Antibacterial surface of metal-organic framework-chitosan composite films

Abstract

A substrate having an antibacterial surface includes a chitosan matrix and water-stable metal-organic frameworks dispersed throughout the chitosan matrix. The water-stable metal-organic frame-works are present in an amount of 5% wt/wt to 20% wt/wt based on total solids of the substrate

The following is claimed: 
     
         1 . A substrate having an antibacterial surface, the substrate comprising:
 a chitosan matrix; and   water-stable metal-organic frameworks dispersed throughout the chitosan matrix, the water-stable metal-organic frameworks present in an amount of 5% wt/wt to 20% wt/wt based on total solids of the substrate.   
     
     
         2 . The substrate of  claim 1 , wherein the water-stable metal-organic frameworks are copper-based, water-stable metal organic frameworks. 
     
     
         3 . The substrate of  claim 1 , wherein the water-stable metal-organic frameworks are H 3 [(Cu 4 Cl) 3 —(BTTri) 8 ] (H 3 BTTri=1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene). 
     
     
         4 . The substrate of  claim 1 , wherein the water-stable metal-organic frameworks are crystalline after 72 hours in a nutrient broth media. 
     
     
         5 . The substrate of  claim 1 , wherein the substrate is a biomedical substrate. 
     
     
         6 . The substrate of  claim 1 , wherein the water-stable metal-organic frameworks present in an amount of 5% wt/wt based on total solids of the substrate. 
     
     
         7 . A method of making a substrate having an antibacterial surface, the method comprising:
 dispersing water-stable metal-organic frameworks in a chitosan matrix to form a water-soluble chitosan/water-stable metal-organic framework material, the water-stable metal-organic frameworks present in the water-soluble chitosan/water-stable metal-organic framework material in an amount of 5% wt/wt to 20% wt/wt based on total solids of the material; and   converting the water-soluble chitosan/water-stable metal-organic framework material to a water-insoluble chitosan/water-stable copper-based metal-organic framework material with a buffer solution.   
     
     
         8 . The method of  claim 7 , wherein the water-stable metal-organic frameworks are copper-based, water-stable metal organic frameworks. 
     
     
         9 . The method of  claim 7 , wherein the water-stable metal-organic frameworks are H 3 [(Cu 4 Cl) 3 —(BTTri) 8 ] (H 3 BTTri=1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene). 
     
     
         10 . The method of  claim 7 , wherein the water-stable metal-organic frameworks are crystalline after 72 hours in a nutrient broth media. 
     
     
         11 . The method of  claim 7 , and further comprising forming the water-insoluble chitosan/water-stable copper-based metal-organic framework material into a biomedical device. 
     
     
         12 . The method of  claim 7 , wherein the water-stable metal-organic frameworks present in an amount of 5% wt/wt based on total solids of the substrate. 
     
     
         13 . A method of using a material to reduce adhesion of bacteria on a surface of the material, the method comprising:
 exposing the material comprising copper-based metal-organic frameworks dispersed throughout a chitosan matrix to a solution containing the bacteria, wherein during the exposure the material reduces bacterial adhesion by at least 85% in the first six hours of exposure as compared to material that does not include the copper-based metal-organic frameworks and wherein after the first six hours of exposure the material does not release copper in a bactericidal effective amount.   
     
     
         14 . The method of using the material of  claim 13 , and further comprising:
 removing the material from exposure to the bacteria;   sterilizing the material after the removing step; and   exposing the material to a new environment of bacterial after the sterilizing step, wherein during the second exposing step the material reduces bacterial adhesion by at least 85% in the first six hours of exposure as compared to material that does not include the copper-based metal-organic frameworks and wherein the material is not subject to regeneration before the second exposing step.   
     
     
         15 . The method of  claim 13  wherein the bacteria is  Pseudomonas aeruginosa.