The present invention relates to a method for preparing a three-dimensional polymer scaffold (3D-PS) for use in tissue-engineering, said method comprising the subsequent steps ofa) providing a polymeric precursor scaffold (p-PS) comprising at least one biodegradable natural polymer (PA) ；b) treating the polymeric precursor scaffold (p-PS) with a cross-linking agent comprising glutaraldehyde to induce cross-linking of the natural polymer (PA), thereby forming a cross-linked polymer scaffold (x-PS)；c) subjecting the cross-linked polymer scaffold (x-PS) of step b) to low-pressure plasma treatment involving exposure of the polymer scaffold to an ionized oxygen-containing gas plasma at a pressure in the range of 10-3 to 10-6 bar and a temperature below 40°C.
