Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Preparation, Characterization and Antibacterial Properties of Silver-Chitosan Nanocomposites Using Different Molecular Weight Grades of Chitosan

S Honary¹ , K Ghajar¹, P Khazaeli², P Shalchian²

¹Mazandaran 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:- S Honary Email: shonary@yahoo.com Tel:+981513543084

Received: 14 July 2010 Accepted: 10 January 2011 Published: 14 February 2011

Citation: Honary S, Ghajar K, Khazaeli P, Shalchian P. Preparation, Characterization and Antibacterial Properties of Silver-Chitosan Nanocomposites Using Different Molecular Weight Grades of Chitosan. Trop J Pharm Res 2011; 10(1):69-74 doi: 10.4314/tjpr.v10i1.11

© 2011 The authors.
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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