Injectable bioactive scaffold able to stimulate oral bone regeneration on demand

Bone regeneration in oral surgery remains a challenge, due to the features of the oral environment, characterized by the presence of saliva and extensive interaction with external pathogens. Recent advances in this field highlighted that biomimetic apatites in which Ca²⁺ is replaced by Fe²⁺/Fe³⁺ ions are promising candidates to guide bone regeneration with on demand activation control. In this study the Fe-doped apatite nanoparticles (FeHA) were developed and compared with magnetite nanoparticles, as new magnetic bio-activator, to be embedded in apatitic injectable paste/cement. Upon self-hardening, the new injectable cement generates a mechanically competent 3D superparamagnetic scaffold, endowed with remote activation by using static magnetic fields. We investigated the alkaline phosphatase expression and activity, as well as the behaviour of cells, when seeded onto the scaffold. The results show the ability of the cement to stimulate cell colonization and differentiation and how, when magnetized, they can further boost such phenomena. The proposed devices, in association with a magnetic aligner, can represent a new approach in oral surgery, able to tune the bone remodelling on demand, when the regenerative potential is impaired by physiological conditions such as aging or chronic diseases.