Scanning electron microscopy (SEM) was used to test surfaces of the materials, including fibers diameter and pore sizes, as earlier described [23]. The contact angle was determined with a Drop Shape Analyzer DSA 25 (Kruss GmbH, Hamburg, Germany), as described in the manufacturer’s instructions.

A Universal Zwick/Roell Z100 (Zwick Roell AG, Ulm, Germany) test bench was used to study mechanical properties of scaffolds, as described in ISO 7198:1998 (4 replicates for every scaffold) [23]. A “wet” sample was obtained after incubation of a matrix in water for 30 min at 20–23 °C to moisten the 3D matrix completely. The strength and elongation of matrices were determined from the constructed tensile curves in four replicates. Young’s modulus was determined in experiments with statistical loading. Before testing, the material was conditioned by loading the test specimen 5 times (each for 10–20 s) using 30–50% of the elastic limit load determined in the preliminary test. The static load was increased in steps of 10 g (to 60–70% of the elastic limit) that were applied for 20 s with a subsequent measuring of the deformation after unloading. The load that induced more than 5% elongation after unloading was considered the elastic limit.