Effects of enamel matrix derivative on mineralized tissue formation during bone wound healing in rat parietal bone defects

Abstract

Enamel matrix derivative (EMD: Emdogain) has been reported to stimulate the biosynthesis and regeneration of trabecular bone. To address whether the biological action of EMD is dependent on the local environment of osseous tissue, circular perforations were made in parietal bones and immediately filled with either EMD or its carrier, propylene glycol alginate (PGA), as control. On post-operative days 4-60, the dissected bones were examined by various histological techniques. New bone matrix, which was immunoreactive for bone sialoprotein (BSP), was formed from the periosteum at the peripheral area of perforations. Different from the findings reported in injured long bones, mineralized tissue was produced in the regenerating connective tissue within bone defects. This mineralized tissue was hardly immunostained for BSP, contained few collagen fibres, and lacked osteocytic lacunae and layers of osteoblasts and osteoid. Energy-dispersive X-ray analysis showed that Ca and P weight % and Ca/P molar ratio of this mineralized tissue were similar to or slightly higher than those in the pre-existing parietal bones. In addition, most multinucleated cells located in mineralized tissue lacked a ruffled border structure and showed weak immunoreaction for the lysosomal cysteine proteinase, cathepsin K, whereas those located in the bone matrix exhibited ruffled borders and strong cathepsin K expression. However, multinucleated cells located in both tissues were strongly stained for tartrate-resistant acid phosphatase. The volume fraction of such mineralized tissue appeared to be higher in EMD-applied bones than in PGA-applied controls. The mineralized tissue-forming stromal cells within bone defects appeared to show greater accumulation in EMD-applied bones than in PGA-applied controls. Our results suggest that the bioactive effects of EMD on bone wound healing and mineralized tissue formation depend, at least in part, on the local osseous environment where EMD has been applied.

Bone grafting material in combination with Osteogain for bone repair: a rat histomorphometric study

“…The key components improving new bone formation in the present study were the effects of enamel matrix proteins which have been shown to affect new bone formation under various models and also utilizing various carrier systems [20,[31][32][33][34][35]. In a classical study by Boyan et al, it was shown that although EMD does not possess osteoinductive potential, it possessed osteopromotive benefits when it is combined with active demineralized freeze-dried bone allografts (DFDBA) and resulted in enhanced bone induction [31].…”

Skeletal Development of Mice Lacking Bone Sialoprotein (BSP) - Impairment of Long Bone Growth and Progressive Establishment of High Trabecular Bone Mass

“…BSP is expressed in hypertrophic chondrocytes [15], and given its effects on endothelial cells migration on the one hand [16] and hydroxyapatite nucleation on the other hand [17], one could expect an effect of the lack of BSP on the onset of endochondral ossification. Surprisingly, this process does not seem to be affected in BSP−/− mice, as no delay appears in the onset of ossification centers, and trabecular BV/TV and osteoclast parameters in newborn femurs are similar between genotypes.…”

Effect of coating Straumann® Bone Ceramic with Emdogain on mesenchymal stromal cell hard tissue formation

“…While Emdogain has been reported to possess osteopromotive effects on bone healing during repair of bone defects [51,52], other studies have indicated that Emdogain is not truly osteogenic in terms of its ability to induce bone production when implanted into ectopic sites [53,54]. Interestingly, Emdogain has been reported to inhibit the ectopic osteogenic capacity of dentin [53].…”