Videos Nerve Regeneration in collagen-based hydrogelsNerve Regeneration in fibrin-based hydrogelsNerve Regeneration in fibrin-based hydrogelsHydrogel stiffness affects cardiac contraction in 3-DHydrogel stiffness affects cardiac contraction in 3-DSemi-synthetic protein polymer hydrogels for 3-D cell cultureConfocal microscopy of 3-D cell cultures in fibrin hydrogelsConfocal microscopy of 3-D cell cultures in PEG-fibrinogen hydrogelsMatrix stiffness affects cell spreadingMatrix stiffness affects cell spreading