Biomedical Engineering Reference
In-Depth Information
of high-quality reviews have been produced on the development of magnetic
nanoparticles for targeted drug and gene delivery [16-18] and on the physical
principles of magnetic nanoparticles for biomedical applications [19]. However,
this chapter is the fi rst to consider the wider potential of magnetosomes in bio-
medical applications, and the future developments which will place them at the
center of advanced healthcare solutions. In the chapter, we will discuss the bio-
medical applications of magnetic nanoparticles and their required specifi cations.
Magnetosomes represent an ideal material to be modifi ed for magnetically tar-
geted therapies, as they are high-quality in nature, morphologically uniform, and
have an inherent lipid coating that increases their dispersion in solution and pro-
vides a biocompatible shell that can easily be adapted to several applications. The
chapter will contextualize magnetic bacteria, magnetosomes and how they are
formed, and also discuss their unique properties and how these properties can be
utilized in magnetic biomedical nanotechnology. A review will be provided of the
latest developments in these fi elds - how such developments will affect the bio-
medical application of magnetosomes, and how we can build on current research
strategies in order to exploit magnetosomes for applications such as targeted drug
delivery and hyperthermic treatments.
11.2
Magnetic Nanoparticles for Medical Applications
11.2.1
Introduction
The concept of using magnetic nanoparticles for biomedical applications is a
simple one: the small size of nanoparticles allows them to travel unhindered
throughout the body, where their magnetic properties can then be exploited for a
range of biomedical purposes. This includes using the particles to: (i) guide any
drugs that are tethered to the particle to a target site by using a magnetic fi eld; (ii)
to activate a drug or heat a site by using an alternating magnetic fi eld; (iii) to reduce
magnetic relaxation times so as to enhance contrast for magnetic resonance
imaging ( MRI ) scanning; or (iv) simply to separate - magnetically - biomolecules
from a biological matrix or solution. Although the idea of using magnetic nanopar-
ticles for biomedical applications, such as targeted drug delivery, was fi rst pro-
posed during the late 1970s [2], its realization has been slow to materialize, with
the fi rst demonstration of magnetically targeted transfection recorded only in 2000
[20]. A major problem in the development of this technology has been the chal-
lenges of designing and fabricating nanoscale, uniform, functionalized particles,
that would produce a consistent and predictable response, but with limited
toxicity.
In recent years, however, nanoscience research has expanded rapidly, and this
has led to the provision of many more tools and methods for the creation of high-
quality nanomaterials for medical purposes. Furthermore, the increased interest
