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Assessing the axonal translocation of CeO2 and SiO2 nanoparticles in the sciatic nerve fibers of the frog: an ex vivo electrophysiological study.

Kastrinaki G, Samsouris C, Kosmidis EK, Papaioannou E, Konstandopoulos AG, Theophilidis G - Int J Nanomedicine (2015)

Bottom Line: For the CeO2, we also demonstrated that the translocation depends on both axonal integrity and electrical activity.The speed of translocation for the two species was estimated in the range of 0.45-0.58 mm/h, close to slow axonal transportation rate.Transmission electron microscopy provided direct evidence for the presence of SiO2 in the treated nerves.

View Article: PubMed Central - PubMed

Affiliation: Aerosol and Particle Technology Laboratory (APTL), CERTH/CPERI, Thessaloniki, Greece.

ABSTRACT
The axonal translocation of two commonly used nanoparticles in medicine, namely CeO2 and SiO2, is investigated. The study was conducted on frog sciatic nerve fibers in an ex vivo preparation. Nanoparticles were applied at the proximal end of the excised nerve. A nerve stimulation protocol was followed for over 35 hours. Nerve vitality curve comparison between control and exposed nerves showed that CeO2 has no neurotoxic effect at the concentrations tested. After exposure, specimens were fixed and then screen scanned every 1 mm along their length for nanoparticle presence by means of Fourier transform infrared microscopy. We demonstrated that both nanoparticles translocate within the nerve by formation of narrow bands in the Fourier transform infrared spectrum. For the CeO2, we also demonstrated that the translocation depends on both axonal integrity and electrical activity. The speed of translocation for the two species was estimated in the range of 0.45-0.58 mm/h, close to slow axonal transportation rate. Transmission electron microscopy provided direct evidence for the presence of SiO2 in the treated nerves.

No MeSH data available.


Related in: MedlinePlus

FTIR traces from different regions of CeO2-treated sciatic nerve of the frog.Notes: Arrows indicate CeO2 presence compared to control (CeO2 NP). Peaks approximately 1,640 cm−1 are attributed to the ν2′ band of the hydrogen bond of water.Abbreviations: FTIR, Fourier transform infrared microscopy; NP, nanoparticle.
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f2-ijn-10-7089: FTIR traces from different regions of CeO2-treated sciatic nerve of the frog.Notes: Arrows indicate CeO2 presence compared to control (CeO2 NP). Peaks approximately 1,640 cm−1 are attributed to the ν2′ band of the hydrogen bond of water.Abbreviations: FTIR, Fourier transform infrared microscopy; NP, nanoparticle.

Mentions: In six out of eight treated nerves, CeO2 NPs translocated within the nerves. CeO2 was observed mainly in the middle and distal regions of the nerve. In all six nerves, no NPs were observed in the proximal region. In the other two nerves, there was no transport. In Figure 2, exemplary FTIR traces are shown from such an experiment. The bottom trace is the negative control (control nerve, free of NPs) and the trace at the top (CeO2 NPs) the positive. CeO2 NPs presence is indicated with arrows. The nerve was screened scanned every 1 mm. The middle FTIR trace (Figure 2, no CeO2) is indicative of the proximal, distal, and of the first 13 mm of the middle part, where no NPs were detected, (compare traces marked with no CeO2 and CeO2). It is worth mentioning that the absorption spectrum indicating the presence of CeO2 NPs appeared only in a short region as a bundle at the middle part of the nerve (insert at the right of Figure 2). In this particular case, NPs were located between 14 and 15 mm of the middle part (according to Figure 1B). The difference in size of the CeO2 characteristic peak at 600–800 cm−1 indicates that at 14 mm (low CeO2 trace), the concentration of CeO2 NPs is lower than at 15 mm (high CeO2 trace). Although the exact terminal positioning of the NPs differed among the six nerves examined between 14 and 20 mm, a constant observation was that CeO2 NPs tended to cluster and travel together as a bundle.


Assessing the axonal translocation of CeO2 and SiO2 nanoparticles in the sciatic nerve fibers of the frog: an ex vivo electrophysiological study.

Kastrinaki G, Samsouris C, Kosmidis EK, Papaioannou E, Konstandopoulos AG, Theophilidis G - Int J Nanomedicine (2015)

FTIR traces from different regions of CeO2-treated sciatic nerve of the frog.Notes: Arrows indicate CeO2 presence compared to control (CeO2 NP). Peaks approximately 1,640 cm−1 are attributed to the ν2′ band of the hydrogen bond of water.Abbreviations: FTIR, Fourier transform infrared microscopy; NP, nanoparticle.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664516&req=5

f2-ijn-10-7089: FTIR traces from different regions of CeO2-treated sciatic nerve of the frog.Notes: Arrows indicate CeO2 presence compared to control (CeO2 NP). Peaks approximately 1,640 cm−1 are attributed to the ν2′ band of the hydrogen bond of water.Abbreviations: FTIR, Fourier transform infrared microscopy; NP, nanoparticle.
Mentions: In six out of eight treated nerves, CeO2 NPs translocated within the nerves. CeO2 was observed mainly in the middle and distal regions of the nerve. In all six nerves, no NPs were observed in the proximal region. In the other two nerves, there was no transport. In Figure 2, exemplary FTIR traces are shown from such an experiment. The bottom trace is the negative control (control nerve, free of NPs) and the trace at the top (CeO2 NPs) the positive. CeO2 NPs presence is indicated with arrows. The nerve was screened scanned every 1 mm. The middle FTIR trace (Figure 2, no CeO2) is indicative of the proximal, distal, and of the first 13 mm of the middle part, where no NPs were detected, (compare traces marked with no CeO2 and CeO2). It is worth mentioning that the absorption spectrum indicating the presence of CeO2 NPs appeared only in a short region as a bundle at the middle part of the nerve (insert at the right of Figure 2). In this particular case, NPs were located between 14 and 15 mm of the middle part (according to Figure 1B). The difference in size of the CeO2 characteristic peak at 600–800 cm−1 indicates that at 14 mm (low CeO2 trace), the concentration of CeO2 NPs is lower than at 15 mm (high CeO2 trace). Although the exact terminal positioning of the NPs differed among the six nerves examined between 14 and 20 mm, a constant observation was that CeO2 NPs tended to cluster and travel together as a bundle.

Bottom Line: For the CeO2, we also demonstrated that the translocation depends on both axonal integrity and electrical activity.The speed of translocation for the two species was estimated in the range of 0.45-0.58 mm/h, close to slow axonal transportation rate.Transmission electron microscopy provided direct evidence for the presence of SiO2 in the treated nerves.

View Article: PubMed Central - PubMed

Affiliation: Aerosol and Particle Technology Laboratory (APTL), CERTH/CPERI, Thessaloniki, Greece.

ABSTRACT
The axonal translocation of two commonly used nanoparticles in medicine, namely CeO2 and SiO2, is investigated. The study was conducted on frog sciatic nerve fibers in an ex vivo preparation. Nanoparticles were applied at the proximal end of the excised nerve. A nerve stimulation protocol was followed for over 35 hours. Nerve vitality curve comparison between control and exposed nerves showed that CeO2 has no neurotoxic effect at the concentrations tested. After exposure, specimens were fixed and then screen scanned every 1 mm along their length for nanoparticle presence by means of Fourier transform infrared microscopy. We demonstrated that both nanoparticles translocate within the nerve by formation of narrow bands in the Fourier transform infrared spectrum. For the CeO2, we also demonstrated that the translocation depends on both axonal integrity and electrical activity. The speed of translocation for the two species was estimated in the range of 0.45-0.58 mm/h, close to slow axonal transportation rate. Transmission electron microscopy provided direct evidence for the presence of SiO2 in the treated nerves.

No MeSH data available.


Related in: MedlinePlus