Sialic Acid-Conjugate Modified Liposomes Targeting Neutrophils for Improved Tumour Therapy

Neutrophils are the most abundant white blood cells in humans, and many tumour treatment methods have been developed that are related to tissue infiltration and the activation of neutrophils. Therefore, one strategy that promises to improve tumour treatment is the exploitation or targeting of activated neutrophils. Peripheral blood neutrophils (PBNs) from tumour-bearing mice show high expression of L-selectin, and sialic acid (SA) is a well-known targeting ligand for L-selectin. Hence, in this research, we developed a drug delivery platform comprising liposomes modified with an SA conjugate that target activated PBNs. The uptake of doxorubicin (DOX)-loaded liposomes by PBNs did not alter their activation and transmigration. In tumour-bearing mice, SA-modified liposomes displayed greater tumour-targeting ability and stronger tumour-treatment efficacy, this was mediated by neutrophil infiltration induced by inflammatory factors released from the tumour microenvironment. In conclusion, SA-modified liposomal DOX was shown to be an effective neutrophil-mediated drug delivery system for tumour therapy.