Biomedical Engineering Reference
In-Depth Information
Figure 10.4
PGA as capping agent of silver nanoparticles.
h e literature has described the synthesis of composites of sil-
ver nanoparticles with polymers such as cellulose [63], polyurethane
[64], poly(acrylamide) [65], chitosan [66], poly(e-caprolactone) [67],
poly(styrene) [68], poly(methylmethacrylate) [69], montmorillonite [70],
polyvinyl alcohol [71], etc. h ese have provided materials in the forms
of i lms, scaf olds, i bers or grat s. h e literature has also describes the
obtaining of poly(l-lactide) and poly(lactide-co-glycolide) nanoi bers
containing AgNps using an electrospinning method [72], as well as the
obtaining of poly(lactide-co-glycolide) /silver composite grat s by extrac-
tion methods [73].
In the study of Stevanovic
et a
l, polyglutamic acid (PGA) (Figure 10.4)
was used as the organic layer (a capping agent) for silver nanoparticles
obtained using saccharose as a reducing agent. PGA was chosen as the cap-
ping agent to make the AgNps more biocompatibile and to protect them
from agglomerating in the medium [74].
In general, stabilization of nanoparticles is achieved by adding cap-
ping agents, which bind to the nanoparticle surface via covalent bonds
or by chemical interaction. h ese capping agents are essential to prevent
nanoparticle aggregation and increase the solubility of the nanosystem,
and also can be used as a site for bioconjugation of the nanoparticle with
important molecules. Dif erent capping agents include biodegradable
polymers, oligosaccharides and polysaccharides.
PGA-capped AgNps (AgNpPGAs) were additionally encapsulated
within poly(lactide-co-glycolide) spheres to ensure their release over an
extended period of time, and therefore their extended antimicrobial ef ects
.
Sureshkumar
et al
have successfully developed a facile method to pre-
pare a magnetic silver nanocomposite [63]. h e 3-D nanoi brous structure
of bacterial cellulose was homogenized with a ferric and ferrous mixture
by a high speed blender. Magnetite nanoparticles were precipitated and
