Which are the most echogenic of ultrasound contrast agents?() A: Microbubbles B: Solid<br/>nanoparticles C: liquid nanoparticles D: nanobubbles

Quantum dots, another type of nanoparticles, are used mainly for_________.

Which of the following is not an active targeting system? A: Long circulating nanoparticles B: Targeted Prodrugs C: Immunoliposomes D: Colon-targeted prodrugs