Emory University

Bristol-myers Squibb Compnay

Collin J Weber

Susan A Safley

Peter S Linsley

Judith A Kapp

Kereen S Gordon

Mary K Hagler

Nicholas E Simpson

Jennifer Ayres-Price

This disclosure relates to compositions and methods for encapsulating biomaterials such as cells to prevent immune responses. In certain embodiments, the disclosure relates to capsules comprising a cell or cells gelled in alginate coated with a layer that prevents migration of immune molecules to the cell surface and an outer capsule layer comprising non-immunogenic material optionally containing immunosuppressive agents. In certain embodiments, the cells are capable of generating insulin that emanates from the capsule.

Compositions for encapsulating biomaterials and uses related thereto

This invention provides a method of inhibiting viable cells transplanted into a subject from being destroyed by the subject's immune system which comprises: a) containing the viable cells, or tissue comprising the viable cells, prior to transplantation within a device comprising a semipermeable membrane; and b) treating the subject with a substance which inhibits an immune-system costimulation event in an amount effective to inhibit the subject's immune system from responding to said contained cells or tissue. In one embodiment, the substance which inhibits an immune-system costimulation event is CTLA4. Also provided by this invention is a method of treating diabetes in a subject which comprises: a) containing viable insulin-producing cells, or tissue comprising such cells, within a device comprising a semipermeable membrane; b) transplanting an effective amount of such contained viable insulin-producing cells into the subject; and c) treating the subject with an effective amount of a substance which inhibits an immune-system costimulation event.

Method of inhibiting immune system destruction of transplanted viable cells

A core material such as animal tissue or cells is contained within a semipermeable vessel which may be a microcapsule, hollow fiber or plastic membrane having a semipermeable wall by a method that prevents the core material from incorporation into the wall of the vessel. This is accomplished by suspending the core material in a solution of polysaccharide gum such as an alkali metal alginate in an amount between about 0.2% and about 0.5%, removing and washing the core material to remove all but a thin layer of polysaccharide gum, and gelling the polysaccharide gum with multivalent cations or other means to form a pretreated core material. The pretreated core material is contained within a semipermeable vessel such as by suspending the pretreated core material in a solution of alkali metal alginate, forming the suspension into droplets, gelling the droplets to form temporary shape-retaining capsules and treating the capsules with a polymeric material having groups that react with and crosslink acid groups of the capsules to form a permanent semipermeable membrane around the capsules. A second permanent semipermeable membrane may be formed around the capsules to form double-walled microcapsules by further treating the capsules with the polymeric material. The semipermeable vessel may be impermeable to immune factors. Cells or tissue can be transplanted from a donor to a subject such as by using pancreatic islet tissue or cells as the core material of the double-walled microcapsules and transplanting the microcapsules by intraperitoneal injection into a diabetic subject.

Method of containing core material in microcapsules

Growing community of inventors

Atlanta, GA, United States of America

Collin J Weber