Construction Of Multifunctional Polyphenol Film Based On The Aggregation Of Controllable Self-polymerizing Particles

Interfaces of biomaterials of great significance for biomaterial applications.Traditional methods of modifying the surface of biomaterials include chemical and physical methods.The chemical methods can give the substrate a higher graft density and stronger surface adhesion,but the substrate needs to be pretreated,and the process is cumbersome.The modification process of the physical methods is relatively simple,but the bonding force between the modified coating and the substrate is weak.Therefore,it is necessary to develop a simple,efficient,strong binding,and suitable strategy for various substrate modifications.Polyphenol materials have the advantages of easy availability of raw materials,low price,broad-spectrum substrate adhesion,active physical and chemical properties,and good biocompatibility.Tannic acid,as the molecule with the largest number of phenolic hydroxyl groups in polyphenols,has more reaction sites and better reactivity.At present,tannic acid materials mainly modify the substrate through hydrogen bonding/electrostatic layer-by-layer deposition,auto-oxidation deposition and metal ion chelation deposition.However,these methods have the disadvantages of serious waste of raw materials,low phenolic hydroxyl activity,and the inability to leave the substrate to form a free-standing film independently.In response to these problems,our group used the host-guest interaction between tannic acid(TA)and polycyclodextrin(PCD)in previous work to prepare tannic acid-polycyclodextrin particles(TPP),and then the tannic acid-polycyclodextrin film(TPF)was prepared by the solvent volatilization method,which solves the defects of low raw material utilization rate cumbersome preparation process and low phenolic hydroxyl activity compared with traditional tannic acid modification methods.However,there are still insufficient researches on the proof of the host-guest role between TA and PCD,the regulation of TPP self-polymerization speed,and the independent existence of membrane materials from the substrate.This paper used computer simulation and a two-dimensional nuclear magnetic field to prove the host-object combination between TA and PCD.By changing the molar ratio of PCD/TA,the speed of self-polymerization of TPP was controlled,and the self-polymerization and broad-spectrum substrate adhesion of TPP was used to prepare TPP into TPF.Compared with the traditional hydrogen bonding layer deposition,auto-oxidation deposition and metal ion chelation deposition of tannic acid film,TPF has the highest residual amount of phenolic hydroxyl group(93%).TPF also possessed p H responsiveness.The interaction between TPF and substrate can be destroyed in a buffer with a p H value of 6.7-9,while retaining the host-guest role between TA and PCD,and achieving complete peeling of TPF from the substrate.Combined with the non-specific adhesion of TPF's high phenolic hydroxyl activity to cells and proteins,cell sheets(93% cell activity)and protein membranes(90% protein activity)that can be peeled under physiological conditions can be prepared.In addition,TPF can be doped with different metal ions and multifunctional particles to show different properties.The iron ion-doped TPF/Fe films were prepared by the doping of iron ions,and the TPF/Fe was stable in the p H range of 1-13.Under alkaline conditions,TPF/Fe can be quickly peeled from the substrate within 30 minutes.A composite material with host-guest self-repair and conductivity capabilities was fabricated by doping the reduced graphene oxide.Moreover,increasing the concentration of TA and PCD can be used to prepare a high-viscosity glue,which had strong adhesion to various substrates such as polymer,glass and metal.Compared with common glues,this glue has self-healing and repeatability,and It can maintain viscosity for a long time in a water environment.