Magneto-sensitive decellularized bone matrix with or without low frequency-pulsed electromagnetic field exposure for the healing of a critical-size bone defect

Bioactive ECM-based materials mimic the complex composition and structure of natural tissues. Decellularized cancellous bone matrix (DBM) has potential for guiding new bone formation and accelerating the regeneration process. On the other hand, low frequency-pulsed electromagnetic field (LF-PEMF) has been shown to enhance the regeneration capacity of bone defects. The present study sought to explore the feasibility of using DBM and DBM/MNP, and LF-PEMF for treating critical-size bone defects. Firstly, decellularization protocol was optimized to obtain a bioactive DBM, then MNPs were incorporated. Later, the physical, chemical and biological properties of DBM and DBM/MNP were assessed in vitro. MNPs homogeneously distributed into the DBM were not found to be toxic to human osteoblast cultures. Finally, an in vivo study was carried out with DBM and DBM/MNP composites in a bilateral critical-size rat cranial defect model (n = 48) with or without LF-PEMF exposure for 45 and 90 days. The histomorphometric and radiographic evaluations revealed that, while the collagen (positive control) and Sham (negative control) groups showed high incidence of fibrous connective tissue together with low level of osteogenic activity, both the DBM and DBM/MNP-grafted groups significantly promoted new bone tissue formation and angiogenesis, by the appropriate use of LF-PEMF for 90 days.

Automated summary

Bioactive ECM-based materials such as DBM and DBM/MNP have shown potential in treating critical-size bone defects by promoting new bone formation and angiogenesis. The use of LF-PEMF further enhances the regeneration capacity of these materials, as evidenced by in vitro and in vivo studies.