Optimization of Gold Nanoparticles for Efficient Delivery of Catalase to Macrophages for Alleviating Inflammation

Inflammation-associated diseases are the leading causes of death worldwide. They are associated with oxidative stress that is the overexpression of reactive oxygen species, such as hydrogen peroxide (H2O2) secreted by macrophages. In this study, gold nanoparticles (AuNPs) were used to deliver catalase that metabolizes H2O2 to macrophages. Ten different types were tested, including five spherical AuNPs with various sizes (50, 80, 100, 200, and 400 nm) and five shapes of AuNPs (cube, hexagon, bean, rod, and tetrapod). After catalase conjugation to AuNPs, optimum size and shape were selected by the highest uptake of AuNPs by macrophages. More than 80% macrophages were infected by AuNPs when treated with spherical AuNPs (100, 200, or 400 nm) of cube or bean shape. All of them reduced the exogenous H2O2 to match the control; however, bean AuNPs were superior in cell viability under H2O2 treatment. Based on the results, we anticipate numerous applications of bean AuNPs in the treatment of inflammation-associated diseases.