The Role Of Peptide Self-assembly In The Construction Of Responsive Biofunctional Materials

With the advances in biology and material science,numerous biofunctional materials have been developed over the past decades,and traditional biofunctional materials have been found to be excellent but some limitations,such as: no targeting,biocompatibility to be investigated,inability to control on demand,etc.The use of these stimulus changes to construct bio-functional materials is of great interests because of many stimulus changes existing in vivo and in vitro usually causing no damage to tissues and cells.In recent years,researchers have made great progress in the study of stimuli-responsive biofunctional materials,which can be broadly classified as photo-responsive biofunctional materials,pH-responsive biofunctional materials,thermal-responsive biofunctional materials,molecular-responsive biofunctional materials,and oxidation-responsive biofunctional materials,etc.Most of the functional materials in nature are composed of proteins,due to the high biocompatibility,designable structure and easy to modification of peptides,many proteins and peptides were used in constructing responsive biofunctional materials.Peptide self-assembling plays a significant role in constructing responsive biofunctional materials.Peptides are composed of different amino acid residues,with different active functional groups on the peptide sequences,which can be easily modified by artificial methods.It can form various ordered nanostructures,such as nanofibers,nanotubes,nanorods,nanosheets,etc,by intermolecular hydrogen bonding,hydrophobic and electrostatic interactions spontaneously in aqueous environment.Exploiting the easy modification of peptides can drive the self-assembly of various functional molecules to form functionalized nanostructures.In this thesis,we described the use of peptide self-assembly to construct responsive biofunctional materials and demonstrated the responsiveness of the prepared materials as follows.(1)Binding the self-assembled peptide Fmoc-FF to the covalent system interface of phenylboronic ester.Self-assembling functional sequences at the interface endows the interface with capture ability of E.coli and with dual response release ability of sugars and enzymes.(2)Two modified pH-responsive peptides were synthsized,one of which was bound to the silica interface and the other one was attached to the bacterial recognition sequence,two peptides were co-assembled in a neutral environment to endow the interface with bacterial recognition ability,and controlled bacterial release was achieved by adjusting the pH to acid.This work provided an alternative for constructing the dynamic biointerface by peptide self-assembling.(3)Two pH-responsive cationic antimicrobial peptides were designed to prepare antimicrobial nanofibers,and the peptides were assembled and disassembled by pH regulation,and integrated into the agar film to make the hybrid film material have antimicrobial properties.