Novel heparin/alginate gel combined with basic fibroblast growth factor promotes nerve regeneration in rat sciatic nerve.

We have developed an alginate gel crosslinked with covalent bonds for regeneration of dermis, nerve, and bone. Recently, a novel matrix (H/A gel) which consists of heparin and alginate covalently crosslinked with ethylenediamine, was designed. It can stabilize and release biologically active basic fibroblast growth factor (bFGF) for 1 month, which is one of the heparin-binding growth factors. In the present report, we examined the effect of this novel H/A gel on nerve regeneration in the rat sciatic nerve. In this study, regenerated axons in H/A gel with bFGF grew faster than in ordinary alginate gel with bFGF in the early stage. Myelinated fibers showed a tendency to increase in diameter toward the normal size in the later stage. Nerve bundles in the implantation exhibited minimal fibrosis and good vascularization. H/A gel with bFGF exhibited better-developed vascularization than ordinary alginate gel with bFGF. These findings suggested that H/A gel with bFGF could serve not only as an efficient cellular scaffold, but also as a stabilizing matrix for bFGF for peripheral nerve regeneration.