Collagen based Hydrogel Films as Wound Dressing Materials

Collagen/chitosan (coll/chitosan) and collagen/chitosan/poly(N-isopropylacrylamide) (coll/chitosan/p(NIPAm)) interpenetrating network (IPN) hydrogels were synthesized in film form using glutaraldehyde and poly(ethylene glycol)diacrylate as crosslinkers for the purpose of wound dressing materials. Morphological characterization of the prepared hydrogels were done by optic microscope images and it was found that the surface of the hydrogels possess microporous structure with the pore size of 1-20 μm. The structural and thermal characterizations of the hydrogels were evaluated by using FT-IR spectroscopy and thermal gravimetric analysis (TGA). The equilibrium swelling capacity of collagen/chitosan and collagen/chitosan/p(NIPAm) IPN hydrogels were measured at pH 5.4, 7.4 and 9,0 values and collagen/chitosan/p(NIPAm) hydrogels was found to have the highest equilibrium swelling capacity was found at pH 5.4 with 428±97 % swelling ratio. In addition, the equilibrium swelling properties of the hydrogels between 25 and 50 oC were measured and observed that collagen/chitosan hydrogels have the almost same swelling capacity for all temperatures with nearly 200 % swelling ratio whereas collagen/chitosan/p(NIPAm) hydrogels have the swelling ratio of 312±14 % at 25 oC and shrunk to % 59±2 % at 50 oC due to the thermo responsive p(NIPAm) in the structure. Moreover, the prepared collagen/chitosan based IPN hydrogels were used in release of drug and it was observed that collagen/chitosan hydrogels were released 114.06±2.9 mg/g dexamethasone drug within 15 hours whereas coll/chitosan/p(NIPAm) were released about 51.3±1.2 mg/g at the same time