3 research outputs found
Cellular uptake, genotoxicity and cytotoxicity of cobalt ferrite magnetic nanoparticles in human breast cells
Magnetic nanoparticles (MNPs) have been increasingly used for many years
as MRI agents and for gene delivery and hyperthermia therapy, although
there have been conflicting results on their safety. In this study,
cobalt ferrite magnetic nanoparticles (CoFe-MNPs) were prepared by the
co-precipitation method and their surfaces were modified with silica by
the sol-gel method. The particle and hydrodynamic sizes, morphology and
crystal structure of the bare and silica-coated CoFe-MNPs were evaluated
by transmission electron microscopy (TEM), dynamic light scattering
(DLS), X-ray diffraction spectroscopy (XRD) and Fourier transform
infrared spectroscopy (FTIR). The size of the bare CoFe-MNPs was in the
range 8-20 nm and they were homogeneously coated with 3-4 nm silica
shells. The bare and silica-coated CoFe-MNPs were agglomerated at
physiological pH. However, the sizes of the agglomerates were below 200
nm both in water and complete medium. The cytotoxic and genotoxic
potentials of the bare and silica-coated CoFe-MNPs were evaluated in a
metastatic breast cancer cell line, MDA-MB-231, as well as a
noncancerous mammary epithelial cell line, MCF-10A, by using XTT
cytotoxicity, single-cell gel electrophoresis (comet), and
cytokinesis-blocked (CB) micronucleus (CBMN) assays. Characterization
studies with TEM, inductively coupled plasma optical emission
spectroscopy (ICP-OES) and Prussian blue staining indicated that the
CoFe-MNPs were internalized into the cells by energy-dependent
endocytosis. The highest amount of uptake was observed in the cancer
cells and the uptake of the silica-coated CoFe--MNPs was higher than
that of the bare ones in both cell lines. The bare CoFe-MNPs showed
higher levels of both cytotoxicity and genotoxicity than the
silica-coated CoFe-MNPs. Moreover, the cancer cells seemed to be more
susceptible to the CoFe-MNPs' toxicity compared to the noncancerous
cells. There was a concentration and time-dependent increase in DNA
damage and the micronucleus (MN) frequency, which was statistically
significant starting with the lowest concentration of bare CoFe-MNPs (p
< 0.05), while no significance was observed below the concentration of
250 mu g mL(-1) for the silica-coated MNPs. Also, the extent of both DNA
damage and MN frequency was much higher in the cancer cells compared to
the noncancerous cells. According to our results, the silica coating
ameliorated both the cytotoxicity and genotoxicity as well the
internalization of the CoFe-MNPs
A Novel Acetylcholinesterase Biosensor: Core–Shell Magnetic Nanoparticles Incorporating a Conjugated Polymer for the Detection of Organophosphorus Pesticides
To construct a sensing interface,
in the present work, a conjugated
polymer and core–shell magnetic nanoparticle containing biosensor
was constructed for the pesticide analysis. The monomer 4,7-diÂ(furan-2-yl)ÂbenzoÂ[<i>c</i>]Â[1,2,5]Âthiadiazole (FBThF) and core–shell magnetic
nanoparticles were designed and synthesized for fabrication of the
biosensing device. The magnetic nanoparticles were first treated with
silica and then modified using carboxyl groups, which enabled binding
of the biomolecules covalently. For the construction of the proposed
sensor a two-step procedure was performed. First, the polyÂ(FBThF)
was electrochemically generated on the electrode surface. Then, carboxyl
group modified magnetic nanoparticles (f-MNPs) and acetylcholinesterase
(AChE), the model enzyme, were co-immobilized on the polymer-coated
surface. Thereby, a robust and novel surface, conjugated polymer bearing
magnetic nanoparticles with pendant carboxyl groups, was constructed,
which was characterized using Fourier transform infrared spectrometer,
cyclic voltammetry, scanning electron microscopy, and contact angle
measurements. This novel architecture was then applied as an immobilization
platform to detect pesticides. To the best of our knowledge, a sensor
design that combines both conjugated polymer and magnetic nanoparticles
was attempted for the first time, and this approach resulted in improved
biosensor characteristics. Hence, this approach opens a new perspective
in the field of enzyme immobilization and sensing applications. Paraoxon
and trichlorfon were selected as the model toxicants. To obtain best
biosensor performance, optimization studies were performed. Under
optimized conditions, the biosensor in concern revealed a rapid response
(5 s), a low detection limit (6.66 × 10<sup>–3</sup> mM),
and high sensitivity (45.01 μA mM<sup>–1</sup> cm<sup>–2</sup>). The <i>K</i><sub>M</sub><sup>app</sup> value of polyÂ(FBThF)/f-MNPs/AChE were determined as 0.73 mM. Furthermore,
there was no considerable activity loss for 10 d for polyÂ(FBThF)/f-MNPs/AChE
biofilm