Nerve growth factor (NGF) and laminin are important factors for neural development and regeneration. We examined the effects of increasing the local concentration and duration of action of NGF and laminin on peripheral nerve regeneration in the adult mouse sciatic nerve. A Silastic (silicone rubber) channel with intraluminal NGF solution was secured between transected nerve ends. The second channel tested, formed from a polysaccharide called chitosan, was prepared with NGF and laminin in the channel walls and provided a sustained release of NGF. At six weeks post-implantation, no improvement in nerve regeneration was identified in those channels prepared with NGF when comparing electromyographic thresholds (microA), maximum potentials (mV), nerve diameter, myelin sheath thickness, myelinated axon counts, or diameter. However, increased angiogenesis was demonstrated within the chitosan and Silastic channels prepared with NGF compared to those channels without NGF. Silastic exhibited minimal inflammation. Chitosan was associated with inflammation in many nerve channels.

Chitosan was precipitated onto wood pulp, glass and polypropylene fibers suitable for papermaking. The coating which formed on the fibers was characterized by photomicrography after the formation of colored derivatives, and by scanning electron microscopy. The most uniform and adherent coatings were formed on the wood pulp fibers and the least were formed on the polypropylene fibers. Paper handsheets were readily formed from the chitosan-coated wood pulp and glass fibers, but not from the chitosan-coated polypropylene fibers.