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Rafael Del Caño, Lucia Mateus, Guadalupe Sánchez-Obrero, José Manuel Sevilla, Rafael Madueño, Manuel Blázquez, Teresa Pineda
In this work, we report on the electrochemical behavior of bioconjugates prepared with gold nanoparticles (AuNP) capped with three different molecular layers (citrate anions, 6-mercaptopurine and ω-mercaptoundecanoic acid) and the protein hemoglobin (Hb). Freshly formed bioconjugates are deposited on a glassy carbon electrode and assayed for electroactivity. A pair of redox peaks with formal potential at -0.37V is obtained, in contrast with the free Hb protein that is inactive on the glassy carbon substrate...
January 1, 2018: Talanta
Marta García-Cortés, María Teresa Fernández-Argüelles, José M Costa-Fernández, Alfredo Sanz-Medel
Herein, high-quality Mn-doped ZnS quantum dots (QDs) have been synthesized using a facile approach directly in aqueous media. The surface of the obtained QDs was further modified by cap-exchange of the native cysteine shell with dihydrolipoic acid (DHLA) ligands resulting in nanocrystals with high water-stability having an intense phosphorescent signal. Covalent bioconjugation of the DHLA-coated nanoparticles with an anti-IgG antibody was then carried out. Interestingly the QD immunoprobe (QD-labelled antibodies) maintained an intense phosphorescence emission, without any significant spectral-shift (as compared to the free QDs)...
September 22, 2017: Analytica Chimica Acta
Siyao Liu, Jeannie Horak, Markus Höldrich, Michael Lämmerhofer
The ability to accurately quantify the protein coverage on nanoparticles is critical for assessing the quality of the surface chemistry and the success of the functionalization process of protein-nanoparticle conjugates. Surface coverage determination is therefore an integral part in the quality control of protein-modified nanoparticles in industrial nanotechnology. In this work, a novel and conventional method was established for direct quantification of the protein surface coverage on metallic nanoparticles...
October 9, 2017: Analytica Chimica Acta
Xiaofeng Fang, Xuanze Chen, Rongqin Li, Zhihe Liu, Haobin Chen, Zezhou Sun, Bo Ju, Yifei Liu, Sean Xiao-An Zhang, Dan Ding, Yujie Sun, Changfeng Wu
Aggregation induced emission (AIE) has attracted considerable interest for the development of fluorescence probes. However, controlling the bioconjugation and cellular labeling of AIE dots is a challenging problem. Here, this study reports a general approach for preparing small and bioconjugated AIE dots for specific labeling of cellular targets. The strategy is based on the synthesis of oxetane-substituted AIEgens to generate compact and ultrastable AIE dots via photo-crosslinking. A small amount of polymer enriched with oxetane groups is cocondensed with most of the AIEgens to functionalize the nanodot surface for subsequent streptavidin bioconjugation...
September 12, 2017: Small
Natalie M Rachel, Jacynthe L Toulouse, Joelle N Pelletier
General approaches for controlled protein modification are increasingly sought-after in the arena of chemical biology. Here, using bioorthogonal reactions, we present combinatorial chemoenzymatic strategies to effectuate protein labeling. Three metal-free conjugations were simultaneously or sequentially incorporated in a one-pot format with microbial transglutaminase (MTG) to effectuate protein labeling. MTG offers the particularity of conjugating residues with-in a protein sequence, rather than at its extremities, providing a route to labeling the native protein...
September 12, 2017: Bioconjugate Chemistry
Yang Li, Yanhong Duo, Shiyun Bao, Lisheng He, Kai Ling, Jinfeng Luo, Yue Zhang, Hao Huang, Han Zhang, Xiaofang Yu
DM1, a maytansine derivative, is a highly potential cytotoxic agent but with severe side effects; therefore, its application in clinical cancer therapy is limited. Here, in order to mitigate this intrinsic drawback of DM1, we developed mesoporous silica nanoparticles (MSNs) loaded with DM1 and surface-decorated with hydrochloride dopamine (PDA), polyethylene glycol (PEG), and epithelial cell adhesion molecule (EpCAM) aptamer (APt) for the targeted treatment of colorectal cancer (CRC). In this system, the PDA coating could be used as pH-sensitive gatekeepers to control the release of DM1 from MSNs in response to the pH stimulus and EpCAM APt-guided active targeting enables the increased delivery of DM1 to CRC as well as a reduction in toxicity and side effects by minimizing the exposure of normal tissues to DM1...
2017: International Journal of Nanomedicine
Burcin Akgun, Caishun Li, Yubin Hao, Gareth Lambkin, Ratmir Derda, Dennis G Hall
Fast, high-yielding and selective bioorthogonal 'click' reactions employing non-toxic reagents are in high demand for their great utility in the bioconjugation of biomolecules in live cells. Although a number of click reactions were developed for this purpose, many are associated with drawbacks and limitations that justify the development of alternative systems for both single- or dual-labeling applications. Recent reports highlighted the potential of boronic ester formation as a bioorthogonal click reaction between abiotic boronic acids and diols...
September 11, 2017: Journal of the American Chemical Society
Adrian Moreno, Diego Garcia, Marina Galia, Joan Carlos Ronda, Virginia Cadiz, Gerard Lligadas, Virgil Percec
Ethyl lactate (EtLa), a green and safe agrochemical solvent, is gifted with some properties that make it a good candidate for SET-LRP. It dissolves CuBr2, mediates an efficient disproportionation of CuBr in the presence of tris(2-(dimethylamino)ethyl)amine (Me6-TREN), and is capable to dissolve both aqueous (polar) and hydrocarbon (non-polar) soluble monomers and polymers. Here, we report that EtLa is an excellent solvent for the Cu(0) wire-catalyzed SET-LRP to produce both hydrophilic and hydrophobic polyacrylates that exhibit precise chain end functionality...
September 11, 2017: Biomacromolecules
Zhenghui Xu, Peter Michael Moyle
Traditional vaccines derived from attenuated or inactivated pathogens are effective at inducing antibody-based protective immune responses, but tend to be highly reactogenic, causing notable adverse effects. Vaccines with superior safety profiles can be produced by subunit approaches, utilizing molecularly defined antigens (e.g. proteins and polysaccharides). These antigens, however, often elicit poor immunological responses, necessitating the use of adjuvants. Immunostimulatory adjuvants have the capacity to activate antigen presenting cells directly through specific receptors (e...
September 11, 2017: Bioconjugate Chemistry
Diego Bouzas-Ramos, Marta García-Cortes, Alfredo Sanz-Medel, Jorge Ruiz Encinar, José M Costa-Fernández
Coupling of asymmetric flow field-flow fractionation (AF4) to an on-line elemental detection (inductively coupled plasma-mass spectrometry, ICP-MS) has been recently proposed as a powerful diagnostic tool for characterization of the bioconjugation of CdSe/ZnS core-shell Quantum Dots (QDs) to antibodies. Such approach has been used herein to demonstrate that cap exchange of the native hydrophobic shell of core/shell QDs with the bidentate dihydrolipoic acid ligands directly removes completely the eventual side nanoparticulated populations generated during simple one-pot synthesis, which can ruin the subsequent final bioapplication...
August 30, 2017: Journal of Chromatography. A
Wei Peng, Fei Ding
Chirality is a ubiquitous basic attribute of nature, which inseparably relates to the life activity of living organisms. However, enantiomeric differences have still failed to arouse enough attention during the biological evaluation and practical application of chiral substances, and this poses a large threat to human health. In the current study, we explore the enantioselective biorecognition of a chiral compound by an asymmetric biomolecule, and then decipher the molecular basis of such a biological phenomenon on the static and, in particular, the dynamic scale...
September 8, 2017: Molecular BioSystems
Andrzej Stanislaw Pitek, Yunmei Wang, Sahil Gulati, Huiyun Gao, Phoebe L Stewart, Daniel I Simon, Nicole F Steinmetz
Thrombotic cardiovascular disease, including acute myocardial infarction, ischemic stroke, and venous thromboembolic disease, is the leading cause of morbidity and mortality worldwide. While reperfusion therapy with thrombolytic agents reduces mortality from acute myocardial infarction and disability from stroke, thrombolysis is generally less effective than mechanical reperfusion and is associated with fatal intra-cerebral hemorrhage in up to 2-4% of patients. To address these limitations, we propose the tobacco mosaic virus (TMV)-based platform technology for targeted delivery of thrombolytic therapies...
September 7, 2017: Molecular Pharmaceutics
Philipp Leippe, Julia Koehler Leman, Dirk Trauner
Genetics and pharmacology are often seen as two distinct approaches to interrogating, elucidating, and manipulating biological systems. The former is renowned for its precision whereas the latter for its fast kinetics, reversibility, and practicality. Here, we show that both can be joined as "tethered pharmacology", wherein a genetically programmed bioconjugation site provides selectivity and a tethered pharmacophore provides function. The speed of onset, and especially cessation, of pharmacological activity can be greatly enhanced by incorporating photoswitches and using light as the trigger ("tethered photopharmacology")...
September 14, 2017: Biochemistry
Ariel L Furst, Matthew J Smith, Matthew B Francis
DNA has unique capabilities for molecular recognition and self-assembly, which have fostered its widespread incorporation into devices that are useful in science and medicine. Many of these platforms rely on thiol groups to tether DNA to gold surfaces, but this method is hindered by a lack of control over monolayer density and by secondary interactions between the nucleotide bases and the metal. In this work, we report an electrochemically activated bioconjugation reaction as a mild, reagent-free strategy to attach oligonucleotides to gold surfaces...
August 31, 2017: Journal of the American Chemical Society
Yanyi Xu, Derek Luong, Jason M Walker, David Dean, Matthew L Becker
Poly(propylene fumarate) (PPF) has been highlighted as one of the most promising materials for bone regeneration. Despite the promising advantages of using polymer scaffolds for biomedical applications, their inherent lack of bioactivity has limited their clinical application. In this study, PPF was successfully functionalized with Bioglass and a novel catechol-bearing peptide bioconjugate containing bioactive short peptide sequences of basic fibroblast growth factor, bone morphogenetic protein 2, and osteogenic growth peptide...
August 31, 2017: Biomacromolecules
Han Gu, Tak Ian Chio, Zhen Lei, Richard J Staples, Jennifer S Hirschi, Susan Bane
A recent addition to the suite of fast bioorthogonal reactions combines hydrazines and hydroxylamines with ortho-carbonyl substituted phenylboronic acids. Carbohydrazides are easily incorporated into biomolecules, making them appealing substrates in these reactions. Here we show that simple alkyl carbohydrazides form a single product with ortho-formylphenylboronic acid in an organic solvent and in the solid state. The solution structures of the products formed from the carbohydrazides in buffered aqueous solution, however, are markedly different from those identified in the organic solvent and solid state...
August 30, 2017: Organic & Biomolecular Chemistry
Céline Epaule, Andrey Maksimenko, Gérard Bastian, Joachim Caron, Didier Desmaële, Fatima Zouhiri, Patrick Couvreur, Jean Doucet
Currently, the in vivo distribution of drugs is investigated by non-spatial quantitative techniques. With the emergence of personal therapies using nanomedicines, deeper investigations are required to precisely know the in vivo fate of entrapped drugs, especially to predict possible toxicity. Here, we assess the capabilities of SR-μXRF for i) detecting drugs into nanomedicines without adding any marker, ii) mapping their distribution into tissues and iii) locally quantifying the drugs loaded into nanomedicines...
August 26, 2017: International Journal of Pharmaceutics
Roel Hammink, Loek J Eggermont, Themistoklis Zisis, Jurjen Tel, Carl G Figdor, Alan E Rowan, Kerstin G Blank
Water-soluble polyisocyanopeptides (PICs) are a new class of synthetic polymers that mimic natural protein-based filaments. Their unique semiflexible properties combined with a length of several hundred nanometers have recently enabled a number of biomedical applications ranging from tissue engineering to cancer immunotherapy. One crucial step toward the further development of PICs for these applications is the efficient and controlled synthesis and purification of PIC-biomolecule conjugates. Considering the large size of PICs and the biomolecules to be conjugated, conjugation reactions do usually not proceed to completion due to steric effects...
September 15, 2017: Bioconjugate Chemistry
Ozlem I Kalaoglu-Altan, Azize Kirac-Aydin, Burcu Sumer Bolu, Rana Sanyal, Amitav Sanyal
Biodegradable polymeric nanofibers have emerged as promising candidates for several biomedical applications such as tissue engineering and regenerative medicine. Many of these applications require modification of these nanofibers with small ligands or biomolecules such as peptides and other growth factors, which necessitates functionalization of these materials in mild and benign fashion. This study reports the design, synthesis and functionalization of such nanofibers and evaluates their application as a cell culture scaffold...
August 28, 2017: Bioconjugate Chemistry
Amanda G Jarvis, Lorenz Obrecht, Peter J Deuss, Wouter Laan, Emma K Gibson, Peter P Wells, Paul C J Kamer
Artificial metalloenzymes (ArMs) are hybrid catalysts that offer a unique opportunity to combine the superior performance of natural protein structures with the unnatural reactivity of transition-metal catalytic centers. Therefore, they provide the prospect of highly selective and active catalytic chemical conversions for which natural enzymes are unavailable. Herein, we show how by rationally combining robust site-specific phosphine bioconjugation methods and a lipid-binding protein (SCP-2L), an artificial rhodium hydroformylase was developed that displays remarkable activities and selectivities for the biphasic production of long-chain linear aldehydes under benign aqueous conditions...
August 25, 2017: Angewandte Chemie
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