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Abulikemu N, Gao X, Wang W, He Q, Wang G, Jiang T, Wang X, Cheng Y, Chen M, Li Y, Liu L, Zhao J, Li J, Jiang C, Wang Y, Han H, Wang J. Mechanism of extracellular space changes in cryptococcal brain granuloma revealed by MRI tracer. Front Neurosci 2022; 16:1034091. [PMID: 36605557 PMCID: PMC9808069 DOI: 10.3389/fnins.2022.1034091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose This study aimed to investigate the changes in extracellular space (ECS) in cryptococcal brain granuloma and its pathological mechanism. Materials and methods The animal model of cryptococcal brain granuloma was established by injecting 1 × 106 CFU/ml of Cryptococcus neoformans type A suspension into the caudate nucleus of Sprague-Dawley rats with stereotactic technology. The infection in the brain was observed by conventional MRI scanning on days 14, 21, and 28 of modeling. The tracer-based MRI with a gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) as a magnetic tracer was performed on the rats with cryptococcal granuloma and the rats in the control group. The parameters of ECS in each area of cryptococcal brain granuloma were measured. The parameters of ECS in the two groups were compared by independent sample t-test, and the changes in ECS and its mechanism were analyzed. Results Up to 28 days of modeling, the success rate of establishing the brain cryptococcal granuloma model with 1 × 106 CFU/ml Cryptococcus neoformans suspension was 60%. In the internal area of cryptococcal granuloma, the effective diffusion coefficient D* was significantly higher than that of the control group (t = 2.76, P < 0.05), and the same trend showed in the volume ratio α (t = 3.71, P < 0.05), the clearance rate constant k (t = 3.137, P < 0.05), and the tracer half-life T1/2 (t = 3.837, P < 0.05). The tortuosity λ decreased compared with the control group (t = -2.70, P < 0.05). At the edge of the cryptococcal granuloma, the D* and α decreased, while the λ increased compared with the control group (D*:t = -6.05, P < 0.05; α: t = -4.988, P < 0.05; λ: t = 6.222, P < 0.05). Conclusion The internal area of the lesion demonstrated a quicker, broader, and more extended distribution of the tracer, while the edge of the lesion exhibited a slower and narrower distribution. MRI tracer method can monitor morphological and functional changes of ECS in pathological conditions and provide a theoretical basis for the treatment via ECS.
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Affiliation(s)
- Nuerbiyemu Abulikemu
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Xin Gao
- Shanghai Universal Medical Imaging Diagnostic Center, Shanghai University, Shanghai, China
| | - Wei Wang
- Department of Rehabilitation Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Qingyuan He
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China,Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Gang Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Imaging Center, Xi’an Gem Flower Changqing Hospital, Xi’an, China
| | - Tao Jiang
- The Animal Experimental Center, Xinjiang Medical University, Ürümqi, China
| | - Xiaodong Wang
- Department of Dermatology, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Yumeng Cheng
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yanran Li
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Lulu Liu
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Jingjing Zhao
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Jin Li
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Chunhui Jiang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Yunling Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Hongbin Han
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China,Department of Radiology, Peking University Third Hospital, Beijing, China,Hongbin Han,
| | - Jian Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Shanghai Universal Medical Imaging Diagnostic Center, Shanghai University, Shanghai, China,*Correspondence: Jian Wang,
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Transport in the Brain Extracellular Space: Diffusion, but Which Kind? Int J Mol Sci 2022; 23:ijms232012401. [PMID: 36293258 PMCID: PMC9604357 DOI: 10.3390/ijms232012401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/17/2022] Open
Abstract
The mechanisms of transport of substances in the brain parenchyma have been a hot topic in scientific discussion in the past decade. This discussion was triggered by the proposed glymphatic hypothesis, which assumes a directed flow of cerebral fluid within the parenchyma, in contrast to the previous notion that diffusion is the main mechanism. However, when discussing the issue of “diffusion or non-diffusion”, much less attention was given to the question that diffusion itself can have a different character. In our opinion, some of the recently published results do not fit into the traditional understanding of diffusion. In this regard, we outline the relevant new theoretical approaches on transport processes in complex random media such as concepts of diffusive diffusivity and time-dependent homogenization, which expands the understanding of the forms of transport of substances based on diffusion.
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Kazachkina NI, Zherdeva VV, Meerovich IG, Saydasheva AN, Solovyev ID, Tuchina DK, Savitsky AP, Tuchin VV, Bogdanov AA. MR and fluorescence imaging of gadobutrol-induced optical clearing of red fluorescent protein signal in an in vivo cancer model. NMR IN BIOMEDICINE 2022; 35:e4708. [PMID: 35106848 DOI: 10.1002/nbm.4708] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/15/2022] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Multimodality registration of optical and MR images in the same tissue volume in vivo may be enabled by MR contrast agents with an optical clearing (OC) effect. The goals of this study were to (a) investigate the effects of clinical MR contrast agent gadobutrol (GB) and its combinations as a potential OC agent assisting in fluorescence intensity (FI) imaging in vivo and (b) evaluate MRI as a tool for imaging of topical or systemic application of GB for the purpose of OC. Subcutaneous tumor xenografts expressing red fluorescent marker protein were used as disease models. MRI was performed at 1 T 1 H MRI using T1 -weighted 3D gradient-echo (T1w-3D GRE) sequences to measure time-dependent MR signal intensity changes by region of interest analysis after image segmentation. Topical application of 1.0 M or 0.7 M GB-containing OC mixture with water and dimethyl sulfoxide showed similar 30-40% increases of tumor FI during the initial 15 min. Afterwards, the OC effect of GB on FI and tumor/background FI ratio showed a decrease over time in the case of 1.0 M GB, unlike the 0.7 M GB mixture, which resulted in a steady increase of FI and tumor/background ratio for 15-60 min. The use of T1w-3D GRE MR pulse sequences showed that concentrated 1.0 M GB resulted in MR signal loss of the skin due to high magnetic susceptibility and that signal loss coincided with the OC effect. Intravenous injection of 0.3 mmol GB/kg resulted in a rapid but transient 40% increase of FI of the tumors. Overall, 1 T MRI enabled tracking of GB-containing OC compositions on the skin surface and tumor tissue, supporting the observation of a time-dependent FI increase in vivo.
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Affiliation(s)
- Natalia I Kazachkina
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Victoria V Zherdeva
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Irina G Meerovich
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Asiya N Saydasheva
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Ilya D Solovyev
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Daria K Tuchina
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
- Saratov State University, Saratov, Russian Federation
- National Research Tomsk State University, Tomsk, Russian Federation
| | - Alexander P Savitsky
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Valery V Tuchin
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
- Saratov State University, Saratov, Russian Federation
- National Research Tomsk State University, Tomsk, Russian Federation
- Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russian Federation
| | - Alexei A Bogdanov
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
- Department of Radiology, UMASS Chan Medical School, Worcester, Massachusetts, USA
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Miller ADC, Ozbakir HF, Mukherjee A. Calcium-responsive contrast agents for functional magnetic resonance imaging. ACTA ACUST UNITED AC 2021; 2:021301. [PMID: 34085055 DOI: 10.1063/5.0041394] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/15/2021] [Indexed: 02/07/2023]
Abstract
Calcium ions represent one of the key second messengers accompanying neural activity and synaptic signaling. Accordingly, dynamic imaging of calcium fluctuations in living organisms represents a cornerstone technology for discovering neural mechanisms that underlie memory, determine behavior, and modulate emotional states as well as how these mechanisms are perturbed by neurological disease and brain injury. While optical technologies are well established for high resolution imaging of calcium dynamics, physical limits on light penetration hinder their application for whole-brain imaging in intact vertebrates. Unlike optics, magnetic resonance imaging (MRI) enables noninvasive large-scale imaging across vertebrates of all sizes. This has motivated the development of several sensors that leverage innovative physicochemical mechanisms to sensitize MRI contrast to intracellular and extracellular changes in calcium. Here, we review the current state-of-the-art in MRI-based calcium sensors, focusing on fundamental aspects of sensor performance, in vivo applications, and challenges related to sensitivity. We also highlight how innovations at the intersection of reporter gene technology and gene delivery open potential opportunities for mapping calcium activity in genetically targeted cells, complementing the benefits of small molecule probes and nanoparticle sensors.
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Affiliation(s)
- Austin D C Miller
- Biomolecular Science and Engineering, University of California, Santa Barbara, California 93106, USA
| | - Harun F Ozbakir
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
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Wellm V, Groebner J, Heitmann G, Sönnichsen FD, Herges R. Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Vanessa Wellm
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
| | - Jens Groebner
- Department of Electrical Engineering and Information Technology South Westphalian University of Applied Sciences Bahnhofsallee 5 58507 Luedenscheid Germany
| | - Gernot Heitmann
- IWS Innovations- und Wissenstrategien GmbH Aviares Research Network Deichstraße 25 20459 Hamburg Germany
| | - Frank D. Sönnichsen
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
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6
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Wellm V, Groebner J, Heitmann G, Sönnichsen FD, Herges R. Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging. Angew Chem Int Ed Engl 2021; 60:8220-8226. [PMID: 33606332 PMCID: PMC8048480 DOI: 10.1002/anie.202015851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Indexed: 12/27/2022]
Abstract
Temperature can be used as clinical marker for tissue metabolism and the detection of inflammations or tumors. The use of magnetic resonance imaging (MRI) for monitoring physiological parameters like the temperature noninvasively is steadily increasing. In this study, we present a proof-of-principle study of MRI contrast agents (CA) for absolute and concentration independent temperature imaging. These CAs are based on azoimidazole substituted NiII porphyrins, which can undergo Light-Driven Coordination-Induced Spin State Switching (LD-CISSS) in solution. Monitoring the fast first order kinetic of back isomerisation (cis to trans) with standard clinical MR imaging sequences allows the determination of half-lives, that can be directly translated into absolute temperatures. Different temperature responsive CAs were successfully tested as prototypes in methanol-based gels and created temperature maps of gradient phantoms with high spatial resolution (0.13×0.13×1.1 mm) and low temperature errors (<0.22 °C). The method is sufficiently fast to record the temperature flow from a heat source as a film.
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Affiliation(s)
- Vanessa Wellm
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
| | - Jens Groebner
- Department of Electrical Engineering and Information TechnologySouth Westphalian University of Applied SciencesBahnhofsallee 558507LuedenscheidGermany
| | - Gernot Heitmann
- IWS Innovations- und Wissenstrategien GmbHAviares Research NetworkDeichstraße 2520459HamburgGermany
| | - Frank D. Sönnichsen
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
| | - Rainer Herges
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
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7
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Porous Phantoms Mimicking Tissues-Investigation of Optical Parameters Stability Over Time. MATERIALS 2021; 14:ma14020423. [PMID: 33467152 PMCID: PMC7829841 DOI: 10.3390/ma14020423] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 11/17/2022]
Abstract
Optical phantoms are used to validate optical measurement methods. The stability of their optical parameters over time allows them to be used and stored over long-term periods, while maintaining their optical parameters. The aim of the presented research was to investigate the stability of fabricated porous phantoms, which can be used as a lung phantom in optical system. Measurements were performed in multiple series with an interval of 6 months, recreating the same conditions and using the same measuring system consisting of an integrating sphere, a coherent light source with a wavelength of 635 nm and a detector. Scattering and absorption parameters were determined on the basis of the measured reflectance and transmittance. The tested samples were made of silicone and glycerol in various proportions.
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8
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Musina GR, Dolganova IN, Chernomyrdin NV, Gavdush AA, Ulitko VE, Cherkasova OP, Tuchina DK, Nikitin PV, Alekseeva AI, Bal NV, Komandin GA, Kurlov VN, Tuchin VV, Zaytsev KI. Optimal hyperosmotic agents for tissue immersion optical clearing in terahertz biophotonics. JOURNAL OF BIOPHOTONICS 2020; 13:e202000297. [PMID: 32881362 DOI: 10.1002/jbio.202000297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/20/2020] [Accepted: 08/28/2020] [Indexed: 05/05/2023]
Abstract
In this work, a thorough analysis of hyperosmotic agents for the immersion optical clearing (IOC) in terahertz (THz) range was performed. It was aimed at the selection of agents for the efficient enhancement of penetration depth of THz waves into biological tissues. Pulsed spectroscopy in the frequency range of 0.1 to 2.5 THz was applied for investigation of the optical properties of common IOC agents. Using the collimated transmission spectroscopy in visible range, binary diffusion coefficients of tissue water and agent in ex vivo rat brain tissue were measured. IOC agents were objectively compared using two-dimensional nomogram, accounting for their THz-wave absorption coefficients and binary diffusion coefficients. The results of this study demonstrate an interplay between the penetration depth enhancement and the diffusion rate and allow for pointing out glycerol as an optimal agent among the considered ones for particular applications in THz biophotonics.
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Affiliation(s)
- Guzel R Musina
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Irina N Dolganova
- Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka, Russian Federation
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Nikita V Chernomyrdin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Arsenii A Gavdush
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Vladislav E Ulitko
- Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka, Russian Federation
| | - Olga P Cherkasova
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
- Institute of Laser Physics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation
- National Research Tomsk State University, Tomsk, Russian Federation
| | - Daria K Tuchina
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
- National Research Tomsk State University, Tomsk, Russian Federation
- Saratov State University, Saratov, Russian Federation
| | - Pavel V Nikitin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
- Burdenko Neurosurgery Institute, Moscow, Russian Federation
| | - Anna I Alekseeva
- Research Institute of Human Morphology, Moscow, Russian Federation
| | - Natalia V Bal
- Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Gennady A Komandin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Vladimir N Kurlov
- Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka, Russian Federation
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Valery V Tuchin
- National Research Tomsk State University, Tomsk, Russian Federation
- Saratov State University, Saratov, Russian Federation
- Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russian Federation
| | - Kirill I Zaytsev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russian Federation
- Bauman Moscow State Technical University, Moscow, Russian Federation
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Tuchina DK, Meerovich IG, Sindeeva OA, Zherdeva VV, Savitsky AP, Bogdanov AA, Tuchin VV. Magnetic resonance contrast agents in optical clearing: Prospects for multimodal tissue imaging. JOURNAL OF BIOPHOTONICS 2020; 13:e201960249. [PMID: 32687263 DOI: 10.1002/jbio.201960249] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Skin optical clearing effect ex vivo and in vivo was achieved by topical application of low molecular weight paramagnetic magnetic resonance contrast agents. This novel feature has not been explored before. By using collimated transmittance the diffusion coefficients of three clinically used magnetic resonance contrast agents, that is Gadovist, Magnevist and Dotarem as well as X-ray contrast agent Visipaque in mouse skin were determined ex vivo as (4.29 ± 0.39) × 10-7 cm2 /s, (5.00 ± 0.72) × 10-7 cm2 /s, (3.72 ± 0.67) × 10-7 cm2 /s and (1.64 ± 0.18) × 10-7 cm2 /s, respectively. The application of gadobutrol (Gadovist) resulted in efficient optical clearing that in general, was superior to other contrast agents tested and allowed to achieve: (a) more than 12-fold increase of transmittance over 10 minutes after application ex vivo; (b) markedly improved images of skin architecture obtained with optical coherence tomography; (c) an increase of the fluorescence intensity/background ratio in TagRFP-red fluorescent marker protein expressing tumor by five times after 15 minutes application into the skin in vivo. The obtained results have immediate implications for multimodality imaging because many contrast agents are capable of simultaneously enhancing the contrast of multiple imaging modalities.
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Affiliation(s)
- Daria K Tuchina
- Saratov State University, Saratov, Russia
- Tomsk State University, Tomsk, Russia
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Irina G Meerovich
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | | | - Victoria V Zherdeva
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Alexander P Savitsky
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Alexei A Bogdanov
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Valery V Tuchin
- Saratov State University, Saratov, Russia
- Tomsk State University, Tomsk, Russia
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russia
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10
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Adams CJ, Krueger R, Meade TJ. A Multimodal Ca(II) Responsive Near IR-MR Contrast Agent Exhibiting High Cellular Uptake. ACS Chem Biol 2020; 15:334-341. [PMID: 31967770 DOI: 10.1021/acschembio.9b00638] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ca(II) ions are critical for the proper function of neurons by contributing to synaptic signaling and regulating neuronal plasticity. Dysregulation of Ca(II) is associated with a number of pathologies that cause neurodegeneration; therefore the ability to monitor Ca(II) intracellularly is an important target for molecular imaging. Contrast-enhanced MR imaging is a promising modality for imaging changes in Ca(II) concentrations. However, the majority of Ca(II) responsive MR agents are limited to the extracellular space or hindered by poor cellular uptake. Here, we describe a new class of multimodal, bioresponsive Ca(II) magnetic resonance agents that are coupled to the NIR probe IR-783. This new design is based on previous generations of our Ca(II) MR agents but overcomes two significant challenges: (1) the presence of the NIR probe dramatically increases cellular uptake of the agent and (2) provides histological validation of the MR signal using NIR fluorescence imaging. IR-783 targets organic anion transporter polypeptides, and we demonstrate that the agents are not toxic in HT-22 or U-87 MG cells up to 20 μM. The cellular uptake of complex 1 was measured to be greater than 16 femtomoles per cell (where ∼1 femtomole/cell is detectable in acquired MR images). Complex 1 is simultaneously detectable by both MR and NIR fluorescence imaging in vitro and is activated (turned on) by intracellular Ca(II) at concentrations between 1 and 10 μM.
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Affiliation(s)
- Casey J. Adams
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, Illinois 60208, United States
| | - Ruby Krueger
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, Illinois 60208, United States
| | - Thomas J. Meade
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, Illinois 60208, United States
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11
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Savić T, Gambino G, Bokharaie VS, Noori HR, Logothetis NK, Angelovski G. Early detection and monitoring of cerebral ischemia using calcium-responsive MRI probes. Proc Natl Acad Sci U S A 2019; 116:20666-20671. [PMID: 31548425 PMCID: PMC6789561 DOI: 10.1073/pnas.1908503116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cerebral ischemia is one of the leading causes of mortality and disability in infants and adults and its timely diagnosis is essential for an efficient treatment. We present a methodology for fast detection and real-time monitoring of fluctuations of calcium ions associated with focal ischemia using a molecular functional MRI approach. We used a dinuclear paramagnetic gadolinium(III) complex chelate that changes MR image contrast through its reversible interaction with extracellular calcium ions, while applying a remote transient middle cerebral artery occlusion as a model for ischemic stroke. Our method sensitively recognizes the onset and follows the dynamics of the ischemic core and penumbra with submillimeter spatial and second-scale temporal resolution, thus paving the way for noninvasive monitoring and development of targeted treatment strategies for cerebral ischemia.
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Affiliation(s)
- Tanja Savić
- MR Neuroimaging Agents Group, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany
| | - Giuseppe Gambino
- MR Neuroimaging Agents Group, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany
| | - Vahid S Bokharaie
- Neuronal Convergence Group, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany
| | - Hamid R Noori
- Neuronal Convergence Group, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany
| | - Nikos K Logothetis
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany;
- Department of Imaging Science and Biomedical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Goran Angelovski
- MR Neuroimaging Agents Group, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany;
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12
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Yuan N, Zhang X, Cao Y, Jiang X, Zhao S, Feng Y, Fan Y, Lu Z, Gao H. Contrast-enhanced computerized tomography combined with a targeted nanoparticle contrast agent for screening for early-phase non-small cell lung cancer. Exp Ther Med 2017; 14:5063-5068. [PMID: 29201215 DOI: 10.3892/etm.2017.5140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 05/11/2017] [Indexed: 12/13/2022] Open
Abstract
Non-small cell lung cancer (NSCLC) is a major cause of morbidity and mortality, and patients with NSCLC are frequently diagnosed at an advanced stage. This is primarily due to a lack of advanced and sensitive protocols for the detection of early stage NSCLC. Therefore, methods for the accurate diagnosis of early stage NSCLC are urgently required to improve survival rates. The present study investigated the use of contrast-enhanced computerized tomography (CECT) combined with a targeted nanoparticle contrast agent (TNCA) to diagnose early-stage NSCLC in a mice xenograft model. The TNCA used was lenvatinib, a multi-target tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor 1-3, fibroblast growth factor receptor 1-4, platelet-derived growth factor receptor β, proto-oncogene tyrosine-protein kinase receptor Ret and mast/stem cell growth factor receptor Kit. Xenograft NSCLC mice were established and used to analyze the efficacy of CECT-TNCA compared with CT scanning alone. The TNCA was inhaled with the use of an atomizer. The results demonstrated that CECT-TNCA improved the sensitivity of the diagnosis of early stage NSCLC. In addition, imaging using the TNCA enabled the visualization of nodules in the lung in mice with early stage NSCLC. In addition, lung nodule signal enhancement was increased in CECT-TNCA compared with CT, suggesting a high accurate accumulation of the TNCA in tumor nodules. Mice diagnosed with early stage NSCLC exhibited a higher eradication rate of NSCLC after treatment with cisplatin compared with mice with advanced stage NSCLC. These data indicate that the sensitivity and accuracy of CT imaging for the diagnosis of early stage NSCLC was improved through combination with the liposome-encapsulated TNCA.
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Affiliation(s)
- Ninglu Yuan
- Department of Radiology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Xiaohe Zhang
- Department of Cardiothoracic Surgery, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Yonghui Cao
- Department of Radiology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Xiaojie Jiang
- Department of Computerized Tomography, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Si Zhao
- Department of Radiology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Yingying Feng
- Department of Radiology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Yimeng Fan
- Department of Computerized Tomography, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Zhitao Lu
- Department of Radiology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Hongmei Gao
- Department of Radiology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
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13
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Zhang K, Du X, Yu K, Zhang K, Zhou Y. Application of novel targeting nanoparticles contrast agent combined with contrast-enhanced computed tomography during screening for early-phase gastric carcinoma. Exp Ther Med 2017; 15:47-54. [PMID: 29387181 PMCID: PMC5769276 DOI: 10.3892/etm.2017.5388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 05/05/2017] [Indexed: 12/12/2022] Open
Abstract
Gastric cancer is one of the most common human tumors worldwide. The biggest bottleneck is a lack of advanced and sensitive protocols for the diagnosis of patients with early-stage gastric cancer. Therefore, more sensitive methods of diagnosing gastric cancer are urgently required to improve survival rates. In this clinical study, contrast-enhanced computed tomography (CECT) with targeting nanoparticles contrast agent (CECT-TNCA) was used to diagnose early-stage gastric cancer. The specific-targeted tyrosine kinase inhibitors of gastric cancer, including platelet-derived growth factor receptor-β, Ret and Kit, were used as TNCAs. A total of 484 patients with suspected gastric cancer were voluntarily recruited to investigate the efficacy of CECT-TNCA in the diagnosis of patients with early-stage gastric cancer. Patients with suspected gastric cancer were subjected CT and CECT-TNCA to detect whether gastric tumors existed. TNCA was orally administered before CT and CECT-TNCA (20 min). Our diagnostic data revealed that CECT-TNCA improved sensitivity and provided a new protocol to diagnose tumors in patients with suspected gastric cancer at the early stage. In addition, imaging using CECT-TNCA enabled the visualization of tiny nodules in the gastric area. CECT-TNCA diagnosed 182 patients with suspected gastric cancer as tumor-free. CECT-TNCA confirmed gastric cancer in 302 patients. Our novel diagnosis indicated significantly (P<0.01) differential signal enhancement in the gastric nodules via CECT-TNCA compared with CT, suggesting higher accuracy and the accumulation of TNCA in tumor nodules in the stomach. Furthermore, survival rates of patients detected by early-diagnosis of CECT-TNCA were significantly higher than the mean five-year survival (P<0.01). In conclusion, our investigations demonstrate that the sensibility and accuracy of CT is improved through combination with liposome-encapsulated nanoparticle contrast agent for the diagnosis of early stage gastric cancer when compared with single CT detection. CECT-TNCA improves the accuracy of CT and diagnostic confidence in assessing mural enhancement in patients with suspected gastric cancer.
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Affiliation(s)
- Kaimin Zhang
- Physical Examination Center, Xianning Central Hospital, Xianning, Hubei 437000, P.R. China
| | - Xijian Du
- Department of Radiology, Xianning Central Hospital, Xianning, Hubei 437000, P.R. China
| | - Kaihu Yu
- Department of Radiology, Xianning Central Hospital, Xianning, Hubei 437000, P.R. China
| | - Kaiyu Zhang
- Department of Radiology, The First People's Hospital of Xianning City, Xianning, Hubei 437000, P.R. China
| | - Yicheng Zhou
- Department of Radiology, Tongji Medical College, Huazhong University of Science Tongji Hospital, Wuhan, Hubei 430030, P.R. China
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14
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Angelovski G. Heading toward Macromolecular and Nanosized Bioresponsive MRI Probes for Successful Functional Imaging. Acc Chem Res 2017; 50:2215-2224. [PMID: 28841293 DOI: 10.1021/acs.accounts.7b00203] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The quest for bioresponsive or smart contrast agents (SCAs) in molecular imaging, in particular magnetic resonance imaging (MRI), is progressively increasing since they allow for the monitoring of essential biological processes on molecular and cellular levels in a dynamic fashion. These are offshoot molecules of common contrast agents that are sensitive to biochemical changes in their environment, capable of reporting on such changes by inducing MRI signal alteration. Various mechanistic approaches and different types of SCAs have been developed in order to visualize desired processes, using diverse imaging protocols and methods. To date, the most frequently exploited probes are paramagnetic molecules that change longitudinal or transverse relaxation at proton frequency, or so-called T1- and T2-weighted probes, respectively. Moreover, SCAs operating by the chemical exchange saturation transfer mechanism, suitable for 19F MRI or possessing hyperpolarized nuclei have also appeared in the past decade, slowly finding their role in functional imaging studies. Following these mechanistic principles, a large number of SCAs suitable for diverse targets have been reported to date. This Account condenses this exciting progress, particularly focusing on probes designed for abundant targets that are suitable for practical, in vivo utilization. To date, the greatest advancements have been certainly made in the preparation of pH sensitive probes, which usually contain protonable groups that interact with paramagnetic centers, or take advantage of supramolecular (dis)assembling to induce the MRI signal change, thereupon enabling pH mapping in vivo. In a complementary approach, a combination of metal chelating ligands for Ca2+ or Zn2+ with MR reporting units results in a wide variety of SCAs that operate with different contrast mechanisms and can be used for initial functional experiments. Finally, the first examples of molecular sensing by creating host-guest complexes to track neurotransmitter flux have also been recently reported, allowing the study of brain function in an unprecedented manner. Nevertheless, wider SCA utilization in vivo has not yet been achieved. There are a few reasons for this disparity between their nominal potential and practical usage, with one of the major reasons being the low sensitivity of the MRI technique. Subsequently, the production of detectable signal change can be achieved using higher concentrations of the bioresponsive probe; however, the biocompatibility of these probes then starts to play an important role. An elegant solution to these practical challenges has been found with the integration of multiple small-sized SCAs into macromolecular and nanosized probes. In such case, the multivalent SCAs are able to circumvent the sensitivity issue, thus enhancing the MR signal and desired contrast changes. Moreover, they prolong the probe tissue retention time, while often reducing their toxicity. Finally, with altered size and properties, they allow for exploitation of mechanisms that induce the contrast change which is not possible with small-sized SCAs. To this end, this Account also discusses the current approaches that aim to develop macromolecular and nanosized SCAs suitable for practical MRI applications. With these, further progress of this exciting field is affirmed, with remarkable results expected in the near future on both the probe preparation and their utilization in functional molecular imaging.
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Affiliation(s)
- Goran Angelovski
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, D-72076 Tuebingen, Germany
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15
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MacRenaris KW, Ma Z, Krueger RL, Carney CE, Meade TJ. Cell-Permeable Esterase-Activated Ca(II)-Sensitive MRI Contrast Agent. Bioconjug Chem 2016; 27:465-73. [PMID: 26689452 DOI: 10.1021/acs.bioconjchem.5b00561] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calcium [Ca(II)] is a fundamental transducer of electrical activity in the central nervous system (CNS). Influx of Ca(II) into the cytosol is responsible for action potential initiation and propagation, and initiates interneuronal communication via release of neurotransmitters and activation of gene expression. Despite the importance of Ca(II) in physiology, it remains a challenge to visualize Ca(II) flux in the central nervous system (CNS) in vivo. To address these challenges, we have developed a new generation, Ca(II)-activated MRI contrast agent that utilizes ethyl esters to increase cell labeling and prevent extracellular divalent Ca(II) binding. Following labeling, the ethyl esters can be cleaved, thus allowing the agent to bind Ca(II), increasing relaxivity and resulting in enhanced positive MR image contrast. The ability of this probe to discriminate between extra- and intracellular Ca(II) may allow for spatiotemporal in vivo imaging of Ca(II) flux during seizures or ischemia where large Ca(II) fluxes (1-10 μM) can result in cell death.
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Affiliation(s)
- Keith W MacRenaris
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Zhidong Ma
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Ruby L Krueger
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Christiane E Carney
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Thomas J Meade
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
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16
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Moussaron A, Vibhute S, Bianchi A, Gündüz S, Kotb S, Sancey L, Motto-Ros V, Rizzitelli S, Crémillieux Y, Lux F, Logothetis NK, Tillement O, Angelovski G. Ultrasmall Nanoplatforms as Calcium-Responsive Contrast Agents for Magnetic Resonance Imaging. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:4900-4909. [PMID: 26179212 DOI: 10.1002/smll.201500312] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 06/17/2015] [Indexed: 06/04/2023]
Abstract
The preparation of ultrasmall and rigid platforms (USRPs) that are covalently coupled to macrocycle-based, calcium-responsive/smart contrast agents (SCAs), and the initial in vitro and in vivo validation of the resulting nanosized probes (SCA-USRPs) by means of magnetic resonance imaging (MRI) is reported. The synthetic procedure is robust, allowing preparation of the SCA-USRPs on a multigram scale. The resulting platforms display the desired MRI activity—i.e., longitudinal relaxivity increases almost twice at 7 T magnetic field strength upon saturation with Ca(2+). Cell viability is probed with the MTT assay using HEK-293 cells, which show good tolerance for lower contrast agent concentrations over longer periods of time. On intravenous administration of SCA-USRPs in living mice, MRI studies indicate their rapid accumulation in the renal pelvis and parenchyma. Importantly, the MRI signal increases in both kidney compartments when CaCl2 is also administrated. Laser-induced breakdown spectroscopy experiments confirm accumulation of SCA-USRPs in the renal cortex. To the best of our knowledge, these are the first studies which demonstrate calcium-sensitive MRI signal changes in vivo. Continuing contrast agent and MRI protocol optimizations should lead to wider application of these responsive probes and development of superior functional methods for monitoring calcium-dependent physiological and pathological processes in a dynamic manner.
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Affiliation(s)
- Albert Moussaron
- Laboratoire MATEIS, INSA de Lyon, 69621, Villeurbanne Cedex, France
| | - Sandip Vibhute
- Department for Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
| | - Andrea Bianchi
- CRMSB, UMR 5536, Université Bordeaux, 33076, Bordeaux, France
| | - Serhat Gündüz
- MR Neuroimaging Agents Group, Max Planck Institute for Biological Cybernetics, Spemannstr. 41, 72076, Tübingen, Germany
| | - Shady Kotb
- Institut Lumière Matière, UMR CNRS 5306 - Université Lyon 1, 69622, Villeurbanne Cedex, France
| | - Lucie Sancey
- Institut Lumière Matière, UMR CNRS 5306 - Université Lyon 1, 69622, Villeurbanne Cedex, France
| | - Vincent Motto-Ros
- Institut Lumière Matière, UMR CNRS 5306 - Université Lyon 1, 69622, Villeurbanne Cedex, France
| | | | | | - Francois Lux
- Institut Lumière Matière, UMR CNRS 5306 - Université Lyon 1, 69622, Villeurbanne Cedex, France
| | - Nikos K Logothetis
- Department for Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
- Department of Imaging Science and Biomedical Engineering, University of Manchester, Manchester, M13 9PT, UK
| | - Olivier Tillement
- Institut Lumière Matière, UMR CNRS 5306 - Université Lyon 1, 69622, Villeurbanne Cedex, France
| | - Goran Angelovski
- MR Neuroimaging Agents Group, Max Planck Institute for Biological Cybernetics, Spemannstr. 41, 72076, Tübingen, Germany
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17
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Gündüz S, Nitta N, Vibhute S, Shibata S, Mayer ME, Logothetis NK, Aoki I, Angelovski G. Dendrimeric calcium-responsive MRI contrast agents with slow in vivo diffusion. Chem Commun (Camb) 2015; 51:2782-5. [PMID: 25383973 DOI: 10.1039/c4cc07540d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We report a methodology which enables the preparation of dendrimeric contrast agents sensitive to Ca(2+) when starting from the monomeric analogue. The Ca-triggered longitudinal relaxivity response of these agents is not compromised by undertaking synthetic transformations, despite structural changes. The in vivo MRI studies in the rat cerebral cortex indicate that diffusion properties of dendrimeric contrast agents have great advantages as compared to their monomeric equivalents.
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Affiliation(s)
- Serhat Gündüz
- MR Neuroimaging Agents Group, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.
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18
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Kuda-Wedagedara ANW, Allen MJ. Enhancing magnetic resonance imaging with contrast agents for ultra-high field strengths. Analyst 2015; 139:4401-10. [PMID: 25054827 DOI: 10.1039/c4an00990h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Contrast agents are diagnostic tools that often complement magnetic resonance imaging. At ultra-high field strengths (≥7 T), magnetic resonance imaging is capable of generating desirable high signal-to-noise ratios, but clinically available contrast agents are less effective at ultra-high field strengths relative to lower fields. This gap in effectiveness demands the development of contrast agents for ultra-high field strengths. In this minireview, we summarize contrast agents reported during the last three years that focused on ultra-high field strengths.
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19
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Gündüz S, Power A, Maier ME, Logothetis NK, Angelovski G. Synthesis and Characterization of a Biotinylated Multivalent Targeted Contrast Agent. Chempluschem 2014; 80:612-622. [DOI: 10.1002/cplu.201402329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Indexed: 12/29/2022]
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20
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Angelovski G, Gottschalk S, Milošević M, Engelmann J, Hagberg GE, Kadjane P, Andjus P, Logothetis NK. Investigation of a calcium-responsive contrast agent in cellular model systems: feasibility for use as a smart molecular probe in functional MRI. ACS Chem Neurosci 2014; 5:360-9. [PMID: 24712900 DOI: 10.1021/cn500049n] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Responsive or smart contrast agents (SCAs) represent a promising direction for development of novel functional MRI (fMRI) methods for the eventual noninvasive assessment of brain function. In particular, SCAs that respond to Ca(2+) may allow tracking neuronal activity independent of brain vasculature, thus avoiding the characteristic limitations of current fMRI techniques. Here we report an in vitro proof-of-principle study with a Ca(2+)-sensitive, Gd(3+)-based SCA in an attempt to validate its potential use as a functional in vivo marker. First, we quantified its relaxometric response in a complex 3D cell culture model. Subsequently, we examined potential changes in the functionality of primary glial cells following administration of this SCA. Monitoring intracellular Ca(2+) showed that, despite a reduction in the Ca(2+) level, transport of Ca(2+) through the plasma membrane remained unaffected, while stimulation with ATP induced Ca(2+)-transients suggested normal cellular signaling in the presence of low millimolar SCA concentrations. SCAs merely lowered the intracellular Ca(2+) level. Finally, we estimated the longitudinal relaxation times (T1) for an idealized in vivo fMRI experiment with SCA, for extracellular Ca(2+) concentration level changes expected during intense neuronal activity which takes place upon repetitive stimulation. The values we obtained indicate changes in T1 of around 1-6%, sufficient to be robustly detectable using modern MRI methods in high field scanners. Our results encourage further attempts to develop even more potent SCAs and appropriate fMRI protocols. This would result in novel methods that allow monitoring of essential physiological processes at the cellular and molecular level.
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Affiliation(s)
| | | | - Milena Milošević
- Institute
for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Beograd 11000, Serbia
| | | | - Gisela E. Hagberg
- Biomedical
Magnetic Resonance, Department of Radiology, Tübingen University Hospital, 72076 Tübingen, Germany
| | | | - Pavle Andjus
- Institute
for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Beograd 11000, Serbia
| | - Nikos K. Logothetis
- Division
of Imaging Science and Biomedical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
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