Table 1.

Photoinhibitors and Photoabsorbers

type	description	absorption wavelength	cytocompatibility	ref
Photoinhibitors
2,2,6,6-tetramethylpiperidin-l-yl)oxyl (TEMPO)	stable free radical adds to end of growing polymer chain and quenches reaction soluble in aqueous media and organic solvents	N/A	cytotoxic	92
butyl nitrite	alkyl nitrite prepared from n-butanol UV activation induces photolysis of butyl nitrite to generate nitric oxide that terminates chain propagation	moderate absorbance at near-UV with weak absorbance in the blue region	cytotoxic	87
tetraethylthiuram disulfide (TETD)	chain transfer reaction with propagating radical species reduces polymerization rates	moderate absorbance at near-UV with weak absorbance in the blue region	cytotoxic	85,86,101,102
bis [2-(o-chlorophenyl)-4,5-diphenyl imidazole] (o-Cl-HABI)	activation of lophyl radicals generated upon HABI photolysis terminates chain propagation	moderate absorbance at near-UV with weak absorbance in the blue region	N/A	89
Photoabsorbers
tartrazine	yellow food coloring also known as FD&C yellow 5, E102 water-soluble	strong absorbance in the near-UV to blue visible light	cytocompatible	93,94
curcumin	lipophilic derived from turmeric	strong absorbance in the near-UV to blue visible light	cytotoxic	94–96
anthocyanin	derived from blueberries water-soluble	strong absorbance in the blue to yellow visible light range	cytotoxic	94,97,103
inorganic gold nanoparticles	diameters between 12 and 41 nm	strong absorbance from blue to green visible light region	cytocompatible	100
2-hydroxy-4-methoxy-benzophenone-5-sulfonic acid (HMBS)	common FDA approved chemical with UV light absorbing properties in sunscreen and cosmetics	UV	cytotoxic	92
reactive orange 16 (ROl6) (disodium(3Z)-6-acetamido-4-oxo-3-[[4-(2-sulfonatooxyethylsulfonyl) phenyl]hydrazinylidene] naphthalene-2-sulfonate)	anionic azo dye water-soluble	strong absorbance in the UV and from blue to green visible light region	N/A	98,99