Synthesis,assembly Regulation And Application Of Coumarin-based Amphiphilic Molecules

In recent years,light-responsive nanomaterials based on peptide self-assembly have shown promising applications in biomedicine due to their good biological activity and photo responsive property.Coumarin photosensitizer with UV and NIR light responsiveness has been a hot researh.Based on coumarin,C4-Bhc-COOH and C4-Bhc-EE-NH2 with UV and NIR photo light responsiveness have been designed and synthesized.To make these synthesized molecules to form super-molecule nanomaterials by non-covalent interactions,we investigate assembly of two molecules and study the compounding behaviors with C14DMAO and C14-FKK-NH2,respevtively.The surface tension measurement,Cryo-TEM and DLS results show that the sodium salt of PAS could form micelles at proper concentration.And at proper concentration the micelles could be destroyed by UV and NIR light irradiation.PAS and surfactant tetradecyldimethylamine oxide?C14DMAO?could co-assemble into wormlike micelles and vesicles.These wormlike micelles and vesicles could be be also degraded by UV and NIR irradiation due to the participation of PAS.The stimulus-responsive system was used to control the diffusion of hydrophobic and hydrophilic molecules.And it has shown controllable release effects on both the hydrophobic and hydrophilic molecules.TEM and AFM results revealed that C₄-Bhc-EE-NH₂ self-assembled into irregular spherical aggregates.While C₄-Bhc-EE-NH₂ and cationic lipopeptide C14-FKK-NH2 could a coiled nanofiber cluster structure and their solutions showed viscoelasticity.The nanofiber cluster structure disintegrated and fractured to some extent after UV and NIR light irradiation.Both the pH of the solution and the proportion of the peptide influenced the co-assembly behavior.CD and FITR results showed that with the increase of the amount of C₄-Bhc-EE-NH₂,the secondary structure of the mixed system changed from?-sheet to random coil.The entangled nanofiber clusters are mainly formed by the electrostatic interaction and?-?stacking through H1-NMR,UV spectrophotometer,CD results.Due to the special fiber cluster structure of the C₄-Bhc-EE-NH₂/C₁₄-FKK-NH₂system,it showed good encapsulation ability for DOX and BSA both at high concentration and low concentration.The peptide complex system showed a better entrapment efficiency for DOX compared with BSA.And the entrapped molecules could be released rapidly under the UV and NIR irradiation.The Hela cells were almost completely killed after the peptide system containing DOX interacted with Hela cells for 48 hours.While the Hela cells were almost completely killed within 12hours when NIR light was adopted.This result proved the photoregulation of the light responsive peptide-based material on drug delivery.