Figure 3.

  Induction and morphogenesis of large mineralized and corticalized ossicles by 25 μg hTGF‐β2 implanted in the rectus abdominis muscle. (a) Induction of large heterotopic ossicles on day 30. Mineralization of the newly formed bone in blue surrounding scattered remnants of the collagenous matrix. Chondrogenesis on day 30 after implantation of 25 μg hTGF‐β2 (inset in a). (b) Detail of mineralized bone covered by osteoid seams at the zone of fusion of the coalesced ossicles. (c inset) Detail of newly formed trabecula covered by osteoid seams populated by contiguous osteoblasts in contact with invading capillaries. (d–g) Details of the induction of bone formation with newly formed mineralized bone in blue covered by osteoid seams. (h–j) Mineralized bone surfaced by large osteoid seams in ossicles generated by 25 μg hTGF‐β2 on day 90. Chondrogenesis on day 90 with vascular invasion and chondrolysis (inset in h). Undecalcified sections cut at 5 μm and stained free‐floating with Goldner’s trichrome (a) original magnification ×2.7; (b) original magnification ×25; (c) ×275; (d–g) original magnification ×75, 175, 125, 200, 275 respectively; (h–j) original magnification ×45, 60, 125 respectively.