Direct Generation of High-Concentration Lipid-Shell Ultrafine Bubbles via Thin-Film High-Speed Agitation

Yutaro Yamasaki – Assistant Professor, Department of Anatomy, Fukuoka University Faculty of Medicine; Hitomi Endo – Associate Professor, Department of Anatomy, Fukuoka University Faculty of Medicine; Loreto Feril – Associate Professor, Department of Anatomy, Fukuoka University School of Medicine; Ktatsuro Tachibana – Professor, Institute of General Medical Science, Fukuoka University School of Medicine

Introduction: Ultrafine bubbles (UFBs) are submicron bubbles that have attracted attention as ultrasound-responsive nanocarriers possessing a gaseous core. UFBs formed with compound shells, particularly phospholipid-based shells enable versatile surface modification and functionalization. However, lipid- shell UFBs are often generated indirectly through lipid suspensions or liposomal intermediates, limiting achievable concentration and reproducibility. Here, we aimed to establish a manufacturing strategy for direct generation of high-concentration lipid-shell UFBs via thin-film–based high-speed agitation, focusing on physicochemical and acoustic properties.