Biomedical Engineering Reference
In-Depth Information
Vimala
et al.
have reported the preparation of semi-interpenetrating
hydrogel networks (SIHNs) based on crosslinked poly(acrylamide) pre-
pared through an optimized rapid redox-solution polymerization with
N,N-methylenebisacrylamide in the presence of three dif erent carbohy-
drate polymers, namely gum acacia, carboxymethylcellulose and starch.
h ey have obtained highly stable and uniformly distributed silver nanopar-
ticles with hydrogel networks as nanoreactors via
in situ
reduction of silver
nitrate using sodium borohydride as reducing agent. h e formation of sil-
ver nanoparticles has been coni rmed with ultraviolet visible spectroscopy,
Fourier transform infrared spectroscopy, and X-ray dif raction analyses.
h ermogravimetric analysis provides the amounts of silver nanoparticles
that exist in the hydrogel networks. Transmission electron microscopy
results demonstrate that acacia employed hydrogels have regulated the
silver nanoparticles size to 2-5 nm, whereas carboxymethylcellulose and
starch composed hydrogel networks 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 the
investigation 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
+
existing 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 potential
