hydrogelThe prepared nano fibrin constructs were suspended in water(1 mg/ml) and sonicated (Sonics, Germany) for 2–3 min. The madesuspension was combined with the prepared hydrogel (Algi-nate/PVA hydrogel and the Alginate/O-CMC hydrogel) which weremixed in the ratio of 8:2, i.e. eight parts of the polymer solutionand two parts of fibrin nano suspension. The complete solutionswere stirred continuously for 2 min with addition of their respec-tive cross-linker agents. Gelation was observed after 2–3 s and theformed samples were incubated at 37◦C (Fig. 1A and B). The sam-ples were lyophilized after 24 h (Martin Christ, Germany).