Speaker
Ms
Zorica Kačarević-Popović
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Description
Silver (Ag) impregnated dressings are intended to promote healing,
prevent infection, to produce a sustained, steady supply of active Ag
and to meet the challenges about safety. Hydrogels impregnated with
nanocrystalline Ag (AgNPs) have the potential to meet most of these
requirements.
Here hydrogel nanocomposite formulations are based on thermo- (NiPAAm)
and pH-sensitive (IA) copolymer hydrogel matrix doped with AgNPs,
(Ag-P(NiPAAm/IA), as a system for the controlled release of
therapeutically active Ag ions with the aim to obtain the effective
smart, antibacterial and nontoxic device. Synthesis of cross-linked
polymer matrix (hydrogel) and in situ incorporation of AgNPs is made
by biocompatible radiolytic products of water (using
a $^{60}$Co source) which provides a basis for the wide range
of advanced or innovative applications in the biomedical field.
The aim of the work was to investigate structural characteristics of
the AgNPs, the micromorphologycal and physicochemical characteristics
of hydrogel, and biomedical potential of $\gamma$-irradiation
synthesized nanosystems.
FTIR analysis confirms formation of 3D structure of copolymeric
hydrogel with thermo- and pH responses. Swelling experiment was
performed at different temperature ($25^\circ$C and $37^\circ$C) and
pH ($2.2$, $4.5$ and $46.8$) values. Internal morphology, examined by
SEM and micro-CT analysis, showed the porous structure, dependent on
the IA content, while AgNPs have no influence on the micro-structure.
UV-Vis confirmed the synthesis of spherical AgNPs by the peak at
around $400$ nm. XRD studies confirmed the face centred cubic (fcc)
crystal structure of AgNPs with the diffraction maxima at $2\Theta$
angle values that correspond to the Bragg reflections from the crystal
planes $(111)$, $(200)$, $(220)$ and $(311)$. The changes of lattice
parameter, interplanar spacing, strain, stress, and dislocation
density of crystalline AgNPs depend on the pore size and the diameter
of AgNPs.
The controlled release of active substances was monitored by the
release kinetics of Ag ions in a buffer solution (pH${=} 7.4$,
$T=37^\circ$C). The content of Ag ions was determined by Argon arc
plasma and obtained results are modelled by pharmacokinetic models
(Korsmeyer-Peppas, Higuchi, Hixson-Crowel, Kopcha and Makoid-Banakar).
Antibacterial potential against the gram-negative (*Escherichia coli*) and gram-positive (*Staphylococcus
aureus*) bacteria was investigated by the disc diffusion and optical
density methods. Considering that the basic condition for the
biomedical application of these types of materials is absence of
toxicity in the surrounding tissue, cytotoxicity of synthesized
nanocomposite device was examined by the effect on HaCaT cell line
(healthy human keratinocytes). The results show that it is possible
to achieve and fine-tune optimal antibacterial activity, below the
cytotoxicity level, and without any harmful effects on the surrounding
cells.
| Country/Organization invited to participate | Serbia |
|---|
Primary author
Ms
Jelena Spasojević
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Co-authors
Ms
Aleksandra Radosavljević
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Ms
Jelena Krstić
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Ms
Marija Đurić
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Mr
Miodrag Mitrić
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Mr
Petar Milovanović
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
Ms
Zorica Kačarević-Popović
(Vinča Institute of Nuclear Sciences, University of Belgrade, Serbia)
