<p>Assessing Cobalt Metal Nanoparticles Uptake by Cancer Cells Using Live Raman Spectroscopy</p>

Abstract

Nanotechnology applied to cancer treatment is a growing area of research in nanomedicine with magnetic nanoparticle-mediated anti-cancer drug delivery systems offering least possible side effects. To that end, both structural and chemical properties of commercial cobalt metal nanoparticles were studied using label-free confocal Raman spectroscopy. Materials and Methods: Crystal structure and morphology of cobalt nanoparticles were studied by XRD and TEM. Magnetic properties were studied with SQUID and PPMS. Confocal Raman microscopy has high spatial resolution and compositional sensitivity. It, therefore, serves as a label-free tool to trace nanoparticles within cells and investigate the interaction between coating-free cobalt metal nanoparticles and cancer cells. The toxicity of cobalt nanoparticles against human cells was assessed by MTT assay. Results: Superparamagnetic Co metal nanoparticle uptake by MCF7 and HCT116 cancer cells and DPSC mesenchymal stem cells was investigated by confocal Raman microscopy. The Raman nanoparticle signature also allowed accurate detection of the nanoparticle within the cell without labelling. A rapid uptake of the cobalt nanoparticles followed by rapid apoptosis was observed. Their low cytotoxicity, assessed by means of MTT assay against human embryonic kidney (HEK) cells, makes them promising candidates for the development of targeted therapies. Moreover, under a laser irradiation of 20mW with a wavelength of 532nm, it is possible to bring about local heating leading to combustion of the cobalt metal nanoparticles within cells, whereupon opening new routes for cancer phototherapy. Conclusion: Label-free confocal Raman spectroscopy enables accurately localizing the Co metal nanoparticles in cellular environments. The interaction between the surfactant-free cobalt metal nanoparticles and cancer cells was investigated. The facile endocytosis in cancer cells shows that these nanoparticles have potential in engendering their apoptosis. This preliminary study demonstrates the feasibility and relevance of cobalt nanomaterials for applications in nanomedicine such as phototherapy, hyperthermia or stem cell delivery.

Cation and anion topotactic transformations in cobaltite thin films leading to Ruddlesden-Popper phases

“…In Figure 2(e), the Raman spectra showed peaks at 683, 1366, and 1590 cm -1 , which can be assigned to the Raman lines of Co nanoparticles. [44][45][46] Therefore, we refer to this sample as the nanoparticle (NP) sample. The formation of the Co nanoparticles accounts for the loss of Co ions needed in order to form the RP phase, however their small size, low density, and/or random orientation precludes their observation in XRD or STEM measurements.…”

Specific intracellular signature of SARS-CoV-2 infection using confocal Raman microscopy

“…Biomedical applications of Raman spectroscopy have been reported previously due to its noninvasive examination of a single live cell without labeling 14 , 18 – 20 . Raman spectroscopy imaging is known as a well-established method for chemical analysis of intra/extracellular environment 21 , 22 .…”

Specific Intracellular Signature of SARS-CoV-2 Infection Using Confocal Raman Microscopy

“…Coronavirus disease 2019 (COVID- 19) is an ongoing pandemic infection caused by the positive-sense RNA virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1 , provoking untold disruption throughout the world. Symptoms of COVID-19 such as dyspnea, fever, cough, fatigue could be followed by numerous complications including pneumonia, myocarditis, kidney injury, resulting in some cases with death 2 .…”

“…As Raman identi es the chemical modi cation, by investigation of spectral changes induced by a virus in any environment, there is no requirement for any genetic or proteomic information of the virus, 8, 16-18 presenting an additional advantage for the Raman spectroscopy in viral detection. Biomedical applications of Raman spectroscopy have been reported previously due to its noninvasive examination of a single live cell without labeling 15,[19][20][21] . Raman spectroscopy imaging is known as a well-established method for chemical analysis of intra/extracellular environment 22,23 .…”