RESUMO
Thermo-sensitive hydrogels were prepared by graft copolymerization of chitosan and N-Isopropylacrylamide via gamma radiation. Characterization of hydrogels such as 13C-NMR, DSC analysis and swelling test and cell assessments for harvesting living cell sheet were investigated. 13C-NMR and DSC analysis showed chitosan and NIPAAm monomer were grafted via gamma radiation successfully. Swelling ratio and curves results administrated hydrophilicity / hydrophobicity of hydrogel that this property is due to presence of PNIPAAm in different temperatures. The hydrogel was tested for harvesting epithelial cells after carrying out cell culture at 37 degreeC and incubating the confluent cells at 4 degreeC for spontaneous detachment of cell sheet from hydrogel surface without enzyme treatment. Cell viability assay results and microscopic observations demonstrated that cells could attach to the hydrogel surface and maintain high viability and proliferation ability. Cell detachment efficiency from the hydrogel was high. These unique properties of the hydrogel would make it a promising support for epithelial cell grafting especially cornea regeneration