In vivo wound healing response to a modified degradable fibrin scaffold

Pooled donor fibrin with an ultimate fibrinogen concentration of 60 mg/ml was used to study its effect on wound healing of surgically created ulcers in a rabbit ear. Water soluble polymer (PEG Mw = 20 KD) beads of 100-150 microns were added (12% by volume) to the fibrinogen to obtain a porous and rough structure. Five 6 mm-diameter ulcers to the depth of bare cartilage were created on each rabbit ear. There were two periods of study (4 and 8 days), with 15 ulcers in each time period, 5 of which were treated with a modified fibrin scaffold, 5 with a non-modified fibrin scaffold, and 5 served as control ulcers. The ulcer sites were subjected to routine histological processing and histomorphometrical quantification. Data analysis revealed significant increases in volume fraction of fibroblast and number of blood vessels in the modified fibrin scaffold treated ulcers over control and non-modified fibrin scaffold treated groups.