Patent ID: 8697044
Filing Date: 2014-04-15
Classification: A61L,A61M,A61P

Abstract:
1. A method for preparing a tri-layer composition, the method comprising the steps of: a) forming a first composition by contacting hyaluronic acid (HA) solution comprising HA and having a pH of about 9 to about 12 with a cross-linker to allow cross-linking of the HA by the cross-linker; b) homogenizing the first composition; c) forming a second composition by contacting the first composition with collagen solution comprising collagen and having a pH of about 2 to about 3 to allow cross-linking of the collagen by the cross-linker to the first composition, wherein the second composition has a cross-linked HA core with a layer of collagen surrounding and cross-linked to the cross-linked HA core; and d) forming a tri-layer composition by contacting the second composition with a HA in a solution comprising HA and having a pH of about 6 to about 8 to allow cross-linking of the HA by the cross-linker to the second composition, wherein the tri-layer composition has a cross-linked HA core, a middle layer of collagen layer surrounding and cross-linked to the cross-linked HA core, and an outer layer of HA surrounding and cross-linked to the middle layer of collagen.