['The', 'patterned', 'hydrogel', 'films', 'can', 'be', 'triggered', 'consecutively', 'allowing', 'for', 'successive', 'rolling', 'and', 'unrolling', 'depending', 'on', 'the', 'aqueous', 'pH.', 'The', 'choice', 'of', 'PEGDMA', 'hydrogel', 'provides', 'a', 'versatile', 'platform', 'for', 'creating', 'a', 'variety', 'of', 'hydrogel', 'scaffolds', ',', 'and', 'while', 'being', 'non', '-', 'fouling', 'and', 'nontoxic', 'it', 'is', 'permeable', 'to', 'proteins', '.']