Biocompatible Magnetic Oxide Nanoparticles with Metal Ions Coated with Organic Shell as Potential Therapeutic Agents in Cancer

Abstract

The magnetic nanoparticles (MNPs) of oxide with metal ions (MeIs-O) encapsulated with biological membranes or decorated with different organic shells are widely used in nano-biotechnology and nanomedicine, either as drug carriers in diagnosis and therapeutic biomedical fields or as a result of their specific magnetic effects on biological tissues. The MNP applications in pharma are closely related with their coating, shape, surface charge, core, and hydrodynamic size. The main characteristic of MNPs is the possibility to manipulate them with an external magnetic field (e-MF), which strongly depends on the magnetic structure of nanoparticles (NPs), multi-domain structure, in the case of NPs having sizes greater than approximately 30 nm or single domain in the case of NPs of sizes generally below 30 nm (depending on the type of NPs). A special structure of MNPs is the superparamagnetic (SPM) state when the magnetization of single-domain NPs is not stable and fluctuates along the easy magnetization axis under the action of thermal activation. This effect generally occurs when NPs have sizes smaller than approximately 15 nm. Depending on the targeted application in biotechnology/nanomedicine, only the NPs having the magnetic characteristics suitable for the type of application envisaged should be considered, in order to obtain the expected effect. In this chapter, we present the specific magnetic properties of MNPs depending on their size, the physical principle of handling NPs with an e-MF, magnetization of NPs, biocompatible MNPs (BC-MNPs) with salicylic acid (SA) and other organic coating, vascular nanoblocking of tumors, in vivo results using the chick embryo chorioallantoic membrane (CAM) model, and cytotoxicity of SA-MNPs.