Characterization
of lipoplex-protein complexes as a function of
protein concentration. Size (panel a) and zeta potential (panel b)
of lipoplex-protein complexes prepared from CL1 and CL2 as a function
of human plasma (HP) percentage (%). As PLs are positively charged
systems, PL-protein complexes exhibit the typical features of cationic-anionic
assemblies, i.e., re-entrant condensation and charge
inversion at the isoelectric point. On the other side, the size of
the DDL-protein complexes is poorly affected by HP and zeta potential
tends to assume similar values. Vertical gray lines indicate the inversion
point where PL-protein complexes undergo massive aggregation (panel
a) caused by charge neutralization (panel b). (c) Molecular weight
(MW) distributions of protein patterns bound to lipoplexes as a function
of HP %. While protein patterns of DDL1- and DDL2-protein complexes
were almost superimposable up to HP = 20%, those of PL1- and PL2-protein
complexes were clearly distinguishable over the protein range especially
between 45 and 80 kDa. Color code: DDL1 (blue), DDL2 (cyan), PL1 (red),
PL2 (gold).