Preparation of silica-coated AgI nanoparticles by an amine-free process and their X-ray imaging properties

Abstract

AgI nanoparticles coated with silica shell (AgI/SiO 2 ) were prepared with an amine-free process, i.e. a modified Stöber method. A colloid solution of 3.9 © 10 ¹4 M AgI nanoparticles was prepared mixing silver perchlorate at 3.9 © 10 ¹4 M and potassium iodide at 7.8 © 10 ¹4 M. A silica-coating was performed at 4.5 © 10 ¹6 M 3-mercaptopropyltrimethoxysilane, 0.1 © 10 ¹3 2.0 © 10 ¹3 M NaOH, 1125 M H 2 O, and 0.4 © 10 ¹3 80 © 10 ¹3 M tetraethylorthosilicate (TEOS) in the presence of 1.0 © 10 ¹4 M AgI nanoparticles in ethanol. The AgI/SiO 2 particles with a size of 53.2 « 9.3 nm and an AgI core size of 13.5 « 4.2 nm were prepared at 1.2 © 10 ¹3 M NaOH, 15 M H 2 O, and 4.0 © 10 ¹3 M TEOS. The AgI concentration of 1.0 © 10 ¹4 M in the as-prepared colloid solution was increased up to an AgI concentration of 0.32 M by salting-out and centrifugation. The coreshell structure of AgI/ SiO 2 particles was undamaged, and the colloid solution was still colloidally stable, even after the condensation. The concentrated AgI/SiO 2 colloid solution showed a high-contrast X-ray image, and its computed tomography value was 2908 « 37 HU. Internal organs in a mouse could be imaged injecting the concentrated colloid solution into it.

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

“…First, the AgI particle . TEM observation performed in our previous work [32] revealed that these preparation conditions resulted in production of silica-coated particles with an average particle size of 53.2 ± 9.3 nm, which contained the AgI nanoparticles with an average particle size of 13.5 ± 4.2 nm. Third, PEGylation of AgI/SiO 2 particle surface was performed by using the M-PEG-SLN, or PEG with a silicone alkoxide group, since the M-PEG-SLN is expected to be introduced on the AgI/SiO 2 particle surface through a reaction between the silanol groups on the particle surface and alkoxide groups of the M-PEG-SLN.…”

“…An AgI/SiO 2 /PEG particle colloid solution was prepared by a process composed of a method for producing AgI/SiO 2 nanoparticle colloid solution, which was reported in our previous work [32] and a method for PEGylation of the AgI/SiO 2 particle surface. First, the AgI particle .…”

“…Samples for TEM were prepared by dropping and evaporating the nanoparticle suspensions on a collodion-coated copper grid. X-ray images and CT values of samples such as Iopamiron 300, the AgI/SiO 2 /PEG particle colloid solutions, and an ICR mouse were obtained with an Aloka La theta LCT-200 CT system, according to our previous work [32]. The samples were put into a tube with a diameter of 3.7 cm and a length of 29.5 cm, and then their images were taken as if the samples were cut into round slices.…”

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

“…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.…”

Imaging Processes Using Core-Shell Particle Colloid Solutions for Medical Diagnosis

“…Coating of the particles with shell inert to living bodies is a candidate for controlling the adverse reactions, since the particles cannot contact with living bodies. Our research group has recently studied on development of methods for preparing colloid solutions of coreshell particles composed of core of materials with imaging ability and shell of silica that is inert to living bodies, and on their imaging properties (Ayame et al, 2011;Kobayashi et al, 2007Kobayashi et al, , 2010aKobayashi et al, , 2010bKobayashi et al, , 2011Kobayashi et al, , 2012aKobayashi et al, , 2013aKobayashi et al, , 2013b. The methods used are based on hydrolysis and condensation of silicone alkoxide in the presence of particles such as iodine compound nanoparticless prepared by mixing AgClO 4 aqueous solution with KI aqueous solution (Ayame et al, 2011;Kobayashi et al, 2012a), metallic Au nanoparticles prepared by reducing HAuCl 4 with citrate (Kobayashi et al, 2011(Kobayashi et al, , 2013b, silica nanoparticles coated with Gd compound (GdC) shell by a homogeneous precipitation method (Kobayashi et al, 2007), and commercially-available QD (Kobayashi et al, 2010a(Kobayashi et al, , 2010b(Kobayashi et al, , 2013a.…”