Surfactant-immobilized fibronectin enhances bioactivity and regulates sensory neurite outgrowth

A PEG-containing surface coating was investigated as a means to control neu rite outgrowth in the presence of serum. Various ratios of end-group-activa ted triblock copolymer Pluronic(TM) F108 were used to immobilize the extrac ellular matrix protein fibronectin (FN). Primary cultures of dorsal root ga nglion neurons were cultured on F108-immobilized FN or, as a control, on FN adsorbed from solution directly to polystyrene. Although FN surface concen tration could be controlled in a dose-dependent manner by either technique, dose-dependent control of neuronal behaviors was best achieved on F108-imm obilized FN. This effect was similar regardless of the presence of serum in the culture medium. F108-immobilized FN supported twofold greater maximal neurite outgrowth than did directly adsorbed FN. Furthermore, at similar su rface concentrations, F108-FN was significantly more active in promoting ne urite outgrowth. Polypropylene filament bundles treated with F108-immobiliz ed FN supported robust outgrowth from explants of dorsal root ganglia, demo nstrating the utility of the surface coating on clinically relevant materia ls with more complex shapes. The ability to control neuronal behaviors in a serum-resistant manner, coupled with enhanced biologic activity, demonstra tes the potential for surfactant-based immobilization as a method for gener ating biointeractive materials for tissue engineering. (C) 2000 John Wiley & Sons, Inc.