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Research Article
Preparation,
Characterization and Antibacterial Properties of Silver-Chitosan
Nanocomposites Using Different Molecular Weight Grades
of Chitosan
S Honary1*, K Ghajar1, P Khazaeli2
and P Shalchian2
1
Mazandaran
University of Medical Sciences, School of Pharmacy&
Pharmaceutical Sciences Research Center, Sari, Iran;
2Kerman University of Medical Sciences,
School of Pharmacy, Kerman, Iran
*For correspondence:
E-mail:
shonary@yahoo.com,
SHonary@mazums.ac.ir; Tel: +98 151
3543084, 151 3246491; Fax: +98 151 2224521
Received: 14 July
2010 Revised
accepted: 10 January 2011
Tropical
Journal of Pharmaceutical Research, February 2011;
10(1):
69-74
Abstract
Purpose:
To study the effect of chitosan molecular weight on the
physicochemical and antibacterial properties of silver-chitosan
nanoparticles.
Methods:
A series of silver-chitosan
nanoparticles of different sizes were produced using
various molecular weight (MW) grades of chitosan by an
aqueous chemical reduction method. The nanoparticles
were characterized by ultraviolet-visible absorption
spectroscopy (UV-Vis), scanning electron microscopy (SEM),
differential scanning calorimetry (DSC), dynamic light
scattering (DLS) and laser Doppler electrophoresis (LDE).
The antibacterial properties of the nanoparticles were
also evaluated by agar diffusion method.
Results:
The size of the silver-chitosan nanoparticles, ranging
from 21.9 to 175.3 nm, was influenced by chitosan MW as
well as by other process conditions. Although, the
nanoparticles were not stable in liquid form, they
however showed good stability in the solid state due to
their low zeta potential. SEM images indicate that the
nanoparticles were spherical. The antibacterial activity
of the nanoparticles against Staphylococcus aureus
increased with decrease in particle size owing to
increase in surface area. The smallest particle size
(21.9 nm) was obtained by using high chitosan MW at 4
°C
and a stirring speed of 800 rpm.
Conclusion:
Chitosan is an
effective agent for the preparation of silver
nanoparticles. The size of the nanoparticles can be
modulated by varying both chitosan MW and process
conditions such as temperature and stirring speed.
Keywords:
Chitosan; Antibacterial activity; Silver nanoparticles;
Molecular weight; Particle size; Dynamic light
scattering; Laser Doppler electrophoresis |
