Raman spectroscopy analysis and mapping the biodistribution of inhaled carbon nanotubes in the lungs and blood of mice

Abstract

Because of their small size, robust structure, and unique characteristics, carbon nanotubes (CNTs) are increasingly used in a variety of biomedical applications, materials, and products. As their use increases, so does the likelihood of unintended release and human exposure. Therefore, it is important to establish their potential biodistribution and biopersistence to better understand the potential effects of their exposure to humans. This study examines distribution of CNTs in CD-1 mice following exposure by inhalation of single-walled carbon nanotubes (SWCNTs) and investigates the possibility that inhaled nanoparticles could enter the circulatory system via the lungs. Raman spectroscopy was used to detect the presence of CNTs in lung tissue and blood based on their unique spectroscopic signatures. These studies have important implications concerning the potential effects of exposure to SWCNTs and about their use as potential transport vehicles in nanomedicine.

Complementary analysis of tissue homogenates composition obtained by Vis and NIR laser excitations and Raman spectroscopy

“…1 and 3-8 that Raman spectra of investigated biosamples and recorded by 632.8 nm laser excitation exhibit low S/N ratio. Since a similar Raman spectra of blood and lung were recorded by Ingle and coworkers [27] by using a different Raman instrumentation, a primary reason for this observation is probably a low quantum efficiency of the detector and grating that are usually optimized for the 488 and 532 nm excitations. Thus, a good quality 633 nm Raman bio-spectrum is recorded when Raman scattering is Raw spectra of the liver tissue from three animals (blue, red and green spectra for each animal) recorded using a 532 nm laser excitation that demonstrate the intra-and inter-sample variability.…”

“…1 and 4). This problem was also noticed in Raman studies on unfixed (air-dried) cross sections of lung tissues collected by using these laser lines [26,27]. Despite this fact bands present in all spectra provide some information about lipids and proteins.…”

“…Additionally, since Raman features depend on the wavelength of the laser excitation as well as the contribution of resonance Raman (RR) effect of chromophoric components, we recorded Raman spectra of the tissues with the use of the most common laser lines in the radiation range from 488 to 785 nm. Although most Raman studies on animal and human tissues have been mainly carried out using the NIR laser excitation (785 nm) due to the RR effect of heme-based metalloproteins and fluorescence background [3,4,6,11,12,18], some investigations have been also performed with an excitation in the Vis region of radiation [13,15,21,[26][27][28][29]. It is possible since recent technological developments allow for tight laser focusing (creating a small voxel), and consequently eliminating the contribution of fluorescent components to Raman spectrum registered from a larger volume of the laser spot [8,13,15,21].…”

Application of nanoparticles in cancer detection by Raman scattering based techniques

“…For instance, nanotubes can be used for cancer detection. Ingle et al used functionalized single-walled carbon nanotubes (SWCNT) in the form of an aerosol in the lungs of mice to detect lung cancer [59]. Analysis showed that after the arrival of the aerosol to the lungs of mice, blood samples can be used for the detection based on SERS.…”

Carbon nanotubes – Characteristic of the substance, biological effects and occupational exposure levels

“…(2013) [20] podają, że u myszy inhalowanych aerozolem SWCNT (średnica włókien 0,8-2,4 nm) zaobserwowano translokację nanorurek węglowych do układu krążenia. Zwierzęta inhalowano przez 15 min i badano po 24 godz.…”