Laser Raman tweezer spectroscopy to explore the bisphenol A-induced changes in human erythrocytes

The dermal penetration of bisphenol-A (BPA) from thermal papers into the human skin is a matter of major health concern due to its extensive use in developing countries like India, one of its largest users in the world. Bisphenol A is widely used in the manufacture of many consumer goods like polycarbonate water bottles, baby bottles, food containers, home appliances, thermal papers used in billing and tickets, the inner lining of food cans, etc. BPA can be easily adsorbed into the blood rapidly. The integration of optical tweezers with Raman spectroscopic techniques has realized avenues for interpreting single cell investigations. In the present work, the impact of BPA from thermal papers on individual human erythrocytes (red blood cells) has been investigated using micro-Raman spectroscopy. Significant intensity variations were noticed for hemoglobin oxygenation markers in the Raman spectra of red blood cells (RBCs). Raman spectral variations supporting RBC hemoglobin depletion were also found in the presence of BPA. Evident morphological changes are also observed in RBCs due to BPA in vitro exposures, which ultimately lead to cell bursting at higher concentrations.