The homogenous fibrin films cross-linked to glass slides will be prepared. Blot concentrations will be modulated using the overprinting strategy. Pattern accuracy and surface concentration of growth factors and their persistence will be verified for FGF2. BMP2 bio-inks will be diluted to 10 µg/ml in 20 mM sodium acetate, pH 7.4. Preliminary experiments on immobilization and persistence of BMP2 on fibrin films indicate at least 6 day persistence.