Monoclonal antibody-targeted, temperature-sensitive liposomes: In vivo tumour chemotherapeutics in combination with mild hyperthermia

The development of actively targeted, responsive delivery vectors holds great promise for cancer therapy. Here, we investigated whether enhanced therapeutic activity of temperature sensitive liposomes (TSL) could be obtained by mild hyperthermia-triggered release of the chemotherapeutic drug doxorubicin (DOX) after hCTMO1 monoclonal antibody (anti-MUC-1) binding and uptake into cancer cells. We showed that traditional TSL (TTSL) liposome systems maintained their physicochemical and thermal properties after conjugation to hCTMO1 full IgG. Receptor-mediated cellular uptake and cytotoxic efficacy of antibody-targeted TTSL (TTSL-Ab) were investigated using 2D and 3D cell culture models. Significant enhancement in cellular uptake and cytotoxic activity after 1 h of heating at 42°C was observed for TTSL-Ab compared to non-targeted liposomes in MUC-1 over-expressing breast cancer cells (MDA-MB-435). Tissue distribution and in vivo therapeutic activity were studied using different heating protocols to explore the effect of mild hyperthermia on the tumor accumulation of targeted TTSL and their therapeutic effect. Application of local, mild hyperthermia (42°C) significantly increased the tumor accumulation of targeted TSL compared to non-targeted liposomes, associated with a moderate improvement in therapeutic activity and survival.