When the ethanol concentration achieves a critical value, the hydrogel collapses into a more compact state. At ethanol concentrations of 15% v/v pure hydrogel has lost the 50% of its initial swelling capacity and pAA-Sc-4 approximately 30%. For ethanol concentration larger than 50% v/v, the hydrogels with and without cells are not able to swell. Therefore, ethanol behaves as a non-solvent for polyacrylamide chains. When nonsolvent and water are mixed, the molecules of the solvents present attractive interactions increasing the free energy of chain polymer. The upper affinity among polymer segments would induce the collapse of the polymer network.