Characterization and bioactivity of self-assembled anti-angiogenic chondroitin sulfate-ES2-AF nanoparticle conjugate

Xing, Liang; Sun, Feng; Wang, Zhendong; Li, Yan; Yang, Zhifang; Wang, Fengshan; Zhai, Guangxi; Tan, Haining

To conclude, ES2-AF was synthesized by a solid-phase method in this study and CS-ES2-AF was obtained by chemical modification of a new peptide ES2-AF with CS. First, 1 H-NMR spectrum showed that CS successfully bound to ES2-AF and that there were two peptides per one CS chain. Then, the in vitro activities of ES2-AF and CS-ES2-AF were studied. The results showed that CS-ES2-AF had better ability to inhibit the proliferation and metastasis of endothelial cells than ES2-AF. Then, the binding ability of ES2-AF and CS-ES2-AF in vitro and in vivo was studied. ELISA results showed that the glycosylation-modified product CS-ES2-AF inhibited the binding ability of VEGF to its receptor, better than the peptide ES2-AF; SPR results showed that the binding ability of CS-ES2-AF to CD44 receptor was better than that of ES2-AF; in vivo imaging experiments showed that the distribution of CS-ES2-AF in tumor-bearing nude mice was targeted. In addition, bioimaging results showed that CS-ES2-AF had a longer metabolic time compared to ES2-AF in vivo, which may be due to the increased stability of CS-ES2-AF in plasma. That was consistent with the in vivo half-life experiments. The half-life of CS-ES2-AF was approximately threefold longer than that of ES2-AF. These data strongly suggest that CS has the desired effect of extending the half-life of this peptide drug.