Modified PAMAM dendrimers as a matrix for the photostabilization of curcumin

Abstract

Six recently synthesised poly(amidoamine) (PAMAM) dendrimers from zero, first and second generations modified with 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (curcumin) and 2,4-dihydroxybenzophenone (CU-1, CU-2, CU-3, CU-4, CU-5 and CU-6) have been investigated in water/dioxane (4 : 1) (v/v) solution by absorption and fluorescence spectroscopy in order to determine their photostability. It has been found that the photostability of curcumin is enhanced upon its incorporation into the dendrimer molecule, and a new additional stabilization is achieved by bonding of 2,4-dihydroxybenzophenone as a UV absorber to the dendrimer molecule. It has also been established that the generation of dendrimers impacts upon this parameter as the photostabilizing effect enhances at a higher dendrimer generation. The photostability of the dendrimers has also been investigated after their deposition onto a polyethylene terephthalate (PET) fabric.