Method of encapsulating biological substances in microspheres

• US 5,656,469 A
• Filed: 08/14/1995
• Issued: 08/12/1997
• Est. Priority Date: 08/27/1993
• Status: Expired due to Term

• Current Assignee: Neurotech S.A. (LivaNova Plc)
• Original Assignee: Brown University
• Inventors: Tresco, Patrick A., Mills, John F.
• Primary Examiner(s): Lovering, Richard D.
• Application Number:
  US08/514,780
• Time in Patent Office: 729 Days
• Field of Search: 264/4, 264/4.3, 264/4.6, 264/4.7, 425/5, 435/178, 435/182, 935/54, 424/93.1, 424/424, 424/425, 424/493, 424/494, 424/497, 514/866, 514/885, 514/962, 427/508
• US Class Current: 435/182
• CPC Class Codes: A61K 9/5089 Processes
• CPC Class Codes: B01J 13/04 by physical processes, e.g. drying, spraying
• CPC Class Codes: B01J 13/14 Polymerisation; cross-linking
• CPC Class Codes: C12N 11/04 entrapped within the carrier, e.g. gel or hollow fibres
• CPC Class Codes: C12N 2533/30 Synthetic polymers
• CPC Class Codes: C12N 5/0012 Cell encapsulation

Abstract

A method for encapsulating biological substances in biocompatible microcapsules is disclosed, the method comprising:

(a) maintaining a coating-forming liquid film sheet transverse to a vertical plane, said sheet comprising an organic polymerizable monomer liquid,

(b) causing droplets comprising biological substances in an aqueous medium to fall downwardly through said liquid film sheet to form microcapsules comprising cores of said droplets coated by said film,

(c) permitting said microcapsules to fall downwardly from said liquid film sheet, and

(d) polymerizing said liquid film coatings during descent of said microcapsules below said sheet to form a permeable polymer coating of a sufficient structural integrity so that said microcapsules are self-supporting.

Claims

1. A method for encapsulating biological substances in biocompatible microcapsules comprising:

(a) maintaining a coating-forming liquid film sheet transverse to a vertical plane, said sheet comprising an organic polymerizable monomer liquid,

(b) causing droplets comprising biological substances in an aqueous medium to fall downwardly through said liquid film sheet to form microcapsules comprising cores of said droplets coated by said film,

(c) permitting said microcapsules to fall downwardly from said liquid fill sheet, and

(d) polymerizing said liquid film coatings during descent of said microcapsules below said sheet to form a permeable polymer coating of a sufficient structural integrity so that said microcapsules are self-supporting.

2. The method of claim 1 in which said biological substances comprise cells capable of secreting a selected biologically active product or of providing a selected biological function to an individual.

3. The method of claim 1 in which said monomer comprises a modified polyetheylene glycol.

4. The method of claim 1 in which polymerization of step (d) is performed by photopolymerization.