A wound dressing for burn patients comprises a two layer compress made of ly-.epsilon.-caprolactone material. One layer is configured for optimum wound contact while the other is configured for moisture control.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to the fields of medicine and organic chemical 
engineering. More particularly, the invention relates to the manufacture 
of healing promoting wound dressings. By way of further characterization, 
the invention pertains to a moisture control burn wound dressing used in 
instances where skin growth is necessary. More particularly, but without 
limitation thereto, the invention will be disclosed as it relates to a 
laminated article to serve as artificial skin during the treatment and 
healing of skin damaging burns. 
2. Description of the Prior Art 
A burn covering has two functions. First, it should prevent excessive loss 
of body fluids and proteins due to uncontrolled evaporative water loss 
from the burned area. This water loss can be of the order of ten times 
greater than the normal rate of evaporation through the skin. For a victim 
with severe burns over a large portion of his body, the total loss is 
substantial and can lead to shock and death during the immediate (0-5 
days) postburn period. Second, it should promote the formation of a viable 
interface between the wound and covering. 
A viable interface is defined as a living, growing fibrin network and is 
desirable for two reasons. One, neutrophils and macrophages readily enter 
the network and kill bacteria. This action helps not only to prevent burn 
wound sepsis--a major cause of limb loss or death--but also to remove 
exudate which is typically found in a wound. Two, once the fibrin network 
is developed, the damaged area will more readily accept an autograft--the 
ultimate goal of burn therapy. A viable interface is indicated by 
adherence of the covering to the wound. The covering must be flexible in 
order to conform to the contours of the body so adherence is complete. 
Presently, human-donor and porcine skin are the most successful and widely 
used burn coverings. Both promote the formation of a viable interface and 
control the evaporative water loss from the burn area. Coverings composed 
of those skins must be removed or are rejected by the body every three to 
five days. New skins are then applied. Collagen film has also been tested 
as an artificial skin. 
Laminates of synthetic, non-biodegradable materials are also available for 
burn treatment. Silastic film laminated with nylon velour has been applied 
to animals. For example, fabrics impregnated with latex and commercially 
available synthetic plastic compositions have been used. Metallic foils 
have also been used as backing material for these types of wound 
dressings. Although satisfactory for limited purposes and applications, 
the known burn dressings lack one or more optimum parameters for burn 
treatment applications where skin growth is an important factor. 
It is also known in the art to spray the burned portion of the patient with 
a solution of poly-.epsilon.-caprolactone in a solvent which evaporates to 
leave a covering layer. Such a treatment, although practical for emergency 
treatment of flash burn victims, lacks the advantages of compress type 
treatment in promoting the growth of new skin. 
SUMMARY OF THE INVENTION 
The invention relates to a dressing useful in treatment of burns using a 
plasticized poly-.epsilon.-caprolactone vapor control and support layer 
bonded to a porous layer of the same material formed from a foam, a 
flocked fabric, or a velvet. The porous layer configures to promote new 
skin growth. 
Accordingly, it is an object of the invention to provide a lamination 
useful in treatment of wounds. 
Another object of the invention is the provision of a laminate which is 
biodegradable. 
A further object of the invention is the provision of a wound dressing 
which promotes the growth of skin over a wound. 
These and other objects of the invention will become clear in considering 
the following description, claims, and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the wound dressing of the invention is indicated 
generally at 11. A layer of plasticized poly-.epsilon.-caprolactone 12 
provides a body conforming support for the laminate and is configured as a 
sheet to control moisture transmission therethrough. Layer 12 is from 
0.001 to 0.01 inches in thickness and the poly-.epsilon.-caprolactone has 
a molecular weight between 2,000 and 300,000. The material thus formed has 
the advantage of permitting sufficient moisture flow to prevent the 
collection of excess amounts of body fluid thereunder and yet prevent 
dehydration of the wound area. A layer 14 is bonded to layer 12 at a 
junction 13. This bonding is accomplished by taking the film 12 and 
moistening it with a suitable solvent and pressing the layer 14 
thereagainst. The softening provided by the solvent interacts with both 
layers 14 and 12 to permit a welding or joining along the contacting 
surface. 
The layer 14 which contacts the wound area where it is desirable to promote 
the growth of skin is, in the illustrated arrangement, made of a plush or 
velvet material having a woven backing 15 and a contained fibrous nap 16. 
Both the woven back 15 and the plush 16 are made of the same 
poly-.epsilon.-caprolactone as is backing sheet 12. This dressing has 
proven to be more comfortable for patients than the silastic-nylon velours 
of the prior art and have not exhibited failure of the bonding lamination 
as was common with other known arrangements. 
Both the plush and backing sheets may be plasticized by using triacetin or 
triethylcitrate, or mixtures thereof. These plasticizers prevent hardening 
of the two layers and permit easy applications and body conforming contact 
of the laminate. These plasticizing materials are the triacetic acid ester 
of glycerol and the triester of ethyl alcohol and citric acid, 
respectively. The hydrolysis products of these esters are ingredients 
which are found in living organisms and are considered to be 
bio-compatible. Additionally, these particular plasticizers make the 
laminate more conformable without lowering the watering permability of the 
structure beyond the desired range. 
The cut plush nap 16 of the arrangement shown in FIG. 1 is particularly 
easy to remove from the wound without tearing newly formed tissue in 
comparison to the velours and plushes used heretofor. 
For certain burn applications and various parts of the body where the 
growth of skin is different, other configurations of the invention may be 
substituted for the embodiment illustrated in FIG. 1. 
Referring to FIG. 2, an alternate form of the invention is illustrated 
wherein a foam layer 18 is substituted for the velvet plush layer 14 and 
bonded to layer 12. The same bonding technique used for the species of 
FIG. 1 may be employed in this arrangement. 
Likewise, in some instances, a knit or woven fabric made of 
poly-.epsilon.-caprolactone may be employed. In this instance a layer of 
such fabric indicated at 21 is bonded to the backing 12 to produce the 
illustrated laminate shown at 19. 
In production a polished surface such as stainless steel is used to receive 
a layer of poly-.epsilon.-caprolactone in solvent solution thereon and it 
is allowed to form a solid film of the desired thickness by allowing the 
solvent to evaporate. A suitable solvent such as acetone is spread over 
this layer and the layer 14 or the sponge 18 or the fabric 21 is then 
impressed on the backing film 12 and held in contact therewith to promote 
the bonding therebetween. This bond has proven to be adequate in test 
applications and no instances of layer separation has been noted. 
The foregoing description taken together with the appended claims 
constitutes a disclosure such as to enable a person skilled in the 
biochemical arts and having the benefits of the teachings contained 
therein to make and use the invention. Further, the structure herein 
described meets the aforegoing objects of the invention, and generally 
constitutes a meritorious advance in the art.