Development of gelatin/chitosan/PVA hydrogels: Thermal stability, water state, viscoelasticity, and cytotoxicity assays

ABSTRACT Gelatin/chitosan/poly(vinyl alcohol) (PVA) hydrogels were fabricated with different polymer ratio using the freeze‐drying process. The thermal stability, water state, rheological, and cytotoxic properties of the hydrogels were evaluated. Thermogravimetric/differential scanning calorimetry analyses showed a decomposition onset temperature below 242.7 ± 2.7 °C. The samples did not show statistical differences ( p < 0.05) on the onset temperature values. Nonfreezing water reached a constant value around of 1 g water/g polymer. Freezing water increased linearly with the increase of the water content independently of the polymer ratio. The hydrogels showed an equilibrium water content from 9 to 13 times their mass. The hydrogels exhibited a solid‐viscoelastic behavior. The elastic modulus was higher with the increase of chitosan concentration ( G ′ = 22 170 ± 85 Pa) independently of the temperature (5–55 °C). In vitro assay showed that hydrogels are nontoxic in the HT29‐MTX‐E12 cell line. These results indicate that the gelatin/chitosan/PVA hydrogels could be considered for biomedical applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47149.