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Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

submitted on 13.02.2020, 03:09 and posted on 13.02.2020, 11:09 by Shatadru Chakravarty, Jeremy Hix, Kaitlyn Wieweora, Maximilian Volk, Elizabeth Kenyon, Dorela D. Shuboni-Mulligan, Barbara Blanco-Fernandez, Matti Kiupel, Jennifer Thomas, Lorenzo F. Sempere, Erik Shapiro
Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.


MSU Foundation Strategic Partnership Grant

NIH R21 CA185163

NIH R21 EB017881

NIH R21 CA226579


Email Address of Submitting Author


Michigan State University


United States

ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest