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Bioconjugate Chemistry

Zhang Hu, Ying Sim, Oi Lian Kon, Wai Har Ng, António J M Ribeiro, Maria J Ramos, Pedro A Fernandes, Rakesh Ganguly, Bengang Xing, Felipe García, Edwin K L Yeow
In this study, unique methyl-functionalized derivatives (T*PP(+)) of the drug carrier triphenylphosphonium (TPP(+)) that exhibit significant enhancement of the accumulation of both the cation and its conjugated cargo in cell mitochondria are designed. We show that the presence of methyl group(s) at key positions within the phenyl ring results in an increase in the hydrophobicity and solvent accessible surface area of T*PP(+). In particular, when the para position of the phenyl ring in T*PP(+) is functionalized with a methyl group, the cation is most exposed to the surrounding environment, leading to a large decrease in water entropy and an increase in the level of van der Waals interaction with and partition into a nonpolar solvent...
January 18, 2017: Bioconjugate Chemistry
Sanne A M van Lith, Sander M J van Duijnhoven, Anna C Navis, Edward Dolk, Jos W H Wennink, Cornelus F van Nostrum, Jan C M van Hest, William P J Leenders, Sanne A M van Lith, Sander M J van Duijnhoven, Anna C Navis, William P J Leenders, Edward Dolk, Jos W H Wennink, Cornelus F van Nostrum, Jan C M van Hest
Conjugation of llama single domain antibody fragments (Variable Heavy chain domains of Heavy chain antibodies, VHHs) to diagnostic or therapeutic nanoparticles, peptides, proteins, or drugs offers many opportunities for optimized targeted cancer treatment. Currently, mostly nonspecific conjugation strategies or genetic fusions are used that may compromise VHH functionality. In this paper we present a versatile modular approach for bioorthogonal VHH modification and conjugation. First, sortase A mediated transPEGylation is used for introduction of a chemical click moiety...
January 18, 2017: Bioconjugate Chemistry
Norifumi Kawakami, Hiroki Kondo, Masayuki Muramatsu, Kenji Miyamoto
We here report the production of highly spherical protein nanoparticles based on the domain-swapping oligomerization of a circularly permuted trimeric protein, major histocompatibility complex (MHC) class II-associated chaperonin. The size distribution of the nanoparticles can be adjusted to between 40-100 nm in diameter and thus these particles are suitable as drug carriers following purification under basic conditions. Our approach involves no harsh treatments and could provide an alternative approach for protein nanoparticle formation...
January 16, 2017: Bioconjugate Chemistry
Bingbo Zhang, Jun Wang, Jiani Yu, Xiangming Fang, Xiuli Wang, Donglu Shi
Various biomimetic nanoparticles have been fabricated for cancer nanotheranostics with a diverse range of proteins. However, the operating mechanisms of these reactions are still unclear, especially on the interaction between metal ions and protein, the precise binding sites, and the existence format of nanoparticles. Assuming shortening of the amino acids sequence into several, namely short peptides, it would be much easier to investigate the biomimetic reaction mechanism. In this study, a modular peptide, possessing Au3+ ions coordination motifs and Gd3+ ions chelation sequence, is designed and synthesized...
January 13, 2017: Bioconjugate Chemistry
Joseph J Whittenberg, Hairong Li, Haiying Zhou, Jan Koziol, Amit V Desai, David Edward Reichert, Paul J A Kenis
There is a growing demand for diagnostic procedures including in vivo tumor imaging. Radiometal-based imaging agents are advantageous for tumor imaging because radiometals (i) have a wide range of half-lives and (ii) are easily incorporated into imaging probes via a mild, rapid chelation event with a bifunctional chelator (BFC). Microfluidic platforms hold promise for synthesis of radiotracers because they can easily handle minute volumes, reduce consumption of expensive reagents, and minimize personnel exposure to radioactive compounds...
January 13, 2017: Bioconjugate Chemistry
Noriko Miyamoto, Shinichi Mochizuki, Shota Fujii, Kenta Yoshida, Kazuo Sakurai
Cancer vaccine has the ability to directly eradicate tumor cells by creating and activating cytotoxic T lymphocytes (CTLs). To achieve efficient CTL activity and to induce Th1 responses, it is essential to administer an appropriate adjuvant as well as an antigen. CpG-ODN is known as a ligand of Toll-like receptor 9 (TLR9) and strongly induces Th1 responses. In our previous study, we developed a CpG-ODN delivery system by use of the formation of complexes between ODN and a β-glucan SPG, denoted as CpG/SPG, and demonstrated that CpG/SPG induces high Th1 responses...
January 13, 2017: Bioconjugate Chemistry
Yuji Fujita, Yoshihiro Murakami, Akihiro Noda, Sosuke Miyoshi
An easily obtainable thiol-selective labeling reagent [(18)F]FBSEM (N-[2-(4-[(18)F]fluoro-N-methylbenzenesulfonamido)ethyl]maleimide) was developed. The advantage of the design is that the precursor and [(18)F]FBSEM have the same backbone and backbone construction is not required; in contrast, known thiol-specific labeling reagents do require backbone construction, and this is thought to be the cause of their complicated synthesis. [(18)F]FBSEM was successfully obtained in higher yield (25%) and in a simpler way (two fluorination and deprotection steps in 65 min) than the widely used [(18)F]FBEM (N-[2-(4-[(18)F]fluorobenzamide)ethyl]maleimide)...
January 13, 2017: Bioconjugate Chemistry
Yiming Zhao, Travis M Shaffer, Sudeep Das, Carlos Pérez-Medina, Willem J M Mulder, Jan Grimm
Cerenkov luminescence (CL) is an emerging imaging modality that utilizes the light generated during the radioactive decay of many clinical used isotopes. Although it is increasingly used for background-free imaging and deep tissue photodynamic therapy, in vivo applications of CL suffer from limited tissue penetration. Here, we propose to use quantum dots (QDs) as spectral converters that can transfer the CL UV-blue emissions to near-infrared light that is less scattered or absorbed in vivo. Experiments on tissue phantoms showed enhanced penetration depth and increased transmitted intensity for CL in the presence of near-infrared (NIR) QDs...
January 12, 2017: Bioconjugate Chemistry
Ruel Z B Desamero, Adam A Profit, Jayson Del Rosario Vedad
Human islet amyloid polypeptide (hIAPP), also known as amylin, is a 37 residue peptide hormone that is stored and co-secreted with insulin. hIAPP plays a pivotal role in type 2 diabetes and is the major component of amyloid deposits found in the pancreas of patients afflicted with the disease. The self-assembly of hIAPP and the formation of amyloid is linked to the death of insulin producing -cells. Recent findings suggest soluble hIAPP oligomers are the cytotoxic species responsible for -cell loss whereas amyloid fibrils themselves may indeed be innocuous...
January 10, 2017: Bioconjugate Chemistry
Jirina Zackova Suchanova, Jitka Neburkova, Hana Spanielova, Jitka Forstova, Petr Cigler
Virus-like particles based on polyomaviruses (PVLPs) are promising delivery devices for various cargoes, including nucleic acids, imaging probes, and therapeutic agents. In biological environments, the major coat protein VP1 interacts with ubiquitously distributed sialic acid residues, and therefore PVLPs show a broad tropism. For selective targeting, appropriate engineering of the PVLP surface is needed. Here, we describe a chemical approach to retarget PVLPs to cancer cells displaying abnormally high levels of transferrin receptor...
January 10, 2017: Bioconjugate Chemistry
Elisa Andreozzi, Antonella Antonelli, Michela Cangiotti, Barbara Canonico, Carla Sfara, Anna Pianetti, Francesca Bruscolini, Karin Sahre, Dietmar Appelhans, Stefano Papa, Maria Francesca Ottaviani
Poly(propyleneimine) glycodendrimers fully modified with maltose units were administered to different cancer cell lines and their effect on cell viability was evaluated by using MTS assay and flow cytometry. The mechanism of dendrimer-cell interactions was investigated by the electron paramagnetic resonance (EPR) technique by using a new nitroxide-conjugated glycodendrimer. The nitroxide groups did not modify both the biological properties (cell viability and apoptosis degree) of the dendrimers in the presence of the cells and the dendrimer-cell interactions...
January 9, 2017: Bioconjugate Chemistry
Li Xiao, Tinghui Li, Mengmeng Ding, Jiezuan Yang, José R Rodríguez-Corrales, Nicholas C Nacey, David B Weiss, Li Jin, Harry C Dorn, Xudong Joshua Li
Differential diagnosis of chronic post-traumatic osteomyelitis (CPO) from aseptic inflammation remains challenging, since both pathological processes share similar clinical symptoms. Here we utilized a novel targeted metallofullerene nanoparticle based magnetic resonance imaging (MRI) probe IL-13-TAMRA-Gd3N@C80(OH)30(CH2CH2COOH)20 to detect CPO in mouse tibia via over-expressed IL-13Rα2 receptors. The functionalized metallofullerene was characterized by X-ray photoelectron spectroscopy. Upon lipopolysaccharides (LPS) stimulation, macrophage Raw 264...
January 6, 2017: Bioconjugate Chemistry
Brian A Mendelsohn, Stuart D Barnscher, Josh T Snyder, Zili An, Jennifer M Dodd, Julien Dugal-Tessier
Antibody drug conjugates offer a targeted cancer treatment for the delivery of potent cytotoxic drugs. Derivatives of the natural product dolastatin 10 containing pyridines and other basic amines were examined with the objective of determining if a more hydrophilic auristatin derivative would be potent enough for use as part of an ADC. This may be advantageous if a less hydrophobic drug makes a better ADC. A pyridine derivative, monomethyl auristatin PYE, showed the greatest potency when tested in vivo. While only a modest tumor growth inhibition was observed when the HCC1954 human breast cancer xenografts were treated with"non-cleavable" linker ADCs, tumor regression was seen when treated with an enzymatically degradable "cleavable" linker ADC when conjugated to trastuzumab...
January 6, 2017: Bioconjugate Chemistry
Imran Ozer, Ashutosh Chilkoti
As potent and selective therapeutic agents, peptides and proteins are an important class of drugs, but they typically have suboptimal pharmacokinetic profiles. One approach to solve this problem is their conjugation with "stealth" polymers. Conventional methods for conjugation of this class of polymers to peptides and proteins are typically carried out by reactions that have poor yield and provide limited control over the site of conjugation and the stoichiometry of the conjugate. To address these limitations, new chemical and biological approaches have been developed that provide new molecular tools in the bioconjugation toolbox to create stealth polymer conjugates of peptides and proteins with exquisite control over their properties...
January 6, 2017: Bioconjugate Chemistry
Anshika Kapur, Fadi Aldeek, Xin Ji, Malak Safi, Wentao Wang, Ada Del Cid, Oliver Steinbock, Hedi Mattoussi
The ability of Au and other metal nanostructures to strongly quench the fluorescence of proximal fluorophores (dyes and fluorescent proteins) has made AuNP-conjugates attractive for use as platforms for sensor development based on energy transfer interactions. In this study, we first characterize the energy transfer quenching of mCherry fluorescent proteins immobilized on AuNPs via metal-imidazole coordination, where parameters such as NP size and number of attached proteins are varied. Using steady-state and time-resolved fluorescence measurements, we recorded very high mCherry quenching, with efficiency reaching ≈ 95-97%, independent of the NP size or number of bound fluorophores (i...
January 4, 2017: Bioconjugate Chemistry
Wataru Hatanaka, Miki Kawaguchi, Xizheng Sun, Yusuke Nagao, Hiroyuki Ohshima, Mitsuru Hashida, Yuriko Higuchi, Akihiro Kishimura, Yoshiki Katayama, Takeshi Mori
We developed a strategy to modify cell membranes with an artificial transmembrane receptor. Coulomb's force on the receptor, caused by the membrane potential, was used to achieve membrane penetration. A hydrophobically-modified cationic peptide was used as a membrane potential sensitive region, which was connected to biotin through a transmembrane oligoethylene glycol (OEG) chain. This artificial receptor gradually disappeared from the cell membrane via penetration, despite the presence of a hydrophilic OEG chain...
January 4, 2017: Bioconjugate Chemistry
Yang Liu, Juneyoung Lee, Kathryn M Mansfield, Jeong Hoon Ko, Sahar Sallam, Chrys Wesdemiotis, Heather D Maynard
Biocompatible polymers such as poly(ethylene glycol) (PEG) have been successfully conjugated to therapeutic proteins to enhance their pharmacokinetics. However, many of these polymers, including PEG, only improve the in vivo lifetimes and do not protect proteins against inactivation during storage and transportation. Herein, we report a polymer with trehalose side chains (PolyProtek) that is capable of improving both the external stability and the in vivo plasma half-life of a therapeutic protein. Insulin was employed as a model biologic, and high performance liquid chromatography and dynamic light scattering confirmed that addition of trehalose glycopolymer as an excipient or covalent conjugation prevented thermal or agitation-induced aggregation of insulin...
January 3, 2017: Bioconjugate Chemistry
Ludan Yue, Jinlong Wang, Zhichao Dai, Zunfu Hu, Xue Chen, Yafei Qi, Xiuwen Zheng, Dexin Yu
Multifunctional nanotheranostic agents have been highly commended due to the application to realize image-guided cancer therapy. Herein, based on the chemically disordered face centered cubic (fcc) FePt nanoparticles (NPs) and graphene oxide(GO), we develop a pH-responsive FePt-based multifunctional theranostic agent for potential in vivo and in vitro dual modal MRI/CT imaging and in-situ cancer inhibition. The fcc-FePt will release highly active Fe ions due to the low pH in tumor cells, which would catalyze H2O2 decomposition into reactive oxygen species (ROS) within the cells and further induce cancer cell apoptosis...
January 2, 2017: Bioconjugate Chemistry
Maria-Jose Bañuls, Pilar Jiménez-Meneses, Albert Meyer, Jean-Jacques Vasseur, François Morvan, Jorge Escorihuela, Rosa Puchades, Angel Maquieira
Nucleic acid microarray-based assay technology has recognized lacks in reproducibility, reliability and analytical sensitivity. Here, a new strategy of probe attachment modes for silicon-based materials is built up. Thus, hybridization ability is enhanced combining thiol-ene or thiol-yne click chemistry reactions, with a multi-point attachment of polythiolated probes. The viability and performance of this approach were demonstrated determining specifically Salmonella PCR products up to 20 pM sensitivity level...
January 2, 2017: Bioconjugate Chemistry
Mikhail Valeryevich Zyuzin, Paula Díez, Meir Goldsmith, Susana Carregal-Romero, Cristina Teodosio, Joanna Rejman, Neus Feliu, Alberto Escudero, María Jesús Almendral, Uwe Linne, Dan Peer, Manuel Fuentes, Wolfgang J J Parak
The inmunocompatibility of polyelectrolyte capsules synthesized by Layer-by-Layer deposition, has been investigated. Capsules of different architecture and composed either of nondegradable or biodegradable polymers, with either positively or negatively charged outer surface, and with micrometer size, have been used, and the capsule uptake by different cell lines has been studied and quantified. Immunocompatibility studies were performed with peripheral blood mononuclear cells (PBMCs). Data demonstrate that incubation with capsules, at concentrations relevant for practical applications, did not result in a reduced viability of cells, as it did not show an increased apoptosis...
January 2, 2017: Bioconjugate Chemistry
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