Premium
Thickness and Sphericity Control of Hollow Hard Silica Shells through Iron (III) Doping: Low Threshold Ultrasound Contrast Agents
Author(s) -
Huang ChingHsin,
Wang James,
Yang Jian,
Oviedo Juan Pablo,
Nam Seungjin,
Trogler William C.,
Blair Sarah L.,
Kim Moon J.,
Kummel Andrew C.
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201900893
Subject(s) - materials science , ultrasound , particle (ecology) , biomedical engineering , sphericity , nanoparticle , particle size , contrast (vision) , nanotechnology , composite material , chemical engineering , acoustics , optics , medicine , oceanography , physics , engineering , geology
Abstract Silica particles are convenient ultrasound imaging contrast agents because of their long imaging time and ease of modification; however, they require a relatively high insonation power for imaging and have low biodegradability. In this study, 2 µm ultrathin asymmetric hollow silica particles doped with iron (III) (Fe(III)‐SiO 2 ) are synthesized to produce biodegradable hard shelled particles with a low acoustic power threshold comparable with commercial soft microbubble contrast agents (Definity) yet with much longer in vivo ultrasound imaging time. Furthermore, high intensity focused ultrasound ablation enhancement with these particles shows a 2.5‐fold higher temperature elevation than with Definity at the same applied power. The low power visualization improves utilization of the silica shells as an adjuvant in localized immunotherapy. The data are consistent with asymmetric engineering of hard particle properties that improve functionality of hard versus soft particles.