5,586 results match your criteria Bioconjugate Chemistry [Journal]


Simple synthesis of biocompatible stable CeO2 nanoparticles as antioxidant agents.

Bioconjug Chem 2018 Jun 22. Epub 2018 Jun 22.

Cerium oxide (IV) nanoparticles offer a high redox ability, while maintaining nontoxicity and high stability. Thus, dispersed nanoceria is a promising candidate as antioxidant material for human cells. In this work, we report on a fast and simple one-pot process that yield a final nanoparticle size of 2-4 nm in polar solvents such as water and alcohols. Read More

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June 2018
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Multicolored protein nanoparticles: synthesis, characterization and cell uptake.

Bioconjug Chem 2018 Jun 22. Epub 2018 Jun 22.

Synthesis, characterization, and applications of strongly fluorescent, multicolored protein nanoparticles (GlowDots) are re-ported here. Bovine serum albumin was cross-linked under controlled conditions to form nanoparticles, where particle size was controlled from 20 to 100 ± 10 nm by choosing appropriate reaction conditions. The absorption as well as the emission wavelengths were controlled without changing the particle size, unlike quantum dots. Read More

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Magnetic Cytoskeleton Affinity (MiCA) Purification of Microtubule Motors conjugated to Quantum Dots.

Bioconjug Chem 2018 Jun 22. Epub 2018 Jun 22.

We develop Magnetic Cytoskeleton Affinity (MiCA) purification, which allows for rapid isolation of molecular motors conjugated to large multivalent quantum dots, in miniscule quantities, which is especially useful for single-molecule applications. When purifying labeled molecular motors, an excess of fluorophores or labels is usually used. However, large labels tend to sediment during the centrifugation step of microtubule affinity purification, a traditionally powerful technique for motor purification. Read More

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Tuning the Diels-Alder Reaction for Bioconjugation to Maleimide Drug-Linkers.

Bioconjug Chem 2018 Jun 22. Epub 2018 Jun 22.

Department of Chemistry and Biochemistry , University of California , Santa Barbara , California 93106-9510 , United States.

The thiol-maleimide linkage is widely used for antibody-drug conjugate (ADC) production; however, conjugation of maleimide-drugs could be improved by simplified procedures and reliable conjugate stability. Here, we report the evaluation of electron-rich and cyclic dienes that can be appended to antibodies and reacted with maleimide-containing drugs through the Diels-Alder (DA) reaction. Drug conjugation is fast and quantitative due to reaction acceleration in water, and the linkage is more stable in serum than in the corresponding thiol-maleimide adduct with the same drug. Read More

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Novel Structural Modification Based on Evans Blue Dye to Improve Pharmacokinetics of a Somastostatin Receptor Based Theranostic Agent.

Bioconjug Chem 2018 Jun 21. Epub 2018 Jun 21.

Development of somastatin (SS) peptide analogs for detection and treatment of neuroendocrine tumors has been successful with the recent FDA approval of 68Ga-DOTA-TATE and 177Lu-DOTA-TATE. The structure of these peptide constructs contains the peptide binding motif that binds to the receptor with high affinity, a chelator to complex the radioactive metal, and a linker between the peptide and chelator. However, these constructs suffer from rapid blood clearance, which limit their tumor uptake. Read More

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Insights into the kinetics of the resistance formation of bacteria against ciprofloxacin poly(2-methyl-2-oxazoline) conjugates.

Bioconjug Chem 2018 Jun 21. Epub 2018 Jun 21.

The influence on the resistance formation of polymers attached to antibiotics is rarely investigated. In this study, ciprofloxacin (CIP) was conjugated to poly(2-methyl-2-oxazoline)s with an ethylene diamine end group (Me-PMOx28-EDA) via two different spacers (CIP modified with α,α´-dichloro-p-xylene - xCIP, CIP modified with chloroacetyl chloride - eCIP). The antibacterial activity of the conjugates against a number of bacterial strains shows a great dependence on the nature of the spacer. Read More

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Mitochondria-targeting Polydopamine Nanocomposites as Chemo-photothermal Therapeutics for Cancer.

Bioconjug Chem 2018 Jun 21. Epub 2018 Jun 21.

Mitochondria plays a key role in a variety of physiological processes, and the mitochondria-targeting drug delivery is helpful and effective in cancer therapy.Rhodamine123 (Rhod123) and Doxorubicin (Dox) are not new chemical molecules, and they both can inhibit cancerous cells. Here, we combine these two "old" chemicals with polydopamine nanoparticles (PDA NPs) to strengthen the antitumor effect with the aid of near infrared irradiation. Read More

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Simple D-A-D Structural Bisbithiophenyl Diketopyrrolopyrrole (TDPP) as Efficient Bioimaging and Photothermal Agents.

Bioconjug Chem 2018 Jun 20. Epub 2018 Jun 20.

Design and synthesis of biocompatible and multi-functional photothermal agents is crucial for effective cancer phototherapy. In order to achieve this ambition, simple D-A-D structural bisbithiophenyl diketopyrrolopyrrole (TDPP) was fabricated. In this molecule, the donor, 2-thiophenylboric acid, was conjugated via Suzuki coupling reaction, which could expand the emission wavelength to the red region of the spectrum. Read More

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Development of Anti-CD74 Antibody-Drug Conjugates to Target Glucocorticoids to Immune Cells.

Bioconjug Chem 2018 Jun 20. Epub 2018 Jun 20.

Glucocorticoids (GCs) are excellent anti-inflammatories but are dose-limited by on-target toxicity. We sought to solve this 13 problem by delivering GCs to immune cells with antibody drug conjugates (ADCs) using antibodies containing site-specific 14 incorporation of a non-natural amino acid, novel linker chemistry for in vitro and in vivo stability, and existing and novel 15 glucocorticoid receptor (GR) agonists as payloads. We directed fluticasone to human antigen-presenting immune cells to 16 afford GR activation that was dependent on the targeted antigen. Read More

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Engineering ROS-resistant Galectin-1 Dimers with Enhanced Lectin Activity.

Bioconjug Chem 2018 Jun 19. Epub 2018 Jun 19.

Galectin-1 is an immunomodulatory carbohydrate-binding protein with demonstrated efficacy in various pre-clinical models. However, its potential for clinical use is challenged by two features of the protein. First, galectin-1 (Gal-1) can be inactivated in oxidative environments, such as sites of inflammation, via covalent crosslinking of surface-exposed cysteine residues. Read More

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A Facile Approach for the Doxorubicine Delivery in Cancer Cells by Responsive and Fluorescent Core/shell Quantum Dots.

Bioconjug Chem 2018 Jun 15. Epub 2018 Jun 15.

Biocompatible thermo-responsive copolymers based on 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) and oligo (ethylene glycol) methacrylate (OEGMA) were grown from the surface of ZnO Quantum Dots (QDs) by Surface Initiated Atom Transfer Radical Polymerization with Activators Regenerated by electron Transfer (SI-ARGET ATRP) in order to design smart and fluorescent core/shell nanosystems to be used towards cancer cells. Tunable lower critical solution temperature (LCST) values were obtained and studied in water and in culture medium. The complete efficiency of the process was demonstrated by the combination of spectroscopic and microscopic studies. Read More

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June 2018
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Novel Cluster and Monomer-Based GalNAc Structures Induce Effective Uptake of siRNAs in Vitro and in Vivo.

Bioconjug Chem 2018 Jun 13. Epub 2018 Jun 13.

GalNAc conjugation is emerging as a dominant strategy for delivery of therapeutic oligonucleotides to hepatocytes. The structure and valency of the GalNAc ligand contributes to the potency of the conjugates. Here we present a panel of multivalent GalNAc variants using two different synthetic strategies. Read More

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Hyaluronic acid surface modified liposomes prepared via orthogonal aminoxy coupling: synthesis of nontoxic aminoxylipids based on symmetrically α-branched fatty acids, preparation of liposomes by microfluidic mixing and targeting to cancer cells expressing CD44.

Bioconjug Chem 2018 Jun 13. Epub 2018 Jun 13.

New synthetic aminoxy lipids are designed and synthesized as building blocks for the formulation of functionalised nanoliposomes by microfluidisation using a NanoAssemblr®. Orthogonal binding of hyaluronic acid onto the outer surface of functionalised nanoliposomes via aminoxy coupling (N-oxy ligation) is achieved at hemiacetal function of hyaluronic acid and the structure of hyaluronic acid-liposomes is visualised by transmission electron microscopy and cryo- transmission electron microscopy. Observed structures are in a good correlation with data obtained by dynamic light scattering (size and ζ-potential). Read More

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A Protein Capsid-Based System for Cell Delivery of Selenocysteine.

Bioconjug Chem 2018 Jun 12. Epub 2018 Jun 12.

Selenocysteine (Sec) has received a lot of attention as a potential anti-cancer drug. However, its broad cytotoxicity limits its therapeutic usefulness. Thus, Sec is an attractive candidate for targeted drug delivery. Read More

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June 2018
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Cross Linked Enzyme Aggregates as Versatile Tool for Enzyme Delivery: Application to Polymeric Nanoparticles.

Bioconjug Chem 2018 Jun 12. Epub 2018 Jun 12.

Polymeric nanoparticles (NPs) represent one of the most promising tools in nanomedicine and have been extensively studied for the delivery of water-insoluble drugs. However, the efficient loading of therapeutic enzymes and proteins in polymer-based nanostructures remains an open challenge. Here, we report a synthesis method for a new enzyme delivery system based on cross linked enzyme aggregates (CLEAs) encapsulation into poly(lactide-co-glycolide) (PLGA) NPs. Read More

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June 2018
4 Reads

Post-Synthetic Modification of Oligonucleotides via Orthogonal Amidation and Copper Catalyzed Cycloaddition Reactions.

Bioconjug Chem 2018 Jun 12;29(6):1859-1865. Epub 2018 Jun 12.

Department of Process Chemistry , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States.

An efficient multicomponent orthogonal protocol was developed for post-synthetic oligonucleotide modification using commercially available 2'- O-methyl ester and 2'- O-propargyl nucleoside scaffolds. Amidation of methyl esters with primary amines was achieved in the presence of 2'-propargyl groups which were utilized for subsequent copper catalyzed cycloaddition with GalNAc-azide. The methodology was applied to generate siRNA composed of multiple amide and triazole conjugates. Read More

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June 2018
2 Reads

Targeting protumoral tumor-associated macrophages with nanobody-functionalized nanogels through SPAAC ligation.

Bioconjug Chem 2018 Jun 11. Epub 2018 Jun 11.

Tumor-associated macrophages (TAMs) with high expression levels of the Macrophage Mannose Receptor (MMR, CD206) exhibit a strong angiogenic and immune suppressive activity. Thus, they are a highly attractive target in cancer immunotherapy, with the aim to modulate their protumoral behavior. Here, we introduce polymer nanogels as potential drug nanocarriers which were site-specifically decorated with a Nanobody (Nb) specific for the MMR. Read More

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June 2018
1 Read

In Vivo Translation of Peptide-Targeted Drug Delivery Systems Discovered by Phage Display.

Bioconjug Chem 2018 Jun 11. Epub 2018 Jun 11.

Therapeutic compounds with narrow therapeutic windows and significant systemic side effects benefit from targeted drug delivery strategies. Peptide-protein interactions are often exploited for targeting, with phage display a primary method to identify high-affinity peptide ligands that bind cell surface and matrix bound receptors preferentially expressed in target tissues. After isolating and sequencing high-binding phages, peptides are easily synthesized and chemically modified for incorporation into drug delivery systems, including peptide-drug conjugates, polymers, and nanoparticles. Read More

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June 2018
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Enzymatically Activated Glyco-Prodrugs of Doxorubicin Synthesized by a Catalysis-Free Diels-Alder Reaction.

Bioconjug Chem 2018 Jun 21. Epub 2018 Jun 21.

Univ. Grenoble Alpes, CNRS, CERMAV , 38000 Grenoble , France.

The severe side effects associated with the use of anthracycline anticancer agents continues to limit their use. Herein we describe the synthesis and preliminary biological evaluation of three enzymatically activatable doxorubicin-oligosaccharide prodrugs. The synthetic protocol allows late stage variation of the carbohydrate and is compatible with the use of disaccharides such as lactose as well as more complex oligosaccharides such as xyloglucan oligomers. Read More

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June 2018
2 Reads

Site-Specific Incorporation of Selenocysteine by Genetic Encoding as a Photocaged Unnatural Amino Acid.

Bioconjug Chem 2018 Jun 21. Epub 2018 Jun 21.

Research School of Chemistry , Australian National University , Canberra , ACT 2601 , Australia.

Selenocysteine (Sec) is a naturally occurring amino acid that is also referred to as the 21st amino acid. Site-specific incorporation of Sec into proteins is attractive, because the reactivity of a selenol group exceeds that of a thiol group and thus allows site-specific protein modifications. It is incorporated into proteins by an unusual enzymatic mechanism which, in E. Read More

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June 2018
3 Reads

Immobilization and Intracellular Delivery of Circular Proteins by Modifying a Genetically Incorporated Unnatural Amino Acid.

Bioconjug Chem 2018 Jun 14. Epub 2018 Jun 14.

School of Biological Sciences , Nanyang Technological University , 60 Nanyang Drive , 637551 , Singapore.

Backbone-cyclic proteins are of great scientific and therapeutic interest owing to their higher stability over their linear counterparts. Modification of such cyclic proteins at a selected site would further enhance their versatility. Here we report a chemoenzymatic strategy to engineer site-selectively modified cyclic proteins by combining butelase-mediated macrocyclization with the genetic code expansion methodology. Read More

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June 2018
4 Reads

Squalene-PEG-exendin as high-affinity constructs for pancreatic beta-cells.

Bioconjug Chem 2018 Jun 5. Epub 2018 Jun 5.

Novel drug delivery systems targeting native, transplanted or cancerous beta-cells are of utmost importance. Herein, we present new exendin-4 derivatives with modified unnatural amino acids at strategic positions within the polypeptide sequence. The modified peptides allowed modular orthogonal chemical modifications to attach imaging agents and amphiphilic squalene-PEG groups. Read More

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June 2018
2 Reads

Radioligand Therapy of Prostate Cancer with a Long-Lasting Prostate-Specific Membrane Antigen Targeting Agent Y-DOTA-EB-MCG.

Bioconjug Chem 2018 Jun 15. Epub 2018 Jun 15.

Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering (NIBIB) , National Institutes of Health (NIH) , Bethesda , Maryland 20892 , United States.

Several radioligands targeting prostate-specific membrane antigen (PSMA) have been clinically introduced as a new class of radiotheranostics for the treatment of prostate cancer. Among them, ((( R)-1-carboxy-2-mcercaptoethyl)carbamoyl)-l-glutamic acid (MCG) has been successfully labeled with radioisotopes for prostate cancer imaging. The aim of this study is to conjugate MCG with an albumin binding moiety to further improve the in vivo pharmacokinetics. Read More

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Enhancing Multistep DNA Processing by Solid-Phase Enzyme Catalysis on Polyethylene Glycol Coated Beads.

Bioconjug Chem 2018 Jun 21. Epub 2018 Jun 21.

New England Biolabs Inc. , 240 County Road , Ipswich , Massachusetts 01938 , United States.

Covalent immobilization of enzymes on solid supports provides an alternative approach to homogeneous biocatalysis by adding the benefits of simple enzyme removal, improved stability, and adaptability to automation and high-throughput applications. Nevertheless, immobilized (IM) enzymes generally suffer from reduced activity compared to their soluble counterparts. The nature and hydrophobicity of the supporting material surface can introduce enzyme conformational change, spatial confinement, and limited substrate accessibility, all of which will result in loss of the immobilized enzyme activity. Read More

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June 2018
4 Reads

Polysarcosine as an Alternative to PEG for Therapeutic Protein Conjugation.

Bioconjug Chem 2018 Jun 20. Epub 2018 Jun 20.

The performance of many therapeutic proteins, including human interferon-α2b (IFN), is often impeded by their intrinsic instability to protease, poor pharmacokinetics, and strong immunity. Although PEGylation has been an effective approach to improve the pharmacokinetics of many proteins, a few noticeable limitations have aroused vast research efforts in seeking alternatives to PEG for bioconjugation. Herein, we report our investigation on the use of polysarcosine (PSar), a nonionic and hydrophilic polypeptoid, for IFN modification. Read More

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June 2018
1 Read

The Effect of Lipidation on the Self-Assembly of the Gut-Derived Peptide Hormone PYY.

Bioconjug Chem 2018 Jun 18. Epub 2018 Jun 18.

Department of Applied Physics , Aalto University , P.O. Box 15100, FI-00076 Aalto , Finland.

Lipidation is a powerful strategy to improve the stability in vivo of peptide drugs. Attachment of a lipid chain to a hydrophilic peptide leads to amphiphilicity and the potential for surfactant-like self-assembly. Here, the self-assembly and conformation of three lipidated derivatives of the gastrointestinal peptide hormone PYY is examined using a comprehensive range of spectroscopic, scattering, and electron microscopy methods and compared to those of the parent PYY peptide. Read More

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June 2018
1 Read

Synthesis of Azide-Modified Chondroitin Sulfate Precursors: Substrates for "Click"- Conjugation with Fluorescent Labels and Oligonucleotides.

Bioconjug Chem 2018 Jun 15. Epub 2018 Jun 15.

Department of Chemistry , University of Turku , Vatselankatu 2 , FI 20014 Turku , Finland.

Azidopropyl-modified precursors of chondroitin sulfate (CS) tetrasaccharides have been synthesized, which, after facile conversion to final CS structures, may be conjugated with alkyne-modified target compounds by a one-pot "click"-ligation. RP HPLC was used for the monitoring of the key reaction steps (protecting group manipulation and sulfation) and purification of the CS precursors (as partially protected form, bearing the O-Lev, O-benzoyl, and N-trichloroacetyl groups and methyl esters). Subsequent treatments with aqueous NaOH, concentrated ammonia, and acetic anhydride (i. Read More

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June 2018
4 Reads

FRET Reagent Reveals the Intracellular Processing of Peptide-Linked Antibody-Drug Conjugates.

Bioconjug Chem 2018 Jun 13. Epub 2018 Jun 13.

Department of Protein Chemistry , Genentech, Inc. , 1 DNA Way , South San Francisco , California 94080 , United States.

Despite the recent success of antibody-drug conjugates (ADCs) in cancer therapy, a detailed understanding of their entry, trafficking, and metabolism in cancer cells is limited. To gain further insight into the activation mechanism of ADCs, we incorporated fluorescence resonance energy transfer (FRET) reporter groups into the linker connecting the antibody to the drug and studied various aspects of intracellular ADC processing mechanisms. When comparing the trafficking of the antibody-FRET drug conjugates in various different model cells, we found that the cellular background plays an important role in how the antigen-mediated antibody is processed. Read More

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June 2018
2 Reads

Biocompatible and Biodegradable Fe3+-Melanoidin Chelate as a Potentially Safe Contrast Agent for Liver MRI.

Bioconjug Chem 2018 Jun 1. Epub 2018 Jun 1.

Currently, most MRI probes available for clinical use contain gadolinium, which is a high-risk paramagnetic metal that can cause severe side effects (e.g., nephrogenic systemic fibrosis). Read More

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June 2018
6 Reads

Highly Potent Clickable Probe for Cellular Imaging of MDM2 and Assessing Dynamic Responses to MDM2-p53 Inhibition.

Bioconjug Chem 2018 Jun 12;29(6):2100-2106. Epub 2018 Jun 12.

Astex Pharmaceuticals , 436 Cambridge Science Park , Cambridge CB4 0QA , United Kingdom.

MDM2 is a key negative regulator of the p53 tumor suppressor. Direct binding of MDM2 to p53 represses the protein's transcriptional activity and induces its polyubiquitination, targeting it for degradation by the proteasome. Consequently, small molecule inhibitors that antagonize MDM2-p53 binding, such as RG7388, have progressed into clinical development aiming to reactivate p53 function in TP53 wild-type tumors. Read More

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June 2018
5 Reads

A Quantum Dot-Protein Bioconjugate That Provides for Extracellular Control of Intracellular Drug Release.

Bioconjug Chem 2018 Jun 18. Epub 2018 Jun 18.

Center for Bio/Molecular Science and Engineering, Code 6900 , U.S. Naval Research Laboratory , Washington , D.C. 20375 , United States.

The ability to control the intracellular release of drug cargos from nanobioconjugate delivery scaffolds is critical for the successful implementation of nanoparticle (NP)-mediated drug delivery. This is particularly true for hard NP carriers such as semiconductor quantum dots (QDs) and gold NPs. Here, we report the development of a QD-based multicomponent drug release system that, when delivered to the cytosol of mammalian cells, is triggered to release its drug cargo by the simple addition of a competitive ligand to the extracellular medium. Read More

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June 2018
2 Reads

Targeted Tubulysin B Hydrazide Conjugate for the Treatment of Luteinizing Hormone-Releasing Hormone Receptor-Positive Cancers.

Bioconjug Chem 2018 Jun 13. Epub 2018 Jun 13.

The targeted delivery of chemotherapeutic agents to receptors that are overexpressed on cancer cells has become an attractive strategy to concentrate drugs in cancer cells while avoiding uptake by healthy cells. Luteinizing hormone-releasing hormone receptor (LHRH-R) has attracted considerable interest for this application, since LHRH-R is upregulated in ∼86% of prostate cancers, ∼80% of endometrial cancers, ∼80% of ovarian cancers, and ∼50% of breast cancers, but virtually absent from normal tissues. Although LHRH and related peptides have been used to deliver cytotoxic drugs to LHRH-R overexpressing cancer cells, they have suffered from off-target delivery of the therapeutic agents to the liver and kidneys. Read More

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June 2018
1 Read

Nature-Inspired Bioorthogonal Reaction: Development of β-Caryophyllene as a Chemical Reporter in Tetrazine Ligation.

Bioconjug Chem 2018 Jun 14. Epub 2018 Jun 14.

School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology , Tsinghua University , Beijing 100084 , China.

A nature-inspired bioorthogonal reaction has been developed, hinging on an inverse-electron-demand Diels-Alder reaction of tetrazine with β-caryophyllene. Readily accessible from the cheap starting material through a scalable synthesis, the newly developed β-caryophyllene chemical reporter displays appealing reaction kinetics and excellent biocompatibility, which renders it applicable to both in vitro protein labeling and live cell imaging. Moreover, it can be used orthogonally to the strain-promoted alkyne-azide cycloaddition for dual protein labeling. Read More

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June 2018
6 Reads

Facile Fabrication of 10-Hydroxycamptothecin-Backboned Amphiphilic Polyprodrug with Precisely Tailored Drug Loading Content for Controlled Release.

Bioconjug Chem 2018 Jun 13. Epub 2018 Jun 13.

State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, and College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China.

Polymeric prodrugs with precisely controlled drug loading content (DLC) and rapid intracellular destabilization generally require complicated chemistry that hinders large-scale manufacture. For this purpose, we reported in this study a facile construction of reduction-sensitive amphiphilic polyprodrugs with an anticancer drug, 10-hydroxycamptothecin (HCPT), and a hydrophilic poly(ethylene oxide) (PEG) moiety as the alternating building blocks of the multiblock copolymer using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAc) click coupling between azide-SS-HCPT-SS-azide and alkyne-PEG-alkyne. Adoption of PEGs with two different molecular weights (MWs) of 400 and 1450 Da (PEG400 and PEG1450) afforded two polyprodrugs with different DLCs. Read More

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June 2018
2 Reads

Influence of PEGylation on Domain Dynamics of Phosphoglycerate Kinase: PEG Acts Like Entropic Spring for the Protein.

Bioconjug Chem 2018 Jun 7;29(6):1950-1960. Epub 2018 Jun 7.

Jülich Centre for Neutron Science & Institute of Complex Systems (JCNS-1&ICS-1) , Forschungszentrum Jülich , 52425 Jülich , Germany.

Protein-polymer conjugation is a widely used technique to develop protein therapeutics with improved pharmacokinetic properties as prolonged half-life, higher stability, water solubility, lower immunogenicity, and antigenicity. Combining biochemical methods, small angle scattering (SAXS/SANS), and neutron spin-echo spectroscopy, here we examine the impact of PEGylation (i.e. Read More

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June 2018
4 Reads

Flower-like Surface of Three-Metal-Component Layered Double Hydroxide Composites for Improved Antibacterial Activity of Lysozyme.

Bioconjug Chem 2018 Jun 6;29(6):2090-2099. Epub 2018 Jun 6.

School of Chemistry and Chemical Engineering , University of Chinese Academy of Sciences , Beijing , 100049 , China.

Microbes play an important function in our lives, while some pathogenic bacteria are responsible for many infectious diseases, food safety, and ecological pollution. Layered double hydroxide (LDH) is a kind of natural two-dimensional material and has been applied in many fields. Lysozyme is a green natural antibacterial agent, while the antimicrobial activity of lysozyme is not as good as antibiotics. Read More

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June 2018
7 Reads

Enhanced DNA Binding and Photocleavage Abilities of β-Cyclodextrin Appended Ru(II) Complex through Supramolecular Strategy.

Bioconjug Chem 2018 Jun 6;29(6):1829-1833. Epub 2018 Jun 6.

Photosensitizers with high photocleavage ability are urgently needed to improve photodynamic therapy efficacy. Herein, a supramolecular complex was constructed through host-guest self-assembly using hexa-β-CD-appended ruthenium polypyridyl (6CD-Ru) and adamantane-modified anthracene (ADA-AN) in water. The targeted DNA-intercalation of peripheral anthracenes can remarkably enhance photocleavage ability and antitumor activity of the complex irradiated with visible light. Read More

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June 2018
3 Reads

Mutation of M13 Bacteriophage Major Coat Protein for Increased Conjugation to Exogenous Compounds.

Bioconjug Chem 2018 Jun 1;29(6):1872-1875. Epub 2018 Jun 1.

School of Biosciences , University of Birmingham , Edgbaston, Birmingham , West Midlands , B15 2TT , United Kingdom.

Over the past ten years there has been increasing interest in the conjugation of exogenous compounds to the surface of the M13 bacteriophage. M13 offers a convenient scaffold for the development of nanoassemblies with useful functions, such as highly specific drug delivery and pathogen detection. However, the progress of these technologies has been hindered by the limited efficiency of conjugation to the bacteriophage. Read More

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June 2018
1 Read

Telomerase Responsive Delivery of Doxorubicin from Mesoporous Silica Nanoparticles in Multiple Malignancies: Therapeutic Efficacies against Experimental Aggressive Murine Lymphoma.

Bioconjug Chem 2018 Jun 4;29(6):2107-2119. Epub 2018 Jun 4.

CSIR-Central Salts and Marine Chemicals Research Institute , Bhavnagar 364002 , Gujarat , India.

Mammalian telomerase maintains the length and integrity of telomeres by adding the telomeric repeats to the chromosome end. This work describes the telomerase responsive delivery of doxorubicin against telomerase positive human and murine cancer cells. Wrapping of doxorubicin loaded mesoporous silica nanoparticles with specific oligonucleotide sequence, containing telomeric repeat complementary sequence and a telomerase substrate primer sequence, resulted in slow and sustained release of doxorubicin, contiguous to the tumor cells. Read More

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June 2018
2 Reads

Combinatorially Screened Peptide as Targeted Covalent Binder: Alteration of Bait-Conjugated Peptide to Reactive Modifier.

Bioconjug Chem 2018 Jun 1;29(6):1866-1871. Epub 2018 Jun 1.

Department of Engineering Science, Bioscience and Technology Program, The Graduate School of Informatics and Engineering , The University of Electro-Communications (UEC) , 1-5-1 Chofugaoka , Chofu , Tokyo 182-8585 , Japan.

A peptide-type covalent binder for a target protein was obtained by combinatorial screening of fluoroprobe-conjugated peptide libraries on bacteriophage T7. The solvatochromic fluoroprobe works as a bait during the affinity selection process of phage display. To obtain the targeted covalent binder, the bait in the selected consensus peptide was altered into a reactive warhead possessing a sulfonyl fluoride. Read More

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June 2018
5 Reads

Phosphotriesterase-Magnetic Nanoparticle Bioconjugates with Improved Enzyme Activity in a Biocatalytic Membrane Reactor.

Bioconjug Chem 2018 Jun 6;29(6):2001-2008. Epub 2018 Jun 6.

Institute on Membrane Technology , ITM-CNR, University of Calabria , via P. Bucci, 17/C , 87030 Rende , Cosenza , Italy.

The need to find alternative bioremediation solutions for organophosphate degradation pushed the research to develop technologies based on organophosphate degrading enzymes, such as phosphotriesterase. The use of free phosphotriesterase poses limits in terms of enzyme reuse, stability, and process development. The heterogenization of enzyme on a support and their use in bioreactors implemented by membranes seems a suitable strategy, thanks to the ability of membranes to compartmentalize, to govern mass transfer, and to provide a microenvironment with tuned physicochemical and structural properties. Read More

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June 2018
3 Reads

Non-Natural Linker Configuration in 2,6-Dipeptidyl-Anthraquinones Enhances the Inhibition of TAR RNA Binding/Annealing Activities by HIV-1 NC and Tat Proteins.

Bioconjug Chem 2018 Jun 12. Epub 2018 Jun 12.

Dipartimento di Scienze del Farmaco , Università di Padova , via Marzolo 5 , 35131 Padova , Italy.

The HIV-1 nucleocapsid (NC) protein represents an excellent molecular target for the development of anti-retrovirals by virtue of its well-characterized chaperone activities, which play pivotal roles in essential steps of the viral life cycle. Our ongoing search for candidates able to impair NC binding/annealing activities led to the identification of peptidyl-anthraquinones as a promising class of nucleic acid ligands. Seeking to elucidate the inhibition determinants and increase the potency of this class of compounds, we have now explored the effects of chirality in the linker connecting the planar nucleus to the basic side chains. Read More

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June 2018
1 Read

Fluorogenic Probing of Membrane Protein Trafficking.

Bioconjug Chem 2018 Jun 25;29(6):1823-1828. Epub 2018 May 25.

PASTEUR, Département de Chimie, École Normale Supérieure , PSL University, Sorbonne Université, CNRS , 75005 Paris , France.

Methods to differentially label cell-surface and intracellular membrane proteins are indispensable for understanding their function and the regulation of their trafficking. We present an efficient strategy for the rapid and selective fluorescent labeling of membrane proteins based on the chemical-genetic fluorescent marker FAST (fluorescence-activating and absorption-shifting tag). Cell-surface FAST-tagged proteins could be selectively and rapidly labeled using fluorogenic membrane-impermeant 4-hydroxybenzylidene rhodanine (HBR) analogs. Read More

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June 2018
2 Reads

Dynamic Ligand Presentation in Biomaterials.

Bioconjug Chem 2018 Jun 14. Epub 2018 Jun 14.

Department of Biomedical Engineering , Duke University , 101 Science Drive , Campus Box 90281, Durham , North Carolina 27708-0281 , United States.

The native cell microenvironment is extraordinarily dynamic, with reciprocal regulation pathways between cells and the extracellular matrix guiding many physiological processes, such as cell migration, stem cell differentiation, and tissue formation. Providing the correct sequence of biochemical cues to cells, both in vivo and in vitro, is critical for triggering specific biological outcomes. There has been a diversity of methods developed for exposing cells in culture to spatiotemporally varying cues, many of which have centered on dynamic control over cell-material interactions in an attempt to recapitulate the role of the extracellular matrix in cell signaling. Read More

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June 2018
2 Reads

The Chemistry of Lyophilized Blood Products.

Bioconjug Chem 2018 Jun 13. Epub 2018 Jun 13.

Division of Trauma, Surgical Critical Care & Emergency Surgery , Perelman School of Medicine at the University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States.

With the development of new biologics and bioconjugates, storage and preservation have become more critical than ever before. Lyophilization is a method of cell and protein preservation by removing a solvent such as water from a substance followed by freezing. This technique has been used in the past and still holds promise for overcoming logistic challenges in safety net hospitals with limited blood banking resources, austere environments such as combat, and mass casualty situations where existing resources may be outstripped. Read More

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June 2018
1 Read

Sensitivity Enhancement of Förster Resonance Energy Transfer Immunoassays by Multiple Antibody Conjugation on Quantum Dots.

Bioconjug Chem 2018 Jun 6;29(6):2082-2089. Epub 2018 Jun 6.

NanoBioPhotonics, Institute for Integrative Biology of the Cell (I2BC) , Université Paris-Saclay, Université Paris-Sud, CNRS, CEA , 91400 Orsay , France.

Quantum dots (QDs) are not only advantageous for color-tuning, improved brightness, and high stability, but their nanoparticle surfaces also allow for the attachment of many biomolecules. Because IgG antibodies (AB) are in the same size range of biocompatible QDs and the AB orientation after conjugation to the QD is often random, it is difficult to predict if few or many AB per QD will lead to an efficient AB-QD conjugate. This is particularly true for homogeneous Förster resonance energy transfer (FRET) sandwich immunoassays, for which the AB on the QD must bind a biomarker that needs to bind a second AB-FRET-conjugate. Read More

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June 2018
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Design and Development of Polysaccharide-Doxorubicin-Peptide Bioconjugates for Dual Synergistic Effects of Integrin-Targeted and Cell-Penetrating Peptides for Cancer Chemotherapy.

Bioconjug Chem 2018 Jun 30;29(6):1973-2000. Epub 2018 May 30.

Polymer-drug conjugation is an attractive approach for target delivering insoluble and highly toxic drugs to tumor sites to overcome the side-effects caused by cancer chemotherapy. In this study we designed and synthesized novel polymer-drug-peptide conjugates for improved specificity on targeting cancer cells. Chemically modified polysaccharide, carboxymethylcellulose (CMC), was conjugated with doxorubicin (DOX) anticancer drug by amide bonds and dually biofunctionalized with integrin-target receptor tripeptide (RGD) and l-arginine (R) as cell-penetrating amino acid for synergistic targeting and enhancing internalization by cancer cells. Read More

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June 2018
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Antifibrotic Effect of Ketoprofen-Grafted Alginate Microcapsules in the Transplantation of Insulin Producing Cells.

Bioconjug Chem 2018 Jun 29;29(6):1932-1941. Epub 2018 May 29.

Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Group for Functionalized Biomaterials, EPFL SB ISIC SCI-SB-SG , Station 6, CH-1015 Lausanne , Switzerland.

The controlled release of small molecular modulators of the immune response from hydrogel microspheres (MS) used for cell immobilization is an attractive approach to reduce pericapsular fibrotic overgrowth (PFO) after transplantation. Ketoprofen is a well-known nonsteroidal anti-inflammatory drug involved in the early stage inflammation cascade. PEGylated derivatives of ketoprofen, presenting either ester or amide linkage to the drug, were synthesized and conjugated to the hydroxyl groups of sodium alginate (Na-alg). Read More

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June 2018
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Investigation of the Viability of Cells upon Co-Exposure to Gold and Iron Oxide Nanoparticles.

Bioconjug Chem 2018 Jun 29;29(6):2120-2125. Epub 2018 May 29.

Institute of Nano Biomedicine and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of the Ministry of Education, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering , Shanghai Jiao Tong University , 800 Dongchuan RD , Shanghai 200240 , China.

Cell lines were exposed either to mixtures of gold and iron oxide nanoparticles, or to a hybrid nanoparticle with gold and iron oxide domain. In the case of simultaneous exposure to gold and iron oxide nanoparticles, enhanced toxicity as compared to the exposure to only one type of nanoparticles was observed. An indication was found that, at equivalent concentrations, the hybrid nanoparticles may slightly reduce cell viability more strongly than mixtures of both nanoparticle types. Read More

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June 2018
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