Powder for achieving hemostasis

Abstract

In various aspects, the present disclosure pertains to methods of treating or preventing bleeding at a tissue site comprising applying a chitosan powder composition to the tissue site, In various aspects, the present disclosure pertains to chitosan powder compositions for application to a tissue site, where the powder compositions comprise a chitosan salt, a crosslinked chitosan, a derivatized chitosan, or a combination thereof. In various aspects, the disclosure pertains to catheter assemblies, which are preloaded with a chitosan powder composition and which are configured to deliver the chitosan powder composition a tissue site.

1 - 20 . (canceled) 
     
     
         21 . A composition comprising:
 first particles comprising chitosan derivatized with a multifunctional aldehyde; and   second particles comprising a covalent crosslinking agent;   wherein the composition is in the form of a powder.   
     
     
         22 . The composition of  claim 21 , wherein the chitosan derivatized with the multifunctional aldehyde comprises pendant aldehyde groups. 
     
     
         23 . The composition of  claim 21 , wherein the multifunctional aldehyde comprises glutaraldehyde, glyoxal, or an aldehyde terminated hydrophilic polymer. 
     
     
         24 . The composition of  claim 23 , wherein the multifunctional aldehyde comprises the aldehyde terminated hydrophilic polymer, and wherein the aldehyde terminated hydrophilic polymer comprises poly(ethylene glycol), polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, poly(acrylic acid), or poly(hydroxyethyl methacrylate. 
     
     
         25 . The composition of  claim 21 , wherein the multifunctional aldehyde is poly(ethylene glycol) dialdehyde. 
     
     
         26 . The composition of  claim 21 , wherein the covalent crosslinking agent is a polymeric crosslinking agent. 
     
     
         27 . The composition of  claim 21 , wherein the covalent crosslinking agent comprises a multifunctional molecule having two or more functional groups. 
     
     
         28 . The composition of  claim 27 , wherein the covalent crosslinking agent is a biocompatible hydrophilic polymer having terminal carboxylic acid groups. 
     
     
         29 . The composition of  claim 27 , wherein the two or more functional groups include carboxylic acid groups, amine groups, epoxy groups, and/or aldehyde groups. 
     
     
         30 . The composition of  claim 21 , wherein the first particles have a size ranging from 100 μm to 500 μm. 
     
     
         31 . A method of treating or preventing bleeding at a tissue site comprising applying the composition of  claim 21  to the tissue site via a catheter, wherein the tissue site is tissue of a gastrointestinal tract. 
     
     
         32 . The method of  claim 31 , wherein the composition is fluidized in a gas to form a fluidized powder and blown onto the tissue site. 
     
     
         33 . The method of  claim 32 , wherein the gas is CO 2 . 
     
     
         34 . The method of  claim 32 , wherein the fluidized powder exits the catheter at a velocity ranging from 15 m/s to 50 m/s. 
     
     
         35 . The method of  claim 31 , wherein the composition is applied to the tissue site via the catheter through an endoscope. 
     
     
         36 . A composition comprising:
 first particles comprising chitosan derivatized with a multifunctional aldehyde; and   second particles comprising a covalent crosslinking agent, wherein the cross-linking agent comprises a multifunctional polymer comprising two or more functional groups chosen from carboxylic acid groups, amine groups, epoxy groups, aldehyde groups, or combinations thereof;   wherein the composition is in the form of a powder.   
     
     
         37 . The composition of  claim 36 , wherein the chitosan derivatized with a multifunctional aldehyde comprises chitosan derivatized with glutaraldehyde, chitosan derivatized with glyoxal, or chitosan derivatized with an aldehyde terminated hydrophilic polymer. 
     
     
         38 . The composition of  claim 37 , wherein the aldehyde terminated hydrophilic polymer is approximately 2 monomers to 250 monomers in length. 
     
     
         39 . A method of treating or preventing bleeding at a tissue site, the method comprising administering a composition to the tissue site, wherein the composition is in the form of a powder and comprises:
 first particles comprising chitosan derivatized with a multifunctional aldehyde; and   second particles comprising a covalent crosslinking agent, wherein the covalent crosslinking agent comprises a multifunctional polymer comprising two or more functional groups chosen from carboxylic acid groups, amine groups, epoxy groups, aldehyde groups, or combinations thereof.   
     
     
         40 . The method of  claim 39 , wherein the covalent crosslinking agent is a biocompatible hydrophilic polymer having terminal amine groups.