ABSTRACT
Bioprinting is an emerging technique providing a high level of control for depositing cells and bioactive molecules with a high spatial resolution. In recent years, it has been used to generate cell-laden droplets for biopreservation studies. Using pico- and nanoliter sized droplets for the cryopreservation of the cells increases the rate of cooling, attributed to the lower heat resistance of the droplets, which subsequently reduces the need for a high concentration of cryoprotectant. As a result, osmotic shock and the toxic effects of cryoprotectants will be reduced. In addition, by using bioprinting, mass vitrification in a short amount of time is made possible by transforming a bulk sample of cells into the pico- and nanoliter droplets. The aim of this study is to review the application of emerging droplet-based bioprinting technologies in generating cell-encapsulating pico- and nanoliter droplets for the cryopreservation of biological materials. Moreover, we will discuss the droplet-based vitrification method in both open and closed systems, their application, and the benefits of using a bioprinter for increasing the effectiveness of cryopreservation of biological materials.
