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Natural scaffold

Maciej Lesiak, Sylwia Zawada-Iwańczyk, Magdalena Łanocha, Aneta Klotzka, Michał Lesiak
Bioresorbable scaffolds (BRS) have been introduced to clinical practice to avoid some limitations associated with the presence of permanent metal prostheses in coronary arteries. Due to elimination of the natural vasomotion of the vessel and flow disturbance, stents impair endothelial function, increasing the risk of adverse events such as late and very late thrombosis or accelerated neoatherosclerosis. Additionally, the presence of metallic stents hinders non-invasive imaging of coronaries and may exclude the possibility of bypass graft anastomosis within the stented segment...
March 15, 2018: Minerva Cardioangiologica
Brooke McClarren, Ronke Olabisi
Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into any mesenchymal tissue, including bone, cartilage, muscle, and fat. MSC differentiation can be influenced by a variety of stimuli, including environmental and mechanical stimulation, scaffold physical properties, or applied loads. Numerous studies have evaluated the effects of vibration or cyclic tensile strain on MSCs towards developing a mechanically based method of differentiation, but there is no consensus between studies and each investigation uses different culture conditions, which also influence MSC fate...
2018: International Journal of Biomaterials
Naira F Z Schneider, Claudia Cerella, Jin-Young Lee, Aloran Mazumder, Kyung Rok Kim, Annelise de Carvalho, Jennifer Munkert, Rodrigo M Pádua, Wolfgang Kreis, Kyu-Won Kim, Christo Christov, Mario Dicato, Hyun-Jung Kim, Byung Woo Han, Fernão C Braga, Cláudia M O Simões, Marc Diederich
Cardiac glycosides (CGs) are natural compounds used traditionally to treat congestive heart diseases. Recent investigations repositioned CGs as potential anticancer agents. To discover novel cytotoxic CG scaffolds, we selected the cardenolide glucoevatromonoside (GEV) out of 46 CGs for its low nanomolar anti-lung cancer activity. GEV presented reduced toxicity toward non-cancerous cell types (lung MRC-5 and PBMC) and high-affinity binding to the Na+ /K+ -ATPase α subunit, assessed by computational docking...
2018: Frontiers in Pharmacology
Kathryn E Drzewiecki, Juilee N Malavade, Ijaz Ahmed, Christopher J Lowe, David I Shreiber
As a biomaterial, collagen has been used throughout tissue engineering and regenerative medicine. Collagen is native to the body, is highly biocompatible, and naturally promotes cell adhesion and regeneration. However, collagen fibers and the inherent weak mechanical properties of collagen hydrogels interfere with further development of collagen as a bio-ink. Herein, we demonstrate the use of a modified type-I collagen, collagen methacrylamide (CMA), as a fibril-forming bio-ink for free-form fabrication of scaffolds...
December 2017: Technology
Louise Stjerne Knudsen, Thomas Skovgaard, Thomas Bredahl
INTRODUCTION: The benefits of physical activity for children's health, both mental and physical, and its positive effects on academic achievement are well established. Research also emphasises that schools could provide a natural setting for regular physical activity. There is, however, a limited amount of knowledge about teachers' views when it comes to integrating physical activity as part of teaching. The aim of this study is to understand teachers' motivation for integrating physical activity as part of teaching and to assess their need for guidance and support...
March 14, 2018: BMJ Open
E M Kithsiri Wijeratne, Maria C F Oliveira, Jair Mafezoli, Ya-Ming Xu, Sandro Minguzzi, Pedro H J Batista, Otília D L Pessoa, Luke Whitesell, A A Leslie Gunatilaka
Withanolides constitute a valuable class of bioactive natural products because some members of the class are known to exhibit cytotoxic activity and also induce a cytoprotective heat-shock response. In order to understand the relationship between their structures and these dual bioactivities of the withanolide scaffold, we obtained 25 analogues of withaferin A (WA) and withanolide D (WD) including 17 new compounds by semisynthesis involving chemical and microbial transformations. Hitherto unknown 16β-hydroxy analogues of WA and WD were prepared by their reaction with triphenylphosphine/iodine, providing unexpected 5β-hydroxy-6α-iodo analogues (iodohydrins) followed by microbial biotransformation with Cunninghamella echinulata and base-catalyzed cyclization of the resulting 16β-hydroxy iodohydrins...
March 14, 2018: Journal of Natural Products
Yuan Li, Wan Zhang, Hui Zhang, Wenya Tian, Lian Wu, Shuwen Wang, Mengmeng Zheng, Jinru Zhang, Chenghai Sun, Zixin Deng, Yuhui Sun, Xudong Qu, Jiahai Zhou
Polyketides are a large family of pharmaceutically important natural products, and the structural modification of their scaffolds is significant for drug development. Herein, we report one apo- and two complex structures (with a pentynylmalonyl and benzylmalonyl, respectively) of the broadly selective acyltransferase (AT) from the splenocin polyketide synthase. These structures revealed the molecular basis of the stereo-selectivity and substrate specificity of SpnD-AT and enabled engineering the industrially important Ery-AT6 to broaden its substrate scope to include three new types of extender units...
March 14, 2018: Angewandte Chemie
Lili Jiang, Zhifeng Ren, Shuo Chen, Qinyong Zhang, Xiong Lu, Hongping Zhang, Guojiang Wan
This paper reports a novel loofah-derived hierarchical scaffold to obtain three-dimensional biocarbon-graphene-TiO2 (BC-G-TiO2 ) composite materials as electrodes for supercapacitors. The loofah scaffold was first loaded with G and TiO2 by immersing, squeezing, and loosening into the mixed solution of graphene oxide and titania, and then carbonized at 900 °C to form the BC-G-TiO2 composite. The synergistic effects of the naturally hierarchical biocarbon structure, graphene, and TiO2 nanoparticles on the electrochemical properties are analyzed...
March 13, 2018: Scientific Reports
Chao Han, Shanshan Wang, Zhongrui Li, Chen Chen, Jiqin Hou, Dingqiao Xu, Ruizhi Wang, Yaolan Lin, Jianguang Luo, Lingyi Kong
Countercurrent chromatography (CCC) has gradually become a widely used method for preparative separation of bioactive natural molecules. These molecules generally contain distinct scaffolds and characteristics that cannot be readily isolated from plants. While one-dimensional CCC is typically used for the initial purification with insufficiently resolved peaks after locating bioactive components, two-dimensional (2D) or multi-dimensional CCC strategies are employed to improve the resolution of peaks. However, these methods usually present certain disadvantages, such as complicated procedures and increased time consumption, experimental costs, and equipment requirements...
August 3, 2018: Analytica Chimica Acta
Fengkun Chen, Takayuki Tanaka, Tadashi Mori, Atsuhiro Osuka
Polycyclic heteroaromatic compounds including pyrrole units are promising functional scaffolds owing to their electron-rich nature, bright fluorescence, and applicability to anion recognition at the pyrrolic hydrogen. We report herein the effective synthesis of pseudo-aza[5]helicene and aza[7]helicene derivatives, and unexpected formation of azahepta[8]circulenes by oxidative fusion reactions. By choosing reaction conditions and peripheral substituents attached at the terminal indole moieties, we obtained aza[7]helicenes 10a-c and azahepta[8]circulenes 11a,c selectively in moderate to good yields...
March 13, 2018: Chemistry: a European Journal
Ralph Freund, Ulrich Lächelt, Tobias Gruber, Bastian Rühle, Stefan Wuttke
Green chemistry, in particular, the principle of atom economy, has defined new criteria for the efficient and sustainable production of synthetic compounds. In complex nanomaterials, the number of embedded functional entities and the energy expenditure of the assembly process represent additional compound-associated parameters that can be evaluated from an economic viewpoint. In this Perspective, we extend the principle of atom economy to the study and characterization of multifunctionality in nanocarriers, which we define as "multifunctional efficiency"...
March 13, 2018: ACS Nano
Lindon W K Moodie, Gunnar Cervin, Rozenn Trepos, Christophe Labriere, Claire Hellio, Henrik Pavia, Johan Svenson
By combining the recently reported repelling natural dihydrostilbene scaffold with an oxime moiety found in many marine antifoulants, a library of nine antifouling hybrid compounds was developed and biologically evaluated. The prepared compounds were shown to display a low antifouling effect against marine bacteria but a high potency against the attachment and growth of microalgae down to MIC values of 0.01 μg/mL for the most potent hybrid. The mode of action can be characterized as repelling via a reversible non-toxic biostatic mechanism...
March 13, 2018: Marine Biotechnology
Bastian Vögeli, Sylvain Engilberge, Eric Girard, François Riobé, Olivier Maury, Tobias J Erb, Seigo Shima, Tristan Wagner
Many reactions within a cell are thermodynamically unfavorable. To efficiently run some of those endergonic reactions, nature evolved intermediate-channeling enzyme complexes, in which the products of the first endergonic reactions are immediately consumed by the second exergonic reactions. Based on this concept, we studied how archaea overcome the unfavorable first reaction of isoprenoid biosynthesis-the condensation of two molecules of acetyl-CoA to acetoacetyl-CoA catalyzed by acetoacetyl-CoA thiolases (thiolases)...
March 12, 2018: Proceedings of the National Academy of Sciences of the United States of America
Orestis G Andriotis, Sylvia Desissaire, Philipp J Thurner
Tissue hydration is well known to influence tissue mechanics and can be tuned via osmotic pressure. Collagen fibrils are nature's nanoscale building blocks to achieve biomechanical function in a broad range of biological tissues and across many species. Intrafibrillar covalent cross-links have long been thought to play pivotal role for collagen fibril elasticity, but predominantly at large, far from physiological, strains. Performing nanotensile experiments of collagen fibrils at varying hydration levels by adjusting osmotic pressure in situ during atomic force microscopy experiments, we show the power the intrafibrillar non-covalent interactions have for defining collagen fibril tensile elasticity at low fibril strains...
March 12, 2018: ACS Nano
Zheyong Xue, Zhengwei Tan, Ancheng Huang, Yuan Zhou, Juncong Sun, Xiaoning Wang, Ramesha B Thimmappa, Michael J Stephenson, Anne Osbourn, Xiaoquan Qi
Triterpene synthases, also known as 2,3-oxidosqualene cyclases (OSCs), synthesize diverse triterpene skeletons that form the basis of an array of functionally divergent steroids and triterpenoids. Tetracyclic and pentacyclic triterpene skeletons are synthesized via protosteryl and dammarenyl cations, respectively. The mechanism of conversion between two scaffolds is not well understood. Here, we report a promiscuous OSC from rice (Oryza sativa) (OsOS) that synthesizes a novel pentacyclic triterpene orysatinol as its main product...
March 12, 2018: New Phytologist
Vaibhav Singh Bais, Balaram Mohapatra, Nadim Ahamad, Sanjana Boggaram, Sandeep Verma, Balaji Prakash
Tuberculosis - a disease caused by Mycobacterium tuberculosis (Mtb), is one of the most devastating disease. The discovery of Ser/Thr protein kinases (STPKs) in Mtb opened a new avenue for developing anti-tubercular inhibitors. The in-vivo inhibitory effects of many metal ions have been demonstrated in literature. But, one of the limitations of metal ions as inhibitors is their inability to traverse the hydrophobic membrane due to polar nature and their propensity for non-specific interactions. To overcome this, we attached a metal ion to 2-A9P - an analog derived from a cell permeable scaffold, 2-Aminopurine (2-AP) which is a known kinase inhibitor...
January 2018: Tuberculosis
Mohammad-Hossein Beigi, Atefeh Atefi, Hamid-Reza Ghanaei, Sheyda Labbaf, Fatemeh Ejeian, Mohammad-Hossein Nasr-Esfahani
In the current study the effect of superimposing platelet-rich plasma (PRP) on different culture mediums in a three-dimensional (3D) alginate scaffold encapsulated with adipose mesenchymal stem cells (ADSCs) for cartilage tissue repair is reported. The 3D alginate scaffolds with co-administration of PRP and/or chondrogenic supplements had a significant effect on the differentiation of ADSCs into mature cartilage, as assessed by evaluation of the expression of cartilage related markers of Sox9, Collagen II, Aggrecan and collagen and glycosaminoglycan assays...
March 9, 2018: Journal of Tissue Engineering and Regenerative Medicine
Teofil Jesionowski, Małgorzata Norman, Sonia Żółtowska-Aksamitowska, Iaroslav Petrenko, Yvonne Joseph, Hermann Ehrlich
The biosynthesis, chemistry, structural features and functionality of spongin as a halogenated scleroprotein of keratosan demosponges are still paradigms. This review has the principal goal of providing thorough and comprehensive coverage of spongin as a naturally prefabricated 3D biomaterial with multifaceted applications. The history of spongin's discovery and use in the form of commercial sponges, including their marine farming strategies, have been analyzed and are discussed here. Physicochemical and material properties of spongin-based scaffolds are also presented...
March 9, 2018: Marine Drugs
Mohammed Benadallah, Oualid Talhi, Fatiha Nouali, Nourredine Choukchou-Braham, Khaldoun Bachari, Artur M S Silva
The present review deals with the progress in medicinal chemistry of spirocyclic compounds, a wider class of natural and synthetic organic molecules, defined as a hybrid of two molecular entities covalently linked via a unique tetrahedral carbon. This spiro central carbon confers to the molecules a tridimensional structurally oriented framework, which is found in many medicinally relevant compounds, a well-known example is the anti-hypertensive spironolactone. Various bioactive natural products possess the privileged spiro linkage and different chemo-types thereof become synthetically accessible since the 20th century...
March 9, 2018: Current Medicinal Chemistry
Okiemute Rosa Johnson-Ajinwo, Imran Ullah, Haddijatou Mbye, Alan Richardson, Paul Horrocks, Wen-Wu Li
Thymoquinone (TQ), 2-isopropyl-5-methyl-1,4-benzoquinone, a natural product isolated from Nigella sativa L., has previously been demonstrated to exhibit antiproliferative activity in vitro against a range of cancers as well as the human malarial parasite Plasmodium falciparum. We describe here the synthesis of a series of analogues of TQ that explore the potential for nitrogen-substitution to this scaffold, or reduction to a hydroquinone scaffold, in increasing the potency of this antiproliferative activity against ovarian cancer cell lines and P...
February 27, 2018: Bioorganic & Medicinal Chemistry Letters
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