Flash nanoprecipitation of hafnia nanoparticle computed tomography contrast agent

Hafnium oxide (hafnia) nanoparticles have recently attracted attention for their application as computed tomography (CT) contrast agents due to their high X-ray attenuation and low cost. Here we employ flash nanoprecipitation (FNP) to formulate hafnia nanoclusters (HNCs) consisting of a core of precipitated individual hafnia nanoparticles and polylactic acid homopolymer and an outer coating of the block copolymer polylactic acid-b-polyethylene glycol (PLA-b-PEG). The HNCs can be produced with controlled hydrodynamic size in the range of 100-300 nm using a simple 3D-printed FNP mixer. The CT performance of the HNCs was evaluated in a pre-clinical small animal scanner and in a clinical scanner. In both systems the HNCs displayed similar to 1.5x greater contrast compared to the commercial iodinated molecular contrast agent Omnipaque used clinically.

Automated summary

Hafnium oxide nanoparticles (HNCs) formulated using flash nanoprecipitation (FNP) exhibit high X-ray attenuation and low cost, making them attractive as computed tomography (CT) contrast agents. A simple 3D-printed FNP mixer was used to produce HNCs with controlled hydrodynamic size ranging from 100-300 nm. Evaluation in both pre-clinical small animal scanner and clinical scanner showed that the HNCs provide approximately 1.5 times greater contrast enhancement compared to the commercially used iodinated molecular contrast agent Omnipaque.