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Nanoparticles and molecular imaging

Daiyuan Tang, Wei Gao, Yajiang Yuan, Lingling Guo, Xifan Mei
Nanoprobes are rapidly becoming potentially transformative tools on disease diagnostics for a wide range of in vivo computed tomography (CT) imaging. Compared with conventional molecular-scale contrast agents, nanoparticles (NPs) promise improved abilities for in vivo detection. In this study, novel polyethylene glycol (PEG)-functionalized Au nanoparticles with star shape (AuNS@PEG) with strong X-ray mass absorption coefficient were synthesized as CT imaging contrast agents. Experimental results revealed that AuNS@PEG nanoparticles are well constructed with ultrasmall sizes, effective metabolisability, high computed tomography value, and outstanding biocompatibility...
October 12, 2017: Nanoscale Research Letters
Peng Gao, Huangsheng Pu, Junyan Rong, Wenli Zhang, Tianshuai Liu, Wenlei Liu, Yuanke Zhang, Hongbing Lu
Cone-beam X-ray luminescence computed tomography (CB-XLCT) has been proposed as a new molecular imaging modality recently. It can obtain both anatomical and functional tomographic images of an object efficiently, with the excitation of nanophosphors in vivo or in vitro by cone-beam X-rays. However, the ill-posedness of the CB-XLCT inverse problem degrades the image quality and makes it difficult to resolve adjacent luminescent targets with different concentrations, which is essential in the monitoring of nanoparticle metabolism and drug delivery...
September 1, 2017: Biomedical Optics Express
Chen Xie, Xu Zhen, Yan Lyu, Kanyi Pu
Smart molecular probes that emit deep-tissue penetrating photoacoustic (PA) signals responsive to the target of interest are imperative to understand disease pathology and develop innovative therapeutics. This study reports a self-assembly approach to develop semiconducting macromolecular activatable probe for in vivo imaging of reactive oxygen species (ROS). This probe comprises a near-infrared absorbing phthalocyanine core and four poly(ethylene glycol) (PEG) arms linked by ROS-responsive self-immolative segments...
October 11, 2017: Advanced Materials
Zhiliang Chen, Börje Sellergren, Xiantao Shen
In this work, we developed an efficient "molecularly imprinted polymer microzymes and inorganic magnetic nanozymes" synergistic catalysis strategy for the formation of disulfide bonds in peptides. The polymeric microzymes showed excellent selectivity toward the template peptide as well as the main reactant (linear peptide), and the Fe3O4 magnetic nanoparticle (MNP) nanozymes inhibited the intermolecular reaction during the formation of disulfide bonds in peptides. As a result, the integration of the two different artificial enzymes in one process facilitates the intramolecular cyclization in high product yields (59...
2017: Frontiers in Chemistry
Mahdi Ayoubi, Parvaneh Naserzadeh, Mohammad Taghi Hashemi, Mohammad Reza Rostami, Elnaz Tamjid, Mohammad Mahdi Tavakoli, Abdolreza Simchi
Colloidal quantum dots (CQD) have attracted considerable attention for biomedical diagnosis and imaging as well as biochemical analysis and stem cell tracking. In this study, quasi core/shell lead sulfide/reduced graphene oxide CQD with near infrared emission (1100 nm) were prepared for potential bioimaging applications. The nanocrystals had an average diameter of ~4 nm, a hydrodynamic size of ~8 nm, and a high quantum efficiency of 28%. Toxicity assay of the hybrid CQD in the cultured human mononuclear blood cells does not show cytotoxicity up to 200 µg/ml...
October 10, 2017: Scientific Reports
Rajan Kumar Pandey, Vijay Kumar Prajapati
Nanoparticles have emerged as a boon for the public health applications such as drug delivery, diagnostic, and imaging. Biodegradable and non-bio degradable nanoparticles have been used at a large scale level to increase the efficiency of the biomedical process at the cellular, animal and human level. Exponential use of nanoparticles reinforces the adverse immunological changes at the human health level. Physical and chemical properties of nanoparticles often lead to a variety of immunotoxic effects such as activation of stress-related genes, membrane disruption, and release of pro-inflammatory cytokines...
October 7, 2017: International Journal of Biological Macromolecules
Yang Du, Xiaolong Liang, Yuan Li, Ting Sun, Zhengyu Jin, Huadan Xue, Jie Tian
The over-expression of programmed cell death-1 (PD-1) in tumors as breast cancer makes it a possible target for cancer imaging and therapy. Advances in molecular imaging, including radionuclide imaging and near infrared fluorescence (NIRF) imaging, enable the detection of tumors with high sensitivity. In this study, we aim to develop a novel PD-1 antibody targeted positron emission tomography (PET) and NIRF labeled liposome loaded with doxorubicin (DOX) and evaluate its application for in vivo cancer imaging and therapy...
October 10, 2017: Molecular Pharmaceutics
Danting Cui, Xiaodan Lu, Chenggong Yan, Xiang Liu, Meirong Hou, Qi Xia, Yikai Xu, Ruiyuan Liu
Bombesin (BBN), an analog of gastrin-releasing peptide (GRP), specifically binds to GRP receptors, which are overexpressed in human prostate cancer (PC). Here, we synthesized a BBN-modified gadolinium oxide (Gd2O3) nanoprobe containing fluorescein (Gd2O3-5(6)-carboxyfluorescein [FI]-polyethylene glycol [PEG]-BBN) for targeted magnetic resonance (MR)/optical dual-modality imaging of PC. The Gd2O3-FI-PEG-BBN nanoparticles exhibited a relatively uniform particle size with an average diameter of 52.3 nm and spherical morphology as depicted by transmission electron microscopy...
2017: International Journal of Nanomedicine
Hua He, Xu Liu, Shan Li, Xiaojuan Wang, Qian Wang, Jiqiang Li, Junying Wang, Hao Ren, Baosheng Ge, Shengjie Wang, Xiao-Dong Zhang, Fang Huang
Molecular fluorescence blinking provides a simple and attractive way to achieve super-resolution localization via conventional fluo-rescence microscopy. However, success in super-resolution imaging relies heavily on their blinking characteristics. We here report easily prepared and photostable nanoparticles-carbon dots (CDs) -with desirable fluorescence blinking for high-density super-resolution imaging. The CDs exhibit a low duty cycle (~ 0.003) and high photon output (~ 8000) per switching event, as well as show much higher resistance to photobleaching than Alexa 647 or Cy5 typically used in single molecule localization microscopy...
October 4, 2017: Analytical Chemistry
Yizhong Shen, Yidan Sun, Runqi Yan, Erquan Chen, Huan Wang, Deju Ye, Jing-Juan Xu, Hong-Yuan Chen
Semiconductor quantum dots (QDs) have served as superior optically active nanomaterials for molecular imaging and photodynamic therapy (PDT), but the low singlet oxygen ((1)O2) quantum yield and lack of tumor selectivity have limited their applications for tumor PDT in vivo. Here, we report the rational engineering of QDs into tumor-targeting hybrid nanoparticles through micelle-encapsulating a pre-assembled unique QD-Zn-porphyrin complex, a highly fluorescent organic photosensitizer rhodamine 6G (R6G), and a near-infrared fluorophore NIR775 with folic acid labeled phospholipid polymers...
December 2017: Biomaterials
David C Malaspina, Gabriel Longo, Igal Szleifer
Ligand-receptor binding is of utmost importance in several biologically related disciplines. Ligand binding assays (LBA) use the high specificity and high affinity of ligands to detect, target or measure a specific receptors. One particular example of ligand binding assays are Antibody conjugated Nanoparticles (AcNPs), edge-cutting technologies that are present in several novel biomedical approaches for imaging, detection and treatment of diseases. However, the nano-confinement in AcNPs and LBA nanostructures introduces extra complexity in the analysis of ligand-receptor equilibriums...
2017: PloS One
P B Joshi, T P Anthony, A J Wilson, K A Willets
Gap mode surface-enhanced Raman scattering (SERS) substrates are created when a single nanoparticle is deposited on a thin metal film, creating a region of significant electromagnetic field enhancement in the gap between the nanoparticle and the film due to excitation of a vertically-oriented, out-of-plane dipole plasmon mode, e.g. the gap plasmon. When molecules are located in the gap and couple to the gap plasmon mode, the resulting emission is polarized perpendicular to the thin film, generating SERS emission patterns that have a characteristic donut shape...
September 28, 2017: Faraday Discussions
Enrico Rampazzo, Damiano Genovese, Francesco Palomba, Luca Prodi, Nelsi Zaccheroni
The development of nanostructures devoted to in vivo imaging and theranostic applications is one of the frontier fields of research worldwide. In this context, silica nanoparticles (SiO2-NPs) offer unquestionable positive properties: silica is intrinsically non-toxic, several versatile and accessible synthetic methods are available and many variations are possible, both in terms of porosity and functionalization for delivery and targeting purposes, respectively. Moreover, the accumulation of several dyes within a single nanostructure offer remarkable possibilities to produce very bright and photostable luminescent nanosystems...
September 27, 2017: Methods and Applications in Fluorescence
Khalil Chennit, Jorge Trasobares, Agnès Anne, Edmond Cambril, Arnaud Chovin, Nicolas Clément, Christophe Demaille
The aim of the present work is to explore the combination of atomic force electrochemical microscopy, operated in molecule touching mode (Mt/AFM-SECM), and of dense nanodot arrays, for designing an electrochemically addressable molecular nanoarray platform. A high density nanoarray of single grained gold nanodots (∼15 nm-diameter nanoparticles, 100 nm pitch) is decorated by a model molecular system, consisting of ferrocene (Fc) labeled polyethylene glycol (PEG) disulfide chains. We show that the high resolution of Mt/AFM-SECM enables the electrochemical interrogation of several hundreds of individual nanodots in a single image acquisition...
October 17, 2017: Analytical Chemistry
Dali Wang, Bing Liu, Yuan Ma, Chenwei Wu, Quanbing Mou, Hongping Deng, Ruibin Wang, Deyue Yan, Chuan Zhang, Xinyuan Zhu
Tumor-targeted drug delivery with simultaneous cancer imaging is highly desirable for personalized medicine. Herein, we report a supramolecular approach to design a promising class of multifunctional nanoparticles based on molecular recognition of nucleobases, which combine excellent tumor-targeting capability via aptamer, controlled drug release, and efficient fluorescent imaging for cancer-specific therapy. First, an amphiphilic prodrug dioleoyl clofarabine was self-assembled into micellar nanoparticles with hydrophilic nucleoside analogue clofarabine on their surface...
October 11, 2017: Journal of the American Chemical Society
Vinicius B Tergolina, Alexandre P Dos Santos
In this paper we perform molecular dynamics simulations of a spherical polyelectrolyte brush and counterions in a salt-free medium. The dielectric discontinuity on the grafted nanoparticle surface is taken into account by the method of image charges. Properties of the polyelectrolyte brush are obtained for different parameters, including valency of the counterions, radius of the nanoparticle, and the brush total charge. The monovalent counterions density profiles are obtained and compared with a simple mean-field theoretical approach...
September 21, 2017: Journal of Chemical Physics
Dong-Li Li, Jian-Er Tan, Ying Tian, Shun Huang, Peng-Hui Sun, Meng Wang, Yan-Jiang Han, Hong-Sheng Li, Hu-Bing Wu, Xing-Mei Zhang, Yi-Kai Xu, Quan-Shi Wang
Based on the discordance of human epidermal growth factor receptor-2 (HER2) expression between primary and metastatic/recurrent breast cancer, HER2 molecular imaging, which had potential to systemically assess and dynamically monitor HER2 expression, might improve the selection of patients for anti-HER2 therapy. In this study, designed ankyrin repeat protein (DARPin) G3, a novel binding protein with picomolar affinity for HER2, was used and multifunctional superparamagnetic nanoparticles modified with fluorescein-5-maleimide-labeled DARPin G3 (SPIO-G3-5MF) were developed for HER2 imaging...
September 8, 2017: Biomaterials
Heike E Daldrup-Link
This invited commentary discusses a recent article by Mohanty et al in Molecular Cancer Therapeutics about significant therapeutic efficacies of novel theranostic nanoparticles (TNPs) for the treatment of human brain cancers in mouse models. The TNPs were cleaved by enzymes in the tumor tissue, matrix metalloproteinase (MMP-14), which lead to release of a highly potent therapeutic drug, azademethylcolchicine. Data showed that the TNPs caused selective toxic effects in MMP-14-expressing glioblastoma and not normal brain...
January 2017: Molecular Imaging
Yang Li, Jinyan Lin, Jinyuan Ma, Liang Song, Huirong Lin, Bowen Tang, Dengyue Chen, Guanghao Su, Shefang Ye, Xuan Zhu, Fanghong Luo, Zhenqing Hou
"All-in-one" carrier-free-based nano-multi-drug self-delivery system could combine triple advantages of small molecules, nanoscale characteristics, and synergistic combination therapy together. Researches have showed that dual-acting small-molecular methotrexate (MTX) could target and kill the folate-receptor-overexpressing cancer cells. Inspired by this mechanism, a novel collaborative early-phase tumor-selective targeting and late-phase synergistic anticancer approach was developed for the self-assembly of chemotherapeutic drug-drug conjugate, which showed various advantages of more simplicity, efficiency, and flexibility over the conventional approach based only on single or combination cancer chemotherapy...
October 11, 2017: ACS Applied Materials & Interfaces
Zaman Khan, Abdul Rehman, Muhammad Atif Nisar, Saima Zafar, Syed Zajif Hussain, Inga Zerr, Irshad Hussain, Muhammad Waseem, Muhammad Arif
This study examines the bioremediation potential and cadmium-induced cellular response on a molecular level in Candida tropicalis 3Aer. Spectroscopic analysis clearly illustrated the involvement of yeast cell wall components in biosorption. Cadmium bioaccumulation was confirmed by TEM, SEM, and EDX examination. TEM images revealed extracellular as well as cytoplasmic and vacuolar cadmium nanoparticle formation, further validated by presence of ycf1 gene and increased biosynthesis of GSH under cadmium stress...
September 17, 2017: Applied Microbiology and Biotechnology
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