Ionically Crosslinked Polyelectrolytes as Underwater Adhesives and Controlled Release Vehicles

Abstract

Underwater adhesive materials, methods of making the same, and methods of using the same are described.

What is claimed is: 
     
         1 . A method for controllably releasing a small molecule comprising:
 adding a small molecule to either (i) a first solution comprising non-polysaccharide polymer having two or more amine groups, or (ii) a second solution comprising a multivalent phosphate crosslinker;   mixing the first solution with the second solution, at a pH ranging from about 4 to about 10, to form an adhesive gel; and   applying the adhesive gel to a target location, wherein the small molecule is released from the adhesive gel over a period of time.   
     
     
         2 . A method of delivering an adhesive to a target location comprising:
 mixing a polyamine with a multivalent phosphate crosslinker in acidic or basic solution to obtain a mixture;   injecting the mixture to a target location; and   adjusting the pH of the mixture to ambient pH to form an adhesive gel-like complex in the target location.   
     
     
         3 . The method of  claim 2 , further comprising adjusting the pH to an acidic or basic pH to dissolve the adhesive gel. 
     
     
         4 . A method of delivering an adhesive to a target location comprising:
 mixing a polyamine with a multivalent phosphate crosslinker in a solution to obtain a mixture;   injecting the mixture to a target location; and   adjusting the ionic strength of the solution to form an adhesive gel-like complex in the target location.   
     
     
         5 . The method of  claim 4 , further comprising adjusting the pH to an acidic or basic pH to dissolve the adhesive gel. 
     
     
         6 . A composition comprising:
 a non-polysaccharide polymer having two or more amine groups; and   a multivalent phosphate crosslinker;   the composition comprising an ionically crosslinked network that forms a gel-like coacervate at a pH in the range of from about 4 to about 10.   
     
     
         7 . The composition of  claim 6 , wherein the multivalent phosphate crosslinker is selected from the group consisting of a tetravalent phosphate and a pentavalent phosphate. 
     
     
         8 . The composition of  claim 6 , wherein the multivalent phosphate crosslinker is selected from the group consisting of pyrophosphate (PPi) and tripolyphosphate (TPP). 
     
     
         9 . The composition of  claim 6 , wherein the polymer having two or more amine groups comprises poly(vinylamine). 
     
     
         10 . The composition of  claim 6 , wherein the polymer having two or more amine groups is selected from the group consisting of: poly(vinylamine), polylysine, polyarginine, polyhistidine, polyethyleneimine, polyaminostyrene, polyvinylpyrrolidone, polymethylvinylamine, polyaniline, and poly(vinylpyridine). 
     
     
         11 . The composition of  claim 6 , wherein the composition has a crosslinker:polymer molar ratio above about 0.12:1. 
     
     
         12 . The composition of  claim 6 , wherein the composition has a crosslinker:polymer molar ratio ranging from about 0.10:1 to about 0.25:1. 
     
     
         13 . The composition of  claim 6 , wherein the polymer is present at a concentration ranging from about 0.1 wt % to about 40 wt %. 
     
     
         14 . The composition of  claim 6 , wherein the composition contains water at a concentration ranging from about 20 wt % to about 50 wt %. 
     
     
         15 . The composition of  claim 6 , wherein the composition has a storage modulus of greater than 10 5  Pa. 
     
     
         16 . The composition of  claim 6 , wherein the composition exhibits a self-healing capability when torn. 
     
     
         17 . The composition of  claim 6 , wherein the composition has a tensile adhesion strength of greater than about 350 kPa. 
     
     
         18 . The composition of  claim 6 , wherein the composition is capable of adhering to hydrophobic and hydrophilic surfaces under water. 
     
     
         19 . The composition of  claim 6 , wherein the composition is capable of adhering to human skin. 
     
     
         20 . The composition of  claim 6 , further comprising an active payload for long-term release.