MAGNETIC MICROSPHERE AND METHOD OF FORMING A MICROSPHERE

• US 20100124572A1
• Filed: 11/16/2009
• Published: 05/20/2010
• Est. Priority Date: 11/17/2008
• Status: Active Grant

• Current Assignee: Hong Kong University of Science and Technology
• Original Assignee: Hong Kong University of Science and Technology
• Inventors: Sheng, Ping, WEN, Weijia, Gong, Xiuqing, Peng, Suili
• Granted Patent: US 9,457,034 B2
• Time in Patent Office: Days
• US Class Current: 424/490
• CPC Class Codes: A61K 31/43 Compounds containing 4-thia-1-azabicyclo [3.2.0] heptane ring systems, i.e. compounds containing a ring system of the formula , e.g. penicillins, penems
• CPC Class Codes: A61K 31/60 Salicylic acid; Derivatives thereof
• CPC Class Codes: A61K 31/616 by carboxylic acids, e.g. acetylsalicylic acid
• CPC Class Codes: A61K 9/0009 involving or responsive to electricity, magnetism or acoustic waves; Galenical aspects of sonophoresis, iontophoresis, electroporation or electroosmosis microelectromechanical systems A61K9/0097
• CPC Class Codes: A61K 9/5031 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/5036 Polysaccharides, e.g. gums, alginate; Cyclodextrin
• CPC Class Codes: A61K 9/5138 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates

Abstract

The microspheres have many possible applications including smart drug delivery, breaking and damper devices. In one arrangement, a microsphere comprises a shell 120 and a core 110. The core comprises a liquid, which may be a drug, while the shell comprises magnetic particles. The microsphere is deformable in response to to application of an external magnetic field. Also disclose is an arrangement in which a microsphere has a magnetic core and a PDMS shell.

Claims

1. A microsphere comprising a shell and a core;

wherein the core comprises a liquid, the shell comprises magnetic particles and the microsphere is deformable in response to a magnetic field.

2. The microsphere of claim 1 wherein the liquid comprises a drug.

3. The microsphere of claim 1 wherein the shell comprises said magnetic particles in a substrate of organic material.

4. The microsphere of claim 2 wherein the drug comprises aspirin or amoxicillin.

5. The microsphere of claim 1 having a diameter of 50 to 200 microns.

6. A method of forming a microsphere comprising the steps of providing a first fluid, a second fluid comprising magnetic particles and mixing said first and second fluids such that the first fluid forms a core of the microsphere and the second fluid forms a shell of the microsphere.

7. The method of claim 6 wherein the first fluid comprises a drug.

8. The method of claim 6 wherein said first and second fluids are mixed using a fluid flow device comprising a plurality of channels.

9. The method of claim 8 wherein there are at least first, second and third channels, said second channel being provided between said first and third channels, said first and third channels joining with said second channel at a first junction;

and wherein the first fluid is injected into the second channel and the second fluid is injected into the first and third channels.

10. The method of claim 9 wherein said first, second and third channels are provided between fourth and fifth channels, said fourth and fifth channels joining said second channel at a second junction which is downstream of said first junction;

and wherein the method further comprises the step of injecting carrier fluid into said fourth and fifth channels.

11. The method of claim 6 further comprising a process for solidifying the shell.

12. A method of dispensing a liquid comprising providing a microsphere having a to liquid core and a shell comprising magnetic particles and applying a magnetic field across the microsphere in order to deform the microsphere.

13. The method of claim 12 wherein the magnetic field is varied and the microsphere expands and contracts as the magnetic field is varied.

14. The method of claim 12 wherein the liquid comprises a drug.

15. The method of claim 12 wherein the magnetic field is varied in a step wave form.

16. A microsphere comprising magnetic particles surrounded by elastically deformable material;

the microsphere being elastically deformable in response to application of an external magnetic field.

17. The microsphere of claim 16 wherein the modulus of elasticity of the elastically deformable material is at least 120 kPa.

18. The microsphere of claim 16 wherein the microsphere comprises a magnetic core surrounded by an organic material shell.

19. The microsphere of claim 16 wherein the microsphere is a single phase structure comprising a plurality of magnetic particles dispersed in an organic substrate.

20. The microsphere of claim 16 wherein the elastically deformable material comprises PDMS.