A novel α_Vβ₃ ligand-modified HPMA copolymers for anticancer drug delivery

Abstract

The integrin α_Vβ₃ receptor emerged as one of the most promising targets owing to its high expression on the surface of various malignant tumour cells and tumour angiogenesis endothelial cells, but with little expression in mature endothelial cells and the majority of normal cells. Here, we report a new targeting ligand FQSIYPpIK (FQS) with high affinity to integrin α_Vβ₃ receptor. To take the advantage of the particular interaction between FQS and integrin α_Vβ₃ receptor, FQS was linked to N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers. A model drug doxorubicin (DOX) was simultaneously conjugated to the same HPMA copolymers via pH-sensitive hydrazone linkages (FQS–HPMA–DOX). In in vitro study, FQS–HPMA–DOX could be internalised into α_Vβ₃ receptor-overexpressed B16F10 cells via a highly specific ligand − receptor pathway (5.0 times and 4.5 times higher cellular internalisation than HPMA–DOX and a scrambled peptide (s)-FQS (sequence: SYFIPKQIp)-modified copolymers ((s)-FQS–HPMA–DOX)). It is worth noting that compared with the classical α_Vβ₃ ligand cRGDfK-modified HPMA copolymers (cRGDfK–HPMA–DOX), FQS–HPMA–DOX also showed superior targeting efficiency. In in vivo study in the B16F10 melanoma bearing mice model showed the antitumour efficiency of FQS–HPMA–DOX (83.9%) were significantly higher than HPMA–DOX (44.9%) and cRGDfK–HPMA–DOX (77.5%). These results suggest that FQS peptide can act as an effective targeting ligand for the delivery of therapeutic agents.

Keywords:

• FQS peptide
• cRGDfK peptide
• α_Vβ₃ receptor
• HPMA copolymers

Disclosure statement

The authors report no declarations of interest.

Additional information

Funding

National Natural Science Foundation of China10.13039/501100001809

We gratefully acknowledge financial support from the National Natural Science Foundation of China [81603042, 81473167].