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Enzyme degradable polymers

Lin Liu, WenDong Yao, YueFeng Rao, XiaoYang Lu, JianQing Gao
Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines...
November 2017: Drug Delivery
Miia R Mäkelä, Ourdia Bouzid, Diogo Robl, Harm Post, Mao Peng, Albert Heck, Maarten Altelaar, Ronald P de Vries
The coprophilic ascomycete fungus Podospora anserina was cultivated on three different plant biomasses, i.e. cotton seed hulls (CSH), soybean hulls (SBH) and acid-pretreated wheat straw (WS) for four days, and the potential of the produced enzyme mixtures was compared in the enzymatic saccharification of the corresponding lignocellulose feedstocks. The enzyme cocktail P. anserina produced after three days of growth on SBH showed superior capacity to release reducing sugars from all tested plant biomass feedstocks compared to the enzyme mixtures from CSH and WS cultures...
February 7, 2017: New Biotechnology
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
Sazzad Hossen Toushik, Kyung-Tai Lee, Jin-Sung Lee, Keun-Sung Kim
Cellulose, hemicellulose, pectin (carbohydrate), and lignin (noncarbohydrate) polymers are the main substrates of lignocellulose-degrading enzymes. They are present in large amounts in the primary cell wall and dietary fibers of major fruits and vegetables. During processing of fruits and vegetables to the corresponding final food products, lignocellulosic substrates are hydrolyzed by different lignocellulolytic enzymes. Currently, lignocellulolytic enzymes such as cellulases, xylanases, pectinases, and laccases are extensively used during the processing of fruits and vegetables, in applications like texturizing and flavoring of products in the food industries...
February 2, 2017: Journal of Food Science
Michael Thomas Zumstein, Hans-Peter E Kohler, Kristopher McNeill, Michael Sander
Biodegradable polyesters have the potential to replace non-degradable, persistent polymers in numerous applications and thereby alleviate plastic accumulation in the environment. Herein we present an analytical approach to study enzymatic hydrolysis of polyesters, the key step in their overall biodegradation process. The approach is based on embedding fluorescein dilaurate (FDL), a fluorogenic ester substrate, into the polyester matrix and on monitoring the enzymatic co-hydrolysis of FDL to fluorescein during enzymatic hydrolysis of the polyester...
January 31, 2017: Environmental Science & Technology
Lindi Strydom, Jonathan Jewell, Michael A Meier, Gavin M George, Barbara Pfister, Samuel Zeeman, Jens Kossmann, James R Lloyd
E. coli accumulate or degrade glycogen depending on environmental carbon supply. Glycogen phosphorylase (GlgP) and glycogen debranching enzyme (GlgX) are known to act on the glycogen polymer, while maltodextrin phosphorylase (MalP) is thought to remove maltodextrins released by GlgX. To examine the roles of these enzymes in more detail, single, double and triple mutants lacking all their activities were produced. GlgX and GlgP were shown to act directly on the glycogen polymer, while MalP most likely catabolised soluble malto-oligosaccharides...
January 24, 2017: FEMS Microbiology Letters
Maria Godoy-Gallardo, Cedric Labay, Vasileios Trikalitis, Paul Kempen, Jannik B Larsen, Thomas Lars Andresen, Leticia Hosta-Rigau
Cell organelles are subcellular structures entrapping a set of enzymes to achieve a specific functionality. The incorporation of artificial organelles into cells is a novel medical paradigm which might contribute to the treatment of various cell disorders by replacing malfunctioning organelles. In particular, artificial organelles are expected to be a powerful solution in the context of enzyme replacement therapy since enzymatic malfunction is the primary cause of organelle dysfunction. Although several attempts have been made to encapsulate enzymes within a carrier vehicle, only few intracellularly active artificial organelles have been reported to date and they all consist of single-compartment carriers...
January 24, 2017: ACS Applied Materials & Interfaces
Martín Alcorlo, Siseth Martínez-Caballero, Rafael Molina, Juan A Hermoso
The major component of bacterial cell wall is peptidoglycan (PG), a complex polymer formed by long glycan chains cross-linked by peptide stems. PG is in constant equilibrium requiring well-orchestrated coordination between synthesis and degradation. The resulting cell-wall fragments can be recycled, act as messengers for bacterial communication, as effector molecules in immune response or as signaling molecules triggering antibiotics resistance. Tailoring and recycling of PG requires the cleavage of different covalent bonds of the PG sacculi by a diverse set of specific enzymes whose activities are strictly regulated...
January 19, 2017: Current Opinion in Structural Biology
Wongsakorn Suchaoin, Andreas Bernkop-Schnürch
Pre-uptake metabolism within the GI tract is responsible for the poor oral bioavailability of numerous drugs. As nanocarriers function as a 'shield', protecting incorporated drugs from enzymatic attack, there is an increasing interest in utilizing them as a tool for overcoming drug degradation. Degradation of carriers resulting in the release of incorporated drugs, mucus permeation, enzyme inhibitory properties and their toxicity are crucial factors that must be taken into account when designing proper nanocarriers...
January 17, 2017: Nanomedicine
Brenton Jennewine, Jonathan Fox, Anand Ramamurthi
: Abdominal Aortic Aneurysms (AAA) involve slow dilation and weakening of the aortic wall due to breakdown of structural matrix components, such as elastic fibers by chronically overexpressed matrix metalloproteinases (MMPs), primarily, MMPs-2 and -9. Auto-regenerative repair of disrupted elastic fibers by smooth muscle cells (SMCs) at the AAA site is intrinsically poor and together with chronic proteolysis prevents restoration of elastin homeostasis, necessary to enable AAA growth arrest or regression to a healthy state...
January 10, 2017: Acta Biomaterialia
Alexander V Skurat, Dyann Segvich, Anna A DePaoli-Roach, Peter J Roach
Glycogen, a branched polymer of glucose, functions as an energy reserve in many living organisms. Abnormalities in glycogen metabolism, usually excessive accumulation, can be caused genetically, most often through mutation of the enzymes directly involved in synthesis and degradation of the polymer leading to a variety of glycogen storage diseases (GSDs). Microscopic visualization of glycogen deposits in cells and tissues is important for the study of normal glycogen metabolism as well as diagnosis of GSDs...
January 10, 2017: Glycobiology
S S Thimoteo, A Glogauer, H Faoro, E M de Souza, L F Huergo, B M Moerschbacher, F O Pedrosa
Chitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4) present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading to the isolation and identification of a chitinase gene named metachi18A. The metachi18A gene was subcloned and overexpressed in Escherichia coli BL21 and the MetaChi18A chitinase was purified by affinity chromatography as a 6xHis-tagged fusion protein...
January 5, 2017: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
Jing Niu, Ebru Alazi, Ian D Reid, Mark Arentshorst, Peter J Punt, Jaap Visser, Adrian Tsang, Arthur F J Ram
The expression of genes encoding extracellular polymer-degrading enzymes and the metabolic pathways required for carbon utilization in fungi are tightly controlled. The control is mediated by transcription factors that are activated by the presence of specific inducers, which are often monomers or monomeric derivatives of the polymers. A D-galacturonic acid-specific transcription factor named GaaR was recently identified and shown to be an activator for the expression of genes involved in galacturonic acid utilization in Botrytis cinerea and Aspergillus niger Using a forward genetic screen, we isolated A...
January 2017: Genetics
Shangyong Li, Linna Wang, Jianhua Hao, Mengxin Xing, Jingjing Sun, Mi Sun
Unsaturated alginate disaccharides (UADs), enzymatically derived from the degradation of alginate polymers, are considered powerful antioxidants. In this study, a new high UAD-producing alginate lyase, AlySY08, has been purified from the marine bacterium Vibrio sp. SY08. AlySY08, with a molecular weight of about 33 kDa and a specific activity of 1070.2 U/mg, showed the highest activity at 40 °C in phosphate buffer at pH 7.6. The enzyme was stable over a broad pH range (6.0-9.0) and retained about 75% activity after incubation at 40 °C for 2 h...
December 23, 2016: Marine Drugs
Hwei-Ting Tan, Kendall R Corbin, Geoffrey B Fincher
Plant cell walls are composed predominantly of cellulose, a range of non-cellulosic polysaccharides and lignin. The walls account for a large proportion not only of crop residues such as wheat straw and sugarcane bagasse, but also of residues of the timber industry and specialist grasses and other plants being grown specifically for biofuel production. The polysaccharide components of plant cell walls have long been recognized as an extraordinarily large source of fermentable sugars that might be used for the production of bioethanol and other renewable liquid transport fuels...
2016: Frontiers in Plant Science
Ying Xie, Tracy Murray-Stewart, Yazhe Wang, Fei Yu, Jing Li, Laurence J Marton, Robert A Casero, David Oupický
Combination of anticancer drugs with therapeutic microRNA (miRNA) has emerged as a promising anticancer strategy. However, the promise is hampered by a lack of desirable delivery systems. We report on the development of self-immolative nanoparticles capable of simultaneously delivering miR-34a mimic and targeting dysregulated polyamine metabolism in cancer. The nanoparticles were prepared from a biodegradable polycationic prodrug, named DSS-BEN, which was synthesized from a polyamine analog N(1),N(11)-bisethylnorspermine (BENSpm)...
January 28, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
Silvia Fornalé, Jorge Rencoret, Laura García-Calvo, Antonio Encina, Joan Rigau, Ana Gutiérrez, José Carlos Del Río, David Caparros-Ruiz
Caffeoyl Coenzyme A 3-O-Methyltransferase (CCoAOMT) and Caffeic acid-O-Methyltransferase (COMT) are key enzymes in the biosynthesis of coniferyl and sinapyl alcohols, the precursors of guaiacyl (G) and syringyl (S) lignin subunits. The function of these enzymes was characterised in single and double mutant maize plants. In this work, we determined that the comt (brown-midrib 3) mutant plants display a reduction of the flavonolignin unit derived from tricin (a dimethylated flavone), demonstrating that COMT is a key enzyme involved in the synthesis of this compound...
December 23, 2016: Plant & Cell Physiology
Marvin Kadisch, Andreas Schmid, Bruno Bühler
Fatty acid methyl esters (FAMEs) originating from plant oils are most interesting renewable feedstocks for biofuels and bio-based materials. FAMEs can also be produced and/or functionalized by engineered microbes to give access to, e.g., polymer building blocks. Yet, they are often subject to hydrolysis yielding free fatty acids, which typically are degraded by microbes. We identified BioH as the key enzyme responsible for the hydrolysis of medium-chain length FAME derivatives in different E. coli K-12 strains...
December 24, 2016: Journal of Industrial Microbiology & Biotechnology
Nicholas A Sears, Geraldine Pena-Galea, Stacy N Cereceres, Elizabeth Cosgriff-Hernandez
Herein, we report on the synthesis and characterization of enzymatically labile polyureas for use as a tissue-engineered ligament scaffold. Polyureas were selected due to their excellent tensile properties, fatigue resistance, and highly tunable nature. Incorporation of a collagenase-sensitive peptide into the backbone of the polyurea provided a means to confer cell-responsive degradation to the synthetic polymer. Chemical, morphological, and mechanical testing were used to confirm incorporation of the peptide and characterize polyurea films...
January 2016: Journal of Tissue Engineering
Merav Segal, Ram Avinery, Marina Buzhor, Rona Shaharabani, Assaf J Harnoy, Einat Tirosh, Roy Beck, Roey J Amir
Studying the enzymatic degradation of synthetic polymers is crucial for the design of suitable materials for biomedical applications ranging from advanced drug delivery systems to tissue engineering. One of the key parameters that governs enzymatic activity is the limited accessibility of the enzyme to its substrates that may be collapsed inside hydrophobic domains. PEG-dendron amphiphiles can serve as powerful tools for the study of enzymatic hydrolysis of polymeric amphiphiles due to the monodispersity and symmetry of the hydrophobic dendritic block, which significantly simplifies kinetic analyses...
January 18, 2017: Journal of the American Chemical Society
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