Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster V56
Höfundar / Authors: Erna María Jónsdóttir (1,3), Jens Guðmundur Hjörleifsson (2), Berglind Eva Benediktsdóttir (1,3)
Starfsvettvangur / Affiliations: 1. Faculty of Pharmaceutical Sciences, University of Iceland; 2. Faculty of Life- and Natural Sciences, University of Iceland; 3. Biomedical center, University of Iceland
Kynnir / Presenter: Erna María Jónsdóttir
Triple-negative breast cancer (TNBC) lacks targeted treatment options, making it particularly aggressive. EGFR1 is overexpressed in over a third of TNBC cases and represents a potential therapeutic target. Extracellular vesicles (EVs) have great potential as nanodrug delivery systems due to their reduced immunogenicity, enhanced stability and modifiability, compared to liposomes. This study aimed to engineer HEK293E cells to produce EVs displaying EGFR1-targeting ligands and to load them with the chemotherapeutic agent doxorubicin (Dox). HEK293E cells were transfected to express EGFR1 ligands and GFP. EVs were isolated from conditioned media using Strep-Tactin CD81 Fab-TACS® and characterized via nanoparticle tracking analysis, western blotting, and a cholesterol assay. Dox was loaded passively (incubation) or actively (buffer exchange to 0.3 M ammonium sulfate, sonication, incubation, and ultrafiltration). Fluorometry measured Dox content and encapsulation efficiency (EE). All EVs showed the consistent mode size of ~116 nm, expressed EV markers Alix and Synthenin-1, and lacked the negative marker calnexin. Cholesterol content was significantly higher in EVs vs. cell lysates (p<0.001), confirming identity. GFP detection verified successful engineering. Active loading achieved higher EE (63%) than passive loading (17.5%). Engineered EVs retained key properties and are being tested for EGFR1-specific binding in breast cancer models, aiming at targeted TNBC therapy.