Biomatrix, Inc. was acquired by Genzyme in December 2000. Two of Genzyme Corporation's public subsidiaries -- Genzyme Tissue Repair and Genzyme Surgical Products -- mergedwith Biomatrix to form a new Genzyme tracking stock, Genzyme Biosurgery. Previously, Biomatrix, Inc, had been engaged in the development, manufacture, marketing, and sale of a series of proprietary viscoelastic products, called hylans that are used in therapeutic medical applications and skin care. The materials are used to treat arthritis pain in one formulation and, in another, to fill in facial wrinkles. Genzyme Surgical Repair was selling the Seprafilm product used to prevent post-surgical adhesion between organs. Genzyme Tissue Repair sells skin graft products.