Endocytosis and intracellular traffic of cholesterol-PDMAEMA liposome complexes in human epithelial-like cells

Abstract

Liposomes are generally used as delivery systems, as they are capable of encapsulating a wide variety of molecules (i.e. plasmids, recombinant proteins, therapeutic drugs). However, liposomal drug delivery have to fulfill different requirements, such as the effective internalization by the target cells and avoidance of the degradative activity of the intracellular compartments. The use of polymer lipid complexes (PLCs), by including different polymers in the liposome formulation, could improve internalization and intracellular release of drugs. The aim of the present work is to study the mechanisms of cellular uptaking and the intracellular trafficking of PLCs formed with cholesterol-poly(2-(dimethylamino)ethyl methacrylate) CHO-PDMAEMA and lecithin (LC CHO-PD). Calcein-loaded liposomes were used to determine cellular uptake and intracellular localization by flow cytometry and confocal microscopy. Incorporation of CHO-PDMAEMA to lecithin liposomes enhanced the internalization capacity of PLCs. Internalization of PLCs by human epithelial-like cells (HEK-293) diminished at 4°C, suggesting uptake by endocytosis. PLCs showed no co-localization with acidic compartments after internalization. Experiments with endocytosis inhibitors and co-localization of liposomes and albumin, suggested the caveolae endocytic pathway as the most probable route for intracellular trafficking of PLCs. In this work, we demonstrated an efficient uptake of LC CHO-PDs by human epithelial-like cells (HEK-293) through the non-degradative caveolae endocytic pathway. The mode of internalization and the intracellular fate of liposomes under study, suggest a promising use of LC CHO-PDs as drug delivery systems.

Green synthesis of nano-liposomes containing Bunium persicum and Trachyspermum ammi essential oils against Trichomonas vaginalis

“…A similar uptake pattern has been reported for calcein-loaded liposomes [44], as well as for hyaluronic acid-magnetic-loaded liposomes [45]. It has been reported that liposome can interact with cells by four mechanisms, including endocytosis, adsorption to the cell surface, transfer of liposomal lipids to the cell membrane and lipid-mediated fusion with the intracellular membranes, the main pathways for liposomal internalization [46,47,48]. Moreover, factors such as size due to aggregation, surface charge and surface a nity seem to have a major impact on nanoparticle binding to the cell membrane and subsequent cell uptake [49].…”

Long term stability and interaction with epithelial cells of freeze-dried pH-responsive liposomes functionalized with cholesterol-poly(acrylic acid)

“…2). This observation has already been reported for other drug delivery systems and can be ascribed to leakage [33,34]. The release profiles of calcein in physiologic conditions (ca.…”

Cabazitaxel liposomes with aptamer modification enhance tumor‑targeting efficacy in nude mice

“…The results of CLSM and flow cytometry analyses demonstrated that BioTL-Cab/lipo specifically targeted MEAR cells. Liposomes are endocytosed by cells and expel their contents into the cytoplasm (28,29). In the present study, the fluorescence signal of 6-FAM was also detected in the cytoplasm.…”