Osteoinduction of Calcium Phosphate Ceramics in Four Kinds of Animals for 1 Year: Dog, Rabbit, Rat, and Mouse

• HA/β-TCP were transplanted in 4 kinds of animals for a long-term observation.
• HA/β-TCP induced bone formation in dogs, rabbits, and mice, but not in rats.
• The area percentage of new bone in mice was higher than in dogs and rabbits.

IntroductionBone grafts are in great demand. Synthetic materials have been extensively studied as substitutes for autografts. Calcium phosphate ceramics are promising synthetic bone replacement materials. Because they share chemical similarities with human bone mineral, they show excellent biocompatibility and osteoinductivity.ObjectiveCalcium phosphate ceramics have been used to fill bone defects in preclinical study in a variety of animals. This study aimed to investigate the osteogenesis ability of calcium phosphate ceramics in 4 kinds of animals.MethodsΦ3 × 5 mm hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) cylinders were implanted into the dorsal muscle of rats and mice, whereas Φ5 × 10 mm cylinders were implanted into the dorsal muscle of dogs and rabbits. One year after implantation, the ceramics were harvested to perform hematoxylin and eosin (HE) staining and Masson-trichrome staining. The new bone tissues were observed and the area percentage of new bone was compared in the 4 kinds of animals.ResultsA large number of new bone and bone marrow tissues were observed in dogs, rabbits, and mice, but not in rats; and the area percentage of new bone in mice was significantly higher than that in dogs and rabbits (P < .05). Calcium phosphate ceramics have good biocompability and biological safety, and the degree of ease of osteogenesis was as follows: mouse > dog > rabbit > rat.ConclusionTo achieve better effects for bone transplantation, mouse should be chosen as the preferred experimental model based on these advantages: economic, convenience, and osteogenesis ability.