Isolation and implantation of bone marrow-derived mesenchymal stem cells with fibrin micro beads to repair a critical-size bone defect in mice.

Fibrin microbeads (FMBs) made using thermal treatment of fibrin drops in oil can efficiently isolate mesenchymal stem cells (MSCs) from bone marrow (BM) and other similar sources and culture them continuously in suspension culture. The pure mesenchymal profile of MSCs isolated using FMBs and their differentiation potency to different mesenchymal lineages were previously described in detail. In the current study, MSCs were isolated from the BM of GFP+ C57/bl mice using FMBs. Addition of pro-osteogenic medium with 10 mM of s-glycerolphosphate, 50 μg/mL of ascorbic acid, and 10−8 M of dexamethasone for 1 month resulted in ossified bone-like solid cellular structures, as seen using fluorescence and scanning electron microscopy (SEM). Such spontaneously formed structures were implanted in full-depth approximately 5-mm-diameter drilled defects in the skulls of wild-type c57/bl mice. Two months later, the excised upper parts of the skulls with the defects were viewed using fluorescence microscopy for green fluor...