Biological & Pharmaceutical Bulletin
Bin Guo, Bo Wen, Wei Cheng, Xiaoyan Zhou, Xiaolei Duan, Min Zhao, Qianfeng Xia, Shijia Ding
In this research, an enzyme-free and label-free surface plasmon resonance (SPR) biosensing strategy has been developed for ultrasensitive detection of fusion gene based on the heterogeneous target-triggered DNA self-assembly aptamer-based hydrogel with streptavidin (SA) encapsulation. In the presence of target, the capture probes (Cp) immobilized on the chip surface can capture the PML/RARα, forming a Cp-PML/RARα duplex. After that, the aptamer-based network hydrogel nanostructure is formed on the gold surface via target-triggered self-assembly of X shaped polymers...
April 14, 2018: Biosensors & Bioelectronics
Yves M Galante, Luca Merlini, Tiziana Silvetti, Paola Campia, Bianca Rossi, Fiorenza Viani, Milena Brasca
New biomaterials from renewable sources and the development of "functionalized biopolymers" are fields of growing industrial interest. Plant polysaccharides represent a valid alternative to traditional synthetic polymers, which are obtained from monomers of fossil, non-renewable origin. Several polysaccharides, either in their natural or chemically/biochemically modified forms, are currently employed in the biomedical, food and feed, and industrial fields, including packaging. Sustainable biochemical reactions, such as enzyme modifications of polysaccharides, open further possibilities for new product and process innovation...
April 26, 2018: Applied Microbiology and Biotechnology
Harrison T West, Clifford M Csizmar, Carston R Wagner
Enzymes possess unique qualities that make them ideal regulators of supramolecular assembly. They are uniquely sensitive to biomolecules and biological compartments, catalytic in effecting chemical reactions, and present a biocompatible and degradable platform for assembly regulation. Here, we demonstrate the novel utility of Histidine Triad Nucleotide Binding Protein 1 (HINT1) in regulating supramolecular hydrogel formation. We synthesized nucleoside phosphoramidate functionalized self-assembling peptides which we observed to form nanofibers...
April 24, 2018: Biomacromolecules
Uziel Mendez, Hong Zhou, Ariella Shikanov
The functional unit within the ovary is the ovarian follicle, which is also a morphological unit composed of three basic cell types: the oocyte, granulosa, and theca cells. Similar to human ovarian follicles, mouse follicles can be isolated from their ovarian environment and cultured in vitro to study folliculogenesis, or follicle development for days or weeks. Over the course of the last decade, follicle culture in a three-dimensional (3D) environment exponentially improved the outcomes of in vitro folliculogenesis...
2018: Methods in Molecular Biology
Ana Beloqui, Andrei Yu Kobitski, Gerd Ulrich Nienhaus, Guillaume Delaittre
We have established a simple one-step synthesis of single-enzyme nanogels (SENs), i.e. , nanobiocatalysts consisting of an enzyme molecule embedded in a hydrophilic, polymeric crosslinked nanostructure, as a most attractive approach to enhance the stability of enzymes. In contrast to earlier protocols, we demonstrate here that the addition of a small amount of sucrose makes the nanogel formation equally effective as earlier two-step protocols requiring enzyme pre-modification. This provides the dual advantage of skipping a synthetic step and preserving the surface chemistry of the enzymes, hence their native structure...
January 28, 2018: Chemical Science
Natashya Falcone, Heinz-Bernhard Kraatz
Supramolecular gels are a fascinating class of soft materials that have attracted significant attention in recent years. They are composed of small molecule gelators that assemble into supramolecular network structures. The resulting space is filled with solvent. Some gel materials are able to respond to various stimuli making them attractive drug delivery vehicles and as matrices for tissue regeneration. Peptide based gel materials are particularly attractive as they possess numerous advantages including biocompatibility and biodegradability...
April 18, 2018: Chemistry: a European Journal
Maryam Daviran, Sarah M Longwill, Jonah F Casella, Kelly M Schultz
Human mesenchymal stem cells (hMSCs) dynamically remodel their microenvironment during basic processes, such as migration and differentiation. Migration requires extracellular matrix invasion, necessitating dynamic cell-material interactions. Understanding these interactions is critical to advancing materials designs that harness and manipulate these processes for applications including wound healing and tissue regeneration. In this work, we encapsulate hMSCs in a cell-degradable poly(ethylene glycol)-peptide hydrogel to determine how cell-secreted enzymes, specifically matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), create unique pericellular microenvironments...
April 18, 2018: Soft Matter
Tao Li, Xiongbo Song, Changmei Weng, Xin Wang, Jiangyi Wu, Li Sun, Xiaoyuan Gong, Wei-Nan Zeng, Liu Yang, Cheng Chen
Hydrogels with good biocompatibility, proper degradation rates, and tissue-matched elasticity are widely used in tissue engineering, regenerative medicine, and drug delivery. In this study, enzymatically crosslinked biocompatible hydrogels were successfully developed using silk fibroin (SF) and pullulan (PL) under physiological conditions in the presence of both horseradish peroxidase (HRP) and hydrogen peroxide (H2 O2 ). A series of properties of the hydrogels including gelation time, equilibrium swelling, enzyme degradation, morphology, rheological property, and compression modulus of SF/PL hydrogels were studied by varying the concentration of PL...
April 14, 2018: International Journal of Biological Macromolecules
Juneyoung Lee, Jeong Hoon Ko, Kathryn M Mansfield, Peter C Nauka, Erhan Bat, Heather D Maynard
Effective delivery of therapeutic proteins is important for many biomedical applications. Yet, the stabilization of proteins during delivery and long-term storage remains a significant challenge. Herein, a trehalose-based hydrogel is reported that stabilizes insulin to elevated temperatures prior to glucose-triggered release. The hydrogel is synthesized using a polymer with trehalose side chains and a phenylboronic acid end-functionalized 8-arm poly(ethylene glycol) (PEG). The hydroxyls of the trehalose side chains form boronate ester linkages with the PEG boronic acid cross-linker to yield hydrogels without any further modification of the original trehalose polymer...
April 17, 2018: Macromolecular Bioscience
Fausto N Comba, Marcelo R Romero, Fernando S Garay, Ana M Baruzzi
This work reports an amperometric enzyme-electrode prepared with glucose oxidase, which have been immobilized by a cross-linking step with glutaraldehyde in a mixture containing albumin and a novel carbon nanotubes-mucin composite (CNT-muc). The obtained hydrogel matrix was trapped between two polycarbonate membranes and then fixed at the surface of a Pt working electrode. The developed biosensor was optimized by evaluating different compositions and the analytical properties of an enzymatic matrix with CNT-muc...
April 9, 2018: Analytical Biochemistry
Li Xu, Zijie Zhang, Xiaoqiang Fang, Yibo Liu, Biwu Liu, Juewen Liu
Metal coordination with organic ligands often produce crystalline metal-organic frameworks (MOF) and sometimes amorphorous nanoparticles. In this work, we explore a different type of material from the same chemistry: hydrogels. Lanthanides are chosen as the metal component because of their important technological applications and continously tunable properties. Adenosine monophosphate (AMP) and lanthanides form two types of coordination materials: the lighter lanthanides from La3+ to Tb3+ form nanoparticles, while the rest heavier ones initially form nanoparticles but later spontaneously transform to hydrogels...
April 12, 2018: ACS Applied Materials & Interfaces
Xiaoxia Mao, Guifang Chen, Zihan Wang, Yuanguang Zhang, Xiaoli Zhu, Genxi Li
Hydrogels are of great interest in the field of biosensing for their good biocompatibility, plasticity, and capability of providing 3D scaffolds. Nevertheless, the application of hydrogels has not been linked with broad surface biosensing systems yet. To overcome the limitations, here for the first time, surface-immobilized pure DNA hydrogels were synthesized using a surficial primer-induced strategy and adopted for biosensing applications. The DNA hydrogel 3D scaffold is successfully constructed on a transparent ITO electrode, which facilitates both colourimetric and electrochemical measurements...
January 28, 2018: Chemical Science
Mian Fu, Chenyu Zhang, Yuxuan Dai, Xue Li, Miaobo Pan, Wenlong Huang, Hai Qian, Liang Ge
Closed-loop glucose-responsive insulin delivery with excellent biocompatibility has the potential to improve the health and quality of life of diabetic patients. Herein, we developed an excellent glucose-responsive insulin delivery system using a pH-sensitive peptide hydrogel loaded with insulin and a glucose-specific enzyme. The designed peptide can be used as a carrier that is loaded with insulin and enzyme via a self-assembly process under physiological conditions. When hyperglycemia is encountered, the enzymatic conversion of glucose into gluconic acid leads to a decrease in the local pH, and the hydrogel is disassembled because of the strong inter- and intramolecular electrostatic repulsions between ornithine (Orn) residues; this is followed by the release of insulin...
April 6, 2018: Biomaterials Science
Nitin Joshi, Jing Yan, Seth Levy, Sachin Bhagchandani, Kai V Slaughter, Nicholas E Sherman, Julian Amirault, Yufeng Wang, Logan Riegel, Xueyin He, Tan Shi Rui, Michael Valic, Praveen K Vemula, Oscar R Miranda, Oren Levy, Ellen M Gravallese, Antonios O Aliprantis, Joerg Ermann, Jeffrey M Karp
Local delivery of therapeutics for the treatment of inflammatory arthritis (IA) is limited by short intra-articular half-lives. Since IA severity often fluctuates over time, a local drug delivery method that titrates drug release to arthritis activity would represent an attractive paradigm in IA therapy. Here we report the development of a hydrogel platform that exhibits disassembly and drug release controlled by the concentration of enzymes expressed during arthritis flares. In vitro, hydrogel loaded with triamcinolone acetonide (TA) releases drug on-demand upon exposure to enzymes or synovial fluid from patients with rheumatoid arthritis...
April 3, 2018: Nature Communications
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