Exosome cell entry is facilitated by filopodia surfing, grabbing, and pulling. (a) Human primary fibroblasts incubated with 100 pM HEK293 CD63-emGFP exosomes (green). SEM (left) or live cell DIC/CLSM (right) visualization of apparent contacts of nanovesicles/exosomes with filopodia (arrows). (b) Exosome surfing on filopodia documented by live cell DIC/CLSM (Video 5, 12 frames/min). Vesicle trajectories are color coded for speed as indicated (0–0.5 µm/s). (c) Exosome pulling by filopodia documented by TIRF live cell microscopy of actin-RFP (black) expressing human fibroblasts grown on a line substrate (2 frames/min). Successive filopodia outreach and pulling movements are indicated by blue and pink arrows, respectively. Exosome trajectory in pink. (d) Grabbing of exosomes (arrows) by filopodia documented by live cell DIC/CLSM. (right) Overview image, with white box indicating the area shown in the close-up time series.