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https://www.readbyqxmd.com/read/28437627/tumor-acidity-activatable-tat-targeted-nanomedicine-for-enlarged-fluorescence-magnetic-resonance-imaging-guided-photodynamic-therapy
#1
Meng Gao, Feng Fan, Dongdong Li, Yue Yu, Kuirong Mao, Tianmeng Sun, Haisheng Qian, Wei Tao, Xianzhu Yang
Nanoparticles simultaneously integrated the photosensitizers and diagnostic agents represent an emerging approach for imaging-guided photodynamic therapy (PDT). However, the diagnostic sensitivity and therapeutic efficacy of nanoparticles as well as the heterogeneity of tumors pose tremendous challenges for clinical imaging-guided PDT treatment. Herein, a polymeric nanoparticle with tumor acidity (pHe)-activatable TAT targeting ligand that encapsulates the photosensitizer chlorin e6 (Ce6) and chelates contrast agent Gd(3+) is successfully developed for fluorescence/magnetic resonance (MR) dual-model imaging-guided precision PDT...
April 18, 2017: Biomaterials
https://www.readbyqxmd.com/read/28425537/using-fluorescently-labeled-magnetic-nanocomposites-as-a-dual-contrast-agent-for-optical-and-magnetic-resonance-imaging
#2
Taofeng Zhu, Xiuqin Ma, Ruhua Chen, Zhijun Ge, Jun Xu, Xiaoke Shen, Lei Jia, Tao Zhou, Yifeng Luo, Tieliang Ma
Dual-modality imaging probes synergistically combine magnetic resonance (MR) and fluorescence into a single nanocomposite. This promising technique affords a new level of flexibility for molecular imaging uses in biomedical research. In this study, we report a new strategy for the synthesis of a novel attapulgite nanorod-based atta@Fe3O4@[Ru(bpy)2(fmp)]Cl2 nanocomposite (atta@Fe3O4@Ru NC). Our synthesized NC has both photoluminescent and magnetic properties, bright fluorescence, as well as significant magnetic resonance...
April 20, 2017: Biomaterials Science
https://www.readbyqxmd.com/read/28422344/use-of-blood-pool-agents-with-steady-state-mri-to-assess-the-vascular-system
#3
Avnesh S Thakor, John Chung, Premal Patel, Anthony Chan, Amdad Ahmed, Graeme McNeil, David M Liu, Bruce Forster, Darren Klass
Over the past two decades there have been significant advances in the use of magnetic resonance imaging (MRI) to assess the vascular system. New imaging sequences and improvements in magnet design have enabled the creation of higher spatial resolution images. MRI is now a viable alternative imaging modality when compared to both invasive angiography and computed tomographic angiography. The use of blood pool agents has further facilitated the use of MR angiography (MRA); their high molecular weight allows for lower doses of contrast medium administration while their prolonged presence in the blood stream allows for repeated high-quality volumetric imaging of both the arterial and venous circulation...
April 19, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28419613/peg-poly-l-lysine-based-polymeric-micelle-mri-contrast-agent-feasibility-study-of-a-gd-micelle-contrast-agent-for-mr-lymphography
#4
Hiroyuki Akai, Kouichi Shiraishi, Masayuki Yokoyama, Koichiro Yasaka, Masanori Nojima, Yusuke Inoue, Osamu Abe, Kuni Ohtomo, Shigeru Kiryu
PURPOSE: To investigate the feasibility of polymeric micelle of poly(ethyleneglycol) (PEG)-b-poly(L-lysine-DOTA) (Gd-micelle) as a contrast agent for magnetic resonance lymphography (MRL). MATERIALS AND METHODS: Twenty-four female BALB/c mice were randomly divided into four groups of six mice each. Among them, mice of two groups were injected of complete Freund's adjuvant to obtain inflamed lymph nodes. We subcutaneously injected 0.5 μmol Gd per mouse of Gd-micelle or gadofluorine P in the right rear footpad...
April 17, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28415493/multifunctional-baybf5-gd-er-upconversion-nanoparticles-for-in-vivo-tri-modal-upconversion-optical-x-ray-computed-tomography-and-magnetic-resonance-imaging
#5
Xiaolong Li, Zhigao Yi, Zhenluan Xue, Songjun Zeng, Hongrong Liu
Development of high-quality upconversion nanoparticles (UCNPs) with combination of the merits of multiple molecular imaging techniques, such as, upconversion luminescence (UCL) imaging, X-ray computed tomography (CT), and magnetic resonance (MR) imaging, could significantly improve the accuracy of biological diagnosis. In this work, multifunctional BaYbF5: Gd/Er (50:2mol%) UCNPs were synthesized via a solvothermal method using oleic acid (OA) as surface ligands (denoted as OA-UCNPs). The OA-UCNPs were further treated by diluted HCl to form ligand-free UCNPs (LF-UCNPs) for later bioimaging applications...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28409916/surfactant-free-aqueous-synthesis-of-novel-ba2gdf7-yb-3-er-3-peg-upconversion-nanoparticles-for-in-vivo-trimodality-imaging
#6
Yang Feng, Hongda Chen, Lina Ma, Baiqi Shao, Shuang Zhao, Zhenxin Wang, Hongpeng You
In this work, we developed the surfactant-free aqueous synthesis of novel polyethylene glycol (PEG) coated Ba2GdF7:Yb(3+), Er(3+) upconversion nanoparticles (named as, Ba2GdF7:Yb(3+), Er(3+)@PEG UCNPs) for in vivo multimodality imaging including upconversion luminescence (UCL), X-ray computed tomography (CT), and T1-weighted magnetic resonance (MR). The as-prepared Ba2GdF7:Yb(3+), Er(3+)@PEG UCNPs not only present bright UCL and reasonably high CT/MR enhancements but also exhibit excellent colloidal stability, inappreciable cytotoxicity, and negligible organ toxicity...
April 24, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28388272/anomalous-coronary-arteries-that-need-intervention-review-of-pre-and-postoperative-imaging-appearances
#7
Prachi P Agarwal, Carole Dennie, Elena Pena, Elsie Nguyen, Troy LaBounty, Bo Yang, Smita Patel
Coronary artery anomalies constitute a diverse group of abnormalities, ranging from anatomic variants to those having hemodynamic consequences. This review focuses on major anomalies that have clinical implications requiring treatment, including anomalous origin of the coronary artery from the opposite sinus with interarterial course specifically with an intramural course, coronary artery origin from the pulmonary artery, and coronary artery fistula. Comprehensive imaging evaluation is necessary to precisely delineate the anatomy as well as pathophysiologic aspects of the anomaly before determining treatment options for a specific patient...
April 7, 2017: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/28379730/paraspinal-edema-is-the-most-sensitive-feature-of-lumbar-spinal-epidural-abscess-on-unenhanced-mri
#8
Anna Shifrin, Qin Lu, Michael H Lev, Timothy M Meehan, Ranliang Hu
OBJECTIVE: Spinal epidural abscess (SEA) is a serious infection requiring prompt treatment and potential neurosurgical intervention. Although contrast-enhanced spine MRI is the mainstay for diagnosis of SEA, unenhanced MRI is typically performed for patients with nonspecific symptoms or insufficient clinical information. We evaluated the sensitivity and specificity of imaging features suggestive of SEA at unenhanced spine MRI. MATERIALS AND METHODS: We searched our database for contrast-enhanced lumbar spine MRI examinations from January 1, 2000, through August 1, 2014, with "epidural abscess" in the report...
April 5, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28371584/ultrasmall-ferrite-nanoparticles-synthesized-via-dynamic-simultaneous-thermal-decomposition-for-high-performance-and-multifunctional-t1-magnetic-resonance-imaging-contrast-agent
#9
Huan Zhang, Li Li, Xiao Li Liu, Ju Jiao, Cheng-Teng Ng, Jia Bao Yi, Yan E Luo, Boon-Huat Bay, Ling Yun Zhao, Ming Li Peng, Ning Gu, Hai Ming Fan
Large-scale synthesis of monodisperse ultrasmall metal ferrite nanoparticles as well as understanding the correlations between chemical composition and MR signal enhancement is critical for developing next-generation, ultrasensitive T1 magnetic resonance imaging (MRI) nanoprobes. Herein, taking ultrasmall MnFe2O4 nanoparticles (UMFNPs) as a model system, we report a general dynamic simultaneous thermal decomposition (DSTD) strategy for controllable synthesis of monodisperse ultrasmall metal ferrite nanoparticles with sizes smaller than 4 nm...
April 6, 2017: ACS Nano
https://www.readbyqxmd.com/read/28368576/manganese-based-nanogels-as-ph-switches-for-magnetic-resonance-imaging
#10
Carlos Caro, María Luisa García-Martín, Manuel Pernia Leal
pH-responsive nanogels (NGs) were used to prepare high-efficiency magnetic resonance imaging dual T1/T2 contrast agents for pH imaging. The polymeric NG matrix acts as a strong polydentate ligand that chelates the Mn cations in its inner cavity generating a hybrid NG structure. The Mn chelate NG is sensitive to pH changes, such that protonation induces a change of the polymer hydration state and consequent swelling. The swollen nanogel allows water molecules to enter and interact with the Mn chelate, shortening the relaxation time (switch ON) and giving rise to positive or negative contrast on T1- or T2-weighted magnetic resonance images...
April 14, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28361281/europium-phenolic-network-coated-bagdf5-nanocomposites-for-tri-modal-computed-tomography-magnetic-resonance-luminescence-imaging
#11
Wei Zhu, Shuang Liang, Jing Wang, Zhe Yang, Li Zhang, Tianmeng Yuan, Zushun Xu, Haibo Xu, Penghui Li
Multifunctional nanocomposites based on BaGdF5 nanoparticles (NPs) and metal phenolic network (MPN) have been engineered as novel contrast agents for potential applications in X-ray computed tomography, magnetic resonance and luminescence imaging. The BaGdF5@MPN nanocomposites were synthesized at room temperature by coating BaGdF5 NPs with europium-phenolic network, which was obtained by the coordination of europium (III) with tannic acid (TA). The in vitro cytotoxicity assays against HepG2 cells revealed that the BaGdF5@MPN nanocomposites presented better cytocompatibility and lower cytotoxity than pure BaGdF5 NPs...
May 2017: Journal of Materials Science. Materials in Medicine
https://www.readbyqxmd.com/read/28358240/molecular-mr-imaging-of-myeloperoxidase-distinguishes-steatosis-from-steatohepatitis-in-nonalcoholic-fatty-liver-disease
#12
Benjamin Pulli, Gregory Wojtkiewicz, Yoshiko Iwamoto, Muhammad Ali, Matthias W Zeller, Lionel Bure, Cuihua Wang, Yuri Choi, Ricard Masia, Alex R Guimaraes, Kathleen E Corey, John W Chen
Purpose To test whether myeloperoxidase (MPO) with bis-5-hydroxytryptamide-diethylenetriaminepentaacetate-gadolinium (MPO-Gd), an activatable molecular magnetic resonance (MR) imaging agent specific for MPO activity, could detect MPO activity in nonalcoholic steatohepatitis (NASH) mouse models and human liver biopsy samples. Materials and Methods In this study, 20 leptin receptor-deficient and three MPO knockout mice were injected with endotoxin (lipopolysaccharide) or fed a methionine and choline-deficient (MCD) diet to induce experimental NASH and underwent MR imaging with MPO with MPO-Gd...
March 30, 2017: Radiology
https://www.readbyqxmd.com/read/28350963/gd-dots-with-strong-ligand-water-interaction-for-ultrasensitive-magnetic-resonance-renography
#13
Xiao-Yu Zheng, Kai Zhao, Jinglong Tang, Xin-Yu Wang, Lin-Dong Li, Nai-Xiu Chen, Yan-Jie Wang, Shuo Shi, Xiaodong Zhang, Sivakumar Malaisamy, Ling-Dong Sun, Xiaoying Wang, Chunying Chen, Chun-Hua Yan
Magnetic resonance imaging contrast agents with both significantly enhanced relaxivity and minimal safety risk are of great importance for sensitive clinical diagnosis, but have rarely been reported. Herein, we present a simple strategy to improve relaxivity by introducing surface ligands with strong interaction to water molecules. As a proof of concept, NaGdF4 nanoparticles (NPs) capped by poly(acrylic acid) (PAA) show superior relaxivity to those capped by polyethylenimine and polyethylene glycol, which is attributed to the strong hydrogen-bond capacity of PAA to water molecules as revealed by theoretical calculation...
March 30, 2017: ACS Nano
https://www.readbyqxmd.com/read/28344811/the-role-of-imaging-in-the-diagnosis-of-primary-prostate-cancer
#14
Hugh Harvey, Nandita M deSouza
Ultrasound and magnetic resonance imaging (MRI) are key imaging modalities in prostate cancer diagnosis. MRI offers a range of intrinsic contrast mechanisms (T2, diffusion-weighted imaging (DWI), MR spectroscopy (MRS)) and extrinsic contrast-generating options based on tumour vascular state following injection of weakly paramagnetic agents such as gadolinium. Together these parameters are referred to as multiparametric (mp)MRI and are used for detecting and guiding biopsy and staging prostate cancer. Although sensitivity of mpMRI is <75% for disease detection, specificity is >90% and a standardised reporting system together with MR-guided targeted biopsy is the optimal diagnostic pathway...
December 2016: Journal of Clinical Urology
https://www.readbyqxmd.com/read/28343127/direct-immobilization-of-manganese-chelates-on-silica-nanospheres-for-mri-applications
#15
Marcell Pálmai, Adrienn Pethő, Lívia Naszályi Nagy, Szilvia Klébert, Zoltán May, Judith Mihály, András Wacha, Katalin Jemnitz, Zsuzsanna Veres, Ildikó Horváth, Krisztián Szigeti, Domokos Máthé, Zoltán Varga
The development of tissue specific magnetic resonance imaging (MRI) contrast agents (CAs) is very desirable to achieve high contrast ratio combined with excellent anatomical details. To this end, we introduce a highly effective manganese(II) containing silica material, with the aim to shorten the longitudinal (T1) relaxation time. The microporous silica nanospheres (MSNSs) with enlarged porosity and specific surface area were prepared by a surfactant assisted aqueous method. Subsequently, the surface silanol groups were amino-functionalized, reacted with diethylenetriaminepentaacetic (DTPA) dianhydride and finally deposited with Mn(2+)...
March 14, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28336868/eu-gd-codoped-yttria-nanoprobes-for-optical-and-t%C3%A2-weighted-magnetic-resonance-imaging
#16
Timur Sh Atabaev, Jong Ho Lee, Yong Cheol Shin, Dong-Wook Han, Ki Seok Choo, Ung Bae Jeon, Jae Yeon Hwang, Jeong A Yeom, Hyung-Kook Kim, Yoon-Hwae Hwang
Nanoprobes with multimodal functionality have attracted significant interest recently because of their potential applications in nanomedicine. This paper reports the successful development of lanthanide-doped Y₂O₃ nanoprobes for potential applications in optical and magnetic resonance (MR) imaging. The morphology, structural, and optical properties of these nanoprobes were characterized by transmission electron microscope (TEM), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and photoluminescence (PL)...
February 10, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28334490/mr-cholangiography-in-potential-liver-donors-quantitative-and-qualitative-improvement-with-administration-of-an-oral-effervescent-agent
#17
Heon-Ju Kwon, Kyoung Won Kim, Sang Hyun Choi, Jin-Hee Jung, So Yeon Kim, Se-Young Kim, Jeongjin Lee, Dong-Hwan Jung, Tae-Yong Ha, Gi-Won Song, Sung-Gyu Lee
PURPOSE: To determine whether an oral effervescent agent improves magnetic resonance cholangiography (MRC) images, both qualitatively and quantitatively, in potential live liver donors. MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board, and informed consent was waived. Seventy potential liver donors underwent 2D MRC before and after administration of an oral effervescent agent. One radiologist measured relative contrast ratio (rC) and relative signal intensity (rS) for right and left intrahepatic ducts (RHD and LHD), and common hepatic duct (CHD)...
March 23, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28327002/use-of-imaging-to-predict-complete-response-of-colorectal-liver-metastases-after-chemotherapy-mr-imaging-versus-ct-imaging
#18
Min Jung Park, Nurhee Hong, Kyunghwa Han, Min Ju Kim, Yoon Jin Lee, Yang Shin Park, Sung Eun Rha, Sumi Park, Won Jae Lee, Seong Ho Park, Chang Hee Lee, Chung Mo Nam, Chansik An, Hye Jin Kim, Honsoul Kim, Mi-Suk Park
Purpose To compare the diagnostic performances of contrast agent-enhanced computed tomography (CT) and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced liver magnetic resonance (MR) imaging (referred to as EOB MR imaging) in the evaluation of disappearing colorectal liver metastases (CRLMs) after chemotherapy. Materials and Methods The eight institutional review boards approved this retrospective study and waived the requirement for informed consent. On the basis of retrospective searches in eight hospitals, 87 patients with 393 CRLMs, each patient with one or more CRLM that later disappeared on contrast-enhanced CT scans after chemotherapy, and subsequently underwent surgery for the CRLMs, were enrolled...
March 22, 2017: Radiology
https://www.readbyqxmd.com/read/28306727/biodistribution-and-pet-imaging-of-pharmacokinetics-of-manganese-in-mice-using-manganese-52
#19
A Lake Wooten, Tolulope A Aweda, Benjamin C Lewis, Rebecca B Gross, Suzanne E Lapi
Manganese is essential to life, and humans typically absorb sufficient quantities of this element from a normal healthy diet; however, chronic, elevated ingestion or inhalation of manganese can be neurotoxic, potentially leading to manganism. Although imaging of large amounts of accumulated Mn(II) is possible by MRI, quantitative measurement of the biodistribution of manganese, particularly at the trace level, can be challenging. In this study, we produced the positron-emitting radionuclide 52Mn (t1/2 = 5.6 d) by proton bombardment (Ep<15 MeV) of chromium metal, followed by solid-phase isolation by cation-exchange chromatography...
2017: PloS One
https://www.readbyqxmd.com/read/28291267/a-win-win-nanoplatform-tio2-yb-ho-f-for-nir-light-induced-synergistic-therapy-and-imaging
#20
Jie Zhou, Pei Luo, Chong Sun, Lingchang Meng, Weiran Ye, Shanshan Chen, Bin Du
To avoid the defect of low energy transfer efficiency in core-shell UCNP-TiO2 NPs, doping rare earth into TiO2 and improving the photocatalytic activity of TiO2 itself under Vis-NIR light might be a more direct and efficient strategy for high (1)O2 production. Here, we designed a TiO2:Yb,Ho,F-β-CD@DTX/HA nanoplatform using TiO2:Yb,Ho,F as the core, β-CD as the drug carrier, hyaluronic acid (HA) as the capping agent and target, and then applied it for 808 nm induced photodynamic-chemotherapy and 980 nm upconversion fluorescence/MR imaging...
March 14, 2017: Nanoscale
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