Magnetic Nanoparticle for Biomedicine Applications

Abstract

nanometer to micrometer scales is extremely active thanks to their unique physicochemical properties [1-4]. First, these particles are liable to be guided by external magnetic field. Second, MNPs are possible to be coated by functional groups to tailor their physicochemical properties and realize versatility. Besides, the synthesis of MNPs is rather facile and their size is easily controlled by the experimental conditions, making them possible to satisfy different research requirements. Therefore, functionalized MNPs, by allowing the biomolecules, be tagged, detected and controlled magnetically, enable new promising approaches to bioseparation, biodetection and drug delivery [5-9]. The aim of this review article is to summarize the recent progress in the synthesis and functionalization of magnetic nanoparticles and their applications in biomedicine, such as bioseparation, molecular detection, drug delivery, Magnetic Resonance Imaging (MRI) and hyperthermia. With the development in the synthesis and functional-ization of the MNPS, the above applications are demonstrating great vitality and have been or may be used in clinical practice. The methods of synthesis influence the properties of MNPs on the dimension, particle-size distribution and morphology [10]. Physical methods including gas phase deposition and electron beam lithography are elaborate procedures that cannot control the size of particles [5,11]. The wet chemical routes to MNPs, which provide a convenient way for the size control and composition modulation, are simpler, more efficient and wildly adopted for the preparation of MNPs [12,13]. The most common wet chemical method used for the preparation of MNPs is co-precipitation. This approach offers a wide range of advantages: 1) It is low-cost because of the use of inexpensive chemicals and mild reaction conditions, 2) It is environmentally friendly because the MNPs can be directly synthesized in water, 3) The method is extremely flexible when it comes to the modulation of the core and surface properties by controlling the experimental parameters such as the reaction temperature, pH value and ionic strength of the media; 4) It is extremely repeatable if the experimental parameters are fixed [14]. For example, by using this method, size-controllable iron oxides (either Fe 3O4 or γ-Fe2O3) nanoparticles can be efficiently synthesized from aqueous Fe 2+ /Fe 3+ salt solutions by the addition of a base at room temperature [15]. Other approaches including microemulsions [16], sol-gel synthesis [17], sonochemical reactions [18], hydrothermal reactions [19], hydrolysis and thermolysis of precursors [20], flow injection synthesis [21], electrospray synthesis [22], and graft copolymer method [23] are reported in the literature as well. For instance, in order to increase the loading amount of the reactive groups on the magnetic particles and to improve the stability and dispersibility of magnetic particles, several magnetic particles have been synthesized by the graft copolymer method, with the flexibility and diversity to control the chemical composition and functional groups on the surface of nanoparticles. XF Sun et al., reported the synthesis of a novel hemicelluloses based magnetic hydrogel by using such a graft Abstract Magnetic Nanoparticles (MNPs) have been widely applied in the area of biomedicine in recent years due to their broad versatility, such as good biological compatibility, unique physicochemical properties and easy guidance by external magnetic fields. In this review, the recent progress in the synthesis and surface modification of MNPs, as well as their applications in biomedicine including bioseparation, molecular detection, drug delivery, hyperthermia and Magnetic Resonance Imaging (MRI) and etc., have been summarized.