Study On The Controlled Molecular Release Of Layer-by-layer Multilayers That Involve Graphene And β-cyclodextrin

In the field of biomedical materials,the total release of drug molecules and sustained release rate is the key to determining the function of material and the effect of treatment.Macromolecules have important applications in the preparation of dosing films,modified medical implants or nanoparticle drug carrier surfaces.At present,it is difficult to adjust the release rate of small molecule drugs in order to achieve sustained and controlled uniform release and to adjust the release rate of multiple drugs,respectively.In this paper,the multi-layer structure of graphene and host guest effect of cyclodextrin was introduced into the sustained release films,and realized the controlled release of small molecules and lay the foundation for the further design and prepare the multilayer which owns the ability to adjust a variety of drug release rate.Firstly,the free-standing of graphene-based multilayers were prepared by covalently crosslinking.The molecular diffusion size was determined by the assembly structure of the graphene sheet.A variety of small molecules with diameters around 1nm,such as MB,RhB,Fluorescein sodium can pass through the film,but peptides and proteins or other macromolecules cannot pass.The diffusion rate of small molecules was adjusted by the number of graphene layers.The graphene-based multilayers can uniform release small molecule up to 9 days.Theβ-cyclodextrin(β-CD)was introduced into the multilayers,selectively adjusted the load and slow release of the peptides by the rapid and reversible assembly behavior of the cyclodextrin and others guest molecule.Host and guest interaction increase the load efficiency of the molecule and slow the rate of diffusion.The effect of host and guest interaction on the sustained-release behavior was analyzed by numerical simulation.The multilayers were loaded with DOX and RGD polypeptides with adamantane guest functional groups at the same time,and adjusted their diffusion curves,respectively.On the sustained release multilayers,contrasting culture of lung cancer cells and lung healthy cells and the result showed that the difference between the two drugs and the flow rate could be used to expand the responsive behavior between tumor and healthy cells,the survival rate of tumor cells was lower than healthy cells.Finally,the graphene composite structure and the host and guest interaction were introduced into the multilayer structure and combining the high loading capacity MP-SiO2 particles fabricated(PAH-SiO2)a-(PAH/GO)m-(PAH/PAA-CD)n multilayer.Small molecular methylene blue was loaded in mesoporous silica,graphene structure to adjust its release rate;Peptides with adamantanes are adsorbed on PAA-CD,and their release rate is regulated by the host-guest interaction.Finally,Cell experiments show that we can adjust the two kinds of drug flow,and realized the difference cellresponse among lung tumor cells and healthy cells.