Wound dressings comprising a plurality of liquid-expandable articles
Inventors
Steinbaugh, John • Bullard, Mary • Barofsky, Andrew
Assignees
Publication Number
US-9623223-B2
Publication Date
2017-04-18
Expiration Date
2032-02-16
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Abstract
Provided herein are self-expanding wound dressings that include a first outer layer, a second outer layer, and a liquid-expandable layer disposed between the first outer layer and the second outer layer, wherein the liquid-expandable layer includes a plurality of liquid-expandable articles retained by a substrate, wherein the plurality of liquid-expandable articles expand to form expanded articles upon contact with a liquid. Also provided is a method of treating an individual having a bleeding wound, the method including applying a self-expanding wound dressing to the wound. Also provided are methods of manufacturing a wound dressing, the methods including forming an absorbent material into a plurality of liquid-expandable articles, coupling the plurality of liquid-expandable articles to a substrate to form a liquid-expandable layer, and positioning the liquid-expandable layer between a first outer layer and a second outer layer to form the wound dressing.
Core Innovation
Embodiments herein provide self-expanding wound dressings that include a first outer layer, a second outer layer, and a liquid-expandable layer positioned between these outer layers. The liquid-expandable layer comprises a plurality of liquid-expandable articles retained by a substrate such as a fibrous mesh or backing layer. Upon contact with a liquid, such as bodily fluids including blood or serum, these liquid-expandable articles rapidly expand to form expanded articles, increasing in volume by at least 2× and up to 10× or more. This expansion results in a soft, pliable layer capable of conforming to irregular wound cavities, providing mechanical pressure to control hemorrhage.
The self-expanding wound dressings may be formed as elongated sheets or shapes suitable for wounds of varying size, and can be wrapped, folded, or preformed for easy application. The liquid-expandable articles may be connected or retained by substrates including backing layers, webs, or directly attached to one or both outer layers to limit movement and maintain flexibility. Various material compositions are disclosed, including regenerated cellulose sponges, polyvinyl alcohol polymers, and compressed absorbent materials. The dressings may also include therapeutic agents such as hemostatic agents, antibiotics, or growth factors to aid healing.
The problem addressed by this invention is the urgent need for effective hemorrhage control in large or irregular wounds, such as those caused by blasts or penetrating trauma, which are difficult to pack with standard gauzes or dressings and may rapidly consume available supplies. Controlling uncontrolled external hemorrhage is critical on the battlefield and in civilian trauma, as well as in postpartum hemorrhage where swift intervention is crucial. Current methods struggle to consistently apply sufficient pressure, especially in austere environments, motivating the development of a self-expanding dressing that rapidly fills wounds, conforms to their shape, and provides hemostasis without excessive external pressure.
Claims Coverage
The claims include one independent claim describing a wound dressing with multiple inventive features relating to the structure and functionality of a self-expanding wound dressing.
Wound dressing structure with liquid-expandable articles attached to a backing layer in a predetermined pattern
The dressing includes a first and second outer layer with a liquid-expandable layer positioned between, wherein the liquid-expandable layer comprises multiple liquid-expandable articles each independently attached to a sheet-form backing layer. The articles are arranged in a predetermined pattern on one major surface of the backing layer with attachment points substantially coplanar. Upon contact with liquid, the articles expand away from the backing layer, principally along the longitudinal dimension.
Porous construction of at least one outer layer
At least one of the first or second outer layers comprises a porous material, providing flexibility and fluid permeability.
Outer layers joined to form pockets containing the liquid-expandable layer
The first and second outer layers are joined to create one or more pockets that receive and contain the liquid-expandable layer.
Use of compressed sponge material in liquid-expandable articles
The plurality of liquid-expandable articles comprise compressed sponge material, specifically regenerated cellulose sponge in some embodiments.
Liquid-expandable articles shaped substantially cylindrically
The liquid-expandable articles have a substantially cylindrical shape to optimize expansion and conformity within wound cavities.
Spacing of liquid-expandable articles for flexibility
The articles in the predetermined pattern are spaced sufficiently apart to maintain flexibility of the wound dressing.
Defined regions without liquid-expandable articles
The predetermined pattern defines one or more regions devoid of liquid-expandable articles, enabling fold or cut lines to enhance flexibility or usability.
Rapid expansion capacity
The liquid-expandable articles expand to 80% or more of their maximum volume within 30 seconds of immersion in water or saline.
Volume expansion ratio
Expanded articles have a volume at least four times greater than their pre-expanded volume.
Laminated sheet formation
The first outer layer, second outer layer, and liquid-expandable layer are laminated to form an elongated sheet suitable for packaging and application.
Controlled pre-expansion volume of articles
Each liquid-expandable article has a pre-expansion volume ranging from 0.7 mm³ to 7000 mm³.
Incorporation of therapeutic agents
The wound dressing further includes one or more therapeutic agents coupled to any of the outer layers or the liquid-expandable layer.
Attachment of secondary plurality of liquid-expandable articles to opposing backing surface
A second plurality of liquid-expandable articles may be attached to the second major surface of the backing layer, expanding in opposing directions.
These inventive features collectively describe a flexible, porous self-expanding wound dressing with liquid-expandable articles attached in a controlled pattern to a backing layer, capable of rapid volume expansion upon liquid contact, designed to conform to wound cavities and include therapeutic agents for enhanced wound treatment.
Stated Advantages
Allows for rapid expansion to quickly fill wound cavities and provide rapid hemostatic effect.
Improves positioning within the wound and tissue apposition due to the conformability of the expanded dressing.
Provides gentle outward pressure multi-directionally within the wound cavity, avoiding excessive pressure that can compromise tissue perfusion.
Maintains positioning in the wound despite arterial bleeding and patient movement, ensuring constant and effective compression.
The soft, pliable nature and spring-like characteristics of the expanded dressing contribute to effective hemorrhage control without external compression.
Documented Applications
Treatment of uncontrolled external hemorrhage including traumatic wounds caused by IEDs, blasts, and small caliber missiles creating large and penetrating wounds.
Hemorrhage control in battlefield and civilian trauma situations where rapid hemostasis is critical.
Treatment of postpartum hemorrhage in low-income countries where non-operative measures are necessary.
Application in large soft tissue wounds in locations such as calf, thigh, buttocks, or shoulder associated with arterial or venous punctures or lacerations.
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