FIBRIN SEALANT MATRIX SUPPORTS OUTGROWTH OF PERIPHERAL SENSORY AXONS

It has been suggested that fibrin-based matrix has an important role d uring the early stage of nerve regeneration. A fibrin sealant matrix, which was made by combining diluted human fibrinogen and thrombin, was used as a substrate for in vitro elongation of neurites and in vivo r egeneration of axons. In the in vitro experiment, dissociated embryoni c chick sensory neurons were cultured on dishes coated with fibrin sea lant matrix and compared with the solution of thrombin/calcium chlorid e, or with poly-D-lysine (PDLctr). After 16 hours, cultures were stain ed immunohistochemically with a monoclonal antineurofilament antibody. The neurons survived well, and an abundant network of neurites, quali tatively similar to that on PDLctr, developed on the fibrin sealant ma trix. The percentage of neurons that had outsprout at 16 hours was the same both in the fibrin sealant matrix and PDLctr groups. By contrast , all the neurons plated on the dishes treated with the solution of th rombin/calcium chloride were dead after 16 hours. Immunohistochemical staining of fibrinogen also showed an even distribution of fibrin matr ix over the culture dishes. For the in vivo experiments, 48 rat sciati c nerves were cut and reconnected with two epineurial stitches. Fibrin sealant matrix or phosphate buffer solution was applied to the transs ected and repaired region. Pinch reflex test showed that the regenerat ion of the leading sensory fibre was significantly faster in the fibri n sealant matrix group than in the control group at 3 and 4 days. Thes e results indicate that fibrin sealant matrix accelerates regeneration of axons in vivo during the early phase, and also supports elongation of neurites in vitro.