A magnetic hydroxyapatite composite scaffold-based magnetic therapy for bone repair: an experimental study in canis lupus familiaris

While the beneficial effect of magnetic nanoparticle on the biological functions of calcium phosphate scaffolds has been well documented, little is known about the effect of magnetic nanoparticle on the in vivo performance of hydroxyapatite (HA) scaffolds. In this study, to further investigate the influence of magnetic hydroxyapatite (MHA) scaffolds on bone repair and the interactions between the magnetic scaffolds and the exterior magnetic field in vivo, we implanted the scaffolds into a beagle dog experimental model of femur transverse defect. Compared with traditional HA scaffolds, the MHA scaffolds could accelerate bone tissue regeneration in situ, especially in the first month. Moreover, it had a synergic effect between external magnetic fields and MHA scaffolds on bone repair in vivo. After 1 month, the bone density on MHA exposed to an external magnetic field was roughly 30% greater than that of HA, and only slightly less than the bone density observed on HA after 3 months. Overall, the results suggest the improvement of bone ingrowth is critical for HA scaffold with magnetic fields, which is significant for the early bone fixation and repair.