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Spontaneous confocal Raman microscopy--a tool to study the uptake of nanoparticles and carbon nanotubes into cells.

Romero G, Rojas E, Estrela-Lopis I, Donath E, Moya SE - Nanoscale Res Lett (2011)

Bottom Line: Confocal Raman microscopy as a label-free technique was applied to study the uptake and internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and carbon nanotubes (CNTs) into hepatocarcinoma human HepG2 cells.Spontaneous confocal Raman spectra was recorded from the cells exposed to oxidized CNTs and to PLGA NPs.For PLGA NPs, it was found that they preferentially co-localized with lipid bodies, while the oxidized CNTs are located in the cytoplasm.

View Article: PubMed Central - HTML - PubMed

Affiliation: CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastian, Spain. smoya@cicbiomagune.es.

ABSTRACT
Confocal Raman microscopy as a label-free technique was applied to study the uptake and internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and carbon nanotubes (CNTs) into hepatocarcinoma human HepG2 cells. Spontaneous confocal Raman spectra was recorded from the cells exposed to oxidized CNTs and to PLGA NPs. The Raman spectra showed bands arising from the cellular environment: lipids, proteins, nucleic acids, as well as bands characteristic for either PLGA NPs or CNTs. The simultaneous generation of Raman bands from the cell and nanomaterials from the same spot proves internalization, and also indicates the cellular region, where the nanomaterial is located. For PLGA NPs, it was found that they preferentially co-localized with lipid bodies, while the oxidized CNTs are located in the cytoplasm.

No MeSH data available.


Related in: MedlinePlus

Confocal Raman imaging of HepG2 cells before and after exposure to PLGA NPs. (a) Raman spectrum recorded at different positions within a cell from the HepG2 line (ν indicates stretching and δ deformation vibration modes; l denote vibrations of lipids and p of protein). (b) Spot Raman spectra (dark blue) in cells exposed to PLGA NPs covered with PEI, pink and green lines denote the component spectra of PLGA NPs and of the cells. The insets correspond to the image of the cell under study
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Figure 2: Confocal Raman imaging of HepG2 cells before and after exposure to PLGA NPs. (a) Raman spectrum recorded at different positions within a cell from the HepG2 line (ν indicates stretching and δ deformation vibration modes; l denote vibrations of lipids and p of protein). (b) Spot Raman spectra (dark blue) in cells exposed to PLGA NPs covered with PEI, pink and green lines denote the component spectra of PLGA NPs and of the cells. The insets correspond to the image of the cell under study

Mentions: CRM experiments were performed in the same experimental conditions, but without labelling of the NPs, and are shown in Figure 2. In Figure 2a, representative Raman spectra, taken at different regions of the cell are shown. The nucleus, cytoplasm and LB can be identified by their chemical signature provided by the Raman spectrum. The symmetric stretch bands of CH2 (2850 cm-1) to CH3 (2935 cm-1) is much more intense in LB (blue line) than in the cytoplasm (green line) due to a lower density of CH2 groups in proteins compared with lipids. The nucleus region was identified by the smallest intensity ratio of CH2 to CH3 bands, as well as by bands assigned as vibration of DNA bases of adenine (A) and guanine (G) (red line). The spectra in Figure 2b correspond to Raman spectra taken from HepG2 cell, before and after incubation with PLGA NPs. A spectrum of the PLGA NPs taken in the dry state is also shown (pink curve). It can be seen that the Raman spectrum of the cells, after incubation with PLGA, represents a superposition of the PLGA particle spectrum (pink) and the spectrum of the control (green). Besides the bands typical from lipids at 2850 and 2900 cm-1, which can be attributed to the LB, the intense CH2 and CH3 vibrations of PLGA are clearly visible. Looking at different spots in the cell, at the same plane and at different positions regarding the z-direction, revealed that when bands characteristic for PLGA NPs were observed, the typical LB signature was also present.


Spontaneous confocal Raman microscopy--a tool to study the uptake of nanoparticles and carbon nanotubes into cells.

Romero G, Rojas E, Estrela-Lopis I, Donath E, Moya SE - Nanoscale Res Lett (2011)

Confocal Raman imaging of HepG2 cells before and after exposure to PLGA NPs. (a) Raman spectrum recorded at different positions within a cell from the HepG2 line (ν indicates stretching and δ deformation vibration modes; l denote vibrations of lipids and p of protein). (b) Spot Raman spectra (dark blue) in cells exposed to PLGA NPs covered with PEI, pink and green lines denote the component spectra of PLGA NPs and of the cells. The insets correspond to the image of the cell under study
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211846&req=5

Figure 2: Confocal Raman imaging of HepG2 cells before and after exposure to PLGA NPs. (a) Raman spectrum recorded at different positions within a cell from the HepG2 line (ν indicates stretching and δ deformation vibration modes; l denote vibrations of lipids and p of protein). (b) Spot Raman spectra (dark blue) in cells exposed to PLGA NPs covered with PEI, pink and green lines denote the component spectra of PLGA NPs and of the cells. The insets correspond to the image of the cell under study
Mentions: CRM experiments were performed in the same experimental conditions, but without labelling of the NPs, and are shown in Figure 2. In Figure 2a, representative Raman spectra, taken at different regions of the cell are shown. The nucleus, cytoplasm and LB can be identified by their chemical signature provided by the Raman spectrum. The symmetric stretch bands of CH2 (2850 cm-1) to CH3 (2935 cm-1) is much more intense in LB (blue line) than in the cytoplasm (green line) due to a lower density of CH2 groups in proteins compared with lipids. The nucleus region was identified by the smallest intensity ratio of CH2 to CH3 bands, as well as by bands assigned as vibration of DNA bases of adenine (A) and guanine (G) (red line). The spectra in Figure 2b correspond to Raman spectra taken from HepG2 cell, before and after incubation with PLGA NPs. A spectrum of the PLGA NPs taken in the dry state is also shown (pink curve). It can be seen that the Raman spectrum of the cells, after incubation with PLGA, represents a superposition of the PLGA particle spectrum (pink) and the spectrum of the control (green). Besides the bands typical from lipids at 2850 and 2900 cm-1, which can be attributed to the LB, the intense CH2 and CH3 vibrations of PLGA are clearly visible. Looking at different spots in the cell, at the same plane and at different positions regarding the z-direction, revealed that when bands characteristic for PLGA NPs were observed, the typical LB signature was also present.

Bottom Line: Confocal Raman microscopy as a label-free technique was applied to study the uptake and internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and carbon nanotubes (CNTs) into hepatocarcinoma human HepG2 cells.Spontaneous confocal Raman spectra was recorded from the cells exposed to oxidized CNTs and to PLGA NPs.For PLGA NPs, it was found that they preferentially co-localized with lipid bodies, while the oxidized CNTs are located in the cytoplasm.

View Article: PubMed Central - HTML - PubMed

Affiliation: CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastian, Spain. smoya@cicbiomagune.es.

ABSTRACT
Confocal Raman microscopy as a label-free technique was applied to study the uptake and internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and carbon nanotubes (CNTs) into hepatocarcinoma human HepG2 cells. Spontaneous confocal Raman spectra was recorded from the cells exposed to oxidized CNTs and to PLGA NPs. The Raman spectra showed bands arising from the cellular environment: lipids, proteins, nucleic acids, as well as bands characteristic for either PLGA NPs or CNTs. The simultaneous generation of Raman bands from the cell and nanomaterials from the same spot proves internalization, and also indicates the cellular region, where the nanomaterial is located. For PLGA NPs, it was found that they preferentially co-localized with lipid bodies, while the oxidized CNTs are located in the cytoplasm.

No MeSH data available.


Related in: MedlinePlus