3.

Morphology of calvarial repair and induction of bone formation by doses of the hTGF-β₃ osteogenic device without (left column) and with (right column) minced fragments of autogenous rectus abdominis muscle harvested 30 days after implantation.(A, C, E, G and I) Lack of bone induction and differentiation in calvarial defects harvested on day 30 after implantation of 25 (A), 125 (C, E, G) and 250 (I) μg of the hTGF-β₃ osteogenic device without the addition of minced cellular fragments of autogenous rectus abdominis muscle. Blue arrow in (G) indicates a very mall island of mineralized bone (in blue) located in the pericranial area of the specimen.(B) Lack of bone differentiation in a calvarial defect implanted with insoluble collagenous bone matrix solo as control 30 days after implantation.(D) Higher power view of (C) illustrating an interfacial region with newly formed mineralized bone at the level of the craniotomy only (dark blue arrows) blending into the remnants of the collagenous matrix. A prominent fibrous layer (light blue arrow) inhibits the induction of bone formation from the margin of the craniotomy.(F, H, J) Calvarial defects harvested on day 30 after implantation of 125 (F and H) and 250 (J) μg the hTGF-β₃ osteogenic device with the addition of minced fragments of autogenous rectus abdominis muscle. Partial restoration of the biological activity and induction of islands of newly formed mineralized bone in blue (arrows) within the implanted hTGF-β₃ osteogenic device. Undecalcified sections cut at 5 μm stained free-floating with Goldner's trichrome.(A, B, C, E, F, G, H, I, J) original magnification ×1.2 (D) original magnification ×7.