Environmental Engineering Reference
In-Depth Information
Chapter 7
Pros and Cons on Magnetic Nanoparticles
Use in Biomedicine and Biotechnologies
Applications
Florina M. Bojin and Virgil Paunescu
Abstract In recent years, the design and synthesis of colloidal magnetic suspen-
sions have attracted an increased interest especially in the fields of biotechnology
and biomedicine because they have many applications including targeted drug
delivery, cell labeling and magnetic cell separation, hyperthermia, tissue repairing,
magnetic resonance imaging (MRI) contrast enhancement, enzyme immobilization,
immunoassays, protein purification, etc.
7.1
Introduction
Magnetic nanoparticles (MNPs) used in biomedicine must meet several require-
ments. They have to be non-toxic, chemically stabile, uniform in size, well stabi-
lized under physiological conditions, biocompatible and to present high
magnetization. Magnetite (Fe
3
O
4
) and maghemite (
-Fe
2
O
3
) are the most suitable
iron oxide nanoparticles employed for biomedical applications because they are
biocompatible, have low toxicity in the human body and show a superparamagnetic
behavior.
Therefore, synthesis of magnetic iron oxide nanoparticles with tailored proper-
ties has attracted considerable scientific and technological interest. Various synthe-
sis routes were developed for producing magnetic particles, such as
co-precipitation, microemulsion method, thermal decomposition of different
organic precursors, spray pyrolysis, and sol-gel method.
For biomedical applications, magnetic iron oxide nanoparticles must be dis-
persed in biocompatible media in order to obtain stable colloidal suspensions. In
order to prevent the particle aggregation and to improve the biocompatibility and
stability, nanoparticles are coated with various surfactants: poly(ethylene glycol),
γ
