Recent advances in superparamagnetic iron oxide nanoparticles (SPIONs) for in vitro and in vivo cancer nanotheranostics

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

“…[729c,732] In fact, protons present in the nucleus have an inherent tendency to be excited and aligned parallel to an external applied magnetic field. [733] The spins of protons are flipped at a particular frequency, known as the "resonance frequency." [11b] Specifically, when the generated radiofrequency (RF) pulse is in resonance with body's hydrogen atoms, makes protons in the hydrogen nucleus to be fully aligned parallel to the applied magnetic field direction.…”

“…T 1 and T 2 are respectively the needed time for longitudinal and transverse components of magnetization vectors to return to their original thermal equilibrium state. [733] Either T 1 or T 2 relaxation times can be measured by receiver coils to subsequently produce an MR image by a computer algorithm. [734] 5.2.1.1.…”

“…[737] In addition, gadolinium chelates suffer from poor cellular uptake and short life span. [733] However, small size tumors cannot be effectively detected due to relatively low sensitivity of traditional techniques. In addition, due to high toxicity of contrast agents such as Gd chelates, it may be risky and difficult to deliver enough of them in cancers.…”

“…[739] Among the promising MNPs, the next generation was (ultrasmall) superparamagnetic iron oxide (SPIOs and USPIOs) nanoparticles that have been developed for both [740] Ferucarbotran, ferumoxtran-10, fetumoxytol (Feraheme), ferumoxides, ferristeneand, and ferumoxsil are of some contrast agents at current clinical trials. [733] Feridex and Resovist are approved by food and drug administration (FDA) for liver imaging. Similar to other paramagnetic substances, SPIOs and USPIOs lose their magnetization by removing the magnetic field.…”

Mechanochemical Preparation and Magnetic Properties of Fe3O4/ZnS Nanocomposite

“…In the above aspects the magnetite (Fe 3 O 4 ) based materials have irreplaceable position due to specific properties of magnetite. By using external magnetic field it is possible to control their biodistribution [6]. Magnetite with its cubic inverse spinel structure (Fe 3+ ) A (Fe 2.5+ ) B O 4 has tetrahedrally (A) and octahedrally (B) coordinated iron cations and strong ferrimagnetism.…”