| Surfaces that resist nonspecific protein adsorption in a complex biological milieu are required for a variety of applications.However,few strategies can achieve a robust antifouling coating on a surface in an easy and reliable way,regardless of material type,morphology,and shape.Herein,the preparation of an antifouling coating by one-step aqueous supramolecular assembly of bovine serum albumin(BSA)is reported.Based on fast amyloid-like protein aggregation through the rapid reduction of the intramolecular disulfide bonds of BSA by tris(2-carboxyethyl)phosphine(TCEP),a dense proteinaceous nanofilm with controllable thickness(～130 nm)could be covered on virtually arbitrary material surfaces in tens of minutes by a simple dipping or spraying process.The nanofilm shows strong stability and adhesion with the underlying substrate,exhibiting excellent resistance to the nonspecific adsorption of wide-spectrum of contaminants including proteins,serum,cell lysate,cells and microbes,etc.In vitro and in vivo experiments show that the nanofilm can prevent the adhesion of microorganisms and the formation of biofilm.Compared with native BSA,the proteinaceous nanofilm coating exposes a variety of functional groups on the surface,which have more-stable adhesion with the surface and can maintain the antifouling property in harsh conditions including ultrasonic,surfactants,organic solvents,and enzymatic digestion.This work highlights an interesting design in which the amyloid-like protein aggregate can simultaneously possess strong interfacial bonding and antifouling,which few previous antifouling materials can achieve.The research outline is as follows:(1)Formation of the phase transited BSA(PTB)nanofilms and interfacial adhesionWe first introduce three simple methods to prepare PTB nanofilms and characterize the morphology of the nanofilms under different reaction conditions.Continuous and dense two-dimensional nanofilms were formed by assembling oligomer nanoparticles at air-water or liquid-solid interface.The nanofilm was colorless with transparent with a controllable thickness.It can stably adhere to the surfaces of substrates with various types and shapes,and can maintain its film morphology and thickness unchanged under various extreme conditions.The features of the film are controllable thickness,colorless and transparent,stable adhesion on the surface of different kinds of substrates,and reliable robustness under various extreme conditions.Then,by characterizing the morphology of the PTB nanofilms formed at different time,it was concluded that the films were formed by the continuous adsorption and gradual fusion of oligomeric particles at the surface.By CD,FTIR,ThT staining and Congo red staining,it was proved that during the BSA phase transition,the secondary structure changed fromα-helix to β-sheet,forming an amyloid-like structure.The combination of Raman spectroscopy and XPS showed that the PTB nanofilm exposed a large number of functional groups on its surface,which provided a platform with multiple flexibility for subsequent surface chemical reactions.The exposure of a large number of functional groups on the PTB surface and the increase in amyloid-like structures were considered to be the reasons for the stable interfacial adhesion of the PTB nanofilm.The PTB nanofilm which can be prepared in a large area,has the merits such as simple preparation method,cheap raw materials and stable adhesion.Amyloid-like protein aggregate of BSA is expected to become a new universal surface modification method.(2)The antifouling tests based on the PTB nanofilmThis work mainly developed a PTB-based nanofilm with broad-spectrum antifouling ability,and experimentally proved that the non-specific adsorption of various pollutants,including biofluids,proteins,and extracellular matrix components were largely inhibited on the PTB nanofilm.The PTB nanofilms could also resist biofilm formation,fungal adhesion,cell adherence and platelet adhesion.The in vitro hemolysis test,platelet adhesion test,cytotoxicity test and histological analysis proved that the PTB nanofilms had good blood compatibility and histocompatibility.Finally,animal experiment proved that the PTB nanofilm could maintain good antifouling effects in vivo,so it has the great potential for biomedical coatings.Compared with other antifouling materials such as zwitterionic polymer brushes,the preparation process for the PTB nanofilm meets the requirements of sustainable development,so it can be used as an ideal antifouling coating for food packaging and medical equipment,etc. |
