Role of Surface Charge of Nanoscale Ultrasound Contrast Agents in Complement Activation and Phagocytosis.

Charged Nano-UCAs show a higher tendency to activated complement system, and are efficiently engulfed by macrophages. The present results provide meaningful insights into the role of the surface charge of nanoparticles in the activation of the innate immune system, which is important not only for the design of targeted Nano-UCAs, but also for the effectiveness and safety of other theranostic agents.