Biomedical Engineering Reference
In-Depth Information
polymers, namely gum acacia, carboxymethylcellulose and starch. h eyhave
obtained highly stable and uniformly distributed silver nanoparticles with
hydrogel networks as nanoreactors via
in situ
reduction of silver nitrate using
sodium borohydride as reducing agent. h e formation of silver nanoparti-
cles has been coni rmed with ultraviolet visible spectroscopy, fourier trans-
form infrared spectroscopy, X-ray dif raction analyses. h ermogravimetric
analysis provides the amounts of silver nanoparticles exist in the hydrogel
networks. Transmission electron microscopy results demonstrate that aca-
cia employed hydrogels have regulated the silver nanoparticles size to 2-5
nm where as carboxymethylcellulose and starch composed hydrogel net-
works result in a heterogeneous size from 2 to 20 nm.
Potara
et al
have reported the formation of chitosan-coated silver
nanoparticles of triangular shape in solution by synergistic action of chito-
san and trisodium citrate in the presence of silver seeds and ascorbic acid
[66]. It has been revealed that these anisotropic AgNps entrapped in bio-
polymeric shells are particularly stable and can be successfully used as ver-
satile plasmonic substrates for molecular sensing in solution. In particular,
the binding of the probe molecule monolayer (para-aminothiophenol) at
the surface of individual chitosan-coated silver nanoparticles was demon-
strated both by LSPR shit s and SERS spectra. While the LSPR-shit assay is
operational for signaling molecular binding events, the SERS allows iden-
tifying the probe molecules and elucidating its orientation on the metal
surface. h e proof of concept for biosensing applications and dual func-
tionality of plasmonic platform are evaluated through the combined LSPR-
SERS detection of signii cant biological molecules, adenine. Potara et al
have stated that the potential of chitosan-silver nanostructures to extend
the standard approach of LSPR sensing by integrating SERS measurements
and operate as dual plasmonic sensors would be very attractive for investi-
gation of analytes in biological l uids.
Nanoi bers of poly(e-caprolactone) (PCL) which poses antimicrobial
activity were prepared by electrospinning of a PCL solution with small
amounts of silver-loaded zirconium phosphate nanoparticles for potential
use in wound dressing applications [67]. h ese i bers have maintained the
strong killing abilities of Ag
+
existed in the nanoAgZ against the tested
bacteria strains and discoloration has not been observed for the nanoi -
bers. h e authors have tested the biocompatibility of nanoi bers as poten-
tial wound dressings, i.e. primary human dermal i broblasts were cultured
on the nanoi brous mats. h e cultured cells were evaluated in terms of cell
proliferation and morphology. h e results indicated that the cells attached
and proliferated as continuous layers on the nanoAgZ-containing nanoi -
bers and maintained the healthy morphology of human dermal i broblasts.
