Synthetic wound covering
First Claim
1. A synthetic wound covering comprising a hydrophilic membrane which is a graft polymer formed from a polyester polyurethane substrate having a modulus of elasticity below 1500 PSI and a hydrophilic acrylamide monomer wherein the monomer is present at at least 50% by weight and is substantially uniformly dispersed through the substrate, whereby the graft polymer has a water permeability in the range from 1000 to 8000 g/m2 /24 hr and a modulus of elasticity below about 600 PSI when wet.
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Abstract
A synthetic hydrophilic membrane is prepared by graft polymerization of hydrophilic monomers with a polyurethane substrate. The resulting material has a water permeability in the range from about 1,000 to 8,000 g/m2 /24hr. The material is particularly useful as a wound covering material where such water permeability corresponds to the elevated water loss from open wounds and allows the wound to heal without desiccation or water accumulation under the covering.
39 Citations
21 Claims
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1. A synthetic wound covering comprising a hydrophilic membrane which is a graft polymer formed from a polyester polyurethane substrate having a modulus of elasticity below 1500 PSI and a hydrophilic acrylamide monomer wherein the monomer is present at at least 50% by weight and is substantially uniformly dispersed through the substrate, whereby the graft polymer has a water permeability in the range from 1000 to 8000 g/m2 /24 hr and a modulus of elasticity below about 600 PSI when wet.
- View Dependent Claims (2, 3, 4, 5)
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4. A synthetic wound covering according to claim 3, wherein average n is from 2.5 to 8.
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5. A synthetic wound covering according to claim 3, wherein R1 and R2 are each a tetramethylene group --(CH2)4 --.
- 6. A wound covering material comprising a graft polymer formed from a polyester polyurethane substrate having a modulus of elasticity below 1500 PSI and a hydrophilic acrylamide monomer present at at least 50% by weight, said material having a water permeability in the range from 1,000 to 8,000 g/m2 /24 hr and a modulus of elasticity below 600 PSI when wet, wherein said covering is sterilized and enclosed in a sealed package.
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8. A method for treating a wound, said method employing a wound covering material comprising a graft polymer formed from a polyester polyurethane substrate having a modulus of elasticity below about 1500 PSI and a hydrophilic acrylamide monomer present at at least 50% by weight, said material having a water permeability in the range from 1000 to 8,000 g/m2 /24 hr and modulus of elasticity below 600 PSI when wet, said method comprising:
applying the covering material to the wound such that the covering conforms to the surface of the wound. - View Dependent Claims (9, 10, 11)
- 12. A process for preparing an elastic hydrophilic membrane, said process comprising graft polymerizing a hydrophilic acrylamide monomer onto a Polyeater polyurethane substrate, wherein said substrate has a modulus of elasticity in the range from 150 to 1500 PSI and the polymerization is continued for an amount of time sufficient to yield a product having at least 50 weight percent hydrophilic acrylamide monomer and a water permeability in the range from 1,000 to 8,000 g/m2 /24 hr.
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15. A process for preparing an elastic hydrophilic membrane, said process comprising:
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preparing a reaction medium having preselected concentrations of a hydrophilic acrylamide monomer and a homopolymerization inhibitor; immersing a polyester polyurethane substrate in the reaction medium, said substrate having a modulus of elasticity in the range from 150 to 1500 PSI; and initiating graft polymerization between the monomer and the substrate and continuing such polymerization for a time sufficient to cause a weight increase of at least 50% relative to the initial weight of the substrate and the resulting hydrophilic membrane attains a water permeability in the range from 1,000 to 8,000 g/m2 /24 hr. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification