ABSTRACT
A set of metal carbonyl cluster-boronic acid conjugates of the group VIII metals (Fe, Ru, and Os) were synthesized and their antiproliferative effects measured against two breast cancer cell lines (MCF-7 and MDA-MB-231) and a noncancerous breast epithelial (MCF-10A) cell line. The cytotoxicity followed the order Ru > Os > Fe for the MDA-MB-231 cells, although the latter two exhibited similar cytotoxicity against MCF-7 and MCF-10A cells. The osmium species {Os3(CO)10(µ-H)[µ-SC6H4-p-B(OH)2]} (2) could be chemically oxidized to its hydroxy analogue [Os3(CO)10(µ-H)(µ-SC6H4 -p-OH)] (2-OH), which showed comparable cytotoxicity. Mode of action studies pointed to an apoptotic pathway for cell death.
ABSTRACT
Transition metal carbonyls exhibit strong CO absorptions in the 2200-1800 cm(-1) region, which is free of interference from other functional groups. This feature has led to their applications in bio-imaging and -sensing, in particular through mid-IR, Raman and more recently, surface-enhanced Raman spectroscopy (SERS). Their use in mid-IR quantitative sensing based on vibrational intensities, and chemical sensing based on frequency shifts and vibrational lifetimes, is reviewed. Their development for Raman sensing following the breakthrough in SERS highlights the potential of coupling metal carbonyls to plasmonic nanostructures as novel optical materials for SERS-based bio-imaging and -sensing.
Subject(s)
Biosensing Techniques/methods , Molecular Imaging/methods , Organometallic Compounds/chemistry , Spectrophotometry, Infrared/methods , Spectrum Analysis, Raman/methods , Vibration , Animals , HumansABSTRACT
High nuclearity carbonyl clusters of ruthenium and osmium are found to exhibit good photoacoustic (PA) activity in the near-IR (NIR) region. Their potential as PA contrast agents for full body imaging has been demonstrated for the first time with mice; intravenous administration of the osmium carbonyl cluster Na2[Os10(µ6-C)(CO)24] afforded up to a four-fold enhancement of the PA signal in various tissues. The cluster exhibits low toxicity, high stability and superior PA stability compared to the clinically approved NIR dye, indocyanine green.
ABSTRACT
A metal carbonyl-functionalized nanostructured substrate can be used in a rapid and simple assay for the detection of A1AT, a potential biomarker for bladder cancer, in clinical urine samples. The assay involves monitoring changes in the carbonyl stretching vibrations of the metal carbonyl via surface-enhanced Raman spectroscopy (SERS). These vibrations lie in the absorption spectral window of 1800-2200 cm(-1), which is free of any spectral interference from biomolecules.
Subject(s)
Biomarkers/metabolism , Body Fluids/metabolism , Spectrum Analysis, Raman/methods , Female , Humans , Male , Surface Plasmon ResonanceABSTRACT
We report, for the first time, the use of a water-soluble organometallic compound as a stable, reliable and high-contrast photoacoustic contrast agent. This gives a significantly higher contrast than that achievable with alternatives such as single-walled carbon nanotubes. Image enhancement of the rat cerebral cortex vasculature was observed using in vivo dark-field photoacoustic microscopy.
Subject(s)
Cerebrovascular Circulation , Contrast Media/chemistry , Neuroimaging , Organometallic Compounds/chemistry , Osmium/chemistry , Photoacoustic Techniques , Water/chemistry , Animals , Molecular Structure , Rats , SolubilityABSTRACT
A triosmium carbonyl cluster-boronic acid conjugate is used as a secondary carbohydrate probe in a SERS-based assay. The assay does not require conjugation of the metal carbonyl probe to a SERS-active species, and it utilizes the CO stretching vibrations of the metal carbonyl, which lies in a silent region of the SERS spectrum (1800-2200 cm(-1)), for quantification. High selectivity for glucose over fructose and galactose is obtained, and a human urine sample doped with glucose is detected accurately.
Subject(s)
Glucose/analysis , Glycosuria/diagnosis , Spectrum Analysis, Raman/methods , Transition Elements/chemistry , Boronic Acids/chemistry , Humans , Osmium/chemistry , Sensitivity and SpecificityABSTRACT
Conjugates of organometallic osmium carbonyl clusters and gold nanoparticles show a strong carbonyl signal in surface-enhanced Raman spectroscopy. The ease of bio-functionalization and the high stability and good dispersibility in aqueous solution make these conjugates excellent candidates for biomedical applications, as demonstrated by live-cell imaging with the carbonyl signals of OM-NP(PEG)-L conjugates.
