Inner-supported, biocompatible cell capsules

Abstract

A biocompatible capsule for containing cells for implantation is prepared containing an inner support that provides tensile strength to the capsule. The capsule may be a tubular semipermeable membrane such as a hollow fiber membrane having both ends sealed. A rod shaped inner support extends through the lumen and ends of the rod are attached to sealed ends of the fiber. Prior to sealing one fiber end, cells are introduced into the lumen. Cells within the capsule may be suspended in a liquid medium or immobilized in a hydrogel or extracellular matrix material, and biologically active molecules can be delivered from the capsule to surroundings or from the surroundings into the capsule. The inner support may have external features such as flutes or a roughened or irregularly-shaped surface, and may be coated with cell-adhesive substance or a cell-viability-enhancing substance. The inner support may be a hollow tube having two channels, one communicating with a filling port that permits injecting cells through the support into the capsule and the other communicating with another port that allows gas to escape through the support as cells are introduced. Anti-inflammatory agents can be incorporated into the capsule membrane to reduce immune response, and angiogenic factors and cell growth factors may be used to stimulate cell culture. Post-coating of capsule can be used to provide a protective barrier against immunogens. A tether for capsule retrieval can be formed integral with the inner support.