Read by QxMD icon Read

Click chemistry

Han Zuilhof, Digvijay Gahtory, Rickdeb Sen, Andriy R Kuzmyn, Jorge Escorihuela
Novel click reactions are of continued interest in fields as diverse as bio-conjugation, polymer science and surface chemistry. Qualification as a proper 'click' reaction requires stringent criteria, including fast kinetics and high conversion, to be met. Herein, we report a novel strain-promoted cycloaddition between cyclopropenes and o-quinones in solution and on a surface. We demonstrate the 'click character' of the reaction in solution and on surfaces for both monolayer and polymer brush functionalization...
March 15, 2018: Angewandte Chemie
Koshonna Brown, Ted Thurn, Lun Xin, William Liu, Remon Bazak, Si Chen, Barry Lai, Stefan Vogt, Chris Jacobsen, Tatjana Paunesku, Gayle E Woloschak
Titanium dioxide (TiO2 ) nanoparticles are produced for many different purposes, including development of therapeutic and diagnostic nanoparticles for cancer detection and treatment, drug delivery, induction of DNA double-strand breaks, and imaging of specific cells and subcellular structures. Currently, the use of optical microscopy, an imaging technique most accessible to biology and medical pathology, to detect TiO2 nanoparticles in cells and tissues ex vivo is limited with low detection limits, while more sensitive imaging methods (transmission electron microscopy, X-ray fluorescence microscopy, etc...
January 2018: Nano Research
Zhengyuan Zhou, Satish K Chitneni, Nick Devoogdt, Michael R Zalutsky, Ganesan Vaidyanathan
In a previous study, we evaluated a HER2-specific single domain antibody fragment (sdAb) 2Rs15d labeled with18 F via conjugation of a residualizing prosthetic agent that was synthesized by copper-catalyzed azide-alkyne cycloaddition (CuAAC). In order to potentially increase overall efficiency and decrease the time required for labeling, we now investigate the use of a strain-promoted azide-alkyne cycloaddition (SPAAC) between the 2Rs15d sdAb, which had been pre-derivatized with an azide-containing residualizing moiety, and an18 F-labeled aza-dibenzocyclooctyne derivative...
March 10, 2018: Bioorganic & Medicinal Chemistry
Katyayani Tatiparti, Samaresh Sau, Kaustubh A Gawde, Arun K Iyer
Triple negative breast cancer (TNBC) is a difficult to treat disease due to the absence of the three unique receptors estrogen, progesterone and herceptin-2 (HER-2). To improve the current therapy and overcome the resistance of TNBC, there is unmet need to develop an effective targeted therapy. In this regard, one of the logical and economical approaches is to develop a tumor hypoxia-targeting drug formulation platform for selective delivery of payload to the drug-resistant and invasive cell population of TNBC tumors...
March 13, 2018: International Journal of Molecular Sciences
Della S Shin, Emi Y Tokuda, Jennifer L Leight, Connor E Miksch, Tobin E Brown, Kristi S Anseth
Proteases are involved in almost every important cellular activity, from embryonic morphogenesis to apoptosis. To study protease activity in situ , hydrogels provide a synthetic mimic of the extracellular matrix (ECM) and have utility as a platform to study activity, such as those related to cell migration, in three-dimensions. While 3-dimensional visualization of protease activity could prove quite useful to elucidate the proteolytic interaction at the interface between cells and their surrounding environment, there has been no versatile tool to visualize local proteolytic activity in real time...
2018: ACS Biomaterials Science & Engineering
Lucía Martínez-Jothar, Sofia Doulkeridou, Raymond M Schiffelers, Javier Sastre Torano, Sabrina Oliveira, Cornelus F van Nostrum, Wim E Hennink
Maleimide-thiol chemistry is widely used for the design and preparation of ligand-decorated drug delivery systems such as poly(lactide-co-glycolide) (PLGA) based nanoparticles (NPs). While many publications on nanocarriers functionalized exploiting this strategy are available in the literature, the conditions at which this reaction takes place vary among publications. This paper presents a comprehensive study on the conjugation of the peptide cRGDfK and the nanobody 11A4 (both containing a free thiol group) to maleimide functionalized PLGA NPs by means of the maleimide-thiol click reaction...
March 8, 2018: Journal of Controlled Release: Official Journal of the Controlled Release Society
Scott K Ferguson, Julie W Harral, David I Pak, Katherine M Redinius, Kurt R Stenmark, Dominik J Schaer, Paul W Buehler, David C Irwin
Free hemoglobin (Hb) associated with hemolysis extravasates into vascular tissue and depletes nitric oxide (NO), which leads to impaired vascular function and could impair skeletal muscle metabolic control during exercise. We tested the hypothesis that: 1) free Hb would extravasate into skeletal muscle tissue, reducing the contracting skeletal muscle O2 delivery/O2 utilization ratio (microvascular PO2 , PO2 mv) to a similar extent as that observed following NO synthase (NOS) blockade, and 2) that the Hb scavenging protein haptoglobin (Hp) would prevent Hb extravasation and inhibit these skeletal muscle tissue effects...
March 8, 2018: Nitric Oxide: Biology and Chemistry
Yi Xie, Shengqiu Chen, Yihui Qian, Weifeng Zhao, Changsheng Zhao
In this paper, a photo-responsive bactericidal and bacteria-resistant membrane was successfully prepared via the integration of atom transfer radical polymerization (ATRP) and click chemistry. Azide-functionalized polycationic poly (N, N-dimethyl-N-(2-(methacryloyloxy)ethyl)-N-((2-nitrobenzyl)oxy)-2-oxoethanaminium bromide) (PDMAEMA-NBE) was synthesized by ATRP. Then, the PDMAEMA-NBE was clicked on alkynyl-functionalized polyethersulfone (PES) membrane surface, and proved by X-ray photoelectron spectrometer (XPS)...
March 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Alessandra Romanelli, Alessandra Affinito, Concetta Avitabile, Silvia Catuogno, Paola Ceriotti, Margherita Iaboni, Jessica Modica, Geroloma Condorelli, Daniele Catalucci
Small therapeutic peptides represent a promising field for the treatment of pathologies such as cardiac diseases. However, the lack of proper target-selective carriers hampers their translation towards a potential clinical application. Aptamers are cell-specific carriers that bind with high affinity to their specific target. However, some limitations on their conjugation to small peptides and the functionality of the resulting aptamer-peptide chimera exist. Here, we generated a novel aptamer-peptide chimera through conjugation of the PDGFRβ-targeting Gint4...
2018: PloS One
Pedro Merino, Mattia Ghirardello, Daniela Perrone, Nicola Chinaglia, David Sadaba, Ignacio Delso, Tomas Tejero, Elena Marchesi, Marco Fogagnolo, Karim Rafie, Daan M F van Aalten
A series of glycomimetics of UDP-GlcNAc in which the β-phosphate has been replaced by either an alkyl chain or a triazolyl ring and the sugar moiety has been replaced by a pyrrolidine ring have been synthesized by using different click-chemistry procedures. Their affinity for human O-GlcNAc transferase (hOGT) has been evaluated and both spectroscopically and computationally studied. The binding epitopes of the best ligands have been determined in solution using saturation transfer difference (STD) NMR spectroscopy...
March 7, 2018: Chemistry: a European Journal
Nabil Bensabeh, Joan Carlos Ronda, Marina Galia, Virginia Cadiz, Gerard Lligadas, Virgil Percec
Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP) of (-)-menthyl acrylate, a biobased hydrophobic monomer, was investigated at 25 ºC in ethanol, iso-propanol, ethyl lactate, 2,2,2-trifluoroethanol (TFE) and 2,2,3,3-tetrafluoropropanol (TFP). All solvents are known to promote, in the presence of N-ligands, the mechanistically required self-regulated disproportionation of Cu(I)Br into Cu(0) and Cu(II)Br2 . Both fluorinated alcohols brought out their characteristics of universal SET-LRP solvents and showed the proper polarity balance to mediate an efficient polymerization of this bulky and hydrophobic monomer...
March 7, 2018: Biomacromolecules
Svetlana V Vasilyeva, Inga R Grin, Boris P Chelobanov, Dmitry A Stetsenko
A conjugate of triphosphorylated 2',3'-dideoxyuridine (ddU) with SiO2 nanoparticles was obtained via the CuAAC click chemistry between a γ-alkynyl ddU triphosphate and azido-modified SiO2 nanoparticles. Assessment of cytotoxicity in human breast adenocarcinoma MCF7 cells demonstrated that ddU triphosphate conjugated to SiO2 nanoparticles exhibited a 50% decrease in cancer cell growth at a concentration of 183 ± 57 µg/mL, which corresponds to 22 ± 7 µM of the parent nucleotide, whereas the parent nucleoside, nucleotide and alkynyl triphosphate precursor do not show any cytotoxicity...
February 7, 2018: Bioorganic & Medicinal Chemistry Letters
Leila S Saleh, Maria Carles-Carner, Stephanie J Bryant
Poly(ethylene glycol) PEG-based hydrogels are promising for cell encapsulation and tissue engineering, but are known to elicit a foreign body response (FBR) in vivo. The goal of this study was to investigate the impact of the FBR, and specifically the presence of inflammatory macrophages, on encapsulated cells and their ability to synthesize new extracellular matrix. This study employed an in vitro co-culture system with murine macrophages and MC3T3-E1 pre-osteoblasts encapsulated in a bone-mimetic hydrogel, which were cultured in transwell inserts, and exposed to an inflammatory stimulant, lipopolysaccharide (LPS)...
March 2, 2018: Acta Biomaterialia
Duo Mao, Fang Hu, Kenry, Shenglu Ji, Wenbo Wu, Dan Ding, Deling Kong, Bin Liu
Bacterial infection is one of the most serious physiological conditions threatening human health. There is an increasing demand for more effective bacterial diagnosis and treatment through noninvasive theranostic approaches. Herein, a new strategy is reported to achieve in vivo metabolic labeling of bacteria through the use of MIL-100 (Fe) nanoparticles (NPs) as the nanocarrier for precise delivery of 3-azido-d-alanine (d-AzAla). After intravenous injection, MIL-100 (Fe) NPs can accumulate preferentially and degrade rapidly within the high H2 O2 inflammatory environment, releasing d-AzAla in the process...
March 5, 2018: Advanced Materials
Pratima Vabbilisetty, Mallorie Boron, Huan Nie, Evgeny Ozhegov, Xue-Long Sun
Introduction of selectively chemical reactive groups at the cell surface enables site-specific cell surface labeling and modification opportunity, thus facilitating the capability to study the cell surface molecular structure and function and the molecular mechanism it underlies. Further, it offers the opportunity to change or improve a cell's functionality for interest of choice. In this study, two chemical reactive anchor lipids, phosphatidylethanolamine-poly(ethylene glycol)-dibenzocyclooctyne (DSPE-PEG2000 -DBCO) and cholesterol-PEG-dibenzocyclooctyne (CHOL-PEG2000 -DBCO) were synthesized and their potential application for cell surface re-engineering via lipid fusion were assessed with RAW 264...
February 28, 2018: ACS Omega
Martina Dvořáčková, Jiří Fajkus
Thanks to recent innovative methodologies, key cellular processes such as replication or transcription can be visualized directly in situ in intact tissues. Many studies use so-called click iT chemistry where nascent DNA can be tracked by 5-ethynyl-2'-deoxyuridine (EdU), and nascent RNA by 5-ethynyl uridine (EU). While the labeling of replicating DNA by EdU has already been well established and further exploited in plants, the use of EU to reveal nascent RNA has not been developed to such an extent. In this article, we present a protocol for labeling of nucleolar RNA transcripts using EU and show that EU effectively highlights the nucleolus...
2018: Frontiers in Plant Science
Hanmanth Reddy Vulupala, Yasodakrishna Sajja, Pankaj K Bagul, Raviteja Bandla, Lingaiah Nagarapu, Sanjay K Benerjee
A novel triazole derivatives(±)-2-(hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b]furan-6(2H)-one (12a-j) were designed and synthesized by the reaction between racemic azide and terminal acetylenes under click chemistry reaction conditions followed by biological evaluation as angiotensin converting enzyme (ACE) inhibitors. β-Amino alcohol derivatives of 1-indanone (15a-l) were synthesized from 5-hydroxy indanone, it was reacted with epichlorohydrin and followed by oxirane ring opening with various piperazine derivatives...
February 24, 2018: Bioorganic Chemistry
Oihane K Arriortua, Maite Insausti, Luis Lezama, Izaskun Gil de Muro, Eneko Garaio, Jesus Martínez de la Fuente, Raluca M Fratila, Maria P Morales, Rocío Costa, Maite Eceiza, Maialen Sagartzazu-Aizpurua, Jesus M Aizpurua
To improve the selectivity of magnetic nanoparticles for tumor treatment by hyperthermia, Fe3 O4 nanoparticles have been functionalized with a peptide of the type arginine-glycine-aspartate (RGD) following a "click" chemistry approach. The RGD peptide was linked onto the previously coated nanoparticles in order to target αv β3 integrin receptors over-expressed in angiogenic cancer cells. Different coatings have been analyzed to enhance the biocompatibility of magnetic nanoparticles. Monodispersed and homogeneous magnetite nanoparticles have been synthesized by the seed growth method and have been characterized using X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, transmission electron microscopy and magnetic measurements...
February 15, 2018: Colloids and Surfaces. B, Biointerfaces
Wenshu Zheng, Huiling Li, Wenwen Chen, Jiangjiang Zhang, Nuoxin Wang, Xuefeng Guo, Xingyu Jiang
A fast (1 min), straightforward but efficient, click chemistry-based system that enables the rapid detection of free copper (Cu) ions in either biological fluids or living cells without tedious pretreatment is provided. Cu can quickly induce the conjugation between graphene oxide (GO) and a fluorescent dye via click reaction. On the basis of the high specificity of bioorthogonal reaction and the effective quenching ability of GO, the assay studied in this paper can respond to Cu ions in less than 1 min with excellent selectivity and sensitivity, which is the fastest sensor for Cu as far as it is known...
March 1, 2018: Small
Jan K Szymański, Yousef M Abul-Haija, Leroy Cronin
Millions of years of biological evolution have driven the development of highly sophisticated molecular machinery found within living systems. These systems produce polymers such as proteins and nucleic acids with incredible fidelity and function. In nature, the precise molecular sequence is the factor that determines the function of these macromolecules. Given that the ability to precisely define sequence emerges naturally, the fact that biology achieves unprecedented control over the unit sequence of the monomers through evolved enzymatic catalysis is incredible...
March 1, 2018: Accounts of Chemical Research
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"