Preparation and Characterization of Agarose-Gelatin Blend Hydrogels as a Cell Encapsulation Matrix: An In-Vitro Study

Cell encapsulation represents an alternative nonviral technique to treat multiple diseases, leading to a reduction or even absence of administration of immuno-suppressants. Hydrogels have been introduced as novel materials suitable for cell encapsulation. This study involves agarose-gelatin blend hydrogels with four different weight percentage ratios (100:0, 75:25, 50:50, 25:75) of agarose to gelatin. Prepared blend hydrogels were assessed in terms of rheological behavior (gel point by using complex viscosity), cell attachment (hemocytometer), cell viability and cytotoxicity (3-(3,4-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliium bromide, MTT assay), and mechanical and integral stability (Bradford test and shear force rupture assay, respectively). Based on the obtained rheological experimental results, the sol-gel transition point for 50:50 was in the physiological condition range (35 degrees C-37 degrees C). The percent of nonattached cells on the surface of the hydrogel decreased from 92% for the 100:0 sample to 46.3% for the 50:50 sample, and the cell viability was more than 95%. A good structural integrity was achieved for samples with weight ratio of 50:50; 20.195% gelatin was released during the 24 h in phosphate buffer solution at 25 degrees C and the mechanical stability of agarose-gelatin microcapsules under shear force were improved about 14% rather than pure agarose microcapsule.