Biomedical Engineering Reference
In-Depth Information
polymer matrix, which in certain systems may be viewed as a form of
assembly [62].
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 form
of i lms, scaf olds, i bers or grat s. h e literature has also described the
obtainment of poly(l-lactide) and poly(lactide-co-glycolide) nanoi bers
containing AgNps using an electrospinning method [72], as well as the
obtainment of poly(lactide-co-glycolide)/silver composite grat s by extrac-
tion methods [73].
In the study of Stevanovic
et al.
, polyglutamic acid (PGA) (Figure 2.4)
was used as the organic layer (a capping agent) for silver nanoparticles
obtained using saccharose as a reducing agent. h e PGA was chosen as
the capping 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.
h e 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
.
Figure 2.4
PGA as capping agent of silver nanoparticles.
