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Method of encapsulating cells in a tubular extrudate
| Details |
Inventors: Aebischer, Patrick; Wahlberg, Lars;
Assignee: Brown University Research Foundation (Providence, RI)
Primary Examiner: Naff; David M.
Assistant Examiner:
Attorney, Agent or Firm: Fish & Neave
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. |
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DETAILED DESCRIPTION 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.
In one aspect of the invention, methods are disclosed in which the cell suspension and the polymeric solution are 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 illustrated embodiment, the tubular extrudate is sealed at intervals to define separate cell compartments connected by polymeric links.
Strings of cell capsules formed in this manner have a number of advantages over conventional, cell-encapsulating products.
The multi-compartment form ensures that breaks in the tubular membrane can be contained to individual cell capsules.
Moreover, the design is particularly advantageous in preparing implantable cell cultures for delivery of biologically-active factors to a subject for therapeutic purposes.
The string of cell capsules can be coiled, twisted or otherwise deposited in various shapes to provide a dense and compact structure for implantation.
Because the cell capsules are connected to each other, they can also be readily retrieved, if necessary, following implantation.
The string-like nature of these products is particularly preferable over individual spherical microcapsules which typically are retrieved by aspiration (often resulting in a high percentage of unretrievable capsules and, consequently, inflamation in the subject).
Multi-compartment cell capsule strings can be formed from the tubular extrudate of the present invention by sealing the extrudate at intervals using various techniques
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Molecular Biology 
