Physical and mechanical properties of alginate-based hydrogel film as carrier for release of acetylthiocholine

The effects of different cross-linkers on mechanical and physical properties of alginate hydrogel films were determined to use prepared films as potential carrier structure for rapid detection system. Xylitol and d-mannitol cross-linked hydrogel films improved mechanical properties and generated more rigid, tough and stretchable film than uncross-linked film. Results exhibited increased tensile strength by 2.3 folds (58.3 +/- 5.8 MPa) and 1.8 folds (47.4 +/- 4.9MPa) when compared to uncross-linked film (25.8 +/- 7.3 MPa) respectively. Young's modulus of d-mannitol cross-linked film was slightly greater (16.8 +/- 2.1 MPa) than that of xylitol (15.7 +/- 2.7 MPa) whereas the elongation at break (E%) value of xylitol cross-linking (5.46 +/- 1.2%) was greater than d-mannitol (2.72 +/- 0.8%) cross-linking. Altered mechanical properties were investigated in terms of different amount of % cumulative release of AchI and DTNB that were immobilized in film matrix. Results showed different release amount depending on types of cross-linkers as following: xylitolcrosslinked (71.5%) > d-mannitol (64.9%) > uncross-linked (58.3%) at 10 min of release period. The exponent value n which determined based on power-law expression was ranged between 0.56 and 0.98, and indicates the release was mediated by anomalous Non-Fickian diffusion.