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Klasson, Anna
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Publikasjoner (10 av 14) Visa alla publikasjoner
Hedlund, A., Ahrén, M., Gustafsson, H., Abrikossova, N., Warntjes, M., Jönsson, J.-I., . . . Engström, M. (2011). Gd2O3 nanoparticles in hematopoietic cells for MRI contrast enhancement. International journal of nano medicine, 6, 3233-3240
Åpne denne publikasjonen i ny fane eller vindu >>Gd2O3 nanoparticles in hematopoietic cells for MRI contrast enhancement
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2011 (engelsk)Inngår i: International journal of nano medicine, ISSN 1178-2013, Vol. 6, s. 3233-3240Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

As the utility of magnetic resonance imaging (MRI) broadens, the importance of having specific and efficient contrast agents increases and in recent time there has been a huge development in the fields of molecular imaging and intracellular markers. Previous studies have shown that gadolinium oxide (Gd2O3) nanoparticles generate higher relaxivity than currently available Gd chelates: In addition, the Gd2O3 nanoparticles have promising properties for MRI cell tracking. The aim of the present work was to study cell labeling with Gd2O3 nanoparticles in hematopoietic cells and to improve techniques for monitoring hematopoietic stem cell migration by MRI. Particle uptake was studied in two cell lines: the hematopoietic progenitor cell line Ba/F3 and the monocytic cell line THP-1. Cells were incubated with Gd2O3 nanoparticles and it was investigated whether the transfection agent protamine sulfate increased the particle uptake. Treated cells were examined by electron microscopy and MRI, and analyzed for particle content by inductively coupled plasma sector field mass spectrometry. Results showed that particles were intracellular, however, sparsely in Ba/F3. The relaxation times were shortened with increasing particle concentration. Relaxivities, r1 and r2 at 1.5 T and 21°C, for Gd2O3 nanoparticles in different cell samples were 3.6–5.3 s-1 mM-1 and 9.6–17.2 s-1 mM-1, respectively. Protamine sulfate treatment increased the uptake in both Ba/F3 cells and THP-1 cells. However, the increased uptake did not increase the relaxation rate for THP-1 as for Ba/F3, probably due to aggregation and/or saturation effects. Viability of treated cells was not significantly decreased and thus, it was concluded that the use of Gd2O3 nanoparticles is suitable for this type of cell labeling by means of detecting and monitoring hematopoietic cells. In conclusion, Gd2O3 nanoparticles are a promising material to achieve positive intracellular MRI contrast; however, further particle development needs to be performed.

sted, utgiver, år, opplag, sider
Manchester, UK: Dove Medical Press Ltd, 2011
Emneord
gadolinium oxide, magnetic resonance imaging, contrast agent, cell labeling, Ba/F3 cells, THP-1 cells
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-72275 (URN)10.2147/IJN.S23940 (DOI)000298164300001 ()
Merknad

funding agencies|Swedish Research Council| 621-2007-3810 621-2009-5148 521-2009-3423 |VINNOVA| 2009-00194 |Center in Nanoscience and Technology at LiTH (CeNano)||

Tilgjengelig fra: 2011-11-24 Laget: 2011-11-24 Sist oppdatert: 2018-10-29
Hedlund, A. (2011). MRI Contrast Enhancement and Cell Labeling using Gd2O3 Nanoparticles. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Åpne denne publikasjonen i ny fane eller vindu >>MRI Contrast Enhancement and Cell Labeling using Gd2O3 Nanoparticles
2011 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

There is an increasing interest for nanomaterials in bio-medical applications and in this work, nanoparticles of gadolinium oxide (Gd2O3 ) have been investigated as a novel contrast agent for magnetic resonance imaging (MRI). Relaxation properties have been studied in aqueous solutions as well as in cell culture medium and the nanoparticles have been explored as cell labeling agents. The fluorescent properties of the particles were used to visualize the internalization in cells and doped particles were investigated as a multimodal agent that could work as a fluorescent marker for microscopy and as a contrast enhancer for MRI. Fluorescent studies show that the Gd2O3 nanoparticles doped with 5% terbium have interesting fluorescent properties and that these particles could work as such multimodal contrast agent. Relaxivity measurements show that in aqueous solutions, there is a twofold increase in relaxivity for Gd2O3 compared to commercial agent Gd-DTPA. In cell culture medium as well as in cells, there is a clear T1 effect and an increase in signal intensity in T1-mapped images. The cellular uptake of Gd2O3 nanoparticles were increased with the use of transfection agent protamine sulfate. This work shows that Gd2O3 nanoparticles possess good relaxation properties that are retained in different biological environments. Gd2O3 particles are suitable as a T1 contrast agent, but seem also be adequate for T2 enhancement in forinstance cell labeling experiments.

sted, utgiver, år, opplag, sider
Linköping: Linköping University Electronic Press, 2011. s. 73
Serie
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1230
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-68802 (URN)978-91-7393-215-8 (ISBN)
Disputas
2011-06-08, Wrannesalen, Universitetssjukhuset, CMIV, Campus US, Linköpings universitet, Linköping, 09:00 (svensk)
Opponent
Veileder
Tilgjengelig fra: 2011-06-07 Laget: 2011-06-07 Sist oppdatert: 2013-09-05bibliografisk kontrollert
Ahrén, M., Selegård, L., Klasson, A., Söderlind, F., Abrikossova, N., Skoglund, C., . . . Uvdal, K. (2010). Synthesis and Characterization of PEGylated Gd2O3 Nanoparticles for MRI Contrast Enhancement. Langmuir, 26(8), 5753-5762
Åpne denne publikasjonen i ny fane eller vindu >>Synthesis and Characterization of PEGylated Gd2O3 Nanoparticles for MRI Contrast Enhancement
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2010 (engelsk)Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 26, nr 8, s. 5753-5762Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Recently, much attention has been given to the development of biofunctionalized nanoparticles with magnetic properties for novel biomedical imaging. Guided, smart, targeting nanoparticulate magnetic resonance imaging (MRI) contrast agents inducing high MRI signal will be valuable tools for future tissue specific imaging and investigation of molecular and cellular events. In this study, we report a new design of functionalized ultrasmall rare earth based nanoparticles to be used as a positive contrast agent in MRI. The relaxivity is compared to commercially available Gd based chelates. The synthesis, PEGylation, and dialysis of small (3−5 nm) gadolinium oxide (DEG-Gd2O3) nanoparticles are presented. The chemical and physical properties of the nanomaterial were investigated with Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and dynamic light scattering. Neutrophil activation after exposure to this nanomaterial was studied by means of fluorescence microscopy. The proton relaxation times as a function of dialysis time and functionalization were measured at 1.5 T. A capping procedure introducing stabilizing properties was designed and verified, and the dialysis effects were evaluated. A higher proton relaxivity was obtained for as-synthesized diethylene glycol (DEG)-Gd2O3 nanoparticles compared to commercial Gd-DTPA. A slight decrease of the relaxivity for as-synthesized DEG-Gd2O3 nanoparticles as a function of dialysis time was observed. The results for functionalized nanoparticles showed a considerable relaxivity increase for particles dialyzed extensively with r1 and r2 values approximately 4 times the corresponding values for Gd-DTPA. The microscopy study showed that PEGylated nanoparticles do not activate neutrophils in contrast to uncapped Gd2O3. Finally, the nanoparticles are equipped with Rhodamine to show that our PEGylated nanoparticles are available for further coupling chemistry, and thus prepared for targeting purposes. The long term goal is to design a powerful, directed contrast agent for MRI examinations with specific targeting possibilities and with properties inducing local contrast, that is, an extremely high MR signal at the cellular and molecular level.

sted, utgiver, år, opplag, sider
American Chemical Society (ACS), 2010
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-54946 (URN)10.1021/la903566y (DOI)000276562300061 ()
Tilgjengelig fra: 2010-04-23 Laget: 2010-04-23 Sist oppdatert: 2018-10-29bibliografisk kontrollert
Petoral, R. M., Söderlind, F., Klasson, A., Suska, A., Fortin, M.-A., Abrikossova, N., . . . Uvdal, K. (2009). Synthesis and Characterization of Tb3+-Doped Gd2O3 Nanocrystals: A Bifunctional Material with Combined Fluorescent Labeling and MRI Contrast Agent Properties. The Journal of Physical Chemistry C, 113(17), 6913-6920
Åpne denne publikasjonen i ny fane eller vindu >>Synthesis and Characterization of Tb3+-Doped Gd2O3 Nanocrystals: A Bifunctional Material with Combined Fluorescent Labeling and MRI Contrast Agent Properties
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2009 (engelsk)Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, nr 17, s. 6913-6920Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Ultrasmall gadolinium oxide nanoparticles doped with terbium ions were synthesized by the polyol route and characterized as a potentially bifunctional material with both fluorescent and magnetic contrast agent properties. The structural, optical, and magnetic properties of the organic-acid-capped and PEGylated Gd2O3:Tb3+ nanocrystals were studied by HR-TEM, XPS, EDX, IR, PL, and SQUID. The luminescent/fluorescent property of the particles is attributable to the Tb3+ ion located on the crystal lattice of the Gd2O3 host. The paramagnetic behavior of the particles is discussed. Pilot studies investigating the capability of the nanoparticles for fluorescent labeling of living cells and as a MRI contrast agent were also performed. Cells of two cell lines (THP-1 cells and fibroblasts) were incubated with the particles, and intracellular particle distribution was visualized by confocal microscopy. The MRI relaxivity of the PEGylated nanoparticles in water at low Gd concentration was assessed showing a higher T-1 relaxation rate compared to conventional Gd-DTPA chelates and comparable to that of undoped Gd2O3 nanoparticles.

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-12944 (URN)10.1021/jp808708m (DOI)000265529700009 ()
Merknad

On the day of the defence date the status of this article was Submitted

Tilgjengelig fra: 2008-02-21 Laget: 2008-02-21 Sist oppdatert: 2018-10-29bibliografisk kontrollert
Söderlind, F., Fortin, M. A., Petoral, R. M., Klasson, A., Veres, T., Engström, M., . . . Käll, P.-O. (2008). Colloidal synthesis and characterization of ultrasmall perovskite GdFeO3 nanocrystals. Nanotechnology, 19(8), 085608
Åpne denne publikasjonen i ny fane eller vindu >>Colloidal synthesis and characterization of ultrasmall perovskite GdFeO3 nanocrystals
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2008 (engelsk)Inngår i: Nanotechnology, ISSN 0957-4484, Vol. 19, nr 8, s. 085608-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Synthesis of very small (about 4 nm) perovskite structured gadolinium orthoferrite nanoparticles (GdFeO3) was performed by the polyol method. The material shows promising relaxivity properties and potential as a contrast agent in magnetic resonance imaging. The perovskite nanoparticles were characterized by x-ray diffraction, transmission electron microscopy, energy dispersive x-ray spectroscopy, Fourier transform infrared spectroscopy, magnetic resonance, and magnetization measurements. Upon heating in air at 800 °C for 3 h the size of the crystals increased to about 40 nm. The crystalline structure of the heat treated compound is in good agreement with perovskite GdFeO3 as the primary product. Contributions from various secondary phases were also identified, including one hitherto unknown phase with the suggested composition 'Gd3FeO6' and isostructural with Gd3GaO6. The novel 'Gd3FeO6' phase appears to be kinetically stabilized in the nano state.

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-13298 (URN)10.1088/0957-4484/19/8/085608 (DOI)000252967400014 ()
Tilgjengelig fra: 2008-05-21 Laget: 2008-05-21 Sist oppdatert: 2015-10-09
Uvdal, K., Ahrén, M., Selegård, L., Abrikossova, N., Klasson, A., Söderlind, F., . . . Käll, P.-O. (2008). Functionalized Gd2O3 Nanoparticles to Be used for MRI Contrast Enhancement. In: AVS,2008.
Åpne denne publikasjonen i ny fane eller vindu >>Functionalized Gd2O3 Nanoparticles to Be used for MRI Contrast Enhancement
Vise andre…
2008 (engelsk)Inngår i: AVS,2008, 2008Konferansepaper, Publicerat paper (Annet vitenskapelig)
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-44596 (URN)77166 (Lokal ID)77166 (Arkivnummer)77166 (OAI)
Merknad
Conference proceedingsTilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2010-07-01
Klasson, A. (2008). MRI Contrast Enhancement using Gd2O3 Nanoparticles. (Licentiate dissertation). : Universitetsbibliotek
Åpne denne publikasjonen i ny fane eller vindu >>MRI Contrast Enhancement using Gd2O3 Nanoparticles
2008 (engelsk)Licentiatavhandling, med artikler (Annet vitenskapelig)
Abstract [en]

There is an increasing interest for nanomaterials in biomedical applications and in this work, nanoparticles of gadolinium oxide (Gd2O3) have been investigated as a novel contrast agent for Magnetic Resonance Imaging (MRI). Relaxation properties have been studied in aqueous solutions as well as in cell culture medium and the nanoparticles have been explored as cell labeling agents. The fluorescent properties of the particles were used to visualize the internalization in cells and doped particles were also investigated as a multimodal agent that could work as a fluorescent marker for microscopy and as a contrast enhancer for MRI.

Results show that in aqueous solutions, there is a twofold increase in relaxivity for Gd2O3 compared to commercial agent Gd-DTPA. In cell culture medium as well as in cells, there is a clear T1 effect and a distinct increase in signal intensity in T1-mapped images. Fluorescent studies show that the Gd2O3 nanoparticles doped with 5% terbium have interesting fluorescent properties and that these particles could work as a multimodal contrast agent.

This study shows that Gd2O3 nanoparticles possess excellent relaxation properties that are retained in more biological environments. Gd2O3 particles are suitable as a T1 contrast agent, but seem also be adequate for T2 enhancement in for instance cell labeling experiments.

sted, utgiver, år, opplag, sider
Universitetsbibliotek, 2008. s. 116
Serie
Linköping Studies in Health Sciences. Thesis, ISSN 1100-6013 ; 85
Emneord
nanoparticles, gadolinium oxide, magnetic resonance imaging, contrast agent
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-11041 (URN)978-91-7393-966-9 (ISBN)
Presentation
2008-03-07, Conrad, Huvudblocket, plan 11, Campus US, Linköpings universitet, Linköping, 13:00 (engelsk)
Veileder
Tilgjengelig fra: 2008-02-21 Laget: 2008-02-21 Sist oppdatert: 2013-09-04
Klasson, A., Ahrén, M., Hellqvist, E., Söderlind, F., Rosén, A., Käll, P.-O., . . . Engström, M. (2008). Positive MRI Enhancement in THP-1 Cells with Gd2O3 Nanoparticles. Contrast Media and Molecular Imaging, 3(3), 106-111
Åpne denne publikasjonen i ny fane eller vindu >>Positive MRI Enhancement in THP-1 Cells with Gd2O3 Nanoparticles
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2008 (engelsk)Inngår i: Contrast Media and Molecular Imaging, ISSN 1555-4309, Vol. 3, nr 3, s. 106-111Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

There is a demand for more efficient and tissue-specific MRI contrast agents and recent developments involve the design of substances useful as molecular markers and magnetic tracers. In this study, nanoparticles of gadolinium oxide (Gd2O3) have been investigated for cell labeling and capacity to generate a positive contrast. THP-1, a monocytic cell line that is phagocytic, was used and results were compared with relaxivity of particles in cell culture medium (RPMI 1640). The results showed that Gd2O3-labeled cells have shorter T1 and T2 relaxation times compared with untreated cells. A prominent difference in signal intensity was observed, indicating that Gd2O3 nanoparticles can be used as a positive contrast agent for cell labeling. The r1 for cell samples was 4.1 and 3.6 s-1 mm-1 for cell culture medium. The r2 was 17.4 and 12.9 s-1 mm-1, respectively. For r1, there was no significant difference in relaxivity between particles in cells compared to particles in cell culture medium, (pr1 = 0.36), but r2 was significantly different for the two different series (pr2 = 0.02). Viability results indicate that THP-1 cells endure treatment with Gd2O3 nanoparticles for an extended period of time and it is therefore concluded that results in this study are based on viable cells.

Emneord
gadolinium oxide, nanoparticles, contrast agent, THP-1 cells, magnetic resonance imaging
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-12945 (URN)10.1002/cmmi.236 (DOI)000257982000002 ()
Tilgjengelig fra: 2008-02-21 Laget: 2008-02-21 Sist oppdatert: 2017-09-22bibliografisk kontrollert
Fortin, M.-A., Petoral Jr, R. M., Söderlind, F., Klasson, A., Engström, M., Veres, T., . . . Uvdal, K. (2007). Polyethylene glycol-cover ultra-small Gd2O3 nanoparticles for positive contras at 1.5 T magnetic resonance clinical scanning. Nanotechnology, 18(39), 395501
Åpne denne publikasjonen i ny fane eller vindu >>Polyethylene glycol-cover ultra-small Gd2O3 nanoparticles for positive contras at 1.5 T magnetic resonance clinical scanning
Vise andre…
2007 (engelsk)Inngår i: Nanotechnology, ISSN 0957-4484, Vol. 18, nr 39, s. 395501-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The size distribution and magnetic properties of ultra-small gadolinium oxide crystals (US-Gd2O3) were studied, and the impact of polyethylene glycol capping on the relaxivity constants (r1, r2) and signal intensity with this contrast agent was investigated. Size distribution and magnetic properties of US-Gd2O3 nanocrystals were measured with a TEM and PPMS magnetometer. For relaxation studies, diethylene glycol (DEG)-capped US-Gd2O3 nanocrystals were reacted with PEG-silane (MW 5000). Suspensions were adequately dialyzed in water to eliminate traces of Gd3+ and surfactants. The particle hydrodynamic radius was measured with dynamic light scattering (DLS) and the proton relaxation times were measured with a 1.5 T MRI scanner. Parallel studies were performed with DEG–Gd2O3 and PEG-silane–SPGO (Gd2O3,< 40 nm diameter). The small and narrow size distribution of US-Gd2O3 was confirmed with TEM (~3 nm) and DLS. PEG-silane–US-Gd2O3 relaxation parameters were twice as high as for Gd–DTPA and the r2/r1 ratio was 1.4. PEG-silane–SPGO gave low r1 relaxivities and high r2/r1 ratios, less compatible with positive contrast agent requirements. Higher r1 were obtained with PEG-silane in comparison to DEG–Gd2O3. Treatment of DEG–US-Gd2O3 with PEG-silane provides enhanced relaxivity while preventing aggregation of the oxide cores. This study confirms that PEG-covered Gd2O3 nanoparticles can be used for positively contrasted MR applications requiring stability, biocompatible coatings and nanocrystal functionalization.

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-13297 (URN)10.1088/0957-4484/18/39/395501 (DOI)000249283300006 ()
Tilgjengelig fra: 2008-05-21 Laget: 2008-05-21 Sist oppdatert: 2015-12-17
Ahrén, M., Olsson, P., Söderlind, F., Klasson, A., Petoral, R. J., Engström, M., . . . Uvdal, K. (2007). Rare earth nanoparticles as contrast agent in MRI: Nanomaterial design and biofunctionalization. In: IVC-17/ICSS-13 ICNT,2007.
Åpne denne publikasjonen i ny fane eller vindu >>Rare earth nanoparticles as contrast agent in MRI: Nanomaterial design and biofunctionalization
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2007 (engelsk)Inngår i: IVC-17/ICSS-13 ICNT,2007, 2007Konferansepaper, Publicerat paper (Annet vitenskapelig)
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-44593 (URN)77163 (Lokal ID)77163 (Arkivnummer)77163 (OAI)
Merknad
Conference proceedingsTilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2010-07-01
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