Stimulus‐responsive nano lipidosome for enhancing the anti‐tumour effect of a novel peptide Dermaseptin‐PP

OBJECTIVE: Dermaseptin‐PP is a newly discovered anticancer peptide with a unique antitumour mechanism and remarkable effect. However, this α‐helix anticancer peptide risks haemolysis when used at high doses, which limits its further application. This study aims to prepare a pH‐responsive liposome, Der‐loaded‐pHSL, using nanotechnology to avoid the haemolysis risk of Dermaseptin‐PP and increase its accumulation in tumour sites to enhance efficacy and reduce toxicity. METHODS: The characterisation of Der‐loaded‐pHSL was carried out employing preparation. The effect of haemolysis and tumour inhibition were investigated by in vitro haemolysis assay and cytotoxicity assay. The cell uptake under different pH conditions was investigated by flow cytometry, and the effect of pH on tumour cell selectivity was evaluated. In order to evaluate the in vivo targeting and antitumour effect of Der‐loaded‐pHSL, the in vivo distribution experiment and the pharmacodynamic experiment were performed using the nude mouse tumour model. RESULTS: The preparation method of the Der‐loaded‐pHSL is simple, and the liposome has good nanoparticle characteristics. When Dermaseptin‐PP was prepared as liposome, haemolysis was significantly decreased, and tumour cell inhibition was significantly enhanced. Compared with ordinary liposomes, this change was more significant in Der‐loaded‐pHSL. The uptake of pH‐sensitive liposomes was higher in the simulated acidic tumour microenvironment, and the uptake showed a specific acid dependence. In vivo experiments showed that Der‐loaded‐pHSL had a significant tumour‐targeting effect and could significantly enhance the antitumour effect of Dermaseptin‐PP. CONCLUSION: Der‐loaded‐pHSL designed in this study is a liposome with a quick, simple, effective preparation method, which can significantly reduce the haemolytic toxicity of Dermaseptin‐PP and enhance its antitumour effect by increasing the tumour accumulation and cell intake. It provides a new idea for applying Dermaseptin‐PP and other anticancer peptides with α‐helical structure.