A survey of the literature on nanoparticle-protein binding
shows that the vast majority of nanoparticle types studied so far
bind apolipoproteins18. At first sight this is a surprising result, and
quite distinct from that for a flat surface. However, the fact that
apolipoproteins are known to be involved in lipoprotein complexes,
which themselves have sizes on the nanoscale (Fig. 2) ranging from
100 nm (chylomicron) to ~10 nm (high density lipoproteins), may
mean that there are specific size-dependent interactions that drive the
binding of apolipoproteins to nanoparticles. This is interesting from
the point of view of nanoparticle interaction with cells, as lipoprotein
complexes are involved in the general cellular processes of cholesterol
metabolism22,23. Thus, there are multiple receptors for apolipoprotein