No abstract

Matrix metalloproteinases (MMPs), specifically MMP-2, MMP-7, and MMP-9, have been discovered to be linked to many forms of vascular diseases such as stroke, and their detection is crucial to facilitate clinical diagnosis. In this work, we prepared a class of optical interference-free SERS nanotags (CO-nanotags) that can be used for the purpose of multiplex sensing of different MMPs. Multiplex detection with the absence of cross-talk was achieved by using CO-nanotags with individual tunable intrinsic Raman shifts of CO in the 1800-2200 cm region determined by the metal core and ligands of the metal carbonyl complex. Boolean logic was used as well to simultaneously probe for two proteolytic inputs. Such nanotags offer the advantages of convenient detection of target nanotags and high sensitivity as validated in the ischemia rat model.

By taking advantage of the spectral properties of metal carbonyls, we have designed a surface-enhanced Raman spectroscopy (SERS) ratiometric assay for measuring cell-free circulating DNA (cfDNA) from Epstein-Barr virus in blood for nasopharyngeal carcinoma (NPC). This assay consists of a rhenium carbonyl (Re-CO) to serve as a DNA probe, an osmium carbonyl (Os-CO) embedded within the SERS-active substrate as an internal reference, and a streptavidin layer on the surface of the substrate. Hybridization of cfDNA with biotinylated-capture sequence leads to immobilization of cfDNA on the substrate. The binding of Re-CO via daunorubicin (DNR) to cfDNA is accompanied by an appearance of a strong symmetry stretching vibrations peak at 2113 cm, which has spectral overlap with Os-CO (2025 cm). This results in an increase in the I/ I ratio and quantitatively correlates with cfDNA. This SERS assay can be readily used to detect cfDNA in blood samples from patients due to the intensity ratio of I/ I lying in a silent region (1780-2200 cm) in the SERS spectrum of the biomolecules.

Utilizing the size-dependent adsorption properties of ruthenium carbonyl clusters (Ru-carbon monoxide (CO)) onto graphene oxide (GO), a facile CO-release platform for in situ vasodilation as a treatment for stroke-related vascular diseases is developed. The rate and amount of formation of the CO-release-active Ru (CO) species can be modulated by a simple mixing procedure at room temperature. The subsequent thermally induced oxidation of Ru (CO) to RuO on the GO surface results in the release of CO. Further modulation of thermal and CO-release properties can be achieved via a hybridization of medium- and high-nuclearity of Ru-CO clusters that produces a RuO /Ru (CO) / Ru-CO-GO composite, where Ru-CO-GO provides a photothermally activated reservoir of Ru (CO) species and the combined infrared absorption properties of GO and RuO provides photothermal response for in situ CO-release. The RuO /Ru (CO) / Ru-CO-GO composite does not produce any cytotoxicity and the efficacy of the composite is further demonstrated in a cortical photothrombotic ischemia rat model.

A facile CO‐release material for in‐situ vasodilation as a treatment for stroke‐related vascular diseases is developed by K.V. Kong, L.D. Liao and co‐workers in article number https://doi.org/10.1002/adhm.201701113. Utilizing the size dependent adsorption properties of ruthenium carbonyl clusters (Ru‐CO) onto graphene oxide (GO), the rate and amount of formation of the CO release‐active RuII(CO)2 species can be modulated by a simple mixing procedure. Further modulation of thermal and CO release properties can be achieved via a hybridization of medium‐ and high‐ nuclearity of Ru‐CO clusters that can provide photo‐thermal response for in‐situ CO release in a cortical photo‐thrombotic ischemia rat model.