On January 4, 2013, MIT sued Shire Pharmaceuticals in the District of Massachusetts for infringing US Patent Numbers 5,759,830; 5,770,417; and 5,770,193. The patents all issued in 1998, and are generally directed towards “three-dimensional fibrous scaffolds containing attached cells for producing vascularized tissue in vivo.” For example, claim 1 of the ‘830 patent recites:
1. A cell-scaffold composition prepared in vitro for growing cells to produce functional vascularized organ tissue in vivo, comprising:
a fibrous three-dimensional scaffold composed of fibers of a biocompatible, biodegradable, synthetic polymer; and
cells derived from a vascularized tissue attached in vitro to the surface of the fibers of the scaffold uniformly throughout the scaffold;
wherein the fibers of the scaffold provide sufficient surface area to permit attachment in vitro of an amount of the cells effective to produce the functional vascularized organ tissue in vivo;
wherein the fibers of the scaffold are spaced apart such that the maximum distance over which diffusion of nutrients and gases must occur through a mass of cells attached to the fibers is between 100 and 300 microns; and
wherein the diffusion provides free exchange of nutrients, gases and waste to and from the cells uniformly attached to the fibers of the scaffold and proliferating throughout the scaffold in an amount effective to maintain cell viability throughout the scaffold in the absence of vascularization.
The allegedly infringing product is Dermagraft, a human fibroblast-derived dermal substitute approved by FDA in 2001 for use in treatment of full thickness diabetic foot ulcers. According to the complaint, Dermagraft is manufactured from human fibroblast cells derived from newborn foreskin tissue, which are seeded onto a bioabsorbable polyglactin three-dimensional mesh scaffold. MIT alleges that the fibroblasts proliferate to fill the interstices of this scaffold and secrete human dermal collagen, matrixproteins, growth factors, and cytokines to create a three-dimensional human dermal substitute containing metabolically active, living cells.