Figure 12.

Polyhydroxylated nanoparticle surfaces activate complement. (a) Synthesis and stabilization with two different forms of Pluronic allowed the generation of polyhydroxylated- or polymethoxylated-nanoparticles. (b) The, -terminal OH groups on Pluronic could be converted to OCH₃ groups. (c) The proposed mechanism where OH groups on the polyhydroxylated nanoparticles can bind to the exposed thioester of C3b to activate complement by the alternative pathway. (d) Nanoparticle-induced complement activation, as measured through C3a presence in human serum after incubation with nanoparticles, was demonstrated to be high with polyhydroxylated nanoparticles but low with polymethoxylated nanoparticles (OH- and CH₃O-NPs, respectively). Results are normalized to control of serum incubation with PBS. Values are means of three independent experiments; error bars correspond to standard error of mean, s.e.m. Reproduced with permission.^[200] Copyright 2007, Nature Publishing Group.