Projects per year
Oxygen homeostasis is important in the regulation of biological function. Disease progression can be monitored by measuring oxygen levels, thus producing information for the design of therapeutic treatments. Noninvasive measurements of tissue oxygenation require the development of tools with minimal adverse effects and facile detection of features of interest. Fluorine magnetic resonance imaging (19F MRI) exploits the intrinsic properties of perfluorocarbon (PFC) liquids for anatomical imaging, cell tracking, and oxygen sensing. However, the highly hydrophobic and lipophobic properties of perfluorocarbons require the formation of emulsions for biological studies, though stabilizing these emulsions has been challenging. To enhance the stability and biological loading of perfluorocarbons, one option is to incorporate perfluorocarbon liquids into the internal space of biocompatible mesoporous silica nanoparticles. Here, we developed perfluorocarbon-loaded ultraporous mesostructured silica nanoparticles (PERFUMNs) as 19F MRI detectable oxygen-sensing probes. Ultraporous mesostructured silica nanoparticles (UMNs) have large internal cavities (average = 1.8 cm3 g-1), facilitating an average 17% loading efficiency of PFCs, meeting the threshold fluorine concentrations needed for imaging studies. Perfluoro-15-crown-5-ether PERFUMNs have the highest equivalent nuclei per PFC molecule and a spin-lattice (T1) relaxation-based oxygen sensitivity of 0.0032 mmHg-1 s-1 at 16.4 T. The option of loading PFCs after synthesizing UMNs, rather than traditional in situ core-shell syntheses, allows for use of a broad range of PFC liquids from a single material. The biocompatible and tunable chemistry of UMNs combined with the intrinsic properties of PFCs makes PERFUMNs a MRI sensor with potential for anatomical imaging, cell tracking, and metabolic spectroscopy with improved stability.
Bibliographical noteFunding Information:
This work was supported in part by the Minnesota Lions Diabetes Foundation, the Schott Family Foundation, the Carol Olson Memorial Diabetes Research Fund, and NIH Grants P41 EB015894 and S10 RR025031. Parts of this work were carried out in the Characterization Facility University of Minnesota, a member of the NSF-funded Materials Research Facilities Network the MRSEC program. Rabbit blood was properly collected under IACUC Protocol 1610-34243A by Ellorie R. Liljequist. Special thanks to members of the Lu Lab, University of Minnesota for providing the gases and apparatus to conduct oximetry studies in blood. A.L.L. would like to acknowledge the NIH chemistry-biology interface training grant 5T32GM008700-18 and the University of Minnesota's Diversity of Views and Experiences Fellowship for funding. C.T.G. would like to acknowledge the NIH chemistry-biology interface training grant T32-GM08700 and the University of Minnesota Interdisciplinary Doctoral Dissertation Fellowship for funding. A.R.J. would like to acknowledge the University of Minnesota Undergraduate Research Opportunities Program for funding.
- magnetic resonance
- mesoporous silica nanoparticles
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 4
PubMed: MeSH publication types
- Journal Article
- Research Support, N.I.H., Extramural
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.