FIGURE 1.

Chemical structures of the polymers (PCL, Meo-PEG-b-PCL, and PCL-b-PPEEA) and schematic illustration of the self-assembly of the polymers into nanoparticles (NPs) for small interfering RNA (siRNA) delivery and CCL-18 silencing in macrophages to inhibit breast cancer migration. The amphiphilic Meo-PEG-b-PCL and PCL-b-PPEEA can spontaneously self-assemble into NPs with hydrophobic PCL chains embedded in the cores and hydrophilic PEG and PPEEA chains positioned on the surface (a). After siCCL-18 loading via the electrostatic interaction (b) and then internalized by macrophages (c,d), the siCCL-18 can knock down CCL-18 expression (e) and thus CCL-18 secretion from the macrophages would be blocked (f), leading to the inhibition of tumor migration (g).