A series of hydrogels from 2-ethyl-2-oxazoline and three bis(2-oxazoline) crosslinkers-1,4-butylene-2,2'-bis(2-oxazoline), 1,6-hexamethylene-2,2'-bis(2-oxazoline), and 1,8-octamethylene-2,2'-bis(2-oxazoline)-are prepared. The hydrogels differ by the length of aliphatic chain of crosslinker and by the percentage of crosslinker (2-10%). The influence of the type and the percentage of the crosslinker on swelling properties, mechanical properties, and state of water is studied. The equilibrium swelling degree in water ranges from 2 to 20. With a proper selection of the crosslinker, Young's modulus can be varied from 10 kPa to almost 100 kPa. To evaluate the potential for medical applications, the cytotoxicity of extracts and the contact toxicity toward murine fibroblasts are measured. The hydrogels with the crosslinker containing a shorter aliphatic exhibit low toxicity toward fibroblast cells. Moreover, the viability and the proliferation of pancreatic beta-cells incubated inside hydrogels for 12 days are analyzed. (C) 2015 Wiley Periodicals, Inc.