The gelatin-based liquid marbles for cell cryopreservation

As an alternative and a straightforward cryopreservation biotechnological tool, liquid marble provides a promising cryopreservation approach. Currently, effective cell preservation mainly based on the addition of dimethyl sulfoxide (DMSO) and fetal bovine serum (FBS). As state-of-the-art cryoprotectant (CPA), DMSO, has intrinsic toxicity, which is the bottleneck of its widespread application. The complex compositions of FBS have the potential risks of pathogenic microorganism contamination. However, efficient cell cryopreservation using liquid marbles, a platform independent of DMSO and FBS, has not been well investigated yet. Herein, we explore the cryoprotection role of liquid marbles based on gelatin solution. Gelatin has a superior biocompatibility, which DMSO is incomparable. During a freeze-thaw cycle, gelatin produces negligible osmotic pressure, and has high ice recrystallization inhibition (IRI) activity to induce the formation of smaller and smooth ice crystals. Moreover, the specific structure of liquid marble also provides favorable supports for cell survival. The cryopreservation efficiency of mouse fibroblasts cells L929 via the gelatin-based liquid marble was as high as 90%, and the recovered cells could maintain their normal functionalities. This work opens a new window of opportunity for non-toxic and efficient cryopreservation of liquid marbles without the need of DMSO and FBS addition.