Self-assembly And Phototherapy Properties Study Of New Conjugated Porphyrins

Currently,cancer has become a major disease that threatens human health.The traditional treatment methods have been unable to meet people's treatment needs due to toxic side effects and long treatment cycles.Photodynamic therapy mainly produces singlet oxygen to damage cells through the energy transfer of photosensitizer.Photothermal therapy converts light energy into heat for thermal ablation of cancer cells.These new methods of phototherapy for tumors have attracted many attentions and develop rapidly due to their high controllability,good selectivity,small trauma and few side effects.Porphyrins play an important role in phototherapy of tumors because of their excellent photophysical properties.Therefore,the porphyrins were modified to overcome the shortcomings of poor water solubility and weak near-infrared absorption.Four free porphyrins were designed and synthesized,and then self-assembled to obtain nanoparticles.The structure was detecteced by ~1HNMR and Maldi-TOF MS.After that,we studied the binding mode and ability of porphyrin compounds to DNA,singlet oxygen production,photothermal effects and photostability,cytotoxicity.The experimental results showed that the porphyrin compounds and DNA had a good combination,Por 3 and Por 3 NPs were external binding modes,and the rest were in the insertion mode.Due to aggregation effect,the nanostructure had large specific surface area and high density,so that the compound had better photophysical and chemical properties.Compared with free porphyrin,the nanoparticle had better UV absorption and better fluorescence quenching,higher singlet oxygen production capacity.The nanoparticles had uniform particle size and good dispersion.The phototoxicity of Por 1 NPs,Por 2 NPs and Por 3NPs was obvious,and the photothermal conversion efficiencies were 21.23%,27.75%and 25.65%,respectively.Among them,Por 4 NPs was a D-A-D structure formed by covalently linking two triphenylamines with porphyrins.It had the best singlet oxygen capacity and a photothermal conversion efficiency of 24.53%.These properties make the new conjugated porphyrins to be the excellent phototherapeutic agent for synergetic photodynamic and photothermal therapy.