Microscopy of oxidized regenerated cellulose-treated defects at 17 days post-surgery. Oxidized regenerated cellulose-treated adjacent 5 μm demineralized bone sections stained with H&E (upper) and Trichrome-EVG at ×2 (left) and ×10 magnification. The edge of the defect is identified with black/green arrows, and the area of magnification shown with a dotted box. Defects show partial healing with newly formed woven bone (light blue arrows) rich in cellular activity (osteoid shown with dark blue arrows). Early fibrotic tissue is observed within the defect (white stars). Blue stars indicate native collagen meshwork within the marrow and defect.