Reinforced absorbable multilayered hemostatic wound dressing

Abstract

The present invention is directed to a reinforced absorbable multilayered hemostatic wound dressing comprising a first absorbable nonwoven fabric, a second absorbable woven or knitted fabric, thrombin and/or fibrinogen.

1 - 18 . (canceled) 
     
     
         19 . A method for making a multilayered wound dressing having a first absorbable nonwoven fabric, one or more second absorbable woven or knitted fabric, thrombin and/or fibrinogen, comprising the steps of:
 (a) crimping absorbable polymer fibers or yarns in the range of about 10 to 30 crimps per inch;   (b) cutting the crimped fibers or yarns to a staple length between about 0.1 and 2.5 inch;   (c) carding the staple to form the first absorbable nonwoven fabric while controlling the humidity to about 20 to 60%, at a room temperature of about 15 to 24° C.;   (d) attaching the first absorbable nonwoven fabric to the second absorbable woven or knitted fabric;   (e) applying thrombin and/or fibrinogen to the first absorbable nonwoven fabric.   
     
     
         20 . The method of  claim 19 , wherein the humidity of the environment for step (c) is from about 40 to 60%, at a room temperature of about 15 to 24° C. 
     
     
         21 . The method of  claim 19 , where the first absorbable nonwoven fabric comprises fibers comprised of aliphatic polyester polymers or copolymers of one or more monomers selected from the group consisting of lactic acid, lactide, glycolic acid, glycolide, ε-caprolactone, p-dioxanone, and trimethylene carbonate. 
     
     
         22 . The method of  claim 21 , where the first absorbable nonwoven fabric comprises glycolide/lactide copolymer. 
     
     
         23 . The method of  claim 21 , where the second absorbable woven or knitted fabric comprises oxidized polysaccharides. 
     
     
         24 . The method of  claim 23 , where the second absorbable woven or knitted fabric comprises oxidized cellulose. 
     
     
         25 . The method of  claim 24 , where the second absorbable woven or knitted fabric comprises oxidized regenerated cellulose. 
     
     
         26 . The method of  claim 24 , where the second absorbable woven or knitted fabric is an absorbable knitted fabric comprising oxidized regenerated cellulose. 
     
     
         27 . The method of  claim 19 , where the first absorbable nonwoven fabric comprises glycolide/lactide copolymer, and the second absorbable woven or knitted fabric comprises oxidized regenerated cellulose. 
     
     
         28 . The method of  claim 27 , where the first absorbable nonwoven fabric comprises staple having a length from about 0.75 to 1.5 inches. 
     
     
         29 . The method of  claim 27 , where the first absorbable nonwoven fabric comprises staple having a length from about 1.0 to 1.3 inches. 
     
     
         30 . The method of  claim 27 , where the first absorbable nonwoven fabric comprises a copolymer of glycolide and lactide, in an amount ranging from about 70 to 95% by molar basis of glycolide and the remainder lactide, and the second absorbable woven or knitted fabric comprises oxidized regenerated cellulose. 
     
     
         31 . The method of  claim 29 , where the staple is derived from fiber of about 1 to 4 denier per filament. 
     
     
         32 . The method of  claim 27 , where the first absorbable nonwoven fabric has a basis weight of about 0.01 to 0.2 g/in 2 ; the second absorbable woven or knitted fabric has a basis weight of about 0.001 to 0.2 g/in 2 ; and the multilayered dressing having the thrombin and/or fibrinogen thereon has a basis weight of about 0.1 and 1.0 g/in 2 . 
     
     
         33 . The method of  claim 27 , wherein the thrombin activity on the multilayered dressing ranges from about 20 to 500 IU/cm 2 , and the fibrinogen on the multilayered dressing ranges from about 2 to 15 mg/cm 2 . 
     
     
         34 . The method according to  claim 19 , further comprising the step of sterilizing the multilayered wound dressing. 
     
     
         35 . The method according to  claim 34 , wherein the multilayered wound dressing is sterilized by radiation. 
     
     
         36 . The method according to  claim 34 , wherein the multilayered wound dressing is sterilized by electron beam radiation. 
     
     
         37 . A method for making a wound dressing comprising an absorbable nonwoven fabric, thrombin and/or fibrinogen, comprising the steps of:
 (a) suspending the thrombin and/or fibrinogen in a perfluorinated hydrocarbon to form a suspension; and   (b) applying the suspension to the absorbable nonwoven fabric.