Lattin James R, Javadi Marjan, McRae Michael, Pitt William G
Chemical Engineering Department and.
J Drug Target. 2015 Jun;23(5):469-79. doi: 10.3109/1061186X.2015.1009074. Epub 2015 Feb 12.
Vaporizing emulsion droplets may aid in endosomal rupture as a drug delivery route to the cytosol. Upon insonation, emulsion droplets formed from perfluorocarbon liquids may vaporize with sufficient expansion to disrupt liposomal or endosomal membranes. Emulsion droplets of perfluorohexane (PFC6) or perfluoropentane (PFC5) were prepared as free droplets in calcein or as droplets encapsulated within liposomes containing calcein. Folate-stimulated endocytosis created an experimental model, wherein calcein was self-quenched until released from the vesicles. Upon release, calcein was diluted below its self-quenching concentration and its release quantified by fluorescence. In this experimental model, folated emulsions or folated eLiposomes were incubated with folate-starved HeLa cells. Samples were exposed to two seconds of 20-kHz ultrasound (US) at 1 W/cm(2). Fluorescence microscopy identified released intracellular calcein. Upon insonation, both free emulsion samples and eLiposome samples produced calcein release to the cytosol. Calcein fluorescence was more intense in samples containing PFC5 compared to PFC6. Insonation of samples without emulsion droplets produced no cytosolic delivery. Likewise, cells that took up emulsion droplets but were not exposed to US did not exhibit fluorescence throughout the cell. These results suggest that vaporizing emulsion droplets are internalized into the cells and can produce endosomal escape of a therapeutic payload.
作为一种向细胞质的药物递送途径，使乳液滴汽化可能有助于内体破裂。在超声作用下，由全氟化碳液体形成的乳液滴可能会充分膨胀汽化，从而破坏脂质体或内体膜。将全氟己烷（PFC6）或全氟戊烷（PFC5）的乳液滴制备成包裹在含有钙黄绿素的脂质体内的液滴或游离于钙黄绿素中的液滴。叶酸刺激的内吞作用建立了一个实验模型，其中钙黄绿素在从囊泡释放之前处于自淬灭状态。释放后，钙黄绿素被稀释至自淬灭浓度以下，并通过荧光对其释放进行定量。在该实验模型中，将叶酸修饰的乳液或叶酸修饰的e脂质体与叶酸饥饿的HeLa细胞一起孵育。样品在1 W/cm(2)的条件下暴露于20 kHz的超声（US）两秒钟。荧光显微镜鉴定释放到细胞内的钙黄绿素。超声作用后，游离乳液样品和e脂质体样品均导致钙黄绿素释放到细胞质中。与含有PFC6的样品相比，含有PFC5的样品中钙黄绿素荧光更强。对不含乳液滴的样品进行超声处理未产生细胞质递送。同样，摄取了乳液滴但未暴露于超声的细胞在整个细胞中均未显示荧光。这些结果表明，汽化的乳液滴被内化到细胞中，并可使治疗性载荷产生内体逃逸。
