Proteomes of Micro- and Nanosized Carriers Engineered from Red Blood Cells

Red blood cell (RBC)-derived systems
offer a potential platform
for delivery of biomedical cargos. Although the importance of specific
proteins associated with the biodistribution and pharmacokinetics
of these particles has been recognized, it remains to be explored
whether some of the key transmembrane and cytoskeletal proteins responsible
for immune-modulatory effects and mechanical integrity of the particles
are retained. Herein, using sodium dodecyl sulfate–polyacrylamide
gel electrophoresis (SDS-PAGE) and quantitative tandem mass tag mass
spectrometry in conjunction with bioinformatics analysis, we have
examined the proteomes of micro- and nanosized erythrocyte ghosts
doped with indocyanine green and compared them with those of RBCs.
We identified a total of 884 proteins in each set of RBCs, micro-,
and nanosized particles, of which 8 and 45 proteins were expressed
at significantly different relative abundances when comparing micro-sized
particles vs RBCs and nanosized particles vs RBCs, respectively. We
found greater differences in relative abundances of some mechano-modulatory
proteins, such as band 3 and protein 4.2, and immunomodulatory proteins
like CD44, CD47, and CD55 in nanosized particles as compared to RBCs.
Our findings highlight that the methods utilized in fabricating RBC-based
systems can induce substantial effects on their proteomes. Mass spectrometry
data are available at ProteomeXchange with the identifier PXD038780.