Method of encapsulating cells in a tubular extrudate

• US 5,389,535 A
• Filed: 12/17/1993
• Issued: 02/14/1995
• Est. Priority Date: 11/17/1987
• Status: Expired due to Term

• Current Assignee: Neurotech S.A. (LivaNova Plc)
• Original Assignee: Brown University
• Inventors: Wahlberg, Lars, Aebischer, Patrick
• Primary Examiner(s): Naff, David M.
• Application Number:
  US08/169,169
• Time in Patent Office: 424 Days
• Field of Search: 435/179, 435/180, 435/182, 435/288, 435/240.22, 435/240.23, 264/4, 264/4.7, 425/382 R, 425/382.2
• US Class Current: 435/182
• CPC Class Codes: A61F 2/022 Artificial gland structures using bioreactors hemodialysis A61M1/16; hemofiltration A61M1/34; other extracorporeal blood treatment A61M1/36
• CPC Class Codes: A61K 2035/126 Immunoprotecting barriers, e.g. jackets, diffusion chambers
• CPC Class Codes: A61K 2035/128 capsules, e.g. microcapsules
• CPC Class Codes: A61K 35/12 Materials from mammals; Compositions comprising non-specified tissues or cells; Compositions comprising non-embryonic stem cells; Genetically modified cells vaccines or medicinal preparations containing antigens or antibodies A61K39/00
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/0085 Brain, e.g. brain implants; Spinal cord
• CPC Class Codes: A61K 9/0092 Hollow drug-filled fibres, tubes of the core-shell type, coated fibres, coated rods, microtubules or nanotubes
• CPC Class Codes: A61K 9/4816 Wall or shell material
• CPC Class Codes: A61K 9/4833 Encapsulating processes; Filling of capsules mechanical aspects A61J3/07
• CPC Class Codes: A61M 2210/0687 Skull, cranium
• CPC Class Codes: A61M 2210/0693 Brain, cerebrum
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: B01J 13/02 Making microcapsules or microballoons for medical preparations A61K9/50
• CPC Class Codes: B01J 13/04 by physical processes, e.g. drying, spraying
• CPC Class Codes: C12N 11/04 entrapped within the carrier, e.g. gel or hollow fibres
• CPC Class Codes: C12N 11/087 Acrylic polymers
• CPC Class Codes: C12N 11/098 formed in the presence of the enzymes or microbial cells
• CPC Class Codes: C12N 2533/30 Synthetic polymers thermoreactive polymers, e.g. PNIPAm, C12N2539/10
• CPC Class Codes: C12N 5/0012 Cell encapsulation
• CPC Class Codes: C12N 5/0614 : Adrenal gland
• CPC Class Codes: C12N 5/0619 : Neurons

Abstract

Methods and systems are disclosed for encapsulating viable cells which produce biologically-active factors. The cells are encapsulated within a semipermeable, polymeric membrane by co-extruding an aqueous cell suspension and a polymeric solution through a common port to form a tubular extrudate having a polymeric outer coating which encapsulates the cell suspension. For example, the cell suspension and the polymeric solution can be extruded through a common extrusion port having at least two concentric bores, such that the cell suspension is extruded through the inner bore and the polymeric solution is extruded through the outer bore. The polymeric solution coagulates to form an outer coating. As the outer coating is formed, the ends of the tubular extrudate can be sealed to form a cell capsule. In one embodiment, the tubular extrudate is sealed at intervals to define separate cell compartments connected by polymeric links.

Claims

1. A method of encapsulating viable cells comprising co-extruding an aqueous cell suspension and a polymeric solution through a common port having at least two concentric bores to form a tubular extrudate having a polymeric outer coating which encapsulates said cell suspension, wherein said cell suspension is extruded through an inner bore and said polymeric solution is extruded through an outer bore and a pressure differential is maintained between said cell suspension and said polymeric solution during co-extrusion to impede solvent diffusion from said polymeric solution into said cell suspension, and said polymeric solution and said cell suspension are chosen so that coagulation of said polymeric solution occurs as the polymeric solution and cell suspension are extruded through the extrusion port.

2. The method of claim 1 wherein the extrusion port is in contact with air.

3. The method of claim 1 wherein the extrusion port is in contact with quenchent.

4. The method of claim 1 wherein said cell suspension comprises cells that secrete a biologically-active factor.

5. The method of claim 1 wherein said cell suspension comprises cells that secrete a neurotransmitter.

6. The method of claim 1 wherein said cell suspension further comprises a nutrient medium.

7. The method of claim 1 wherein said cell suspension further comprises an anchorage substrate material.

8. The method of claim 1 wherein said polymeric solution further comprises a water-miscible solvent component.

9. The method of claim 1 wherein said polymeric solution further comprises a surfactant.

10. The method of claim 1 wherein said polymeric solution further comprises an anti-inflammatory agent.

11. The method of claim 1 wherein said polymeric solution further comprises an antioxidant.

12. The method of claim 1 wherein the method further comprises controlling the viscosity of said polymeric solution, such that upon coagulation said outer polymeric coating will form a semipermeable membrane about said cell suspension.

13. A tubular extrudate comprising a semipermeable, polymeric membrane encapsulating a viable cell culture prepared by the method of claim 1.

14. The tubular extrudate of claim 13 wherein the membrane is permeable to molecules having a molecular weight of about 150,000 or less.

15. The tubular extrudate of claim 13 wherein the maximum outer diameter of the tubular extrudate ranges from abut 0.1 to about 1.0 millimeters.

16. The tubular extrudate of claim 13 wherein the membrane has a wall thickness ranging from abut 10 to about 100 microns.

17. The tubular extrudate of claim 13 wherein the polymeric membrane further comprises a polyacrylate material.

18. The tubular extrudate of claim 13 wherein the polymeric membrane further comprises a surfactant.

19. The tubular extrudate of claim 20 wherein the polymeric membrane further comprises an anti-inflammatory agent.

20. The tubular extrudate of claim 13 wherein the polymeric membrane further comprises an anti-oxidant.