Validating the cryopreservation of tissue engineered constructs within cryobags

The cryopreservation of cells and tissue engineered constructs is determined by multiple factors, such as possible cellular damages due to mass and heat transfer during the freezing and thawing process. It is assumed that the utilization of cryobags improves the heat transfer during freezing and thawing and is therefore superior in comparison to currently applied cryovials and multiwell plates. Therefore, we have analysed the cryopreservation of cell-seeded electrospun polycaprolactone/polylactide scaffolds within cryobags. Additionally, the performance of four different cryoprotective agents was analysed, which included 10% (v/v) dimethyl sulfoxide and 10% (v/v) ethylene glycol as separately applied agents as well as their combination with 0.3 M sucrose. The samples were frozen in in-house made cryobags with a controlled rate freezer. The cell viability was analysed by fluorescence microscopy before freezing and after thawing. The results show, that the application of cryobags in combination with 10% (v/v) ethylene glycol can have a positive impact onto the cell viability.