Production of Inflammatory Mediators by Nanoparticle Stimulated Macrophages.

Nanoparticles are receiving attention because of their many potential applications in drug delivery. The ability to treat humans with Polymethylmethacrylate (PMMA) nanospheres and gold nanoparticles is dependent on the biocompatibility of the nanoparticles. One measure of biocompatibility is the interaction between monocyte derived macrophages (MDM) and nanoparticles. Macrophages initiate many immune reactions with a variety of mechanisms, one such reaction is the release of nitric oxide (NO). Our research shows that RAW 264.7 (murine) and THP-1(human) macrophage cell lines, when treated with gold or PMMA nanoparticles, show the production of nitric oxide and degradation of IKB-α, but not reactive oxygen species. In this study, we used primary human MDMs as a more relevant model system. We report that gold nanoparticles and PMMA nanospheres did not cause the production of the same amounts of NO as their cell line counterparts. Western blot analysis showed the degradation of IKB-α during a 60-minute time course in primary human MDM. These studies suggest that the safety concerns over nanoparticle use are not supported for primary human MDM.