A Research Of The Interaction Between Cucurbit [n] Urea And Mimic Biomembrane

Objective:cell is the basic structural unit of organism,and its function depends on the special molecular structure of cell membrane.Material balance of organisms rely on cell membrane,because the cell membrane phospholipid bilayer structure prevents the cells inside and outside material free access,but combination of phospholipid bilayer membrane proteins,receptors and enzyme molecules can be by active and passive transportation inside and outside the cell to transfer information,material and energy.Due to the complex structure of cell membrane,it is necessary to simplify the structure of cell membrane.Many simple simulated biofilms,including supporting phospholipid bilayer?s-BLM?,liposomes and vesicles,have been widely studied as models of cell membrane or biofilm.In supramolecular chemistry,the study of cucurbit urea has been at its peak in the past ten years because of the special recognition ability of cucurbit urea family.Cucurbituria has been widely used in various molecular assembly,sensors,drug carriers and advanced materials,but its chemical modification is difficult,which limits its application in drug delivery and other fields.In this paper,cucurbit urea is combined with the phospholipid bilayer membrane to form a self-assembly.Through the host-guest interaction,the carbonyl groups on both ends of the cucurbita[n]urea?n=5,6,7,8?can easily combine with the hydrophilic end of the phospholipid bilayer,thus damaging the framework structure of the phospholipid layer and forming ion channels to achieve targeted drug delivery.Methods:phosphatidylcholine and cholesterol were used as raw materials to prepare luciferin liposomes.The fluorescence intensity of carboxyl fluorescein leaking from liposomes was detected by fluorescence spectrometry based on the principle that cucurbit urea can be interacted with liposomes to cause liposome leakage.The mechanism of interaction between hyacinth urea and supported bilayer phospholipid membrane?s-BLM?was studied by cyclic voltammetry.Results:1.The Cucurbit[n]uri(CB[n]?n=5,6,7,8?and liposome through the membrane dispersion,freezing and thawing of CB[n]?n=5,6,7,8?and liposomes prepared by self-assembly,CB[n]?n=5,6,7,8?was studied by fluorescence spectroscopy liposome and interaction,the experimental results show that the CB[n]?n=5,6,7,8?and the interaction of liposome after compared with the standard liposome stability decreases,and the CB[7],[8]interaction after the fluorescence intensity of fluorescence liposomes.2.The platinum electrode was selected as the substrate to prepare the supporting phospholipid film on the platinum electrode,and the electrochemical method proved that the phospholipid film was a bilayer film.Using cyclic voltammetry?CV?method,the interaction between the supporting bilayer membrane and CB[n]?n=5,6,7,8?was studied.It was found that CB[n]?n=5,6,7,8?can generate some holes on the bilayer membrane,through which probe[Fe?CN?₆]^3-/4-molecules can reach the surface of the electrode.The experimental results showed that CB[n]?n=5,6,7,8?can generate strong interaction with s-BLM,inducing s-blm to produce ion channels.Conclusion:cucurbita[n]urea?n=5,6,7,8?can respond to liposomes and generate ion channels on the phospholipid bilayer.