Injectable composite of calcium alginate hydrogel and Adipose-derived Stem Cells to remediate bone defect

To investigate the feasibility of injectable composite of calcium alginate hydrogel and adipose-derived stem cells(ASCs) to remediate bone defect, the experiment was carried out. ASCs from New Zealand rabbit cultured in vitro were mixed with 1.5 % sodium alginate and calcium gluconate, preparing the calcium alginate hydrogel with cell density 5x109/L. The cell growth curve was used to determine the biocompatibility of ASCs and hydrogels. The mixture was injected into the radius defect area of the New Zealand rabbits(group A); the calcium alginate hydrogel without cells was injected into the same area of other rabbits(group B). All rabbits were examined with radiodetection and bone mineral density(BMD) in the 12 postoperative weeks. Radiological assessment showed that 12 weeks after injection, the bone formation was obvious in experimental group A. In group B, a small number of new bone appeared at both ends, with the defect still visible. In group C, no bone formation was found. It also indicated that from 4 to 12 weeks post-surgery, the average BMD value of group A was higher than group B and group C(P<0.01). Percutaneous injection of calcium alginate hydrogel and ASCs composites can help to remediate bone defect in animals