Control of Shell Thickness in Silica-Coating of AgI Nanoparticles

Kobayashi, Yoshio; Misawa, Kiyoto; Takeda, Motohiro; Ohuchi, Noriaki; Kasuya, A.; Konno, Mikio

doi:10.4028/www.scientific.net/amr.29-30.191

Cited by 14 publications

(10 citation statements)

References 17 publications

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“…Silica coating can also be performed for various types of particles. The thickness of the silica can be adjusted to modify the size of the particles (Kobayashi et al 2011).…”

Section: Discussionmentioning

confidence: 99%

“…It is composed of heavy elements and thus thought to be suitable as X-ray contrast media. In fact, we previously showed that AgI possessed high imaging ability in the measurement by X-CT in vitro (Kobayashi et al 2011). However, AgI itself is potentially toxic and can cause bodily reactions, including mucosal irritation.…”

mentioning

confidence: 99%

“…Silica coating is thought to reduce this toxicity and also confer multifunctionality on nanoparticles. Silica-coated AgI nanoparticles (SAgINPs) were developed to insulate biological systems from the functional core of nanoparticles (Kobayashi et al 2004(Kobayashi et al , 2010(Kobayashi et al , 2011. This study evaluated the potential of SAgINPs as a contrast medium and investigated their biological distribution and dynamics along with verifying contrast enhancement.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Development of Silica-Coated Silver Iodide Nanoparticles and Their Biodistribution

Sakurai

Tada

Gonda

et al. 2012

Tohoku J. Exp. Med.

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Nanomaterials have great potential in the field of medicine and have been studied extensively. In a previous study, we addressed the potential of silver iodide (AgI) as X-ray contrast media, because it possessed high imaging ability in the measurement by X-ray computed tomography (X-CT) in vitro, and its surface can be modified with many functional groups. We developed the method of silica coating to make AgI nanoparticles more stable and uniform in size. However, the safety and metabolism of nanoparticles in vivo remains to be determined. The objective of the present study was to evaluate the in vivo biodistribution of silica-coated AgI nanoparticles (SAgINPs). X-CT, transmission electron microscopy (TEM), and inductively coupled plasma atomic emission spectrometry (ICP-AES) were performed prior to and at intervals following the intravenous administration of SAgINPs to rats and rabbits. ICP-AES is a spectral technique that can determine the presence and concentrations of metal samples. The X-CT study showed long-period enhancement in the liver and spleen, but not in the bladder of rats. The TEM study demonstrated that SAgINPs were found in hepatocytes. Using ICP-AES, Ag was detected in the bile juice of rabbits, but not found in the urine of these animals, suggesting that SAgINPs are excreted via the liver. This study shows the quantitative biodistribution of silica-coated nanoparticles for the first time, indicating that our silica coating technique is useful for development of nanoparticles with hepatic excretion. In conclusion, the SAgINPs may provide X-ray contrast media with high imaging ability and biocompatibility.

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“…Silica coating can also be performed for various types of particles. The thickness of the silica can be adjusted to modify the size of the particles (Kobayashi et al 2011).…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Development of Silica-Coated Silver Iodide Nanoparticles and Their Biodistribution

Sakurai

Tada

Gonda

et al. 2012

Tohoku J. Exp. Med.

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“…Tens of particle diameters were measured using the TEM images to determine the volumeaveraged particle size and its standard deviation. Fluorescence imaging and X-ray imaging with the particle colloid solutions were performed using a Xenogen IVIS 100 fluorometer in vivo imaging system (IVIS) and an Aloka La theta LCT-200 CT system, Japan), respectively, which were also used in our previous works (Ayame et al 2011;Kobayashi et al 2011Kobayashi et al , 2012bKobayashi et al , 2013aKobayashi et al , b, c, d, 2014Kobayashi et al , 2015. CT values were estimated on the basis of CT values of -1000 and 0 for air and water, respectively.…”

Section: Characterizationmentioning

confidence: 99%

Fabrication of quantum dot/silica core–shell particles immobilizing Au nanoparticles and their dual imaging functions

Kobayashi

Matsudo

et al. 2015

Appl Nanosci

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The present work proposes preparation methods for quantum dot/silica (QD/SiO 2 ) core-shell particles that immobilize Au nanoparticles (QD/SiO 2 /Au). A colloid solution of QD/SiO 2 core-shell particles with an average size of 47.0 ± 6.1 nm was prepared by a sol-gel reaction of tetraethyl orthosilicate in the presence of the QDs with an average size of 10.3 ± 2.1 nm. A colloid solution of Au nanoparticles with an average size of 17.9 ± 1.3 nm was prepared by reducing Au 3? ions with sodium citrate in water at 80°C. Introduction of amino groups to QD/SiO 2 particle surfaces was performed using (3-aminopropyl)-triethoxysilane (QD/SiO 2 -NH 2 ). The QD/SiO 2 /Au particles were fabricated by mixing the Au particle colloid solution and the QD/SiO 2 -NH 2 particle colloid solution. Values of radiant efficiency and computed tomography for the QD/ SiO 2 /Au particle colloid solution were 2.23 9 10 7 (p/s/ cm 2 /sr)/(lW/cm 2 ) at a QD concentration of 8 9 10 -7 M and 1180 ± 314 Hounsfield units and an Au concentration of 5.4 9 10 -2 M. The QD/SiO 2 /Au particle colloid solution was injected into a mouse chest wall. Fluorescence emitted from the colloid solution could be detected on the skin covering the chest wall. The colloid solution could also be X-ray-imaged in the chest wall. Consequently, the QD/SiO 2 /Au particle colloid solution was found to have dual functions, i.e., fluorescence emission and X-ray absorption in vivo, which makes the colloid solution suitable to function as a contrast agent for dual imaging processes.

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“…Our research group has studied silica coating of various nanoparticles with the sol-gel process [16][17][18][19][20][21][22][23][24][25][26]. Our group has also proposed a method for silica coating of nanoparticles of silver iodide (AgI) that is one of the iodine compounds [27][28][29][30][31][32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Preparation of AgI/Silica/Poly(Ethylene Glycol) Nanoparticle Colloid Solution and X-Ray Imaging Using It

et al. 2013

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This work performed X-ray imaging of mouse by using aqueous colloid solution of AgI nanoparticles coated with silica (AgI/ SiO 2 ) and then surface-modified with poly(ethylene glycol) (PEG) (AgI/SiO 2 /PEG). A colloid solution of AgI nanoparticles was prepared by mixing silver perchlorate and potassium iodide in water. The AgI nanoparticles were surface-modified with 3-mercaptopropyltrimethoxysilane and then were silica-coated by a sol-gel reaction between tetraethylorthosilicate and H 2 O catalyzed with NaOH in ethanol. The AgI/SiO 2 particle surface was modified with PEG by using methoxy PEG silane (CH 3 O(CH 2 CH 2 O) CH 2 CONHC 3 H 6 Si(OC 2 H 5 ) 3 ). The AgI/SiO 2 /PEG colloid solution revealed a computed tomography value as high as 1343.6 HU at an iodine concentration of 0.1 M, which was higher than a commercial X-ray contrast agent with the same iodine concentration. Tissues of mouse could be imaged by injecting the concentrated colloid solution into them.

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Control of Shell Thickness in Silica-Coating of AgI Nanoparticles

Cited by 14 publications

References 17 publications

Development of Silica-Coated Silver Iodide Nanoparticles and Their Biodistribution

Development of Silica-Coated Silver Iodide Nanoparticles and Their Biodistribution

Fabrication of quantum dot/silica core–shell particles immobilizing Au nanoparticles and their dual imaging functions

Preparation of AgI/Silica/Poly(Ethylene Glycol) Nanoparticle Colloid Solution and X-Ray Imaging Using It

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