  Antibodies, disruptive potent therapeutic agents against pharmacological
targets, face a barrier crossing immune-system and cellular-membranes. To
overcome these, various strategies have been explored including shuttling via
liposomes or bio-camouflaged nanoparticles. Here, we demonstrate the
feasibility to load antibodies into exosome-mimetic nanovesicles derived from
human red-blood-cell-membranes. The goat-anti-chicken antibodies are loaded
into erythrocyte-membrane derived nanovesicles and their loading yields are
characterized and compared with smaller dUTP-cargo. Applying dual-color
coincident fluorescence burst methodology, the loading yield of nanocarriers is
profiled at single-vesicle level overcoming their size-heterogeneity and
achieving a maximum of 38-41% antibody-loading yield at peak radius of 52 nm.
The average of 14 % yield and more than two antibodies per vesicle is
estimated, comparable to those of dUTP-loaded nanovesicles after additional
purification through exosome-spin-column. These results suggest a promising
route for enhancing biodistribution and intracellular accessibility for
therapeutic antibodies using novel, biocompatible, and low-immunogenicity
nanocarriers, suitable for large-scale pharmacological applications.
