Preparation of chitosan-coated alginate filament

The coating of alginate filament was achieved simply by the addition of chitosan to the first coagulation bath for alginate filament. The smooth and uniform chitosan coatings were confirmed both by the microscopic picture of ninhydrin-treated filament and the brightness of filament. The enhancement of tensile strength was also observed by the coating of alginate filament by chitosan through ionic interaction. There was significant molecular weight dependency on the tensile strength of chitosan-coated alginate filament especially in wet properties, suggesting the tight interaction of chitosan to alginate filament.