Immunomodulatory Effects of Coated Gold Nanoparticles in LPS-Stimulated In Vitro and In Vivo Murine Model Systems

The ability of nanoparticle surface functionalities to regulate immune responses during an immunological challenge (i.e., inflammation) would open new doors for their use in non-prophylactic therapeutics. We report here the use of functionalized 2-nm-core gold nanoparticles to control the immunological responses of in vitro and in vivo systems presented with an inflammatory challenge. Our results show that nanoparticles bearing a hydrophobic zwitterionic functionality boost inflammatory outcomes, whereas hydrophilic zwitterionic nanoparticles generate minimal immunological responses. Surprisingly, tetra(ethylene glycol) head groups generate a significant anti-inflammatory response both in vitro and in vivo. These results demonstrate the ability of simple surface ligands to provide immunomodulatory properties, making them promising leads for the therapeutic usage of nanomaterials in diseases involving inflammation.