Intellectual Property

Islet Sheet Medical recognizes that the bioartificial pancreas industry is competitive, and that a successful product will be imitated. We intend to protect a monopoly on our Islet Sheet product with a combination of patents and trade secrets.


Our first patent application, filed October 1995, has produced two patents. (Click for list of issued patents.) In September 2000 we filed an application on the most recently invented methods for making sheets.

The broadest claim granted covers all thin sheet devices with high cell density:

"A viable, physiologically active and biocompatible cellular or tissue implant having (a) a total volume greater than 10 cubic millimeters, (b) a tissue or cell content of at least 10% by volume, and (c) dimensions permitting sufficient oxygen diffusion to sustain cell or tissue viability when the implant is implanted into a vascularized site in a patient."

A sheet 10% tissue by volume can be at most 300 micrometers (0.3 mm) thick if it permits "sufficient oxygen diffusion to sustain cell or tissue viability." A 10-mm3 sheet of that thickness has an area equal to the area of a circle 7 mm (1/4 inch) in diameter. In other words, this claim covers all useful sheets larger than a sheet this size:

This remarkably broad coverage is a consequence of the historical fact that essentially all encapsulation research has been on microencapsulation. The patent examiner agreed that our technology for the first time made thin sheets of high tissue density possible.

Within the realm of planar diffusion chambers (sheets are simply thin planar chambers) only a small number of devices have been developed, most in academic laboratories. The Islet Sheet is much superior to any other primarily by virtue of much greater total tissue volume (click here for more).

Islet Sheet Medical U.S. Patents

U.S. Patent 5,855,613
U.S. Patent 6,165,225