Probing Intrinsic and Extrinsic Components in Single Osteosarcoma Cells by Near-Infrared Surface-Enhanced Raman Scattering

Abstract

We report on the capabilities of near-infrared surface-enhanced Raman scattering (SERS) using gold nanoparticles to obtain detailed chemical information with high spatial resolution from within single cancer cells, living or fixed. Colloidal gold particles, 60 nm in size, were introduced into live human osteosarcoma cells by endocytosis by adding them to the growth medium. Rapid SERS mapping of cells indicated that not only could rich vibrational spectra be obtained from intrinsic cellular constituents both in the cytoplasm and nucleus and but also the distribution of extrinsic molecules introduced into the cells, in this case, rhodamine 6G could be characterized, suggesting that the intracellular distribution of chemotherapeutic agents could potentially be measured by this technique. We show that the SERS signal intensity from the cellular components increases and more spectral detail is acquired from dried cells when compared with hydrated cells in buffer. The data also show spectral fluctuations, mainly in intensity but also in peak position, which are dependent upon the intensity of the excitation light and are probably due to diffusion of molecules on the surface of the gold nanoparticles. A detailed understanding of the origins of these effects is still not complete, but the ability to acquire very sensitive SERS inside living cancer cells indicates the potential of this technique as a useful tool in biomedicine.

Raman spectroscopy: techniques and applications in the life sciences

“…SERS targeted measurement and identification of several types of cancer cell has been shown, including osteosarcoma cells using AuNP SERS [303], cancerous renal cell detection [304], and Ag/Au core-shell nanoparticles conjugated with antibodies were used to image PLCγ protein in HEK293 cells [305]. Targeted SERS detection of circulating tumor cells has been shown in the presence of white blood cells [306].…”

Application of nanoparticles in cancer detection by Raman scattering based techniques

“…Feng et al [89] exploited different polarity laser light and demonstrated that left-handed circularly polarized laser excitation has great promise of becoming a clinically useful diagnostic tool for non-invasive gastric cancer detection. Tang et al [90] introduced gold nanoparticles into live human osteosarcoma cells by endocytosis and adding them to the growth medium. By using SERS cell mapping, they suggested the feasibility of the intracellular distribution of chemotherapeutic agent measurement.…”

SERS in Cells: from Concepts to Practical Applications

“…SERS labels are, typically, combinations of gold or silver nanoaggregates and reporter molecules, that can be used to visualize their cellular distribution and to give further information on intracellular parameters by their specific Raman signature. Dye reporters include Indocyanine Green [8], Crystal Violet [9,10], Methylene Blue [9,11], Rhodamine 6G [12], Eosin [11], Giemsa [11], and others. "Colorless" molecules have also been used as Raman reporters.…”