NanoDay 2021 – Poster 08 – Sitong Liu


Preparation and Evaluation of Hafnium Oxide Nanoparticles as CT Contrast Agent

Sitong Liu

Authors: Sitong Liu, Matthew Po, Bo Yu, Carlos Rinaldi-Ramos

Faculty Mentor: Carlos Rinaldi-Ramos, PhD

College: College of Engineering

Department: Chemical Engineering


The high electron density and chemical stability of hafnia makes its nanoparticles good candidates for computed tomography (CT). Iodine is used commonly used clinically. However, iodine-based CT contrast agents can lead to low tolerance to patients with chronic kidney disease. Although thermal decomposition synthesis methods could provide fine control over particle physical properties, they remain poorly investigated for synthesis of hafnia nanoparticles. Additionally, thermal decomposition methods result in particles coated with an organic layer and require phase transfer to aqueous media to enable biomedical applications. Flash nanoprecipitation (FNP) is a simple and scalable method to formulate composite nanoparticles consisting of a hydrophobic core and a hydrophilic layer. Here, we report the preparation of hafnia nanoparticle compositess (HNCs) using hafnia nanoparticles synthesized through thermal decomposition. Hafnia nanoparticles were encapsulated in poly(lactic acid)-b-poly(ethylene glycol) (PLA-b-PEG) by FNP using 3D printed multi-inlet vortex mixers. The CT contrast performance of HNCs was evaluated and compared to the clinical CT contrast agent OMNIPAQUE (active ingredient, iohexol), suggesting better CT contrast for the HNCs. The HNCs were found to be colloidally stable in cell culture media with negligible change in hydrodynamic diameter over a period of 24 hours. This study will be the first to investigate the CT performance of hafnia nanoparticles synthesized from thermal decomposition.