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Bioconjugate Chemistry

Jacopo Movilli, Andrea Rozzi, Roberto Ricciardi, Roberto Corradini, Jurriaan Huskens
Biosensors and materials for biomedical applications generally require chemical functionalization to bestow their surfaces with desired properties, such as specific molecular recognition and anti-fouling properties. The use of modified poly-L-lysine (PLL) polymers with appended oligo(ethylene glycol) (OEG) and thiol-reactive maleimide (Mal) moieties (PLL-OEG-Mal) offers control over the presentation of functional groups. These reactive groups can readily be conjugated to, for example, probes for DNA detection...
November 9, 2018: Bioconjugate Chemistry
George Makris, Lauren L Radford, Marina Kuchuk, Fabio Gallazzi, Silvia S Jurisson, Charles Jeffrey Smith, Heather M Hennkens
With the long-term goal of developing theranostic agents for applications in nuclear medicine, in this work we evaluated the well-known NOTA and NODAGA chelators as bifunctional chelators (BFCs) for the [99m Tc/186 Re]Tc/Re-tricarbonyl core. In particular, we report model complexes of the general formula fac-[M(L)(CO)3 ]+ (M = Re, 99m Tc,186 Re) where L denotes NOTA-Pyr (1) or NODAGA-Pyr (2), which are derived from conjugation of NOTA/NODAGA with pyrrolidine (Pyr). Further, as proof-of-principle, we synthesized the peptide bioconjugate NODAGA-sst2 -ANT (3) and explored its complexation with the fac-[Re(CO)3 ]+ and fac-[99m Tc][Tc(CO)3 ]+ cores; sst2 -ANT denotes the somatostatin receptor (SSTR) antagonist 4-NO2 -Phe-c(DCys-Tyr-DTrp-Lys-Thr-Cys)-DTyr-NH2 ...
November 9, 2018: Bioconjugate Chemistry
Miguel Macias-Contreras, Huan He, Lei Zhu
SNAP-tag is a genetically encoded label for tracking proteins of interest that is known to utilize O6-benzylguanine derivatives as substrates. In this work, mass spectrometric analysis revealed that SNAP-tag also accepts O6-(5-pyridylmethyl)guanine derivatives as substrates. A fluorescently conjugated O6-(5-pyridylmethyl)guanine was synthesized and used to selectively label intracellular compartments. This compound also acts as a zinc(II) ion-sensitive fluorescent indicator, and therefore can be used in organelle-specific zinc(II) imaging...
November 9, 2018: Bioconjugate Chemistry
Noreen Ahmed, Joanna Fréderique De Graaf, Nadine Ahmed, Dana Foss, Julie Delcorde, Peter G Schultz, John Paul Pezacki
Endogenously expressed non-coding RNAs are regulators of mRNA translation and affect diverse biological pathways spanning embryogenesis to cholesterol and fatty acid me-tabolism. Recently, microRNAs have become an important therapeutic target with strategies that employ oligonucleo-tides as both mimics and inhibitors of target microRNAs, successfully altering signal transduction pathways in rele-vant contexts. However, delivery of these exogenous effec-tors remains a major challenge. Here, we present a method for evaluating microRNA delivery using the viral suppressor of RNA silencing (VSRS) protein p19, optimized for cellular delivery of small RNAs...
November 9, 2018: Bioconjugate Chemistry
Mingding Wang, Soie Park, Yoonhee Nam, Jeffery Nielsen, Stewart A Low, Madduri Srinivasarao, Philip S Low
Approximately 6.3 million bone fractures occur annually in the United States, resulting in considerable morbidity, deterioration in quality of life, loss of productivity and wages, and sometimes death (e.g., hip fractures). Although anabolic and antiresorptive agents have been introduced for treatment of osteoporosis, no systemically administered drug has been developed to accelerate the fracture-healing process. To address this need, we have undertaken to target a bone anabolic agent selectively to fracture surfaces in order to concentrate the drug's healing power directly on the fracture site...
November 9, 2018: Bioconjugate Chemistry
Cen Shi, Xiaomei Wang, Jianmei Wan, Duo Zhang, Xuan Yi, Zhuanling Bai, Kai Yang, Juan Diwu, Zhifang Chai, Shuao Wang
Most of the key radionuclides in the nuclear fuel cycle, such as actinides, possess a combination of heavy metal chemotoxicity and radiotoxicity and therefore represent a severe threat to the ecological environment and public safety. The radiotoxicity originates from direct radiation-induced organ damage and indirect damage, mostly through radiation-induced reactive oxygen species (ROS). Although effective chelating agents that can accelerate the excretion of actinides, such as uranium, have been developed in the past several decades, very few of them can reduce radiation-induced damage from internal contamination...
November 9, 2018: Bioconjugate Chemistry
Lili Cui, Chiyi Xiong, Min Zhou, Sixiang Shi, Diana S-L Chow, Chun Li
Copper sulfide (CuS) nanoparticles have been considered one of the most clinical relevant nanosystems because of their straightforward chemistry, small particle size, low toxicity, and intrinsic theranostic characteristics. In our previous studies, radioactive [64Cu]CuS nanoparticles were successfully developed to be used as efficient radiotracers for positron emission tomography and for photothermal ablation therapy of cancer cells using near-infrared laser irradiation. However, the major challenge of CuS nanoparticles as a theranostic platform is the lack of a means for effective targeted delivery to the tumor site...
November 8, 2018: Bioconjugate Chemistry
Xin Su, Boxuan Ma, Jun Hu, Tao Yu, Weihua Zhuang, Li Yang, Gaocan Li, Yunbing Wang
In recent years, intelligent polymeric micelles with multi-functions are in urgent demand for cancer diagnosis and therapy. Herein, pH and redox dual-responsive prodrug micelles with aggregation-induced emission (AIE) active cellular imaging and charge conversion have been prepared for combined chemotherapy and bioimaging based on a novel doxorubicin-conjugated amphiphilic PMPC-PAEMA-P (TPE-co-HD)-ss-P (TPE-co-HD)-PAEMA-PMPC copolymer. The doxorubicin is conjugated via a pH cleavable imine linkage and can be packed in the hydrophobic core along with the glutathione (GSH)-sensitive disulfide bond...
November 8, 2018: Bioconjugate Chemistry
Yawo A Mondjinou, Bradley P Loren, Christopher J Collins, Seok-Hee Hyun, Asher Demoret, Joseph Skulsky, Cheyenne Chaplain, Vivek Badwaik, David H Thompson
A family of five water-soluble Gd3+ :1,4,7,10-tetraazacyclododecane-1,4,7-tetraacetic acid-modified polyrotaxane (PR) magnetic resonance contrast agents bearing mixtures of 2-hydroxypropyl-β-cyclodextrin and 4-sulfobutylether-β-cyclodextrin macrocycles threaded onto Pluronic cores were developed as long circulating magnetic resonance contrast agents. Short diethylene glycol diamine spacers were utilized for linking the macrocyclic chelator to the PR scaffold prior to Gd3+ chelation. The PR products were characterized by 1 H NMR, gel permeation chromatography/multiangle light scattering, dynamic light scattering, and analytical ultracentrifugation...
November 7, 2018: Bioconjugate Chemistry
Junior Gonzales, Susanne Kossatz, Sheryl Roberts, Giacomo Pirovano, Christian Brand, Carlos Pérez-Medina, Patrick Donabedian, M Jason de la Cruz, Willem J M Mulder, Thomas Reiner
The preclinical potential of many diagnostic and therapeutic small molecules is limited by their rapid washout kinetics and consequently modest pharmacological performances. In several cases, these could be improved by loading the small molecules into nanoparticulates, improving blood half-life, in vivo uptake and overall pharmacodynamics. In this study, we report a nanoemulsion (NE) encapsulated form of PARPi-FL. As a proof of concept, we used PARPi-FL, which is a fluorescently labeled sensor for olaparib, a FDA-approved small molecule inhibitor of the nuclear enzyme poly(ADP-ribose)polymerase 1 (PARP1)...
November 7, 2018: Bioconjugate Chemistry
David Peeler, Drew L Sellers, Suzie H Pun
The non-viral delivery of exogenous nucleic acids (NA) into cells for therapeutic purposes has rapidly matured into tangible clinical impact. Synthetic polymers are particularly attractive vectors for NA delivery due to their relatively inexpensive production compared to viral alternatives and their highly tailorable chemical properties; indeed, many preclinical investigations have revealed the primary biological barriers to non-viral NA delivery by systematically varying polymeric material properties. This review focuses on applications of pH-sensitive chemistries that enable polymeric vectors to serially address multiple biological barriers to NA delivery...
November 6, 2018: Bioconjugate Chemistry
Chunlei Yu, Echuan Tan, Yangyang Xu, Jia Lv, Yiyun Cheng
Cytosolic protein delivery is critical for the development of protein-based therapeutics. However, an efficient and robust carrier that can deliver native proteins without biological or chemical modifications into cells is highly desired. Here, we developed a guanidinium-rich polymer consisting of a cationic polymer scaffold modified with both phenyl and biguanide moieties. The polymer showed much higher protein binding affinity and endocytosis and reduced cytotoxicity compared to a control polymer by replacing the biguanide with monoguanide moieties...
November 6, 2018: Bioconjugate Chemistry
Md Kamrul Islam, Soyeon Kim, Hee-Kyung Kim, Yeoun-Hee Kim, Young-Mi Lee, Garam Choi, Ah Rum Baek, Bo Kyung Sung, Minsup Kim, Art E Cho, Hyojeung Kang, Gang-Ho Lee, Seon Hee Choi, Taekwan Lee, Ji-Ae Park, Yongmin Chang
In this study, we designed and synthesized a highly stable manganese (Mn2+ )-based hepatobiliary complex by tethering an ethoxybenzyl (EOB) moiety with an ethylenediaminetetraacetic acid (EDTA) coordination cage as an alternative to the well-established hepatobiliary gadolinium (Gd3+ ) chelates and evaluated its usage as a T1 hepatobiliary magnetic resonance imaging (MRI) contrast agent (CA). This new complex exhibits higher r1 relaxivity (2.3 mM-1 s-1 ) than clinically approved Mn2+ -based hepatobiliary complex Mn-DPDP (1...
November 6, 2018: Bioconjugate Chemistry
Jianxin Wang, Mini Thomas, Peng Lin, Ji-Xin Cheng, Daniela E Matei, Alexander Wei
Small interfering RNA (siRNA) duplexes can be loaded onto gold nanorods (GNRs) at high density using in situ dithiocarbamate (DTC) formation, with femtosecond (fs) near-infrared (NIR) laser pulses used to trigger their intracellular release. The DTC anchors prevent premature siRNA desorption, a common but often overlooked problem in the use of gold nanoparticles as oligonucleotide carriers. Citrate-stabilized GNRs are first coated with oleylsulfobetaine (OSB), a zwitterionic amphiphile, to produce stable dispersions at high ionic strength...
November 5, 2018: Bioconjugate Chemistry
Shunsuke Sugimoto, Yasuhiko Iwasaki
Antigen-presenting cells (APCs) play a dominant role in cancer immunotherapy. However, tumor cells can resort to several mechanisms of immune evasion that ultimately lead to the development of tumor tissues. In the current study, we performed the surface modification of live macrophages with nucleic acid aptamers with the aim to enhance their affinity for tumor cells. This experiment could improve the efficacy of cancer immunotherapy. Intercellular adhesion of tumor cells to surface-immobilized macrophages and the functions of the macrophages when in contact with tumor cells were investigated...
November 5, 2018: Bioconjugate Chemistry
Maelle Vallade, Michal Jewginski, Lucile Fischer, Jérémie Buratto, Katell Bathany, Jean-Marie Schmitter, Marine Stupfel, Frédéric Godde, Cameron David Mackereth, Ivan Huc
Helically folded aromatic foldamers may constitute suitable candidates for the ab initio design of ligands for protein surfaces. As preliminary steps towards the exploration of this hypothesis, a tethering approach was developed to detect interactions between a protein and a foldamer by confining the former at the surface of the latter. Cysteine mutants of two thera-peutically relevant enzymes, CypA and IL4, were produced. Two series of ten foldamers were synthesized bearing different proteinogenic side chains and either a long or a short linker functionalized with an activated disulfide...
November 5, 2018: Bioconjugate Chemistry
Sumeet Manandhar, Jooho Park, Vinoth K Kothandan, Joomin Lee, Farzana Alam, Jun-Pil Jee, Jinsu Hwang, Youngro Byun, Seung Rim Hwang
Tumor-derived exosomes are bound and internalized to organ-specific cells, affecting metastasis. Heparan sulfate proteoglycans mediate the interaction between cells and exosomes. Exosome transfer to the recipient cell can be competitively blocked by heparinoids, because heparin is structurally similar to heparan sulfate. It is hypothesized that there may be structural requirements of heparinoids to attenuate the cellular uptake and metastatic activity of tumor-derived exosomes. Here, we compared the properties of unfractionated heparin (UFH), glycol-split UFH, low-molecular-weight heparin (LMWH), glycol-split LMWH, and ultra-LMWH premixed with A549-derived exosomes...
November 5, 2018: Bioconjugate Chemistry
Ryosuke Kimura, Masahide Shibata, Shuhei Koeda, Atsushi Miyagawa, Hatsuo Yamamura, Toshihisa Mizuno
Peptide gemini-surfactant (PG-surfactant), a kind of lipopeptide, is composed of a short linker peptide (X) between two alkyl-chain-modified Cys residues and peripheral peptides at the N-terminal (Y) and the C-terminal (Z) sides, respectively, of the alkylated Cys residues. In this study, we developed and examined a series of PG-surfactants containing two C12 saturated alkanes and oligo-Lys, arranged at the X-, Y-, or Z-positions. To arrange oligo-Lys at the Y- or Z-positions, a repeat sequence of -Asp-Lys-Asp-Lys- was used at the X-position...
November 5, 2018: Bioconjugate Chemistry
Fatemeh Ostadhossein, Gururaja Vulugundam, Santosh K Misra, Indrajit Srivastava, Dipanjan Pan
Manipulating the chiroptical properties at the nanoscale is of great importance in stereoselective reactions, enantioseparation, self-assembly, and biological phenomena. In recent years, carbon dots have garnered great attention because of their favorable properties such as tunable fluorescence, high biocompatibility, and facile, scalable synthetic procedures. Herein, we report for the first time the unusual behavior of cyclic amino acids on the surface of carbon dots prepared via microwave-based carbonization...
November 5, 2018: Bioconjugate Chemistry
Anna A Nikitina, Sviatlana A Ulasevich, Ilia S Kassirov, Ekaterina A Bryushkova, Elena I Koshel, Ekaterina V Skorb
The development of stimuli-responsive nanocontainers is an issue of utmost importance for many applications such as targeted drug delivery, regulation of the cell and tissue behavior, making bacteria have useful functions and here converting light. The present work shows a new contribution to the design of polyelectrolyte (PE) containers based on surface modified mesoporous titania particles with deposited Ag nanoparticles to achieve chemical light upconversion via biofilms. The PE shell allows slowing down the kinetics of a release of loaded l-arabinose and switching the bacteria luminescence in a certain time...
November 5, 2018: Bioconjugate Chemistry
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