Control of materials and porous magnetic particles

• US 8,377,147 B2
• Filed: 05/16/2007
• Issued: 02/19/2013
• Est. Priority Date: 07/19/2004
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Sailor, Michael J., Park, Ji-Ho, Segal, Ester, Vecchio, Kenneth S., Bhatia, Sangeeta N., Derfus, Austin
• Primary Examiner(s): Norton, Nadine
• Assistant Examiner(s): Remavege, Christopher
• Application Number:
  US12/300,369
• Publication Number:
  US 20090179171A1
• Time in Patent Office: 2,106 Days
• Field of Search: 438/212, 438/217, 438/218, 438/402, 438/403, 438/357, 438/692.1, 977/838, 977/960, 977/962, 428/212, 428/217, 428/218, 428/402, 428/403, 428/357, 428/692.1, 216/2, 216/22, 216/24, 216/39, 216/5, 435/6.1, 435/172.1, 435/173.1
• US Class Current: 977/962
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: H01F 1/0063 in a non-magnetic matrix, e.g. granular solids granular films H01F10/007
• CPC Class Codes: H05B 6/02 Induction heating
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/32 Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Abstract

The present invention uses externally applied electromagnetic stimulus to control and heat porous magnetic particles and material associated with the particles. The particles contain magnetic material, such as superparamagnetic iron oxide and are infused with a material. Application of a DC magnetic field allows them to be moved with their infused material, and application of an AC RF electromagnetic field allows them to be heated with their infused material. The material can be infused into pores of the particles and the particles can also adhere to an aqueous droplet. The present invention also provides a multi-layer porous magnetic particle. The particle includes a host layer having pores sized to accept magnetic nanoparticles. Magnetic nanoparticles are infused within pores of the host layer. An encoding layer includes pores that define a spectral code. The pores in the encoding layer are sized to substantially exclude the magnetic nanoparticles. The encoding layer can also be a multi-layer, exhibiting, for example, a complex spectral code.

Claims

1. A method for control of associated material, the method comprising steps of:

providing a porous microparticle with magnetic material within its pores, wherein the porous microparticle comprises multiple porous layers, a first layer containing a spectral code and a second layer hosting the magnetic material;

infusing the associated material into the pores of the second layer;

with an external magnetic field, controlling the porous microparticle to thereby control the associated material.

2. The method of claim 1, wherein said step of controlling comprises applying an AC radio frequency electromagnetic field to heat the porous microparticles and thereby heat the associated material.

3. The method of claim 2, further comprising adhering the porous microparticle to an aqueous droplet.

4. The method of claim 1, wherein said step of controlling comprises applying a DC magnetic field to move the porous microparticle and thereby move the associated material.

5. The method of claim 4, further comprising a step of adhering the porous microparticle to an aqueous droplet prior to said step of controlling.

21. The method of claim 1, further comprising adhering a plurality of microparticles to a droplet.

22. The method of claim 21, wherein the droplet comprises oligonucleotides.

23. The method of claim 21, wherein said adhering comprises adhering the plurality of microparticles to a plurality of droplets that comprise oligonucleotides, the method further comprising using the external magnetic field to move the droplets together and merge the droplets.

24. The method of claim 1, wherein said controlling comprises moving the microparticle and the associated material.

6. A magnetic porous particle, comprising:

a host layer having pores sized to accept magnetic nanoparticles;

magnetic nanoparticles infused within pores of the host layer;

an encoding layer having pores that define a spectral code, the pores in the encoding layer being sized to substantially exclude the magnetic nanoparticles.

7. The particle of claim 6, wherein the encoding layer comprises multiple layers that exhibit a complex spectral code.

8. The particle of claim 6, wherein the magnetic nanoparticles comprise superparamagnetic nanoparticles.

9. The particle of claim 6, wherein the pores of the encoding layer are sized to accept infusion of an associated material smaller than the magnetic nanoparticles.

10. The particle of claim 6, wherein the host layer and the encoding layer comprise porous silicon.

11. The particle of claim 6, wherein the encoding layer comprises a photonic crystal with a predetermined spectral code.

12. The particle of claim 6, wherein the encoding layer is hydrophobic, with surface-grafted dodecyl moieties.

13. The particle of claim 12, wherein the host layer comprises a hydrophilic oxide host layer and the magnetic nanoparticles comprise Fe₃O₄ nanoparticles.

14. The particle of claim 6, wherein the particle is micron sized.

15. The particle of claim 6, incorporated into a host.

16. The particle of claim 15, wherein the host comprises one of a test kit, assay, power, paste, liquid, glass, and paper.

17. The particle of claim 6, further comprising a specific antibody, oligonucleotide or ligand to provide affinity for a specific antigen, oligonucleotide, or receptor.

18. The particle of claim 6, wherein the magnetic nanoparticles comprise rare earth magnetic materials, gadolinium, or nickel.

19. The particle of claim 6, wherein a size of the particle is 150˜

200 μ

m.

20. The particle of claim 6, adhered to a droplet.