Improvement of schwann cell attachment and proliferation on modified hyaluronic acid strands by polylysine

Hyaluronic acid (HyA) has the intrinsic ability to promote cell proliferati on and reduce scar formation. However, the clinical use of HyA has so far b een limited because of its water solubility and nonadhesive characteristics . Increasing interest in HyA as a clinically useful biomaterial has prompte d our study of altering HyA's physical properties to render it a potential component of nerve grafts. In this study, strands of HyA were cross-linked by glutaraldehyde (Glut), coated with polylysine, and then inoculated with Schwann cells (SCs). Results in vivo and in vitro demonstrated that cross-l inked HyA strands were water insoluble and thus less biodegradable. Poly-D- lysine-resurfaced strands showed significant SC attachment of 350-400 cells /mm(2), compared to uncoated controls (0-10 cells/mm(2), p < 0.01). Fibrobl ast control groups showed an attachment of 40-100 cells/mm(2) on coated str ands. Immunostaining for proliferating cells showed SCs as +++ and fibrobla sts as +. Cells neither adhered to nor proliferated on the modified HyA str ands that were not resurfaced. The results suggest that polylysine promotes SC attachment and proliferation to glutaraldehyde-cross-linked HyA strands , the product being a three-dimensional composite with low solubility that may have potential application in nerve grafts.