Preparing photochromic nanofibers and animal cells using a photochromic compound of 1′,3′,3′-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2′-indoline)

► We synthesize a photochromic compound. ► We make photochromic fibers and cells. ► Especially, we test the bio-toxicity of the photochromic compound.