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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
Patrícia Manuela Ribeiro Pereira, Sandrina Silva, Mafalda Bispo, Mónica da Rocha Zuzarte, Célia Gomes, Henrique Girão, José A S Cavaleiro, Carlos A Fontes Ribeiro, Joao P C Tome, Rosa Fernandes
Here we report the rational design of a new third-generation photosensitizer (PS), a chlorin conjugated with galactodendritic units, ChlGal8, to improve the effectiveness of bladder cancer treatment. ChlGal8 shows better photo-chemical and -physical properties than a recently reported homologous porphyrin, PorGal8. In addition to inheriting excellent photostability, ability to generate singlet oxygen and to interact with the proteins galectin-1 and human serum albumin (HSA), ChlGal8 exhibits high absorption in the red region of the electromagnetic spectrum...
October 17, 2016: Bioconjugate Chemistry
Katarzyna Szot-Karpińska, Piotr Golec, Adam Lesniewski, Barbara Palys, Frank Marken, Joanna Niedziółka-Jönsson, Grzegorz Wegrzyn, Marcin Łoś
With the advent of nanotechnology, carbon nanomaterials such as carbon nanofibers (CNF) have aroused substantial interest in various research fields including energy storage and sensing. Further improvement of their properties might be achieved via application of viral particles such as bacteriophages. In this report we present a filamentous M13 bacteriophage, with a point mutation in gene VII (pVII-mutant-M13), that selectively binds to the carbon nanofibers to form 3D structures. The phage-display technique was utilized for the selection of the pVII-mutant-M13 phage from the phage display peptide library...
October 17, 2016: Bioconjugate Chemistry
Alejandra Tello, Roberto Cao, María José Marchant, Humberto Gomez
Conformation constitutes a vital property of biomolecules, especially in the cases of enzymes and aptamers, and is essential in defining their molecular recognition ability. When biomolecules are immobilized on electrode surfaces, it is very important to have a control on all the possible conformational changes that may occur, either upon the recognition of their targets or by undesired alterations. Both, enzymes and aptamers, immobilized on electrodes are susceptible to conformational changes as a response to the nature of the charge of the surface and of the surrounding environment (pH, temperature, ionic strength, etc...
October 17, 2016: Bioconjugate Chemistry
Javad Garousi, Sarah Lindbo, Hadis Honarvar, Justin Velletta, Bogdan Mitran, Mohamed Altai, Anna Orlova, Vladimir Tolmachev, Sophia Hober
Radionuclide imaging-based stratification of patients to targeted therapies makes cancer treatment more personalized and therefore more efficient. ADAPTs (ABD Derived Affinity ProTeins) constitute a novel group of imaging probes based on the scaffold of an albumin-binding domain (ABD). To evaluate how different compositions of the N-terminal sequence of ADAPTs influence their biodistribution, a series of human epidermal growth factor receptor type 2 (HER2)-binding ADAPT6 derivatives with different N-terminal sequences were created: GCH6DANS (2), GC(HE)3DANS (3), GCDEAVDANS (4) and GCVDANS(5) and compared with the parental variant: GCSS(HE)3DEAVDANS (1)...
October 14, 2016: Bioconjugate Chemistry
Alexander W Scott, Viswanadham Garimella, Colin M Calabrese, Chad A Mirkin
Novel biotin-polyethylene glycol (biotin-PEG) gold nanoparticle probes have been synthesized and used as universal constructs for the detection of protein (prostate-specific antigen, PSA) and nucleic acid targets (microRNAs) from a single sample. Microarray assays based upon these probes enabled sensitive detection of biomarker targets (50 fM for nucleic acid targets and 1 pg/μL for the PSA target). Ways of detecting biomarkers, including nucleic acids and proteins, are necessary for the clinical diagnosis of many diseases, but currently available diagnostic platforms rely primarily on the independent detection of proteins or nucleic acids...
October 14, 2016: Bioconjugate Chemistry
Min Liu, Wei Fang, Shuang Liu
In this study, we evaluated seven new 99mTc(III) complexes [99mTcCl(CDO)(CDOH)2B-R] (99mTc-2Fboroxime: R = 2-formylfuran-3-yl (2F); 99mTc-3Fboroxime: R = furan-3-yl (3F); 99mTc-5Fboroxime: R = 5-formyfuran-2-yl (5F); 99mTc-HPboroxime: R = 6-hydroxylpyridin-2-yl (HP); 99mTc-MPYboroxime: R = 5-methoxypyridin-3-yl (MPY); 99mTc-PMboroxime: R = 1,5-pyrimidin-3-yl (PM), and 99mTc-4PYboroxime: R = pyridin-4-yl (4PY)) for their potential as heart imaging agents. All new 99mTc(III) radiotracers except 99mTc-2Fboroxime were prepared with high radiochemical purity (RCP > 95%)...
October 13, 2016: Bioconjugate Chemistry
Maarten Danial, Angela Stauffer, Frederik R Wurm, Michael J Root, Harm-Anton Klok
A popular strategy to overcome the limited plasma half-life of peptide heptad repeat 2 (HR2) fusion inhibitors against HIV-1 is through conjugation with biocompatible polymers such as poly(ethylene glycol) (PEG). However, despite improved resistance to proteolysis and reduced renal elimination, covalent attachment of polymers often causes a loss in therapeutic potency. In this study, we investigated the molecular origins of the loss in potency upon conjugation of linear, mid-functional and hyperbranched PEG-like polymers to peptides that inhibit HIV-1 - host cell membrane fusion...
October 13, 2016: Bioconjugate Chemistry
Barbara Spolaore, Samanta Raboni, Abhijeet Ajit Satwekar, Antonella Grigoletto, Anna Mero, Isabella Monia Montagner, Antonio Rosato, Gianfranco Pasut, Angelo Fontana
Interferon alpha (IFN α) subtypes are important protein drugs that have been used to treat infectious diseases and cancers. Here, we studied the reactivity of IFN α-2b to microbial transglutaminase (TGase) with the aim to obtain a site-specific conjugation of this protein drug. Interestingly, TGase allowed the production of two mono-derivatized isomers of IFN with high yields. Characterization by mass spectrometry of the two conjugates indicated that they are exclusively modified at the level of Gln101 if the protein is reacted in the presence of an amino containing ligand (i...
October 12, 2016: Bioconjugate Chemistry
Shuaidong Huo, Shizhu Chen, Ningqiang Gong, Juan Liu, Xianlei Li, Yuanyuan Zhao, Xing-Jie Liang
Ultra-small nanoparticles provide us essential alternatives for designing more efficient nanocarriers for drug delivery. However, the fast clearance of ultra-small nanoparticles limits their application to some extent. One of the most frequency compound used to slow the clearance of nanocarriers and nanodrugs is PEG, which also approved by FDA. Nonetheless, few reports explored the effect of the PEGylation of ultra-small nanoparticles on their behavior in vivo. Herein, we investigated the impact of different PEG grafting level of 2 nm core sized gold nanoparticles on their biological behavior in tumor-bearing mice...
October 12, 2016: Bioconjugate Chemistry
Alessandro Gori, Laura Sola, Paola Gagni, Giulia Bruni, Marta Liprino, Claudio Peri, Giorgio Colombo, Marina Cretich, Marcella Chiari
The generation of robust analytical data using microarray platforms strictly relies on optimal ligand-target interaction at the sensor surface which, in turn, is inherently bound to the correct immobilization scheme of the interrogated bioprobes. In the present work, we performed a rigorous comparative analysis of the impact of peptide ligands immobilization strategy in the screening of Burkholderia cepacia complex (BCC) infections in patients affected by cystic fibrosis (CF). We generated arrays of previously validated Burkholderia-derived peptide probes, that were selectively oriented on polymeric coatings by means of different click-type reactions including thiol-maleimide, copper-catalyzed-azide-alkyne-cycloaddition (CuAAC) and strain-promoted-azide-alkyne-cycloaddition (SPAAC)...
October 12, 2016: Bioconjugate Chemistry
Yuliia Vyborna, Mykhailo Vybornyi, Robert Häner
The pathway diversity of the self-assembly of amphiphilic DNA-pyrene conjugates is described. The hydrophobic pyrene units drive the self-assembly of the anionic oligomers in an aqueous environment into ribbon-shaped, DNA-grafted supramolecular polymers. Isothermal mixing of two types of sorted ribbons, each of which contains only one kind of two complementary oligonucleotides, results in the formation of tight networks. Thermal disassembly of these kinetically trapped networks and subsequent re-assembly of the liberated components leads to mixed supramolecular polymers, which now contain both types of oligonucleotides...
October 12, 2016: Bioconjugate Chemistry
Yao Wang, Ping Huang, Minxi Hu, Wei Huang, Xinyuan Zhu, Deyue Yan
The distinct and complementary biochemical mechanisms of folic acid analog methotrexate (MTX) and cytidine analog gemcitabine (GEM) make their synergistic combination effectively. Unfortunately, such a combination faces severe pharmacokinetic problems and several transportation barriers. To overcome these problems, a new strategy of amphiphilic small molecule prodrug (ASMP) is developed to improve their synergistic combination effect. The ASMP was prepared by the amidation of the hydrophilic GEM with the hydrophobic MTX at a fixed ratio...
October 10, 2016: Bioconjugate Chemistry
Anil Kumar Mishra, Surbhi Prakash, Puja Panwar Hazari, Virendra Kumar Meena, Ambika Jaswal, Harleen Khurana, Shrikant Kukreti
A new macrocyclic system 2,2'-(12-amino-11,13-dioxo-1,4,7,10-tetraazacyclotridecane-4,7-diyl)diacetic acid (ATRIDAT) was designed for coordinating metals in +2 and +3 oxidation states particularly 68Ga(III), for PET imaging. ATRIDAT was conjugated to biotin for pretargeting via biotin-avidin interaction. This model provides high tumor targeting efficiency, stability to biotinidase activity leading to modest signal amplification at the tumor site. Cyclization of triethylenetetramine with protected amino malonate resulted in the formation of 13 membered diamide ring...
October 10, 2016: Bioconjugate Chemistry
Yuan Cao, Giang K T Nguyen, Samuel Chuah, James P Tam, Chuan-Fa Liu
Herein we report a novel enzymatic bioconjugation method to prepare peptide dendrimers. Under the catalysis of a newly discovered peptide ligase, butelase 1, peptide dendrimers of di-, tetra- and octabranches were successfully synthesized using thiodepsipeptides as acyl donors for ligation with lysyl dendrimeric scaffolds. The efficient assembly of the highly clustered dendrimeric structure highlighted the versatility of butelase 1. We also showed that our synthetic antibacterial peptide dendrimers containing an RLYR motif are highly potent and broadly active against antibiotic-resistant strains...
October 10, 2016: Bioconjugate Chemistry
Li Lin, Xiaoyou Wang, Xiaoda Li, Yongbo Yang, Xiuli Yue, Qiang Zhang, Zhifei Dai
This article reports an effective method to regulate hydrophobic drug release rate from partially silica-coated bicellar nanodisc generated from proamphiphilic organoalkoxysilane and dihexanoyl phosphatidylcholine by introducing different molar percentages of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-PEG2000 (DSPE-PEG2000) into planar bilayers of hybrid bicelles. It was found that the drug release rate increased with increasing the molar percentages of DSPE-PEG2000, and 57.38%, 69.21%, 78.69%, 81.64% and 82...
October 10, 2016: Bioconjugate Chemistry
Simone Maschauer, Marcus Heilmann, Carmen Wängler, Ralf Schirrmacher, Olaf Prante
Short synthetic octapeptide analogs derived from the native somatostatin peptides SST-14 and SST-28, namely octreotate (TATE) or octreotide (TOC), bind with high affinity to somatostatin receptors (sstr), mainly to subtypes 2 and 5, which are expressed in high density on neuroendocrine tumors (NET). Therefore, radiolabeled TATE or TOC derivatives represent highly valuable imaging probes for NET diagnosis by positron emission tomography (PET). The aim of our study was the development of an 18F-labeled octreotate analog as an alternative radiotracer for the clinically established 68Ga-DOTATOC and 68Ga-DOTATATE...
October 7, 2016: Bioconjugate Chemistry
Joel A Finbloom, Kenneth Han, Ioana L Aanei, Emily C Hartman, Daniel T Finley, Michel T Dedeo, Max Fishman, Kenneth H Downing, Matthew B Francis
Current approaches to nanoscale therapeutic delivery rely on the attachment of a drug of interest to a nanomaterial scaffold that is capable of releasing the drug selectively in a tumor environment. One class of nanocarriers receiving significant attention is protein nanomaterials, which are biodegradable and homogeneous in morphology and can be equipped with multiple functional handles for drug attachment. Although most protein-based nanocarriers are spherical in morphology, recent research has revealed that nonspherical nanomaterials may have favorable tumor uptake in comparison to their spherical counterparts...
October 7, 2016: Bioconjugate Chemistry
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