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Bioconjugate Chemistry

Qi Wang, Chun Zhang, Fangxia Guo, Zenglan Li, Yong Dong Liu, Zhiguo Su
In this paper, we reported a novel strategy for site specific PEGylation of proteins using elevated hydrostatic pressure. The process was similar to the conventional one except the reactor was under elevated hydrostatic pressure. The model protein was recombinant human ciliary neurotrophic factor (rhCNTF), and the reagent was mono-methoxy-polyethylene glycol-maleimide (mPEG-MAL). PEGylation with mPEG-40kDa-MAL at pH 7.0 under normal pressure for 5 hours achieved less than 5% yield. In comparison, when the pressure was elevated, the PEGylation yield was increased dramatically, reaching nearly 90% at 250 MPa...
October 20, 2017: Bioconjugate Chemistry
Nadezhda A Byzova, Irina V Safenkova, Elvira S Slutskaya, Anatoly V Zherdev, Boris B Dzantiev
This comprehensive study is related to gold nanoparticles (GNPs) conjugated with antibodies. The goal of the study is to determine the minimal concentration of antibodies for conjugate synthesis when the conjugates have high antigen-capturing activity. Two systems were studied: gold nanoparticles conjugated with monoclonal antibodies (mAb-GNP) specific to Helicobacter pylori and gold nanoparticles conjugated with polyclonal antibodies (pAb-GNP) specific to mouse immunoglobulins. Several conjugates were synthesized with different GNP-to-antibody molar ratios (from 1:1 to 1:245) through nondirectional and noncovalent immobilization on a surface of GNPs with a diameter of 25...
October 20, 2017: Bioconjugate Chemistry
Dominic Laaf, Pavla Bojarová, Helena Pelantová, Vladimír Křen, Lothar Elling
Galectin-3 (Gal-3), a member of the β-galactoside-binding lectin family, is a tumor biomarker and involved in tumor angiogenesis and metastasis. Gal-3 is therefore considered as a promising target for early cancer diagnosis and anticancer therapy. We here present the synthesis of a library of tailored multivalent neo-glycoproteins and evaluate their Gal-3 binding properties. By the combinatorial use of glycosyltransferases and chemo-enzymatic reactions, we first synthesized a set of N-acetyllactosamine (Galβ1,4GlcNAc; LacNAc type 2)-based oligosaccharides featuring five different terminating glycosylation epitopes, respectively...
October 18, 2017: Bioconjugate Chemistry
Divya Sharma, Jagdish Singh
The aim of this study was to synthesize and characterize fatty acid-grafted-chitosan (fatty acid-g-CS) polymer and their nanomicelles for using as carriers for gene delivery. CS was hydrophobically modified using saturated fatty acids of increasing fatty acyl chain length. Carbodiimide along with N-hydroxysuccinimide was used for coupling carboxyl group of fatty acids with amine groups of CS. Proton nuclear magnetic resonance and Fourier transform-infrared spectroscopy were used to quantify fatty acyl substitution onto CS backbone...
October 17, 2017: Bioconjugate Chemistry
Sakkarapalayam M Mahalingam, Vadim Y Dudkin, Shalom Goldberg, Donna Klein, Fang Yi, Sunil Singhal, Karyn T O'Neil, Philip S Low
Tumor-targeted near-infrared fluorescent dyes have the potential to improve cancer surgery by enabling surgeons to locate and resect more malignant lesions where good visualization tools are required to ensure complete removal of malignant tissue. Although the tumor-targeted fluorescent dyes used in humans to date have been either small organic molecules or high molecular weight antibodies, low molecular weight protein scaffolds have attracted significant attention because they penetrate solid tumors almost as efficiently as small molecules, but can be infinitely mutated to bind almost any antigen...
October 17, 2017: Bioconjugate Chemistry
Matthew Ryan Preiss, Eily Cournoyer, Karissa L Paquin, Elizabeth A Vuono, Kayla Belanger, Edward Walsh, Niall George Howlett, Geoffrey D Bothun
We present an approach to tune the multifunctionality of iron oxide nanoparticles (IONs) using mixed self-assembled monolayers of cationic lipid and anionic polyethylene glycol (PEG) lipid. By forming stable, monodispersed lipid coated IONs (L-IONs) through a solvent exchange technique, we were able to demonstrate the relationship between surface charge, the magnetic transverse relaxivity (r2 from T2 weighted images), and the binding capacity of small interfering ribonucleic acids (siRNAs) as a function of the cationic/anionic (PEG) lipid ratio...
October 16, 2017: Bioconjugate Chemistry
Weiqi Wang, Lei Wang, Shi Liu, Zhigang Xie
As a noninvasive treatment method, photothermal therapy (PTT) has been widely investigated for cancer therapy. In this work, metal-organic frameworks@polymer composites (UiO-66@CyP) with bioimaging and PTT activity were prepared by introducing cyanine-containing polymer (CyP) via multicomponent Passerini reaction in the presence of Zr-based nanoscale metal-organic frameworks (UiO-66). As-prepared UiO-66@CyP not only possesses uniformed size, controllable morphology, and excellent dispersibility in aqueous media, but also indicates strong near-infrared absorption and high photothermal conversion efficiency...
October 16, 2017: Bioconjugate Chemistry
Rishi Sharma, Soo-Young Kim, Anjali Sharma, Zhi Zhang, Siva Pramodh Kambhampati, Sujatha Kannan, Rangaramanujam M Kannan
Brain related disorders have outmatched cancer and cardiovascular diseases worldwide as the leading cause of morbidity and mortality. The lack of effective therapies and the relatively dry central nervous system (CNS) drug pipeline pose formidable challenge. Superior, targeted delivery of current clinically approved drugs may offer significant potential. Minocycline has shown promise for the treatment of neurological diseases owing to its ability to penetrate the blood brain barrier (BBB), and potency. Despite its potential in the clinic, and in preclinical models, the high doses needed to affect a positive therapeutic response has led to side effects...
October 13, 2017: Bioconjugate Chemistry
Hamilton Kakwere, Elizabeth S Ingham, Riley Allen, Lisa M Mahakian, Sarah M Tam, Hua Zhang, Matthew T Silvestrini, Jamal S Lewis, Katherine W Ferrara
Personalized cancer vaccines (PCVs) are receiving attention as an avenue for cancer immunotherapy. PCVs employ immunogenic peptide epitopes capable of stimulating the immune system to destroy cancer cells with great specificity. Challenges associated with effective delivery of these peptides include poor solubility of hydrophobic sequences, rapid clearance, and poor immunogenicity, among others. The incorporation of peptides into nanoparticles has the potential to overcome these challenges, but the broad range of functionalities found in amino acids presents a challenge to conjugation due to possible interferences and lack of reaction specificity...
October 13, 2017: Bioconjugate Chemistry
Xin Shang, Rui Lai, Xi Song, Hui Li, Wei Niu, Jiantao Guo
The 1,3-dipolar cycloaddition reaction between an alkene and a tetrazole represents one elegant and rare example of fluorophore-forming bioorthogonal chemistry. This is an attractive reaction for imaging applications in live cells that requires less intensive washing steps and/or needs spatiotemporal resolutions. In the present work, as an effort to improve the fluorogenic property of the alkene-tetrazole reaction, an aromatic alkene (styrene) was investigated as the dipolarophile. Over 30-fold improvement in quantum yield of the reaction product was achieved in aqueous solution...
October 12, 2017: Bioconjugate Chemistry
Derek Holman, Matthew P Lungren, Jonathan Hardy, Christopher H Contag, Francis G Blankenberg
Bacteriophages (phages) are ubiquitous viruses which have adapted to infect and replicate within target bacteria, their only known hosts, in a strain specific fashion with minimal cross infectivity. The recent steep rise in antibiotic resistance throughout the world has renewed interest in adapting phages for the imaging and treatment of bacterial infection in humans. In this article, we describe the current limitations surrounding the radiolabeling of phage for the imaging and treatment of bacterial infection and methods to overcome these difficulties...
October 11, 2017: Bioconjugate Chemistry
Jing Yu, Lei Sun, Jinge Zhou, Lipeng Gao, Lijuan Nan, Shimin Zhao, Ting Peng, Lin Han, Jing Wang, Weiyue Lu, Lin Zhang, Yiting Wang, Zhiqiang Yan, Lei Yu
To enhance the tumor-penetrating ability and targeting therapeutic effect of polymer-drug conjugates (PDCs), tumor-penetrating peptide RGERPPR (RGE) modified and PEGylated poly(l-γ-glutamylglutamine)-paclitaxel (PGG-PTX) nanoparticles (RGE-PEG/PGG-PTX NPs) were prepared by using a so-called "modular" design strategy. In brief, a RGERPPR-conjugated targeting material, DSPE-PEG-RGERPPR, was first synthesized and assembled with PGG-PTX into RGE-PEG/PGG-PTX NPs based on the hydrophobic interaction between the groups of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) and PTX...
October 10, 2017: Bioconjugate Chemistry
Steven R E Draper, Paul B Lawrence, Wendy M Billings, Qiang Xiao, Nathaniel P Brown, Natalie A Bécar, Derek J Matheson, Andrew R Stephens, Joshua L Price
The development of chemical strategies for site-specific protein modification now enables researchers to attach polyethylene glycol (PEG) to a protein drug at one or more specific locations (i.e., protein PEGylation). However, aside from avoiding enzyme active sites or protein-binding interfaces, distinguishing the optimal PEGylation site from the available alternatives has conventionally been a matter of trial and error. As part of a continuing effort to develop guidelines for identifying optimal PEGylation sites within proteins, we show here that the impact of PEGylation at various sites within the β-sheet model protein WW depends strongly on the identity of the PEG-protein linker...
October 9, 2017: Bioconjugate Chemistry
Chenjie Yao, Yusong Tu, Lin Ding, Chenchen Li, Jiao Wang, Haiping Fang, Yanan Huang, Kangkang Zhang, Quan Lu, Minghong Wu, Yanli Wang
Specific targeting of tumor tissues is essential for tumor imaging and therapeutics but remains challenging. Here, we report an unprecedented method using synthetic sulfonic-graphene quantum dots (sulfonic-GQDs) to exactly target the cancer cell nuclei in vivo without any bio- ligand modification, with no intervention in cells of normal tissues. The key factor for such selectivity is the high interstitial fluid pressure (IFP) in tumor tissues, which allows the penetration of sulfonic-GQDs into the plasma membrane of tumor cells...
October 6, 2017: Bioconjugate Chemistry
Chenchen Xu, Xiu Han, Yujie Jiang, Shengxiao Yuan, Ziheng Wu, Zhenghong Wu, Xiaole Qi
Although aptamers are well-known as cell-specific membrane biomarkers for tumor-targeted therapy, it is important to avoid their degradation by nucleases in vivo. In this study, we developed a MUC1 aptamer-doxorubicin nanoconjugate (APT-DOX) through an acid-labile linkage and embedded APT-DOX into a thermosensitive hydrogel for antitumor therapy. The hydrogels exhibit a sol-gel transition upon intratumoral injection, resulting in the protection and controlled release control of APT-DOX with the shielding of the gel network...
October 5, 2017: Bioconjugate Chemistry
Thaiesha A Wright, Melissa Lucius Dougherty, Benjamin Schmitz, Kevin M Burridge, Katherine Makaroff, Jamie M Stewart, Henry D Fischesser, Jerry T Shepherd, Jason A Berberich, Dominik Konkolewicz, Richard C Page
A thermophilic cellulase, FnCel5a, from Fervidobacterium nodosum was conjugated with various functional polymers including cationic, anionic, and strongly and weakly hydrogen bonding polymers. The activity of FnCel5a toward a high-molecular-weight carboxymethyl cellulose substrate was enhanced by polymer conjugation. Activity enhancements of 50% or greater observed for acrylamide and mixed N,N-dimethyl acrylamide-2-(N,N-dimethylamino)ethyl methacrylate polymers, suggesting that the greatest enhancements were caused by polymers capable of noncovalent interactions with the substrate...
October 5, 2017: Bioconjugate Chemistry
Valentina M Farzan, Egor A Ulashchik, Yury V Martynenko-Makaev, Maksim V Kvach, Ilya O Aparin, Vladimir A Brylev, Tatiana A Prikazchikova, Svetlana Yu Maklakova, Alexander G Majouga, Alexey V Ustinov, German A Shipulin, Vadim V Shmanai, Vladimir A Korshun, Timofei S Zatsepin
We developed a novel technique for the efficient conjugation of oligonucleotides with various alkyl azides such as fluorescent dyes, biotin, cholesterol, N-acetylgalactosamine (GalNAc), etc. using copper-catalysed alkyne-azide cycloaddition on the solid phase and CuI·P(OEt)3 as a catalyst. Conjugation is carried out in an oligonucleotide synthesizer in fully automated mode and is coupled to oligonucleotide synthesis and on-column deprotection. We also suggest a set of reagents for the construction of diverse conjugates...
October 4, 2017: Bioconjugate Chemistry
Yan Chen, Quan Zhou, Xue Li, Fa Wang, Kevin Heist, Rork D Kuick, Scott Owens, Thomas Wang
Hepatocellular carcinoma (HCC) is a common worldwide cancer that is rising rapidly in incidence. MRI is a powerful non-invasive imaging modality for HCC detection but lack of specific contrast agents limits visualization of small tumors. EGFR is frequently overexpressed in HCC and is a promising target. Peptides have fast binding kinetics, short circulatory half-life, low imaging background, high vascular permeability, and enhanced tissue diffusion for deep tumor penetration. We demonstrate a peptide specific for EGFR labeled with an ultra-small paramagnetic iron oxide (UPIO) nanoparticle with 3...
October 3, 2017: Bioconjugate Chemistry
Daquan Wang, Yibo Ren, Yongping Shao, Demei Yu, Lingjie Meng
In this work, we developed a bi-functional nanoplatform for targeted synergistic chemo-photothermal cancer treatment. The nanoplatform was constructed through a facile method, in which poly(N-vinyl pyrrole) (PVPy) was coated on cut multi-walled carbon nanotubes (c-MWNTs); and FA-PEG-SH was then linked by thiol-ene click reaction to improve the active targeting ability, water dispersibility, biocompatibility, and extend the circulation time in blood. The PVPy shell not only enhanced the photothermal effect of c-MWNTs significantly, but also provided a surface that could tailor targeting molecules and drugs...
October 2, 2017: Bioconjugate Chemistry
Zhu Jiang, Qixian Chen, Xi Yang, Xiyi Chen, Zhen Li, De-E Liu, Wei Li, Yingjie Lei, Hui Gao
Tetraphenylene (TPE), characterized to be a lipophilic and aggregation-induced-emissive fluorophore, was attempted to incorporate into an electrostatic self-assembled polyethyleneimine-poly(ethylene glycol) (PEI-PEG)/plasmid DNA (pDNA) complexed micelle. The hydrophobic character of TPE appeared to drive higher degree condensation of the pDNA payload, which consequently resulted in not only strengthened colloidal stability of the constructed polyplex micelle but also improved biocompatibility by virtue of the elevated PEG crowdedness owing to the TPE-induced collapse-down of pDNA...
September 29, 2017: Bioconjugate Chemistry
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