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Bioconjugate Chemistry

Mengli Feng, Zhiyuan Ruan, Jiachen Shang, Lu Xiao, Aijun Tong, Yu Xiang
G-quadruplex-containing DNAzymes and aptamers are widely applied in many research fields because of their high stability and prominent activities versus the protein counterparts. In this work, G-quadruplex DNAs were equipped with photolabile groups to construct photocaged DNAzymes and aptamers. We incorporated TEEP-OH (thioether-enol phosphate, phenol substituted) into phosphodiester backbone of G-quadruplex DNA by a facile postsynthetic method to achieve efficient photocaging of their activities. Upon light irradiation, the peroxidase-mimicking activity of the caged G-quadruplex DNAzyme was activated, through the transformation of TEEP-OH into a native DNA phos-phodiester without any artificial scar...
December 9, 2016: Bioconjugate Chemistry
Svetlana Avvakumova, Elisabetta Galbiati, Laura Sironi, Silvia A Locarno, Luca Gambini, Chiara Macchi, Laura Pandolfi, Massimiliano Ruscica, Paolo Magni, Maddalena Collini, Miriam Colombo, Fabio Corsi, Giuseppe Chirico, Sergio Romeo, Davide Prosperi
Gold nanocages (AuNCs) have been shown to be a useful tool for harnessing imaging and hyperthermia therapy of cancer, thanks to their unique optical properties, low toxicity and facile surface functionalization. Herein, we use AuNCs for selective targeting of prostate cancer cells (PC3) via specific interaction between neuropeptide Y (NPY) receptor and three different NPY analogs conjugated to AuNCs. Localized surface plasmon band of the nanoconjugates was set around 800 nm, which is appropriate for in vivo applications...
November 3, 2016: Bioconjugate Chemistry
Iván Acebrón, Amalia G Ruiz-Estrada, Yurena Luengo, María Del Puerto Morales, José Manuel Guisán, José Miguel Mancheño
Design of generic methods aimed at the oriented attachment of proteins at the interfacial environment of magnetic nanoparticles currently represents an active field of research. With this in mind, we have prepared and characterized agarose-coated maghemite nanoparticles to set up a platform for the attachment of recombinant proteins fused to the β-trefoil lectin domain LSL150, a small protein that combines fusion tag properties with agarose-binding capacity. Analysis of the agarose-coated nanoparticles by dynamic light scattering, Fourier transform infrared spectroscopy, and thermogravimetric studies shows that decoupling particle formation from agarose coating provides better results in terms of coating efficiency and particle size distribution...
November 3, 2016: Bioconjugate Chemistry
Lixiang Liu, Bingxia Li, Qiyan Wang, Zhipeng Dong, Hongmei Li, Qiaomei Jin, Hao Hong, Jian Zhang, Yue Wang
Metal-organic complexes (MOCs) are emerging developing functional materials, the different categories of metal ions and organic biomolecules provide great possibilities for the morphologies, sizes and properties of the products. Enlightened by the previous works of folate-nickel nanotubes (FA-Ni NTs), herein, a series of metal ions are tested to coordinate with folate (FA) by solvothermal method, among which folate-cobalt (2+) complex is formed to be a scaffold for the nanotube with the length of 150-500 nm and inner diameter of 6-11 nm, while the other metal ions fail...
November 1, 2016: Bioconjugate Chemistry
Shrey Sindhwani, Abdullah Muhammad Syed, Stefan Wilhelm, Warren C W Chan
Three dimensional (3D) optical imaging of nanoparticle distribution within cells and tissues can provide insights into barriers to nanoparticle transport in vivo. However, this approach requires the preparation of optically transparent samples using harsh chemical and physical methods which can lead to a significant loss of nanoparticles and decreased sensitivity of subsequent analyses. Here, we investigate the influence of electrophoresis and clearing time on nanoparticle retention within intact tissues and the impact of these factors on the final 3D image quality...
November 1, 2016: Bioconjugate Chemistry
Yuming Yu, Mary J Sabulski, Wiley A Schell, Marcos Moura Pires, John Perfect, Steven L Regen
A strategy has been devised for increasing the cellular selectivity of membrane-disrupting antibiotics based on the attachment of a facially amphiphilic sterol. Using Amphotericin B (AmB) as a prototype, covalent attachment of cholic acid bound to a series of α,ω-diamines has led to a dramatic reduction in hemolytic activity, a significant reduction in toxicity towards HEK293T cells, and significant retention of antifungal activity.
November 1, 2016: Bioconjugate Chemistry
Ashley Kroll, Ronnie H Fang, Liangfang Zhang
The cell membrane-coated nanoparticle is a biomimetic platform consisting of a nanoparticulate core coated with membrane derived from a cell, such as a red blood cell, platelet, or cancer cell. The cell membrane "disguise" allows the particles to be perceived by the body as the source cell by interacting with its surroundings using the translocated surface membrane components. The newly bestowed characteristics of the membrane-coated nanoparticle can be utilized for biological interfacing in the body, providing natural solutions to many biomedical issues...
October 31, 2016: Bioconjugate Chemistry
Yong Il Park, Eunha Kim, Chen-Han Huang, Ki Soo Park, Cesar M Castro, Hakho Lee, Ralph Weissleder
The use of inorganic nanoparticles (NPs) for biosensing requires that they exhibit high colloidal stability under various physiological conditions. Here, we report on a general approach to render hydrophobic NPs into hydrophilic ones, ready for bioconjugation. The method uses peglyated polymers conjugated with multiple dopamines, which results in multidentate coordination. As proof-of-concept, we applied the coating to stabilize ferrite and lanthanide NPs synthesized by thermal decomposition. Both polymer-coated NPs showed excellent water solubility and were stable at high salt concentrations under physiological conditions...
October 28, 2016: Bioconjugate Chemistry
Bharat P Gurale, Yun He, Xikai Cui, Hieu Dinh, Abasaheb N Dhawane, Naomi W Lucchi, Udhayakumar Venkatachalam, Suri S Iyer
A large number of proteins in malaria parasites are anchored using glycophosphatidylinositols (GPIs) with lipid tails. These GPIs are structurally distinct from human GPIs. Plasmodium falciparum GPIs have been considered as potential vaccine candidates as these molecules are involved in inducing inflammatory responses in human hosts and natural anti-GPI antibody responses have been shown to be associated with protection against severe disease. The GPIs can also be considered as targets for rapid diagnostic tests...
October 28, 2016: Bioconjugate Chemistry
Jaewon Lee, Seulgi Choi, Ki Hyun Kim, Hock Gan Heng, Sandra E Torregrosa-Allen, Benjamin S Ramsey, Bennett D Elzey, You-Yeon Won
X-ray computed tomography (CT) is currently one of the most powerful, non-invasive, clinical in vivo imaging techniques, which has resulted from advances in both X-ray device and contrast enhancement technologies. The present study demonstrates, for the first time, that metal tungstates (such as CaWO4) are promising contrast agents for X-ray, radiation and CT imaging, because of the high X-ray mass attenuation of tungsten (W). We have developed a method of formulation, in which CaWO4 (CWO) nanoparticles (NPs) are encapsulated within a bio-compatible poly(ethylene glycol-b-D,L-lactic acid) (PEG-PLA) block copolymer (BCP) capsule...
October 28, 2016: Bioconjugate Chemistry
Hong Yeol Yoon, Sangmin Jeon, Dong Gil You, Jae Hyung Park, Ick Chan Kwon, Heebeom Koo, Kwangmeyung Kim
Recently, nanotechnology has provided significant advances in biomedical applications including diagnosis and therapy. Particularly, nanoparticles have been emerged as valuable outcomes of nanotechnology due to their unique physicochemical properties based on size, shape and surface properties. Among them, large amount of researches has reported imaging and therapeutic applications using inorganic nanoparticles with special properties. Inorganic nanoparticles developed for imaging and therapy contain metal (Au), metal oxide (Fe3O4, WO3, WO2...
October 27, 2016: Bioconjugate Chemistry
Jan-Philip Meyer, Pierre Adumeau, Jason S Lewis, Brian M Zeglis
The advent of click chemistry has had a profound influence on almost all branches of chemical science. This is particularly true of radiochemistry and the synthesis of agents for positron emission tomography (PET), single photon emission computed tomography (SPECT), and targeted radiotherapy. The selectivity, ease, rapidity, and modularity of click ligations make them nearly ideally suited for the construction of radiotracers, a process that often involves working with biomolecules in aqueous conditions with inexorably decaying radioisotopes...
October 27, 2016: Bioconjugate Chemistry
Heebeom Koo, Sei Kwang Hahn, Seok Hyun Yun
We demonstrate a chemically detachable cell-glue system based on linkers containing disulfide bonds as well as functional groups for metabolic glycoengineering and bioorthogonal click chemistry. Azide groups are generated on the cell surface by metabolic glycoengineering, and they are further modified into tetrazine (Tz) or trans-cyclooctene (TCO) using rationally designed cross-linkers. When the Tz-modified and TCO-modified cells are mixed together, cell gluing between these two cell groups is established by Tz-TCO click chemistry...
October 27, 2016: Bioconjugate Chemistry
Chayanon Ngambenjawong, Julio Marco B Pineda, Suzie H Pun
Peptide cyclization is a strategy used to improve stability and/or activity of peptides. The most commonly used cyclization method is disulfide bridge formation of cysteine-containing peptides as typically found in nature. Over the years, an increasing number of alternative chemistries for peptide cyclization with improved efficiency, kinetics, orthogonality, and stability have been reported. However, there has been less appreciation for the opportunity to fine-tune peptide activity via the diverse chemical entities introduced at the site of linkage by different cyclization strategies...
October 25, 2016: Bioconjugate Chemistry
Jessica A Nash, Albert L Kwansa, James Samuel Peerless, Ho Shin Kim, Yaroslava G Yingling
Nanoparticles (NPs) play increasingly important roles in nanotechnology and nanomedicine where nanoparticle surface chemistry allows for control over interactions with other nanoparticles and biomolecules. In particular, for applications in drug and gene delivery, a fundamental understanding of the NP-nucleic acid interface allows for development of more efficient and effective nanoparticle carriers. Computational modeling can provide insights of processes occurring at the inorganic NP-nucleic interface, in detail which is difficult to access by experimental methods...
October 24, 2016: Bioconjugate Chemistry
Satadru Jha, Federico Ramadori, Santina Quarta, Alessandra Biasiolo, Enrica Fabris, Paola Baldan, Gaetano Guarino, Mariagrazia Ruvoletto, Gianmarco Villano, Cristian Turato, Angelo Gatta, Fabrizio Mancin, Patrizia Pontisso, Paolo Scrimin
One of the most daunting challenges of nanomedicine is the finding of appropriate targeting agents to deliver suitable payloads precisely to cells affected by malignancies. Even more complex is to achieve the ability to ensure the nanosystems enter those cells. Here we use 2 nm (metal core) gold nanoparticles to target human hepatocellular carcinoma (HepG2) cells stably transfected with the SERPINB3 (SB3) protein. The nanoparticles were coated with a 85:15 mixture of thiols featuring, respectively, a phosphoryl choline, to ensure water solubility and biocompatibility, and a 28-mer peptide corresponding to the amino acid sequence 21-47 of the hepatitis B virus-PreS1 protein (PreS1(21-47))...
October 22, 2016: Bioconjugate Chemistry
Yinnong Jia, Wenting Zhang, Wei Fan, Susan Brusnahan, Jered Garrison
The neurotensin receptor 1 (NTR1) has been shown to be a promising target, due to its increased level of expression relative to normal tissue, for pancreatic and colon cancers. This has prompted the development of a variety of NTR1-targeted radiopharmaceuticals, based on the neurotensin (NT) peptide, for diagnostic and radiotherapeutic applications. A major obstacle for the clinical translation of NTR1-targeted radiotherapeutics would likely be nephrotoxicity due to the high levels of kidney retention. It is well-known that for many peptide-based agents, renal uptake is influenced by the overall molecular charge...
October 21, 2016: Bioconjugate Chemistry
Alyssa B Chinen, Jennifer R Ferrer, Timothy J Merkel, Chad A Mirkin
Two synthetic approaches that allow one to control PEG content within spherical nucleic acids (SNAs) have been developed. One approach begins with RNA-modified gold nanoparticles followed by a backfill of PEG 2K alkanethiols, and the other involves co-adsorption of the two entities on a gold nanoparticle template. These two methods have been used to explore the role of PEG density on the chemical and biological properties of RNA-SNAs. Such studies show that while increasing the extent of PEGylation within RNA-SNAs extends their blood circulation half-life in mice, it also results in decreased cellular uptake...
October 20, 2016: Bioconjugate Chemistry
Martina Jezowska-Herrera, Dmytro Honcharenko, Alice Ghidini, Roger Stromberg, Malgorzata Honcharenko
An efficient method for synthesis of multiply functionalized oligonucleotides (ONs) utilizing a novel H-phosphonate-alkyne based Linker for Multiple Functionalization (LMF) is developed. The strategy allows for conjugation of various active entities to oligonucleotide through the post-synthetic attachment of LMF at the 5'-terminus of ONs using H-phosphonate chemistry followed by conjugation of various entities via [3+2] copper(I) catalysed cycloaddition in a stepwise manner. Each cycle is composed of attachment of the LMF followed by click reaction with azido containing units...
October 19, 2016: Bioconjugate Chemistry
Giulio F Paciotti, Jielu Zhao, Shugeng Cao, Peggy J Brodie, Lawrence Tamarkin, Marja Huhta, Lonnie D Myer, Jay Friedman, David G I Kingston
The synthesis of a series of thiolated paclitaxel analogs is described as part of a novel nanomedicine program aimed at developing formulations of paclitaxel that will bind to gold nanoparticles for tumor targeted drug delivery. Preliminary evaluation of the new nanomedicine composed of 27 nm gold nanoparticles, tumor necrosis factor alpha (TNFα), thiolated polyethylene glycol (PEG-thiol), and one of several thiolated paclitaxel analogs is presented.
October 18, 2016: Bioconjugate Chemistry
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