(601r) Using Radial Diffusion Method in Fibrin-Agarose Gel Media to Investigate the Role of Plasmin Degradation of Fibrin in Preventing Wound Healing Abnormalities

Millions of people around the world experience tissue injuries annually and abnormalities that arise during the healing process pose additional public health concerns. One of the key aspects of wound healing is the formation of a fibrin clot following injury. Fibrinolysis, the process of breaking down a fibrin clot, has been associated with certain undesirable fibrotic conditions in wound healing when impaired. Certain conditions including an imbalance in the equilibrium between early collagen production and corresponding proteolytic degradation of collagen have also been associated with wound fibrosis. The hypothesis proposed herein is that pre-mature deposition of collagen decreases fibrinolysis.

Laboratory experiments were conducted using agarose-fibrin gel systems with and without collagen to investigate fibrinolysis caused by plasmin (a serine protease). The effects of aprotinin (a serine protease inhibitor) and bromelain (an extract from pineapple) in inhibiting and improving fibrin clot degradation, respectively, in systems with varying concentrations of collagen were also studied. The extent of fibrinolysis was monitored in these in vitro wound models at different plasmin concentrations for a maximum duration of 72 hours. Experimental data obtained at 0.5, 12 and 24 hours were statistically compared in various systems.

Results obtained from the statistical analysis of data using the non-parametric Mann Whitney U significance test showed that aprotinin significantly inhibited fibrinolysis at (p < 0.01 and p < 0.05) in systems containing collagen. Results also showed that bromelain improved fibrinolysis the most after 12 and 24 hours in systems with higher amounts of collagen. Results further showed that the presence of increased amounts of collagen in the systems decreased the extent of fibrinolysis. This suggests that prolonged presence of fibrin matrices is an attribute of early excess of collagen synthesis without corresponding breakdown and may fairly rationalize the incidence of fibrotic disorders that occur during wound healing.