Fig. 3.

Membrane protein retention, particle stability in serum, and the in vivo circulation time of the RBC-membrane-coated NPs. (A) Proteins in emptied RBCs, RBC-membrane-derived vesicles, and purified RBC-membrane-coated PLGA nanoparticles were solubilized and resolved on a polyacrylamide gel. (B) RBC-membrane-coated PLGA nanoparticles, PEG-coated lipid-PLGA hybrid nanoparticles, and bare PLGA nanoparticles were incubated in 100% fetal bovine serum and monitored for absorbance at 560 nm for 4 h. (C) DiD-loaded nanoparticles were injected intravenously through the tail vein of mice. At various time points blood was withdrawn intraorbitally and measured for fluorescence at 670 nm to evaluate the systemic circulation lifetime of the nanoparticles (n = 6 per group).