Chitosan foam medical devices and methods

Abstract

The invention provides a solid foam wound dressing useful for hemorrhage control and wound repair, as well as methods for making such a wound dressing.

1 . A method of making a solid foam wound dressing, comprising:
 I. introducing gas bubbles into the aqueous solution to form an aqueous foam, wherein the aqueous solution comprises chitosan, at least one protic acid and at least one surface active agent;   II. freezing the aqueous foam; and   III. dehydrating the aqueous foam to form a solid foam.   
     
     
         2 . The method of  claim 1 , wherein said dehydrating the aqueous foam comprises freeze drying the aqueous foam. 
     
     
         3 . The method of  claim 1 , further comprising freezing the foam in a reduced pressure environment to expand the gas bubbles in the aqueous foam. 
     
     
         4 . (canceled) 
     
     
         5 . The method of  claim 1 , further comprising compressing the solid foam. 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . The method of  claim 1 , wherein the protic acid is a hydrogen donator acid. 
     
     
         9 . (canceled) 
     
     
         10 . The method of  claim 1 , wherein the surface-active agent is anionic, cationic, non-ionic, or amphoteric. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 1 , wherein the gas is selected from the group consisting of air, nitrogen, helium, hydrogen, argon, and carbon dioxide. 
     
     
         14 . The method of  claim 1 , wherein the gas bubbles are introduced by mixing, beating, agitating, aerating, whipping, or injecting the gas into the aqueous solution. 
     
     
         15 . The method of  claim 1 , wherein the wound dressing is capable of promoting at least one of hemostasis, wound healing, and adherence to wet tissues. 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 1 , wherein the wound dressing is antimicrobial and antiviral. 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 1 , wherein the solid foam comprises at least one of an open-cell structure and a lamella structure. 
     
     
         21 . (canceled) 
     
     
         22 . A solid foam wound dressing comprising chitosan, at least one protic acid and at least one surface active agent wherein said wound dressing has a porous structure that is mechanically flexible and adhesive when in contact with physiological fluids or moisture. 
     
     
         23 . The wound dressing according to  claim 22 , wherein the physiological fluid is blood. 
     
     
         24 . The wound dressing of  claim 22 , wherein the solid foam wound dressing is a compressed solid foam wound dressing. 
     
     
         25 . (canceled) 
     
     
         26 . The wound dressing of  claim 22 , wherein the protic acid is a hydrogen donator acid. 
     
     
         27 . (canceled) 
     
     
         28 . The wound dressing of  claim 22 , wherein the surface-active agent is anionic, cationic, non-ionic, or amphoteric. 
     
     
         29 . (canceled) 
     
     
         30 . The wound dressing of  claim 22 , wherein the surface-active agent is antimicrobial and antiviral. 
     
     
         31 . The wound dressing of  claim 22 , wherein the wound dressing is capable of promoting at least one of hemostasis, wound healing, and adherence to wet tissues. 
     
     
         32 . (canceled) 
     
     
         33 . (canceled) 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . The wound dressing of  claim 22 , wherein the solid porous material comprises at least one of an open-cell structure and a lamella structure. 
     
     
         37 . (canceled) 
     
     
         38 . A method of treating a wound, comprising applying the wound dressing according to  claim 22  to the wound.