Biomedical Engineering Reference
In-Depth Information
(
A
)
(
B
)
Figure 5.3
Ag (
A
) and Fe (
B
) nanoparticles synthesized in the presence of chitosan
derivatives.
bacilliformis
and
Paecilomyces variotii
. h e minimum inhibitory concen-
tration range was found to be 20 times lower than that reported for chi-
tosan [62]. Other metal NPs which have been synthesized with chitosan
include iron, gold, palladium, platinum and copper to name a few [63]. Bae
et al.
have synthesized chitosan oligosaccharide stabilised ferrimagnetic
iron oxide nanoparticles which were utilized in magnetically modulated
cancer hyperthermia [64]. h is study showed promising antitumour ei -
cacy in an animal tumour model [64]. Previously, Ag and Fe nanoparticles
have been synthesized in the presence of chitosan based polymers. h e
TEM images below show the typical morphologies obtained for these par-
ticles [Figure 5.3, A (Ag) & B (Fe) at a resolution of 200 nm].
5.5 Nanoi bres (Electrospinning)
Electrospinning is a method used for the fabrication of ultrai ne i bres,
where macromolecules are spun into i bres as thin as a few nanometres.
Almost any soluble polymer with a sui ciently high molecular weight can
be electrospinned to provide nanoi bres with diameters in the range of
20-200nm. h e principle of electrospinning is the application of an elec-
tric i eld to a polymer l uid where the polymer is introduced to the i eld
via
a capillary needle. h e resultant non-woven i bre mat is collected on a
collector plate (Figure 1.4) [65, 29].
Adjusting the parameters of the electrospinning process produces i bres
with variable structures [66]. Nanoi bres produced have favourable proper-
ties such as large surface area to volume ratios, high porosity, high gas per-
meability and small pore sizes, all of which are advantageous in biomedical
