The anticancer efficacy of paclitaxel liposomes modified with low-toxicity hydrophobic cell-penetrating peptides in breast cancer: an in vitro and in vivo evaluation

In our recent study, hydrophobic cell-penetrating peptides (CPPs) were demonstrated as an effective method of improving cancer treatment. To provide more evidence and broaden the application range for this promising strategy of improving cancer treatment, novel hydrophobic CPP-modified (PFV-modified) nanoliposomes loaded with paclitaxel, termed PFV-Lip-PTX, were developed as a treatment for breast cancer. Physicochemical evaluations of PFV-Lip-PTX revealed spheroid-like regular vesicles of about 120 nm in diameter with negative charge. An in vitro release study indicated that PTX was released from the liposomes in a controlled and sustained manner. A cellular uptake study indicated that PFV-Lip-PTX exhibited higher internalization efficiency in MCF-7 cells than non-modified liposomes. It was also demonstrated that PFV modification improved the cytotoxicity of PTX via a hydrophobic interaction between the PFV-Lip and cell lipid membranes compared with non-modified liposomes. Moreover, in vivo studies demonstrated that the PFV-modified liposomes led to highly efficient targeting and accumulation in an MCF-7 xenograft tumor and improved the antitumor efficacy of PTX. Finally, PFV-Lip-PTX showed low systemic toxicity evidenced by fewer changes in the body weights of mice and no visible histological changes in major healthy organs. Therefore, our results indicate that PFV-Lip-PTX has great potential in tumor-targeting and effective antitumor treatment.