Neutrophil-mediated delivery of pixantrone-loaded liposomes decorated with poly(sialic acid)–octadecylamine conjugate for lung cancer treatment

Abstract

<p>Poly(sialic acid) (PSA) is a natural hydrophilic biodegradable and non-immunogenic biopolymer, receptors for its monomer are expressed on peripheral blood neutrophils (PBNs), which plays important roles in the progression and invasion of tumors. A poly(sialic acid)–octadecylamine conjugate (PSA–ODA) was synthesized and then anchor it on the surface of liposomal pixantrone (Pix-PSL), to achieve an improved anticancer effect. The liposomes were prepared using a remote loading method via a pH gradient, and then assessed for particle size, zeta potential encapsulation efficiency, <i>in vitro</i> release, and <i>in vitro</i> cytotoxicity. Simultaneously, <i>in vitro</i> and <i>in vivo</i> cellular uptake studies confirmed that PSA-decorated liposomes provided an enhanced accumulation of liposomes in PBNs. An <i>in vivo</i> study presented that the anti-tumor activity of Pix-PSL was superior to that of other Pix formulations, probably due to the efficient targeting of PBNs by Pix-PSL, after which PBN containing Pix-PSL (Pix-PSL/PBNs) in the blood circulation are recruited by the tumor microenvironment. These findings suggest that PSA-decorated liposomal Pix may provide a neutrophil-mediated drug delivery system (DDS) for the eradication of tumors, which represents a promising approach for the tumor targeting of chemotherapeutic treatments.</p