In Situ Construction Of Supramolecular Nanomaterials And Their Biological Applications

Supramolecular assembly to form a large variety of nanostructures has received increasing attention for diverse applications,in particular biomedical applications involving drug delivery,bioimaging,therapy and regenerative medicine.Meanwhile,the modulation of morphology and structure of nanoassemblies is a still big challenge.Herein,in this article report a series of supramolecular structures(BP-KLVFFG-PEG,BKP),which consists of three parts,one part is KLVFF polypeptide through the interaction of hydrogen bond self-assemble into nano-fiber structure,BP having a molecular AIE effect through ?-? interactions can be assembled into nanoparticles,PEG can make the material has good biocompatibility.And elucidate that their morphological transformation process is modulated by H-bonding,?-? interactions and hydrophilic/lipophilic balance(HLB).Studies reveal that the hydrophobic and ?-? interactions initially drive the self-assembly of BKP into nanoparticles in a J-type aggregates in water,and the H-bonding interactions further induces in situ spontaneous morphology transformation into nanofibers.The conversion rate is related to the length of hydrophilic chains.The nanofibers are maintained by ?-sheet H-bonds with parallel structure.The study results provide insight of the relationship between molecular structures and morphological transformations of self-assembled nanomaterials,which laid the foundation for designing complex self-assembled materials in biological condition.At the same time,the artcle study that in situ external stimuli induce nanostructures and morphological transformation.Herein,the article report an assembly and transformation process of a supramolecular module,BP-KLVFF-RGD(BKR)which also consists of three parts,one part is KLVFF polypeptide through the interaction of hydrogen bond self-assemble into nano-fiber structure,BP having a molecular AIE effect through ?-? interactions can be assembled into nanoparticles,RGD peptides on cell U87 having specific binding target.BKR were added in solution and on specific living cell surfaces for imaging and treatment.The BKR self-assembled into nanoparticles,which further transformed into nanofibers in situ induced by coordination with Ca2+.As a result,BKR nanoparticles could bind to the Ca2+ on the surface and light up the calcium alginate beads with BKR green fluorescence.More importantly,the BKR nanoparticles could bind to ?v?3 integrin overexpressed on U87 cell membrane through RGD to Ca2+.At the same time,BKR nanoparticles further transformed into nanofibers on the U87 cell surfaces,leading to the cell death.