Figure 6.

Void-forming hydrogels used to transplant MSCs for bone formation. (A) Scheme of the fabrication of a void-forming hydrogel. Cells (green) are loaded in bulk hydrogel precursor solution and co-delivered with porogens (red). Pores form after the porogens degrade; cells migrate to the pores and attach to the pore surface. (B) Image of mouse MSCs stained with calcein-AM (green) in void-forming hydrogels 10 days after encapsulation and cultured in vitro. (Scale bar: 100 μm) (C) Cells numbers post-injection revealed by tracking the fluorescence intensity of mCherry-labeled mouse MSCs in vivo. Void-forming hydrogels lead to more rapid proliferation (31-fold increase) from day 7 to day 30, versus standard hydrogels. (D) Void-forming hydrogels enhance bone formation. Human MSCs were delivered using saline, standard hydrogels, or void-forming hydrogels into cranial defects of nude rats. Bone formation was evaluated using micro-computed tomography 12 weeks after transplantation. Transplanted human MSCs within void-forming hydrogels led to significantly more formation of new bone than standard hydrogels and saline controls.

(A-D) Reproduced with permission. ^[55] Copyright 2015, Nature Publishing Group.