Fabrication of multilayer-coated particles and hollow shells via electrostatic self-assembly of nanocomposite multilayers on decomposable colloidal templates

• US 6,479,146 B1
• Filed: 11/07/2000
• Issued: 11/12/2002
• Est. Priority Date: 03/19/1998
• Status: Expired due to Fees

• Current Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Original Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Inventors: Sukhorukov, Gleb, Caruso, Rachel Anne, Caruso, Frank, Möhwald, Helmuth, Donath, Edwin
• Primary Examiner(s): Le, Hoa T.
• Application Number:
  US09/646,398
• Time in Patent Office: 735 Days
• Field of Search: 428/403, 428/404, 428/407, 106/409
• US Class Current: 428/403
• CPC Class Codes: A61K 9/5089 Processes
• CPC Class Codes: A61K 9/5192 Processes
• CPC Class Codes: B01J 13/02 Making microcapsules or microballoons for medical preparations A61K9/50
• CPC Class Codes: B01J 13/22 Coating
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer

Abstract

The invention refers to a new process for preparing coated particles and hollow shells by coating colloidal particles with alternating layers of oppositely charged nanoparticles and polyelectrolytes and optionally removing the colloidal cores.

Claims

1. A process for preparing coated particles comprising the steps:

(a) providing template particles and

(b) coating said template particles with a multilayer comprising (i) alternating layers of oppositely charged nanoparticles and polyelectrolytes and/or (ii) alternating layers of oppositely charged nanoparticles.

2. The process of claim 1 wherein said template particles have an average diameter of 10 μ

m or less.

3. The process of claim 1, wherein said template particles are at least one member selected from the group consisting of organic particles and inorganic particles.

4. The process of claim 1 wherein said template particles are selected from organic polymer latices and partially cross-linked melamine-formaldehyde particles.

5. The process of claim 1 wherein the polyelectrolyte is a linear molecule.

6. The process of claim 1, wherein the polyelectrolyte is a polycation and the nanoparticle has an overall anionic charge.

7. The process of claim 1, wherein the polyelectrolyte is a polyanion and the nanoparticle has an overall cationic charge.

8. The process of claim 1, wherein said nanoparticles have an average diameter of from 1 to 100 nanometers.

9. The process of claim 1, wherein said nanoparticles are inorganic particles.

10. The process of claim 9, wherein said nanoparticles are selected from ceramic and metal particles.

11. The process of claim 10, wherein said nanoparticles are silicon dioxide particles.

12. The process of claim 1, wherein said nanoparticles are biomolecules.

13. The process of claim 12, wherein said biomolecules are polypeptides.

14. The process of claim 1, further comprising the step of at least partially disintegrating the template particles.

15. The process of claim 14, wherein said disintegration is carried out by thermal treatment, chemical treatment or pH adjustment.

16. A coated particle having a core which is a template particle and a multilayer shell comprising a member selected from the group consisting of alternating layers of (i) oppositely charged nanoparticles and polyelectrolytes, and (ii) oppositely charged nanoparticles.

17. The particle of claim 16 having an average diameter of less than or equal to 15 microns.

18. A hollow shell obtained by disintegrating the template particle of the coated particle of claim 16.

19. The hollow shell of claim 18 which is an inorganic structure.

20. The hollow shell of claim 16 which is an organic structure.

21. The hollow shell of claim 16 which is a composite organic-inorganic structure.

22. The hollow shell of claim 16 which is a composite inorganic-inorganic structure.

23. The shell of claim 16 containing an active agent.

24. The hollow shell of claim 23, wherein said active agent is selected fromthe group consisting of pharmaceuticals, contrasting agents, herbicides, pesticides, catalysts and pigments.

25. The shell of claim 23, wherein the shell provides sustained release of said active agent.

26. The shell of claim 23, wherein said shell provides targeted release of said active substance.