Synthesis And Application Of Coumarin Light Trigger-built Light Response Of The Material

With the rapid development of light-control technology especially in the bio-medicine field, phototriggers based photo-responsive molecules aroused increasing interest. To furtehr improve the control precision of the light-control technology, enrich the structure type of coumarin phototrigger and expand the its applications, herein, we focus on two works upon the intrinsic photo-SNl-dependent cleavage and the strong fluorescence emission characteristics of the coumarin phototrigger:1) Traditional phototrigger molecules are nonselctive, non-target and activated state all the time. To solve this problem, we designed and synthesized a thiol target-activated phototrigger and used it to construct intracellular target-activated photo-controlled drug release system. In view of the significantly different concentration of GSH between intracellular and extracellular environment, disperse red1was conjugated with coumarin through a disulfide bond to quench the S1state of coumarin by fluorescence resonance energy transfer (FRET). Then, the intracellular GSH with high concentration effectively reduced the disulfide bond to destroy the FRET and reactivated the fluorescence and photorelease behavior of coumarin, thus realized the intracellular target-activated photorelease.2) Non virus gene vectors which carry DNA into cells cannot effectively escape from vectors and this character will lead to low transfection efficiency. In order to settle this problem, we prepared a light response gene vector by applying coumarin phototrigger. One the one hand, lysine was introduced to adsorpt DNA; and on the other hand, cholesterol was conjugated as hydrophobic group to improve the cell membrane permeability. After mixing with DNA, nano micelle complexes were formed by the self-assembly, which effectively released DNA upon light irradiation.