Rapid development in engineering and biomedical applications of iron and iron oxide materials has attracted the attention of researchers around the world. discusses the extraction, synthesis, characterization, and applications of iron, iron oxide, and their nanoparticles/nanocomposites. It includes six chapters that address such topics as environmentally friendly techniques for engineering iron nanoparticles, the application of nano-dimensional iron oxide nanoparticles with nanotoxicology, biomedical applications of superparamagnetic iron oxide nanoparticles, and much more.