Engineering of cancer cells to secrete modified membrane vesicles by using membrane fusogenic liposomes

Abstract

As nano-sized vesicles, membrane vesicles (MVs) are secreted from various cells such as cancer and immune cells. They have various functions such as cell-cell interaction, immune responses. Especially, cancer-derived membrane vesicles (CMVs) have an important role in tumorigenesis. They involve in tumor progression, angiogenesis and metastasis. Due to these different properties in tumorigenesis and advantages as a drug carrier such as long circulation time and low toxicity, many researches which try to use CMVs as a drug carrier for cancer treatment have been carried out. In order to load drugs to MVs, many techniques have been used such as incubation of CMVs with drug, genetic engineering and electroporation. But these techniques have some limitations. The stability and natural properties of CMVs can be influenced. The most important thing is the isolated in vitro CMVs may act differently in vivo to reality. In order to use CMVs as a drug carrier for cancer treatment more effectively, the technique which load drugs to MVs without any influence on properties of CMVs and isolation is needed. In this study, we suggest a novel technique for drug loading to MVs. The key point is to engineer cancer cells to secret MVs containing drugs using nanotechnology. We used membrane fusogenic liposomes (MFLs) which fuse with cellular membrane but not cellular uptake by endocytosis. 100nm-sized MFLs go to tumor region by EPR effects, deliver hydrophobic and hydrophilic model drugs to membrane or cytosol of cancer cells and the engineered cancer cells can secret MVs containing model drugs. First, we investigated the fusogenesity of MFLs compared to non-fusogenic liposomes (NFLs) using fusion assay and confocal microscopy. The effects on cancer cells such as cell viability and amount of secreted CMVs by MFLs were investigated and the loading efficiency was compared between MFLs and NFLs. Also, the properties of CMVs such as size, morphology and protein composition were analyzed...