Methylpyrrolidinone chitosan (MPC), a water-soluble derivative of chitosan, was investigated as a carrier material for basic fibroblast growth factor (bFGF), a combination intended for the treatment of wound healing deficiencies. Soft and flexible fleeces of MPC were prepared by freeze drying. The growth factor was incorporated either before drying of the fleeces by mixing bFGF solution with MPC solution or by soaking bFGF solution into a previously prepared fleece and subsequent freeze drying. Release studies using an immunological assay, radioactivity measurements and cell culture techniques revealed a sustained release of biologically active bFGF from the fleeces. Different bFGF loadings and different fleece sizes did not influence the release kinetics.