Lj. Marden et al., PLATELET-DERIVED GROWTH-FACTOR INHIBITS BONE REGENERATION INDUCED BY OSTEOGENIN, A BONE MORPHOGENETIC PROTEIN, IN RAT CRANIOTOMY DEFECTS, The Journal of clinical investigation, 92(6), 1993, pp. 2897-2905
Platelet-derived growth factor (PDGF) is a potent moderator of soft ti
ssue repair through induction of the inflammatory phase of repair and
subsequent enhanced collagen deposition. We examined the effect of rec
ombinant BB homodimer PDGF (rPDGF-BB) applied to rat craniotomy defect
s, treated with and without bovine osteogenin (OG), to see if bone reg
eneration would be stimulated. Implants containing 0, 20, 60, or 200 m
ug rPDGF-BB, reconstituted with insoluble rat collagenous bone matrix
containing 0, 30, or 150 mug OG, were placed into 8-mm craniotomies. A
fter 11 d, 21 of the 144 rats presented subcutaneous masses superior t
o the defect sites. The masses, comprised of serosanguinous fluid enca
psulated by fibrous connective tissue, were larger and occurred more f
requently in rats treated with 200 mug rPDGF-BB, and were absent in ra
ts not treated with rPDGF-BB. The masses underwent resorption within 2
8 d after surgery. OG (2-256 mug) caused a dose-dependent increase in
radiopacity and a marked regeneration of calcified tissue in a dose-de
pendent fashion within defect sites. However, OG-induced bone regenera
tion was inhibited 17-53% in the presence of rPDGF-BB. These results s
uggest that rPDGF-BB inhibited OG-induced bone regeneration and stimul
ated a soft tissue repair wound phenotype and response.