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Antimicrobial activity of iron oxide nanoparticle upon modulation of nanoparticle-bacteria interface.

Arakha M, Pal S, Samantarrai D, Panigrahi TK, Mallick BC, Pramanik K, Mallick B, Jha S - Sci Rep (2015)

Bottom Line: Additionally, the nanocrystals obtained were found to have spherical size with 10-20 nm diameter.However, coating with chitosan molecule resulted significant increase in antimicrobial propensity of IONP.The data, altogether, indicated that the chitosan coating of IONP result in interface that enhances ROS production, hence the antimicrobial activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, National Institute of Technology Rourkela, Odisha 769008, India.

ABSTRACT
Investigating the interaction patterns at nano-bio interface is a key challenge for safe use of nanoparticles (NPs) to any biological system. The study intends to explore the role of interaction pattern at the iron oxide nanoparticle (IONP)-bacteria interface affecting antimicrobial propensity of IONP. To this end, IONP with magnetite like atomic arrangement and negative surface potential (n-IONP) was synthesized by co-precipitation method. Positively charged chitosan molecule coating was used to reverse the surface potential of n-IONP, i.e. positive surface potential IONP (p-IONP). The comparative data from fourier transform infrared spectroscope, XRD, and zeta potential analyzer indicated the successful coating of IONP surface with chitosan molecule. Additionally, the nanocrystals obtained were found to have spherical size with 10-20 nm diameter. The BacLight fluorescence assay, bacterial growth kinetic and colony forming unit studies indicated that n-IONP (<50 μM) has insignificant antimicrobial activity against Bacillus subtilis and Escherichia coli. However, coating with chitosan molecule resulted significant increase in antimicrobial propensity of IONP. Additionally, the assay to study reactive oxygen species (ROS) indicated relatively higher ROS production upon p-IONP treatment of the bacteria. The data, altogether, indicated that the chitosan coating of IONP result in interface that enhances ROS production, hence the antimicrobial activity.

No MeSH data available.


Related in: MedlinePlus

Characterization of n-IONP and p-IONP.(a) XRD spectra (b) ATR-FTIR absorption spectra, and (c) UV-Vis absorption spectra of n-IONP, and p-IONP, (d) Zeta potential analysis of n-IONP (Fig. d–I), and p-IONP (Fig. d–II).
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f1: Characterization of n-IONP and p-IONP.(a) XRD spectra (b) ATR-FTIR absorption spectra, and (c) UV-Vis absorption spectra of n-IONP, and p-IONP, (d) Zeta potential analysis of n-IONP (Fig. d–I), and p-IONP (Fig. d–II).

Mentions: Numerous methods have been formulated for synthesis of IONPs, still synthesis of NPs having small and uniform size distribution with good stability to avoid agglomeration is a matter of intensive research in current era. In this study, we have synthesized IONP by chemical precipitation method followed by surface modification with chitosan, a derivative of chitin. The type of synthesized IONP was studied using X-ray diffraction spectroscopy. Figure 1(a) shows the XRD patterns for both n-IONP and p-IONP. The major diffraction peak at 35° (311) in addition to minor peaks at 30° (220), 43° (400), 53° (422), 57° (511), and 62° (440) confirm the spinel structure of iron oxide (magnetite-Fe3O4 and maghemite- γ-Fe2O3)1, revealing that the synthesized IONP does not contain any other forms of iron oxide such as hematite (α-Fe2O3), goethite (FeO(OH)), or any iron hydroxides in detectable range1. Shan Z. et al. has suggested that the lattice parameter (α) for magnetite and maghemite are 8.3960 Å and 8.3515 Å, respectively19. In our case, the lattice parameter for n-IONP is 8.3840 Å, which is very close to lattice parameter of magnetite, revealing that the synthesized n-IONP contains predominantly magnetite (Fe3O4) population. For further confirmation, we have considered the 2θ value of the (311) peak. As reported in various literatures, the standard values of this peak (311) for magnetite and maghemite are at 35.423° and 35.631°, respectively119. Since the diffraction angle for the synthesised NP is 35.47°, more close to magnetite index than maghemite index. It indicates presence of predominantly magnetite (Fe3O4) lattice with traces of maghemite lattice. From the observations, it is concluded that the synthesized n-IONP is nano-crystal of magnetite (Fe3O4). The surface modification by chitosan does not affect the crystal structure of Fe3O4 NP, since the major peaks at 2θ, 30° (220), 35° (311), 43° (400), 57° (511), and 62° (440), correspond to 8.3840 Å lattice, only. The 2θ value for the peak (311) is 35.46, which is basic characteristic feature of Fe3O4 NP, as described above119. Additionally, the analysis of n-IONP and p-IONP XRD patterns using X’ pert high score software with search and match option reveals that both types of synthesized NPs have Fe3O4 crystals (JCPDS reference code–75-0033). The particle size of n-IONP and p-IONP was determined using Scherrer equation


Antimicrobial activity of iron oxide nanoparticle upon modulation of nanoparticle-bacteria interface.

Arakha M, Pal S, Samantarrai D, Panigrahi TK, Mallick BC, Pramanik K, Mallick B, Jha S - Sci Rep (2015)

Characterization of n-IONP and p-IONP.(a) XRD spectra (b) ATR-FTIR absorption spectra, and (c) UV-Vis absorption spectra of n-IONP, and p-IONP, (d) Zeta potential analysis of n-IONP (Fig. d–I), and p-IONP (Fig. d–II).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594095&req=5

f1: Characterization of n-IONP and p-IONP.(a) XRD spectra (b) ATR-FTIR absorption spectra, and (c) UV-Vis absorption spectra of n-IONP, and p-IONP, (d) Zeta potential analysis of n-IONP (Fig. d–I), and p-IONP (Fig. d–II).
Mentions: Numerous methods have been formulated for synthesis of IONPs, still synthesis of NPs having small and uniform size distribution with good stability to avoid agglomeration is a matter of intensive research in current era. In this study, we have synthesized IONP by chemical precipitation method followed by surface modification with chitosan, a derivative of chitin. The type of synthesized IONP was studied using X-ray diffraction spectroscopy. Figure 1(a) shows the XRD patterns for both n-IONP and p-IONP. The major diffraction peak at 35° (311) in addition to minor peaks at 30° (220), 43° (400), 53° (422), 57° (511), and 62° (440) confirm the spinel structure of iron oxide (magnetite-Fe3O4 and maghemite- γ-Fe2O3)1, revealing that the synthesized IONP does not contain any other forms of iron oxide such as hematite (α-Fe2O3), goethite (FeO(OH)), or any iron hydroxides in detectable range1. Shan Z. et al. has suggested that the lattice parameter (α) for magnetite and maghemite are 8.3960 Å and 8.3515 Å, respectively19. In our case, the lattice parameter for n-IONP is 8.3840 Å, which is very close to lattice parameter of magnetite, revealing that the synthesized n-IONP contains predominantly magnetite (Fe3O4) population. For further confirmation, we have considered the 2θ value of the (311) peak. As reported in various literatures, the standard values of this peak (311) for magnetite and maghemite are at 35.423° and 35.631°, respectively119. Since the diffraction angle for the synthesised NP is 35.47°, more close to magnetite index than maghemite index. It indicates presence of predominantly magnetite (Fe3O4) lattice with traces of maghemite lattice. From the observations, it is concluded that the synthesized n-IONP is nano-crystal of magnetite (Fe3O4). The surface modification by chitosan does not affect the crystal structure of Fe3O4 NP, since the major peaks at 2θ, 30° (220), 35° (311), 43° (400), 57° (511), and 62° (440), correspond to 8.3840 Å lattice, only. The 2θ value for the peak (311) is 35.46, which is basic characteristic feature of Fe3O4 NP, as described above119. Additionally, the analysis of n-IONP and p-IONP XRD patterns using X’ pert high score software with search and match option reveals that both types of synthesized NPs have Fe3O4 crystals (JCPDS reference code–75-0033). The particle size of n-IONP and p-IONP was determined using Scherrer equation

Bottom Line: Additionally, the nanocrystals obtained were found to have spherical size with 10-20 nm diameter.However, coating with chitosan molecule resulted significant increase in antimicrobial propensity of IONP.The data, altogether, indicated that the chitosan coating of IONP result in interface that enhances ROS production, hence the antimicrobial activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, National Institute of Technology Rourkela, Odisha 769008, India.

ABSTRACT
Investigating the interaction patterns at nano-bio interface is a key challenge for safe use of nanoparticles (NPs) to any biological system. The study intends to explore the role of interaction pattern at the iron oxide nanoparticle (IONP)-bacteria interface affecting antimicrobial propensity of IONP. To this end, IONP with magnetite like atomic arrangement and negative surface potential (n-IONP) was synthesized by co-precipitation method. Positively charged chitosan molecule coating was used to reverse the surface potential of n-IONP, i.e. positive surface potential IONP (p-IONP). The comparative data from fourier transform infrared spectroscope, XRD, and zeta potential analyzer indicated the successful coating of IONP surface with chitosan molecule. Additionally, the nanocrystals obtained were found to have spherical size with 10-20 nm diameter. The BacLight fluorescence assay, bacterial growth kinetic and colony forming unit studies indicated that n-IONP (<50 μM) has insignificant antimicrobial activity against Bacillus subtilis and Escherichia coli. However, coating with chitosan molecule resulted significant increase in antimicrobial propensity of IONP. Additionally, the assay to study reactive oxygen species (ROS) indicated relatively higher ROS production upon p-IONP treatment of the bacteria. The data, altogether, indicated that the chitosan coating of IONP result in interface that enhances ROS production, hence the antimicrobial activity.

No MeSH data available.


Related in: MedlinePlus