In the literature several liposomes decorated with homing peptides have been described. However, there is a very few published data in case of thermosensitive liposomes. Because the covered drug can release from thermosensitive liposomes only at higher temperature than the normal body temperature (40 °C – 50 °C) the activity of the drug localized in the tumor will be observed after heating the tumor to the appropriate temperature. Liposomes decorated with homing peptides may localize significantly better in tumors than the non-directed liposomes, therefore their selectivity might be higher. In this project we focus on two tumor types with very bad prognosis, the HER-2 positive breast and pancreatic cancers. For this purpose new thermosensitive liposomes decorated with appropriate homing peptides that recognize the above mentioned tumor types will be developed. Preliminary studies have been made for the selection of efficient targeting peptide sequences. In this project their attachment to the applied liposomal compartment has to be solved. The influence of the number and the structure of the incorporated peptides on tumor recognition and localization of the novel modified liposomes will be investigated. Their stability and thermosensitivity will be also studied.

In addition, the influence of the homing peptides attached to PEG molecules on the liposome formation and stabilization will be studied. Our previous studies indicated that the hydrophil character of the targeting peptide might have advantage for the development of stable liposomes. However, this can be influenced by the covered drug molecules as well, that will be also studied. Another crucial question that have to be answered in this project, when the homing peptide should be attached to the liposome forming compartment, before or after the liposome formation.

Norbert Szoboszlai, Gábor Mező

Result_May 2020