United States Patent:  5,955,095

Assignee:  Brown University Research Foundation (Providence, RI)

Filed:  August 14, 1995

Microporous macrocapsules are disclosed which are useful as implantation devices for cell therapy. The macrocapsule comprises living cells that secrete biological substance that are therapeutically useful and that are released from the macrocapsule to the site of implantation. The capsules can have selected permeability characteristics based upon their particular usage and desired viral retentivity characteristics.

Summary of the Invention

An implantable permselective macrocapsule is described for use in cell therapy. The macrocapsule comprises a core comprising living cells that are capable of secreting a selected biologically active product or of providing a selected biological function and an external jacket which surrounds the core. The jacket comprises a biocompatible material that is substantially free of the encapsulated cells and has a nominal molecular weight cutoff sufficient to retain the cells within said macrocapsule. In some embodiments the nominal molecular weight cutoff of the macrocapsule is below the molecular weight of detrimental viruses which may be shed from said living cells.

A method for determining the viral retentivity of an external jacket of an implantable permselective macrocapsule is also described wherein the external jacket comprises a hollow fiber and virus is loaded into the hollow fiber. The ends of the hollow fiber are then sealed and the fiber is placed into a bath solution. After a time interval, the bath solution is innoculated onto a lawn of bacteria susceptible to the virus and viral retentivity is calculated based on the number of plaques formed.

Claim 1 of 19 Claims

1. An implantable permselective device for use in cell therapy comprising:

(a) a core comprising living cells that are capable of secreting a selected biologically active product or of providing a selected biological function; and

(b) an external jacket surrounding said core, said jacket comprising a biocompatible material substantially free of said cells, said jacket having a nominal molecular weight cutoff greater than about 440 kD; said core and said jacket forming a macrocapsule, which device is substantially non-immunoisolatory.

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