ATR-FTIR, FT-NIR and near-FT-Raman spectroscopic studies of molecular composition in human skinin vivoand pig ear skinin vitro

Abstract

ATR-FTIR, FT-NIR and near-FT-Raman spectroscopy were used to characterize the molecular composition of human skinin vivoand pig ear skinin vitro. Due to different measurement depths the spectroscopic techniques reveal the characteristics of different layers of the skin. Tape stripping was used with the ATR-FTIR technique. Spectral differences concerning lipid content and conformation, protein secondary structure or content of water were found with respect to both gender and species (i.e. human versus pig ear) at all measured skin depths. New assignments of so far unassigned lipid and protein peaks in the FT-NIR and ATR-FTIR spectra of skin were made. PCA and PLS models were used to investigate the division of the recorded spectra into groups. With respect to classification of male and female subjects, the PLS discriminant analysis provided a classification accuracy of 64–93% based on the ATR-FTIR spectra and 83–89% based on the Raman spectra. With respect to classification of human skinin vivoand pig ear skinin vitro, the PLS discriminant analysis provided a classification accuracy of 75–100% based on the Raman spectra and 100% based on the ATR-FTIR spectra.

The use of native chemical functional groups presented by wound beds for the covalent attachment of polymeric microcarriers of bioactive factors

“…We also sought to use Raman microspectroscopy to provide additional evidence for covalent reaction of maleimide groups with sulfhydryl groups on the wound bed. Our approach was motivated by past studies that have used near-IR excited Raman spectroscopy for molecular characterization of full-thickness skin [50, 51], and other biological tissues (such as brain, colon, liver, muscle) [52]. In those past studies, spectral bands were assigned to biochemical components such as protein, lipid, water and disulfide bonds.…”

Anisotropic mechanical behavior of keratin tissue from quill shells of North American porcupine (Erethizon dorsatum)

“…Chemical analyses of the porcupine quill shells were conducted using Fourier transform infrared spectroscopy to characterize differences between the interior surfaces of quills with the exterior surfaces of quills as well as to compare the molecular structure of these porcupine quill tissues with similar tissues reported from other natural sources [37,[48][49][50][51]. Fig.…”

Stimulated Raman scattering microscopy for rapid brain tumor histology

“…24,25 However, intraoperative IR microscopy is hampered by the strong water absorption and low spatial resolution given the longer wavelength ($ 2:5-10 m). 26 Raman spectroscopy of brain tumors have been widely applied in rodent models and ex vivo human brain tissues. 27,28 However, spontaneous Raman imaging of biological tissues has been limited by the weak signal intensities and slow imaging speed.…”