Limits...
Effect of MWCNT surface and chemical modification on in vitro cellular response.

Fraczek-Szczypta A, Menaszek E, Syeda TB, Misra A, Alavijeh M, Adu J, Blazewicz S - J Nanopart Res (2012)

Bottom Line: The results demonstrate that the way of CNT preparation prior to biological tests has a fundamental impact on their behavior, cell viability and the nature of cell-nanotube interaction.Chemical functionalisation of CNTs in an acidic ambient (MWCNT-Fs) facilitates interaction with cells by two possible mechanisms, namely, endocytosis/phagocytosis and by energy-independent passive process.A possible explanation of such a phenomenon is the presence of MWCNT's agglomerates surrounded by numerous cells releasing toxic substances.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, Al Mickiewicza 30, 30-059 Kraków, Poland.

ABSTRACT
The aim of this study was to evaluate the impact of multi-walled carbon nanotubes (MWCNTs with diameter in the range of 10-30 nm) before and after chemical surface functionalisation on macrophages response. The study has shown that the detailed analysis of the physicochemical properties of this particular form of carbon nanomaterial is a crucial issue to interpret properly its impact on the cellular response. Effects of carbon nanotubes (CNTs) characteristics, including purity, dispersity, chemistry and dimension upon the nature of the cell environment-material interaction were investigated. Various techniques involving electron microscopy (SEM, TEM), infrared spectroscopy (FTIR), inductively coupled plasma optical emission spectrometry, X-ray photoelectron spectroscopy have been employed to evaluate the physicochemical properties of the materials. The results demonstrate that the way of CNT preparation prior to biological tests has a fundamental impact on their behavior, cell viability and the nature of cell-nanotube interaction. Chemical functionalisation of CNTs in an acidic ambient (MWCNT-Fs) facilitates interaction with cells by two possible mechanisms, namely, endocytosis/phagocytosis and by energy-independent passive process. The results indicate that MWCNT-F in macrophages may decrease the cell proliferation process by interfering with the mitotic apparatus without negative consequences on cell viability. On the contrary, the as-prepared MWCNTs, without any surface treatment produce the least reduction in cell proliferation with reference to control, and the viability of cells exposed to this sample was substantially reduced with respect to control. A possible explanation of such a phenomenon is the presence of MWCNT's agglomerates surrounded by numerous cells releasing toxic substances.

No MeSH data available.


Related in: MedlinePlus

FT-IR spectra of MWCNT (a), MWCNT-F (b) and MWCNT-NH (c)
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3473194&req=5

Fig3: FT-IR spectra of MWCNT (a), MWCNT-F (b) and MWCNT-NH (c)

Mentions: To clarify the influence of the acid mixture and ethylenediamine on the surface chemistry of MWCNT after the purification and functionalisation processes, the FT-IR investigation was performed and the corresponding results are shown in Fig. 3. The spectrum of the as-prepared MWCNTs shows the C–C stretching bonds in the range of 1,580–1,650 cm−1 characteristic to the expected nanotube phonon modes (Fig. 3a). The H2SO4–HNO3 oxidative treatment produces carboxyl groups on the surface of the MWCNTs, as it is indicated by the presence of characteristic bands at 3,439 and 1,710 cm−1 (MWCNT-F) assigned to the stretching vibrations of ν(OH) and ν(C=O) of the carboxylic groups (COOH), respectively. The peak at 1379 cm−1 was due to sulphate groups ν(OSO3H) and δ(OH) bending vibration of COOH. The band at 1,220 cm−1 for MWCNT-F was assigned to the ν(C–O) stretching vibration. The increased intensity of the O–H peak after oxidation and the appearance of C=O, C–O and OSO3H bonds suggest that oxidation of the CNTs successfully introduced COOH, OH, CO and OSO3H groups onto the walls of the nanotubes (Vukovic et al. 2010; Shen et al. 2007). These functional groups are usually found to be attached to the ends of the nanotubes or defects along their wall, due to the enhanced reactivity of these sites (Barros et al. 2005).Fig. 3


Effect of MWCNT surface and chemical modification on in vitro cellular response.

Fraczek-Szczypta A, Menaszek E, Syeda TB, Misra A, Alavijeh M, Adu J, Blazewicz S - J Nanopart Res (2012)

FT-IR spectra of MWCNT (a), MWCNT-F (b) and MWCNT-NH (c)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3473194&req=5

Fig3: FT-IR spectra of MWCNT (a), MWCNT-F (b) and MWCNT-NH (c)
Mentions: To clarify the influence of the acid mixture and ethylenediamine on the surface chemistry of MWCNT after the purification and functionalisation processes, the FT-IR investigation was performed and the corresponding results are shown in Fig. 3. The spectrum of the as-prepared MWCNTs shows the C–C stretching bonds in the range of 1,580–1,650 cm−1 characteristic to the expected nanotube phonon modes (Fig. 3a). The H2SO4–HNO3 oxidative treatment produces carboxyl groups on the surface of the MWCNTs, as it is indicated by the presence of characteristic bands at 3,439 and 1,710 cm−1 (MWCNT-F) assigned to the stretching vibrations of ν(OH) and ν(C=O) of the carboxylic groups (COOH), respectively. The peak at 1379 cm−1 was due to sulphate groups ν(OSO3H) and δ(OH) bending vibration of COOH. The band at 1,220 cm−1 for MWCNT-F was assigned to the ν(C–O) stretching vibration. The increased intensity of the O–H peak after oxidation and the appearance of C=O, C–O and OSO3H bonds suggest that oxidation of the CNTs successfully introduced COOH, OH, CO and OSO3H groups onto the walls of the nanotubes (Vukovic et al. 2010; Shen et al. 2007). These functional groups are usually found to be attached to the ends of the nanotubes or defects along their wall, due to the enhanced reactivity of these sites (Barros et al. 2005).Fig. 3

Bottom Line: The results demonstrate that the way of CNT preparation prior to biological tests has a fundamental impact on their behavior, cell viability and the nature of cell-nanotube interaction.Chemical functionalisation of CNTs in an acidic ambient (MWCNT-Fs) facilitates interaction with cells by two possible mechanisms, namely, endocytosis/phagocytosis and by energy-independent passive process.A possible explanation of such a phenomenon is the presence of MWCNT's agglomerates surrounded by numerous cells releasing toxic substances.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, Al Mickiewicza 30, 30-059 Kraków, Poland.

ABSTRACT
The aim of this study was to evaluate the impact of multi-walled carbon nanotubes (MWCNTs with diameter in the range of 10-30 nm) before and after chemical surface functionalisation on macrophages response. The study has shown that the detailed analysis of the physicochemical properties of this particular form of carbon nanomaterial is a crucial issue to interpret properly its impact on the cellular response. Effects of carbon nanotubes (CNTs) characteristics, including purity, dispersity, chemistry and dimension upon the nature of the cell environment-material interaction were investigated. Various techniques involving electron microscopy (SEM, TEM), infrared spectroscopy (FTIR), inductively coupled plasma optical emission spectrometry, X-ray photoelectron spectroscopy have been employed to evaluate the physicochemical properties of the materials. The results demonstrate that the way of CNT preparation prior to biological tests has a fundamental impact on their behavior, cell viability and the nature of cell-nanotube interaction. Chemical functionalisation of CNTs in an acidic ambient (MWCNT-Fs) facilitates interaction with cells by two possible mechanisms, namely, endocytosis/phagocytosis and by energy-independent passive process. The results indicate that MWCNT-F in macrophages may decrease the cell proliferation process by interfering with the mitotic apparatus without negative consequences on cell viability. On the contrary, the as-prepared MWCNTs, without any surface treatment produce the least reduction in cell proliferation with reference to control, and the viability of cells exposed to this sample was substantially reduced with respect to control. A possible explanation of such a phenomenon is the presence of MWCNT's agglomerates surrounded by numerous cells releasing toxic substances.

No MeSH data available.


Related in: MedlinePlus