FTIR Spectroscopy Analysis of Bound Water in Dried Saliva Samples: Differentiation of Smoking and Non-Smoking Groups and Implications for Oral Cancer Risk
Background: According to the WHO, oral cancer is the thirteenth most common cancer worldwide, with tobacco use being one of the primary causes of oral cancer. This study aimed to characterize and differentiate the saliva and bound water using FTIR spectroscopy in smoking and non-smoking individuals. Materials and Methods: This prospective observational study analyzed dried saliva samples from control, smoking, and occasional smoking groups using an attenuated total reflectance Fourier Transform Infrared (ATR-FTIR) spectrometer. The high wavenumber spectral region of 2800–3600 cm-¹ was selected for analysis. Results: The results indicate that standard variance normalization (SNV) reduced intragroup variability and highlighted differences in smokers’ spectra within the 3250–3500 cm-¹ region, associated with the absorption of water bound to saliva molecules. Cubic SVM models using SNV spectra demonstrated higher classification accuracy between groups, achieving 15.6% greater sensitivity and 1.3% lower specificity compared to models based on the second-order derivative. RUSBoosted Trees addressed data imbalances, enhancing both sensitivity and specificity. The study suggests that spectral changes may reflect salivary biochemistry linked to smoking and potentially to oral cancer risk. Conclusions: We conclude that differentiation between normal individuals and smokers can be achieved using high wavenumber FTIR spectral analysis. Additionally, we demonstrate the relationship between bound water molecules and salivary biomolecules in control, smoking, and occasional smoking groups. This technique has potential applications in elucidating OH vibrations within biological systems.
Citação
@online{maria_clara_coelho2025,
author = {Maria Clara Coelho , Ferreira and Vitórya Carvalho Pádua De
, Magalhães and Thayná Melo De Lima , Morais and Felipe , Peralta
and Pedro Arthur Augusto , Castro and Denise Maria , Zezell and
Marcelo Saito , Nogueira and Luis Felipe Cs , Carvalho},
title = {FTIR Spectroscopy Analysis of Bound Water in Dried Saliva
Samples: Differentiation of Smoking and Non-Smoking Groups and
Implications for Oral Cancer Risk},
volume = {24},
date = {2025-06-01},
doi = {10.1177/15330338251317304},
langid = {pt-BR},
abstract = {Background: According to the WHO, oral cancer is the
thirteenth most common cancer worldwide, with tobacco use being one
of the primary causes of oral cancer. This study aimed to
characterize and differentiate the saliva and bound water using FTIR
spectroscopy in smoking and non-smoking individuals. Materials and
Methods: This prospective observational study analyzed dried saliva
samples from control, smoking, and occasional smoking groups using
an attenuated total reflectance Fourier Transform Infrared
(ATR-FTIR) spectrometer. The high wavenumber spectral region of
2800–3600 cm-¹ was selected for analysis. Results: The results
indicate that standard variance normalization (SNV) reduced
intragroup variability and highlighted differences in smokers’
spectra within the 3250–3500 cm-¹ region, associated with the
absorption of water bound to saliva molecules. Cubic SVM models
using SNV spectra demonstrated higher classification accuracy
between groups, achieving 15.6\% greater sensitivity and 1.3\% lower
specificity compared to models based on the second-order derivative.
RUSBoosted Trees addressed data imbalances, enhancing both
sensitivity and specificity. The study suggests that spectral
changes may reflect salivary biochemistry linked to smoking and
potentially to oral cancer risk. Conclusions: We conclude that
differentiation between normal individuals and smokers can be
achieved using high wavenumber FTIR spectral analysis. Additionally,
we demonstrate the relationship between bound water molecules and
salivary biomolecules in control, smoking, and occasional smoking
groups. This technique has potential applications in elucidating OH
vibrations within biological systems.}
}