Sugar-Assisted Cryopreservation of Stem Cell-Laden Gellan Gum–Collagen Interpenetrating\nNetwork Hydrogels

Abstract

Tissue engineering\ninvolves the transplantation of stem cell-laden\nhydrogels as synthetic constructs to replace damaged tissues. However,\ntheir time-consuming fabrication procedures are hurdles to widespread\napplication in clinics. Fortunately, similar to cell banking, synthetic\ntissues could be cryopreserved for subsequent central distribution.\nHere, we report the use of trehalose and gellan gum as biomacromolecules\nto form a cryopreservable yet directly implantable hydrogel system\nfor adipose-derived stem cell (ADSC) delivery. Through a modified\ncell encapsulation method and a preincubation step, adequate cryoprotection\nwas afforded at 0.75 M trehalose to the encapsulated ADSCs. At this\nconcentration, trehalose demonstrated lower propensity to induce apoptosis\nthan 10% DMSO, the current gold standard cryoprotectant. Moreover,\nwhen cultured along with trehalose after thawing, the encapsulated\nADSCs retained their stem cell-like phenotype and osteogenic differentiation\ncapacity. Taken together, this study demonstrates the feasibility\nof an “off-the-shelf” biomacromolecule-based synthetic\ntissue to be applied in widespread tissue engineering applications.