RNA transfer from MEG-01 to HUVECs and THP-1 cells. (A) Flow cytometry analysis of 1 μg/mL PAM-treated THP-1 cells cultured in presence of BrUTP-labeled PLPs for 6, 12, and 24 hours. No fusion was observed at 1- and 3-hour time points (*P < .05 compared with PAM). (B) The same experiment was analyzed by confocal microscopy. THP-1 cells demonstrated BrUTP labeling after 24-hour incubation with RNA-labeled PLPs (iii-vi; iv and vi are in bright field; 100× objective). THP-1 control cells stained with IgG (i) and BrdU-FITC (ii). Scale bar denotes 10 μm; 100× objective. (C) HUVECs, treated with 0.5 U/mL thrombin, were coincubated for 1 hour with BrUTP-labeled PLPs and analyzed by flow cytometry (open curve, solid line). Isotype IgG (gray filled curve), control (no PLPs; open curve, dotted line). (D) PAM (1 μg/mL)–treated THP-1 cells cocultured for 24 hours with GFP-PLPs treated (RNase) or not with RNase (PLP). THP-1 + untreated-PLPs were washed, after 24 hours, to eliminate residual PLPs and cultured for additional 24 hours (No PLP 48 h; *P < .05 vs untreated PLPs). (E) HUVECs showed GFP fluorescence, by flow cytometry, after 1-hour coincubation with PLPs containing GFP (open curve, dotted line), cells were then washed and allowed to grow for 24 hours (open curve, solid line). Control (gray filled curve).