Cryopreservation of cell/hydrogel constructs based on a new cell-assembling technique

Organ manufacturing products hold the promise to be used widely in the future for complex organ failings. The cryopreservation of the product is a very important step in the commercialization activities. In this article, a new cell cryopreservation technique, whereby, cryoprotectants were directly incorporated into the cell/hydrogel constructs, prototyped according to the predesigned structure and then subjected to a special freezing/thawing process. The rheological and hydration properties of the cryopreservation systems indicated that the hydratabilities of the gelatin/alginate hydrogels were greatly increased while the eutectic temperatures were greatly decreased by the addition of glycerol. Dextran-40 was found to be effective to improve the cell survival when incorporated with glycerol. The optimal volume concentration of the cryopretectans was 2.5% (v/v) glycerol and 5% (g/mL) dextran-40 in the gelatin/alginate hydrogel. Under these conditions, the cell viability in the construct was 96.3 ± 3.4%. Microscopic, thiazolyl blue (MTT) and hematoxylin and eosin (HE) staining results all indicated that the cells began to proliferate after thawing. The cells in the gelatin/alginate hydrogel with both glycerol and dextran-40 had greater proliferations than with only glycerol or dextran-40. This approach holds promise for a variety of applications in cell assembly for high-throughput drug screening and complex organ manufacturing areas.