Magnetic microsphere and method of forming a microsphere

• US 9,457,034 B2
• Filed: 11/16/2009
• Issued: 10/04/2016
• 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
• Primary Examiner(s): Fisher, Abigail
• Assistant Examiner(s): CHOI, FRANK I
• Application Number:
  US12/619,196
• Publication Number:
  US 20100124572A1
• Time in Patent Office: 2,514 Days
• Field of Search: None
• US Class Current: 1/1
• 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 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 method of forming a microsphere comprising the steps of:

providing a first fluid;

providing a second fluid comprising magnetic particles and a material capable of forming an elastically deformable material; and

mixing said first and second fluids such that the first fluid forms a core of the microsphere and remains in a fluid state in the microsphere and the second fluid forms an elastically deformable shell of the microsphere comprising at least one different material from the core of the microsphere providing a cross-linked structure, forming a solid skin for the microsphere, and comprising the magnetic particles, and the material capable of forming the elastically deformable material which exhibits an increase in permeability when distorted, wherein, in response to a magnetic field, the magnetic particles in the elastically deformable shell cause said elastically deformable shell to deform, resulting in increased permeability of the shell, thereby providing controlled release of a liquid comprising the first fluid from the core of the microsphere in accordance with a magnetic field property, the magnetic field property consisting of at least one of strength of the magnetic field, frequency of the magnetic field and the type of waveform of the magnetic field.

2. The method of claim 1 wherein the first fluid comprises a drug.

3. The method of claim 1 wherein said first and second fluids are mixed using a fluid flow device comprising a plurality of channels.

4. The method of claim 3 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.

5. The method of claim 4 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.

6. The method of claim 1 further comprising a process for solidifying the shell from a liquid to form a magnetically deformable elastomeric shell.