Polysialic acid-polyethylene glycol conjugate-modified liposomes as a targeted drug delivery system for epirubicin to enhance anticancer efficiency.

Polysialic acid (PSA) is a nonimmunogenic and biodegradable polysaccharide. In recent years, PSA has shown its potential applications to cancer treatment. In this study, PSA-polyethylene glycol (PEG) conjugate was synthesized for the decoration of epirubicin (EPI)-loaded liposomes. The study aimed to evaluate the PSA-PEG conjugated modified liposomes (EPI-PSL) in vitro and in vivo to investigate the role of PSA on physicochemical characteristics and antitumor activity in PEGylated liposomes. EPI-PSL showed a particle size of 116.9 ± 5.2 nm, zeta potential of - 40.3 ± 3.5 mV, and encapsulation efficiency of 99.1 ± 1.5%. The results of in vitro release experiments showed a delayed release of EPI from EPI-PSL. Greater cellular uptake of EPI-PSL was observed compared with PEGylated liposomes (EPI-PL) in B16 cells. Cytotoxicity studies suggested that EPI-PSL exhibited stronger cytotoxic activity than EPI-PL. Though EPI-PSL exhibited comparable blood plasma profiles with EPI-PL, biodistribution studies proved that the distribution of EPI-PSL in tumors was more than that of EPI-PL. The superior antitumor efficacy of EPI-PSL was also verified in the B16 xenograft mouse model with a reduction in systemic toxicity. In conclusion, these results therefore indicated that PSA-modified PEGylated liposomes may represent an excellent anticancer drug delivery system for targeted cancer therapy.