Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy Method to Differentiate Between Normal and Cancerous Breast Cells

Abstract

Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) is used to find the structural differences between cancerous breast cells (MCF-7 line) and normal breast cells (MCF-12F line). Gold nanoparticles were prepared and the hydrodynamic diameter of the gold nanoparticles found to be 38.45 nm. The Gold nanoparticles were exposed to both MCF-7 and MCF-12F cells from lower to higher concentrations. Spectroscopic studies founds nanoparticles were within the cells, and increasing the nanoparticles concentration inside the cells also resulted in sharper IR peaks as a result of localized surface Plasmon resonance. Asymmetric and symmetric stretching and bending vibrations between phosphate, COO-, CH2 groups were found to give negative shifts in wavenumbers and a decrease in peak intensities when going from noncancerous to cancerous cells. Cellular proteins produced peak assignments at the 1542 and 1644 cm(-1) wavenumbers which were attributed to the amide I and amide II bands of the polypeptide bond of proteins. Significant changes were found in the peak intensities between the cell lines in the spectrum range from 2854-2956 cm(-1). Results show that the concentration range of gold nanoparticles used in this research showed no significant changes in cell viability in either cell line. Therefore, we believe ATR-FTIR and gold nanotechnology can be at the forefront of cancer diagnosis for some time to come.

Recent applications of ATR FTIR spectroscopy and imaging to proteins

“…In some cases, nanoparticles are used to introduce drugs into specific sites because they have a particularly good uptake within cells [64]. Another exciting application presented by Lane and Seo demonstrated that ATR FTIR spectroscopy can be used to distinguish between cancerous and benign cells containing gold nanoparticles [64].…”

“…The presence of the nanoparticles within the cells allows an enhanced IR absorbance, similar to the effect seen when the surface is modified as described above. The study by Lane and Seo [64] shows the increase in spectral intensity with increasing gold nanoparticles concentration for cancerous and normal cell lines, which could allow for any spectral differences to be seen more easily. This development further emphasises the potential of ATR FTIR spectroscopy for medical diagnostics and is not limited by the reproducibility issues still present within SEIRAS studies.…”

“…This development further emphasises the potential of ATR FTIR spectroscopy for medical diagnostics and is not limited by the reproducibility issues still present within SEIRAS studies. This approach does not depend on the formation of metal island films, like in SEIRAS approach, as the gold nanoparticles are present within the cells themselves and the level of signal enhancement is dependent on the concentration of nanoparticles [64]. It is also possible to study cells using ATR FTIR without the use of gold nanoparticles, as shall be discussed below.…”

Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) Spectroscopy Analysis of Saliva for Breast Cancer Diagnosis

“…FTIR requires only a small amount of sample for analysis with easy and quick preparation if necessary, and it allows automated and repetitive analyses, leading to nonsubjective evaluation of the sample [4,6,7]. Furthermore, ATR, the experimental configuration for FTIR spectra acquisition utilized in this study, presents high signal-to-noise ratio (SNR), does not present unwanted spectral contributions, and enables a sample to be analyzed without further preparation simply by placing it in direct contact with a crystal with a refractive index higher than the sample [8][9][10][11].…”

“…Specifically for breast cancer, FTIR spectroscopy has been used for many purposes [15][16][17][18][19][20][21][22][23][24], mainly for detection [4,[25][26][27][28]. Most FTIR spectroscopy studies in breast cancer used normal breast tissue and breast tumors [4,[29][30][31], breast cell lines [11,32,33], and blood of breast cancer patients [25,27]. To our knowledge, there are no studies using ATR-FTIR spectroscopy for breast cancer diagnosis using saliva as the biological sample.…”