this presentation provides a brief description on the structrue and applications of mangetic nanoparticles

1. Dr.Gurpreet Singh, Ph.D
Assistant Professor
P.G. Department of Biotechnology
(DST-FIST Sponsored)
Lyallpur Khalsa College, Jalandhar (INDIA)
Email: singh.gpbio@gmail.com
MAGNETIC NANOPARTICLES:
CONCEPTS AND APPLICATIONS

2. Iron oxide nanoparticles are iron oxide particles with diameters between about 1 and 100 nanometers.

3. In the paramagnetic state, the individual atomic magnetic moments are
randomly oriented, and the substance has a zero net magnetic moment if there
is no magnetic field. These materials are attracted to magnetic fields. The
magnetic moment drops to zero when the applied field is removed.
But in a ferromagnetic material, all the atomic moments are aligned even
without an external field.
A ferrimagnetic material is similar to a ferromagnet but has two different
types of atoms with opposing magnetic moments. The material has a magnetic
moment because the opposing moments have different strengths.
If they have the same magnitude, the crystal is antiferromagnetic and
possesses no net magnetic moment

4. The classification of metal containing nanoparticles by the shape.

5. Iron is a ferromagnetic material with high magnetic
moment density (about 220 emu/g) and is magnetically
soft. Iron nanoparticles in the size range below 20 nm are
superparamagnetic.
Ferrofluids, the colloidal dispersions of magnetic iron oxides in
hydrocarbon oil, represent probably the first application of magnetic
materials in the new form.

11. Natural magnetic nanoparticles are everywhere [18]:
in human brain [19], in bacteria, algae, birds, ants, bees, etc.
[20–22], in soils and lacustrine sediments [23], in meteorites
[24, 25], and in interstellar space [26, 27].
Classification of magnetic particles
• weak’’-magnetic (diamagnetic and paramagnetic)
• strong’’-magnetic (ferromagnetic, ferrimagnetic,
antiferromagnetic, etc.) materials
Dipole magnetic moment per unit volume is called the magnetization,
M.
The diamagnetic and paramagnetic materials have zero
magnetization at any temperature in the absence of the external
magnetic field.

13. IRON (Fe) nanoparticles

16. Magnetic nanoparticles are spherical
nanocrystals of 10–20 nm of size with a Fe2+
and Fe3+ core surrounded by dextran or PEG
molecules.

26. Different strategies for the surface modification of magnetic NPs.
6322 | Dalton Trans., 2011, 40, 6315–6343

27. (a) Chemical structure of a PEG-phospholipid. (b) Coating procedure: the hydrophobic lipid
tails are incorporated between the alkyl chains of the capping molecules on theNP
surface,whereas the hydrophilic PEG chains point to the outside creating a hydrophilic shell.

28. Chemical structure of a typical multifunctional polymeric ligand.

30. applications
• Active cell targeting
(a) healthy cells only carry a certain number of cell receptors, which can be used for active
targeting,
(b) in cancer cells these receptors are overexpressed, therefore, more NPs can attach to the
malignant cell.

31. (c) Receptor-mediated endocythosis of the NPs: (d)formation of an endosome carrying
the NPs, (e) internalization of the endosome, (f) endosomal acidification by proton
pumps leads to elevated osmotic pressure and swelling, (g) finally, the endosome
ruptures and releases the magnetic NPs