' Antibacterial and antifungal activity of chitosan coated iron oxide nanoparticles

Background and aim: The emergence of resistance against antimicrobial agents has led to the development of more efficient agents and new techniques for treatment of various microbial infections. The aim of the present study is to determine the antibacterial and antifungal activity of bare and chitosan coated Fe3O4 nanoparticles (NPs) against five organisms, Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), Candida albicans (C. albicans), Aspergillus niger (A. niger) and Fusarium solani (F. solani). Methods: Fe3O4 NPs were synthesised by coprecipitation and surface coating was done by chitosan polymer to avoid agglomeration. The antimicrobial property of NPs was tested by agar well diffusion and analysed by measuring the diameter of the inhibition zone. Results: Average particle size of Fe3O4 and chitosan coated Fe3O4 NPs was 10.4 +/- 4.9 and 11.4 +/- 5.2 nm, respectively. Mean diameter of inhibition zone of synthesised chitosan coated Fe3O4 NPs was in the range 14.5 to 18.5 mm. The effect of chitosan coated Iron oxide nanoparticles was F. solani/A. niger < C. albicans < E. coli/B. subtilis (p < 0.001). Conclusions: Chitosan coated Fe3O4 NPs are effective antimicrobial agents and so may be developed as a microbial resistant coating for biomedical devices.