Human bone marrow mesenchymal stem cell-derived exosomes loaded with gemcitabine inhibit pancreatic cancer cell proliferation by enhancing apoptosis.

Background: Pancreatic cancer remains one of the most lethal malignancies, and has limited effective treatment. Gemcitabine (GEM), a chemotherapeutic agent, is commonly used for clinical treatment of pancreatic cancer, but it has characteristics of low drug delivery efficiency and significant side effects. The study tested the hypothesis that human bone marrow mesenchymal stem cell (MSC)-derived exosomes loaded with GEM (Exo-GEM) would have a higher cytotoxicity against human pancreatic cancer cells by enhancing their apoptosis.

Aim: To investigate the cytotoxicity of MSC-derived Exo-GEM against pancreatic cancer cells in vitro.

Methods: Exosomes were isolated from MSCs and characterized by transmission electron microscopy and nanoparticle tracking analysis. Exo-GEM through electroporation, sonication, or incubation, and the loading efficiency was evaluated. The cytotoxicity of Exo-GEM or GEM alone against human pancreatic cancer Panc-1 and MiaPaca-2 cells was assessed by MTT and flow cytometry assays.

Results: The isolated exosomes had an average size of 76.7 nm. The encapsulation efficacy and loading efficiency of GEM by electroporation and sonication were similar and significantly better than incubation. The cytotoxicity of Exo-GEM against pancreatic cancer cells was stronger than free GEM and treatment with 0.02 μM Exo-GEM significantly reduced the viability of both Panc-1 and MiaPaca-2 cells. Moreover, Exo-GEM enhanced the frequency of GEM-induced apoptosis in both cell lines.

Conclusion: Human bone marrow MSC-derived Exo-GEM have a potent cytotoxicity against human pancreatic cancer cells by enhancing their apoptosis, offering a promising drug delivery system for improving therapeutic outcomes.