Crosslinking hyaluronan and chitosanic polymers
Materials and methods related to crosslinking hyaluronan and chitosan are described herein. Also described are products of the described methods.
1. A method of covalently linking hyaluronan and chitosan, comprising the steps of:
(a) providing a solution of hyaluronan with a pH of 4.0 to 4.3;
(b) adding a solution of chitosan such that the resultant mixed solution has a pH of at least 7.2; and
(c) adding a water soluble carbodiimide.
2. A method as claimed in claim 1 , further comprising the step of:
(d) washing the product of(c) with water or PBS.
3. A method as claimed in claim 1 , wherein the pH of the mixed solution is 7.2 to 7.8.
4. A method as claimed in claim 1 , further comprising the steps of:
(d) stirring the solution formed in (c) for 3 hours at room temperature; and
(e) washing the resultant hydrogel in PBS.
5. A method as claimed in claim 1 , further comprising the steps of:
(d) stirring the solution formed in (c) for 3 hours at room temperature;
(e) washing the resultant hydro gel in PBS or water; and
(f) freeze-drying the hydrogel.
6. A method as claimed in claim 1 , further comprising the steps of:
(d) stirring the solution formed in (c) for 30 minutes at room temperature;
(e) casting the solution into a desired form and allowing it to dry; and
(f) washing the resultant film with water or PBS.
7. A method as claimed in claim 1 , wherein the water soluble carbodiimide is 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide methiodide or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), or a derivative thereof.
8. A method as claimed in claim 1 , wherein the pH of the mixed solution is 7.2 to 7.5.
9. A method as claimed in claim 1 , wherein mixing the solution at a pH of at least 7.2 in the presence of the water soluble carbodiimide without forming an ionic bond between hyaluronan and chitosan.