Figure 4.

Light micrographs of cross sections through the samples of Ethisorb (as a sample of a polymeric material) and Bio-Oss (deproteinized bovine bone, DBB) in the two groups (coated polymer bearing an incorporated depot of bone morphogenetic protein-2 (coating-incorporated BMP-2); uncoated polymer bearing an adsorbed depot of BMP-2 (adsorbed BMP-2)), five weeks after implantation in rats and stained with McNeil's tetrachrome, basic fuchsin and toluidine blue O. Scale bars, 200 µm. Newly regenerated bone tissue (indicated by black arrows) was extensively deposited along the surface of the two materials when they were functionalized by coating-incorporated BMP-2; a tremendous amount of bone marrow tissue (black asterisks) filled in the interstitial space. In contrast, bone tissue was sporadically deposited along the surface of the two materials that had an adsorbed depot of BMP-2; bone marrow tissue was rarely found in this group.