Production of polyelectrolyte capsules by surface precipitation

• US 20030175517A1
• Filed: 02/03/2003
• Published: 09/18/2003
• Est. Priority Date: 08/02/2000
• Status: Active Grant

• 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: Voigt, Andreas, Mohwald, Helmuth, Antipov, Alexei, Sukhorukov, Gleb, Radtchenko, Igor, Donath, Edwin
• Granted Patent: US 7,056,554 B2
• Time in Patent Office: Days
• US Class Current: 428/402.2
• CPC Class Codes: A61K 9/5026 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61K 9/5089 Processes
• CPC Class Codes: A61K 9/5138 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• 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 13/10 Complex coacervation, i.e. interaction of oppositely charged particles
• CPC Class Codes: B01J 13/22 Coating
• CPC Class Codes: Y10T 428/2984 Microcapsule with fluid core [includes liposome]

Abstract

The invention concerns a method for producing nanocapsules and microcapsules comprising a polyelectrolyte shell by surface precipitation from the solution, by applying a shell to template particles comprising the steps (a) providing a dispersion of template particles of suitable size in a salt-containing liquid phase which contains the components required to form the shell in a dissolved form and (b) precipitating the components from the liquid phase onto the template particles under conditions which enable the formation of a shell around the template particles that has a thickness of from 1 to 100 nm.

Claims

1. Method for applying a shell to template particles comprising the steps:

(a) providing a dispersion of template particles of suitable size in a salt-containing liquid phase which contains the components required to form the shell in a dissolved form and

(b) precipitating the components from the liquid phase onto the template particles under conditions which enable the formation of a shell around the template particles that has a thickness of from 1 to 100 nm,

wherein the components required to form the shell comprise

(i) two oppositely charged polyelectrolytes,

(ii) a polyvalent low-molecular cation and a negatively charged polyelectrolyte or

(iii) a polyvalent low-molecular anion and a positively charged polyelectrolyte.

2. Method as claimed in claim 1, characterized in that

the template particles are selected from solid, liquid, liquid-crystalline and gaseous particles.

3. Method as claimed in claim 1 or 2, characterized in that

the template particles are selected from particles having a diameter of up to 50 μ

m, in particular of up to 10 μ

m.

4. Method as claimed in one of the claims 1 to 3, characterized in that

the template particles contain an active substance.

5. Method as claimed in claim 4, characterized in that

the active substance is selected from catalysts, in particular enzymes, nanoparticles, pharmaceutical agents, sensor molecules, crystals, polymers and gases.

6. Method as claimed in one of the claims 1 to 5, characterized in that

hollow cell wall particles obtainable from yeasts or other monocellular or multicellular living organisms containing cell walls or hollow pollen wall particles are used as templates.

7. Method as claimed in one of the claims 1 to 3 or 6, characterized in that

soluble particles are used as template particles.

8. Method as claimed in claim 7, characterized in that

partly cross-linked melamine-formaldehyde particles or biological particles such as cells are used as the soluble particles.

9. Method as claimed in one of the previous claims, characterized in that

the components required to form the shell comprise a divalent or trivalent low-molecular cation and a negatively charged polyelectrolyte.

10. Method as claimed in one of the previous claims, characterized in that

the components required to form the shell comprise a divalent or trivalent low-molecular anion and a positively charged polyelectrolyte.

11. Method as claimed in one of the previous claims, characterized in that

the components required to form the shell comprise at least one macromolecule.

12. Method as claimed in claim 11, characterized in that

a biopolymer is used.

13. Method as claimed in claim 11, characterized in that

a mixture of macromolecular and low-molecular biological cell substances is used.

14. Method as claimed in claim 11, characterized in that

a mixture of macromolecular and low-molecular abiogenic substances is used.

15. Method as claimed in claim 11, characterized in that

a mixture of macromolecular and low-molecular biogenic and abiogenic substances is used.

16. Method as claimed in one of the claims 1 to 15, characterized in that

the precipitation according to step (b) comprises adding a component of the shell to the liquid phase.

17. Method as claimed in one of the claims 1 to 15, characterized in that

the precipitation according to step (b) comprises a change in the liquid phase which results in the precipitation of the components of the shell.

18. Method as claimed in claim 17, characterized in that

the change in the liquid phase comprises a change of the pH value or/and a change in the composition of the liquid phase.

19. Method as claimed in one of the claims 1 to 15, characterized in that

the system conditions are changed by bringing together the liquid salt-containing shell phase and the templates in such a manner that the shells are formed spontaneously without further external stimulation with the exception of permanent mixing and remain intact after optional dissolution of the templates.

20. Method as claimed in one of the previous claims additionally comprising at least one additional coating step before or/and after the precipitation step.

21. Method as claimed in claim 20, characterized in that

the additional coating step comprises the application of a lipid layer or/and the application of a polyelectrolyte in layers.

22. Method as claimed in one of the previous claims additionally comprising the disintegration of soluble template particles.

23. Method as claimed in one of the previous claims additionally comprising an at least partial disintegration of the shell.

24. Method as claimed in one of the previous claims, characterized in that

a shell is formed around the template particles which has a thickness of 1 to 50 nm.

25. Method as claimed in one of the previous claims, characterized in that

a shell is formed around the template particles which has a thickness of 5 to 30 nm.