Macroporous starPEG-heparin cryogels.

Macroporous scaffolds with adaptable mechanical and biomolecular properties can be instrumental in enabling cell-based therapies. To meet these requirements, a cryostructuration method was adapted to prepare spongy hydrogels based on chemically cross-linked star-shaped poly(ethylene glycol) (starPEG) and heparin. Subzero temperature treatment of the gel forming reaction mixtures and subsequent lyophilization of the incompletely frozen gels resulted in macroporous biohybrid cryogels showing rapid swelling, porosity of up to 92% with interconnected large pores (30-180 μm), low bulk stiffness, and high mechanical stability upon compression. The applicability of the cryogel scaffolds was investigated using human umbilical vein endothelial cells. Cell attachment and three-dimensional spreading resulted in evenly distributed viable cells within the macroporous starPEG-heparin materials, demonstrating the significant translational potential of the developed three-dimensional cell carriers.