Self-assembly And Photodynamic Performance Of Amphiphilic Corannulene Micelles

As a curved bowl-shaped polycyclic aromatic hydrocarbons(PAHs),corannulene(Cor)exhibits a three-dimensional topological structure,which endows it with a large dipole moment and uneven electron distribution.However,the poor solubility in aqueous solution limit the application of corannulene in the biological system.Based on the molecular structure of Cor,a new kind of amphiphilic PEGylated corannulene derivative(mPEG-Cor)has been designed and synthesized by conjugating Cor with polyethylene glycol(PEG).Due to the hydrophobic interaction and intermolecular ?-? stacking interacion,mPEG-Cor will self assemble into micelle with high drug-loading in water,PEGylated perylene(mPEG-Per)was also synthesized as flat control.Since the curved structure of corannulene showed a substantial dipole moment,the curved corannulene hydrophobic segment formed a more intense micelle by enriched intermolecular electrostatic interaction and enhanced intermolecular ?-? stacking interaction compared with flat control.The curvature was also able to effect the pharmaceutical property of self-assembled micelle,the mPEG-Cor micelle was selected as a model to study the photodynamic therapy(PDT)ability and effect in biological system based on the good stability in aquous media.The successful synthesis of three types of PEGylated corannulene derivetives(PEG-Cor)and mPEG-Per were characterized by nuclear magnetic resonance spectroscopy,mass spectrometry and ultraviolet spectroscopy.The morphology of selfassembled micelles of three types of PEG-Cor was characterized by transmission electron microscope(TEM).The results showed that micelles of the three types of PEGylation strategies all formed well-distributed spherical micelles in water.Curved corannulene and planar perylene were selected as hydrobhobic segments of polymeric micelle separately.The topological architecture of micellar hydrophobic segment can affect the stability matters of self-assembled micelle.Thermodynamic stability was compared by the characterization of critical micelle concentration(CMC),particle size and Zeta potential data.The fluorescence variation upon dilution revealed the difference of the kinetic stability.Meanwhile,the stability of the micelles against time in the biological medium was also measured.The results showed that the spatial and geometrical properties of the hydrophobic segment will affect the stability of self-assembled micelle: compared with the planar perylene,the increased curvature of hydrophobic segment formed a more intense micelle by enriched intermolecular electrostatic interaction and enhanced intermolecular ?-? stacking interaction.mPEGCor micelle was chosen to study the photodynamic therapy ability and effect.Fluorensent probe method was empolyed to display that the corannulene was capable to produce reactive oxygen species(ROS).In the cytotoxicity assay,the half maximal inhibitory concentration(IC50)of mPEG-Cor micelle reached 22.5 ± 2.6 ?M under 15 min UV irradiation,which exhibited a certain photodynamic therapy ability.In summary,mPEG-Cor micelle solved the poor solubility of corannulene.Meanwhile,the curvature of Cor enhanced the stability of self-assemble micelle,and the mPEG-Cor micelle was able to produce ROS under UV irradiation,all the results demonstrated that the curvature can be regarded as a significant parameter to regulate the physical and chemical properties and biological effects of carban materials.