title: A micro-Raman study of live, single red blood cells (RBCs) treated with AgNO3 nanoparticles.
abstract: Silver nanoparticles (Ag NPs) are known to exhibit broad antimicrobial activity. However, such activity continues to raise concerns in the context of the interaction of such NPs with biomolecules. In a physiological environment NPs interact with individual biological cells either by penetrating through the cell membrane or by adhering to the membrane. We have explored the interaction of Ag NPs with single optically-trapped, live erythrocytes (red blood cells, RBCs) using Raman Tweezers spectroscopy. Our experiments reveal that Ag NPs induce modifications within an RBC that appear to be irreversible. In particular we are able to identify that the heme conformation in an RBC transforms from the usual R-state (oxy-state) to the T-state (deoxy-state). We rationalize our observations by proposing a model for the nanoparticle cytotoxicity pathway when the NP size is larger than the membrane pore size. We propose that the interaction of Ag NPs with the cell surface induces damage brought about by alteration of intracellular pH caused by the blockage of the cell membrane transport.
authors: Centre for Atomic and Molecular Physics, Manipal University, Manipal, India.
authors: Aseefhali
authors: A
authors: Bankapur
authors: Centre for Atomic and Molecular Physics, Manipal University, Manipal, India.
authors: Surekha
authors: S
authors: Barkur
authors: Centre for Atomic and Molecular Physics, Manipal University, Manipal, India.
authors: Santhosh
authors: S
authors: Chidangil
authors: Centre for Atomic and Molecular Physics, Manipal University, Manipal, India; Tata Institute of Fundamental Research, Mumbai, India.
authors: Deepak
authors: D
authors: Mathur
mesh_terms: D001692:Biological Transport; D004912:Erythrocytes / Q000187:drug effects*; D006418:Heme / Q000737:chemistry; D006801:Humans; D007473:Ion Channels / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012835:Silver Nitrate / Q000633:toxicity*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D007473:Ion Channels; D006418:Heme; D012835:Silver Nitrate