Preparation And Properties Of Nanomaterials Used To Inhibit Angiogenesis In Tumor Sites

Tumor metastasis as the most common reason of death from cancer has always be a great challenge in both clinical and scientific research.And angiogenesis plays a necessary role in the metastasis.During the growth of tumor tissues,a lot of nutrients and oxygen are needed,which the normal blood vessels not afford.To obtain enough nutrition,tumor cells release the Vascular Endothelial Growth Factor(VEGF)for the induction of angiogenesis.New blood vessels can also provide a pathway for tumor metastasis.During the process of tumor growth,VEGF,as a kind of growth factors of blood vessels which is released by cancer cells can bind to the receptors on the membrane of vascular cells after passing through the extracellular matrix,activate downstream pathways and promote angiogenesis.We designed and synthesized a peptide to target VEGF.The peptide is consisted by 3 motifs: targeting the VEGF sequence: RRRKRR;self-assembly sequence for the formation of nanofibers: KLVFF;high hydrophobicity and fluorescence unit,leading to the formation of nanoparticles: bis-pyrene(BP).Particulate structures for transformable nanoparitcles(TNPs)(49 ± 5 nm)with VEGF were observed for the first day,followed by transformation into NFs((37)= 10 ± 3 nm)in 3 days.These results implied that the structural transformation was induced by VEGF.The transformation of TNPs is validated in vitro and in vivo.Finally,this study demonstrates that the angiogenesis positively relates with tumor growth as well as the tumor metastasis,the antiangiogenic therapy inhibits tumor metastasis with inhibition rate of 65.9%.