Brown University

Lars Wahlberg

Patrick Aebischer

Edward J Doherty

Patrick A Tresco

John F Mills

Elongated seamless capsules containing biological material are prepared by a method in which a coagulant, which includes a cell suspension or other biological material, and a polymeric casting solution are extruded through a common extrusion port having at least two concentric bores, such that the coagulant is extruded through an inner bore and the polymeric casting solution is extruded through an outer bore. Extrusion of the coagulant is initiated subsequent to initiating delivery of the casting solution to form a capsule having a curved and smooth leading edge shape. Delivery of the coagulant is then shut off, and extrusion of the casting solution is terminated either immediately or after some predetermined time. This procedure can be modified to form in the capsule a coaxial rod that is connected to one end but not the other end of the capsule. This is accomplished by drawing casting solution into the inner bore after initiating extrusion of the casting solution through the outer bore, and then initiating delivery of the coagulant through the inner bore so as to coagulate the casting solution therein and form a rod, and ejecting the rod from the inner bore by pressure of the coagulant. Delivery of the coagulant and casting solution are then terminated as described above.

Preparation of elongated seamless capsules containing a coaxial rod and

Elongated seamless capsules containing biological material are prepared by a method in which a coagulant, which includes a cell suspension or other biologically active factor, and a polymeric casting solution are extruded through a common extrusion port having at least two concentric bores, such that the coagulant is extruded through the inner bore and the polymeric casting solution is extruded through the outer bore. The method involves initiating extrusion of the coagulant subsequent to initiating delivery of the casting solution through the respective bores to form a capsule having a curved and smooth leading edge shape. Delivery of the coagulant is then shut off, and extrusion of the casting solution is terminated either immediately or after some predetermined time.

Method of preparing elongated seamless capsules containing biological

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.

Method of encapsulating cells in a tubular extrudate

Living cells such as animal cells which produce biologically active factors are encapsulated within a semipermeable, polymeric membrane such as polyacrylate by co-extruding an aqueous cell suspension and a polymeric solution through a common port having at least one concentric bores to form a tubular extrudate having a polymeric membrane which encapsulates the cell suspension. The cell suspension is extruded through an inner bore and the polymeric solution is extruded through an outer bore while a pressure differential is maintained between the cell suspension and the polymeric solution to impede solvent diffusion from the polymeric solution into the cell suspension. The polymeric solution coagulates to form an outer coating or membrane as the polymeric solution and the cell suspension are extruded through the extrusion port. As the outer membrane is formed, the ends of the tubular extrudate are 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. In another embodiment, a cell capsule connected to a tethering filament is formed. The polymeric membrane may contain additives such as a surfactant, an anti-inflammatory agent or an anti-oxidant and can be coated with a protective barrier. The cell suspension may contain nutrients and an anchorage substrate.

Growing community of inventors

Gavle, Sweden

Lars Wahlberg