Encapsulating ¹¹¹In in Nanocontainers for Scintigraphic Imaging: Synthesis, Characterization, and In Vivo Biodistribution

Abstract

A new strategy for the radiolabeling of porous nanocontainers has been developed, and the first experiments in vivo are reported. Our approach consists of the use of nanometer-sized zeolites whose channels have been filled with the positively charged gamma-emitter (111)In(3+) via simple ion exchange. To avoid leaching of the isotope under physiological conditions, the entrances of the channels have been closed using a specifically designed molecular stopcock. This stopcock has a positively charged group that enters the channels and entraps the loaded radionuclides via electrostatic and steric repulsion. The other side of the stopcock is a bulky triethoxysilane group that can covalently bind to the walls of the zeolite entrances, thereby irreversibly closing the channels. The surface of the zeolites has been functionalized with different chemical groups in order to investigate the different biodistributions depending of the nature of the functionalizations. Preliminary in vivo experiments with Wistar rats have been performed and showed the potential of the approach. This strategy leads to a nanoimaging probe with a very high density of radioisotopes in a confined space, which is highly stable in physiological solution and could allow a large variety of functionalities on its external surface.

First-principles simulation of the absorption bands of fluorenone in zeolite L

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] These are currently investigated for applications in different fields, ranging from sensing in analytical chemistry, biology, and diagnostics, [15][16][17][18] to applications in optical and electro optical devices [3][4][5][19][20][21] and extending to solar energy utilization, e.g. in the form of luminescent solar concentrators.…”

Loading and release of 5-fluorouracil from HY zeolites with varying SiO2/Al2O3 ratios

“…Due to the well-defined pore structure and pore topology, zeolites are widely used for adsorption, catalysis and separations [10]. The use of zeolites in drug delivery [7,8,[11][12][13][14][15][16], adsorption of pharmaceuticals [17] and imaging [18][19][20][21][22][23] has been explored in the literature. Specifically, the loading and release of drugs, such as sulfonamide antibiotics [11,24], ibuprofen [14], doxorubicin [13], and mitoxantrone [16] in zeolites have been investigated.…”

Luminescence Enhancement after Adding Stoppers to Europium(III) Nanozeolite L

“…Siloxane bonds are formed during the refluxing procedure with the OH groups present at the channel entrance (step 2), and with those present to a lesser amount at the coat of NZL. [37,38] The Eu 3+ -(TTA n )-NZL show remarkably enhanced luminescence, which is easily visible by eye upon near UV excitation, after this modification procedure. .…”

“…A solution of this problem could be to selectively plug the channel entrances of the ZL host by means of stopper molecules, a principle that was first communicated by Calzaferri [31] and later used and further developed in several laboratories. [32][33][34][35][36][37][38] Selective modification of ZL with stopper molecules can for example prevent penetration of small molecules that would otherwise enter the channels or it can prevent guests from leaving the host. It is based on the fact that ZL crystals consist of strictly onedimensional channels.…”