Tuned multifunctional magnetic nanoparticles for biomedicine
Magnetic nanoparticles and related devices and methods are described. Compositions and methods can include magnetic nanoparticles having a narrow size distribution for use in diagnostics and therapeutics.
1. A method of producing magnetic nanoparticles with a tuned size distribution for magnetic particle imaging, the method comprising:
selecting a diameter of a magnetic nanoparticle that produces a maximum spatial resolution or a maximum signal intensity at a frequency used in magnetic particle imaging;
producing a population of magnetic nanoparticles having a median diameter of approximately the selected diameter of the magnetic nanoparticle that produces the maximum spatial resolution or the maximum signal intensity, wherein the population of the magnetic nanoparticles has a narrow size distribution.
2. A method for imaging magnetic nanoparticles, the method comprising:
selecting a diameter of a magnetic nanoparticle that produces a maximum spatial resolution or a maximum signal intensity at a frequency used in magnetic particle imaging;
providing a population of magnetic nanoparticles having a median diameter of approximately the selected diameter of the magnetic nanoparticle that produces the maximum spatial resolution or the maximum signal intensity, wherein the population of the magnetic nanoparticles has a narrow size distribution;
administering the population of magnetic nanoparticles to a subject; and
exciting at least one magnetic nanoparticle in the population of magnetic nanoparticles with an imaging system.
3. The method of claim 2 , wherein the imaging system is configured to perform magnetic particle imaging (MPI).
4. The method of claim 2 , wherein the imaging system is configured to perform magnetic resonance imaging (MRI).
5. The method of claim 2 , wherein the imaging system is configured to perform MPI and MRI in combination.
6. The method of claim 2 , wherein greater than about 70% of the magnetic nanoparticles in the population have a magnetic core diameter that is less than 8.8 nm from the median number-weighted diameter.
7. The method of claim 2 , wherein the narrow size distribution comprises a log-normal distribution with median number-weighted magnetic core diameter and a geometric standard deviation of less than about 1.22.
8. The method of claim 2 , wherein greater than about 70% of the magnetic nanoparticles in the population have a magnetic core diameter that is less than 3 nm from the median number-weighted diameter.
9. The method of claim 2 , wherein the narrow size distribution comprises a log-normal distribution with median number-weighted magnetic core diameter and a geometric standard deviation of less than about 1.11.
10. The method of claim 2 , wherein the population of magnetic nanoparticles comprises a median magnetic core diameter ranging from about 12 nm to about 30 nm or from about 5 nm to about 30 nm.
11. The method of claim 2 , wherein the population of magnetic nanoparticles comprises a median hydrodynamic diameter ranging from about 30 nm to about 100 nm in aqueous solution.
12. The method of claim 2 , wherein at least one magnetic nanoparticle of the population of magnetic nanoparticles comprises an iron oxide core coated with a polymer.
13. The method of claim 12 , wherein the iron oxide core is a single crystal.
14. The method of claim 12 , wherein the polymer is selected from the group consisting of an ethylene oxide/propylene oxide block copolymer, polyethylene oxide polymer, polyethylene glycol polymer, poly (maleic anhydride alt-1-octadecene) polymer and poly (maleic anhydride alt-1-octadecene)-polyethylene glycol polymer (PMAO-PEG).