The biomaterials properties influence their degradation and regenerative capabilities because of different cellular reactions.2,3 In addition to the macrophages involved in the wound healing and regeneration process, multinucleated giant cells (MNGCs) are frequently observed within the augmentation site as a response to the implanted biomaterials.4 However, the role of macrophages and MNGCs in the mechanism of degradation and regeneration is still unclear. Comparing Geistlich Bio-Oss® with a synthetic bone substitute, Zhang et al. have now investigated in a histological study in humans the polarization of biomaterial-induced macrophages and MNGCs in pro- and anti-inflammatory subtypes.1
Geistlich Bio-Oss® induced fewer pro-inflammatory MNGCs
Depending on the biomaterial used, macrophages demonstrated different polarization patterns. A significantly higher number of anti-inflammatory macrophages was detected for Geistlich Bio-Oss®. Conversely, polarization toward a pro-inflammatory phenotype of MNGCs was similar for both biomaterials. However, a significantly lower number was found for Geistlich Bio-Oss®.
Fewer MNGCs means: slower degradation and better integration of the biomaterial, stable scaffold function for newly formed bone, and less connective tissue ingrowth into the bone defect.
The authors conclude: "Regardless of the biomaterial origin and properties, the induced MNGCs showed a pro-inﬂammatory characteristic, but their numbers can be altered according to the characteristics of the implanted biomaterial. Biomaterials that induce few MNGCs become integrated into the augmentation area and may provide volume stability in atrophic bone over the long term."