US 8269058 B2 - Absorbable Tissue Dressing Assemblies, Systems, And Methods Formed From Hydrophilic Polymer Sponge Structures Such As Chitosan - The Lens

Absorbable Tissue Dressing Assemblies, Systems, And Methods Formed From Hydrophilic Polymer Sponge Structures Such As Chitosan

Published: Sep 18, 2012
Earliest Priority: Dec 23 2003
Family: 2
Cited Works: 29
Cited by: 13
Cites: 101
Additional Info: Cited Works Full text Published

Abstract

Absorbable tissue dressing assemblies are formed from hydrophilic polymer sponge structures, such as chitosan.

Claims

An absorbable tissue dressing assembly comprising
a tissue dressing matrix including an absorbable hydrophilic polymer material;

a flexible absorbable polymer film or mesh backing layer including at least one of absorbable aliphatic polyesters, aliphatic polyurethanes, hyaluronic acid, a hyaluronate, and a poly-hydroxyl butyrate material; and

wherein the backing layer includes at least one of a woven nano-fiber material and a woven micro-fiber material.
An assembly according to claim 1
wherein the absorbable hydrophilic polymer material comprises a chitosan material.
An assembly according to claim 2
wherein the backing layer is bonded by direct adhesion with a top layer of the absorbable hydrophilic polymer material.
An assembly according to claim 1
wherein the tissue dressing matrix includes spherulitic nucleated structures within a lamella structure.
A method of manufacturing an absorbable tissue dressing assembly as defined in claim 4 comprising the following steps:
subjecting a solution of a chitosan hydrophilic polymer to phase separation by a controlled freezing process that includes a delay interval, followed by a controlled freeze-drying or lyophilization water removal step that occurs at a temperature below the collapse temperature to create the tissue dressing matrix; and

subjecting the tissue dressing matrix, after freeze-drying or lyophilization to a densification process.
An assembly according to claim 1
wherein the backing layer presents an increased surface area that can accelerate biodegradation.
An assembly according to claim 1
wherein the tissue dressing matrix is sized and configured to define a perimeter edge, and the backing layer is sized and configured to extend beyond the perimeter edge to present a skirt of material to receive suture material or staples.
An assembly according to claim 1
wherein the tissue dressing matrix is sized and configured to define an elongated strip having opposite ends, so that the elongated strip can be wrapped around a site, and wherein the backing layer is placed at one opposite end of the elongated strip.
An assembly according to claim 8
wherein the site is a blood vessel and the elongated strip can be wrapped around the blood vessel without collapsing the vessel on itself.
A method comprising
providing an absorbable tissue dressing assembly as defined in claim 1; and

performing a laparoscopic procedure using the absorbable tissue dressing assembly.
A method according to claim 10
wherein the laparoscopic procedure includes at least one of an abdominal aortic aneurysmectomy; spleen, liver, kidney, or gallbladder surgeries; open heart and bypass procedures; hysterectomies; total joint arthoplasties, burns and face lifts; radical neck dissections; trauma such as gun shot, knife wounds, wound debridement; spinal fusions and laminectomies; bowel and colon resections; radial prostatectomies; vascular anastomoses; and laparoscopic nephrectomies.