COVID severity test (CoST sensor)-An electrochemical immunosensing approach to stratify disease severity.

With the evolution of the COVID-19 pandemic, there is now a need for point-of-care devices for the quantification of disease biomarkers toward disease severity assessment. Disease progression has been determined as a multifactor phenomenon and can be treated based on the host immune response within each individual. CoST is an electrochemical immunosensor point-of-care device that can determine disease severity through multiplex measurement and quantification of spike protein, nucleocapsid protein, D-dimer, and IL-2R from 100 µL of plasma samples within a few minutes. The limit of detection was found to be 3 ng/mL and 21 ng/mL for S and N proteins whereas for D-dimer and IL-2R it was 0.0006 ng/mL and 0.242 ng/mL, respectively. Cross-reactivity of all the biomarkers was studied and it was found to be <20%. Inter and intra-assay variability of the CoST sensor was less than <15% confirming its ability to detect the target biomarker in body fluids. In addition, this platform has also been tested to quantify all four biomarkers in 40 patient samples and to predict the severity index. A significant difference was observed between healthy and COVID-19 samples with a p-value of 0.0002 for D-dimer and <0.0001 for other proteins confirming the ability of the COST sensor to be used as a point of care device to assess disease severity at clinical sites. This device platform can be modified to impact a wide range of disease indications where prognostic monitoring of the host response can be critical in modulating therapy.

Emerging applications of exosomes in cancer therapeutics and diagnostics.

Exosomes are nanoscale extracellular vesicles that are shed from different cells in the body. Exosomes encapsulate several biomolecules including lipids, proteins, and nucleic acids, and can therefore play a key role in cellular communication. These vesicles can be isolated from different body fluids and their small sizes make them attractive in various biomedical applications. Here, we review state-of-the art approaches in exosome isolation and purification, and describe their potential use in cancer vaccines, drug delivery, and diagnostics.

Reduced arterial elasticity due to surgical skeletonization is ameliorated by abluminal PEG hydrogel.

Arteries for bypass grafting are harvested either with neighboring tissue attached or as skeletonized vessels that are free of surrounding tissue. There are significant benefits to skeletonization, but reports suggest that skeletonized vessels may develop structural defects and are at risk for atherosclerosis. We investigated the specific short-term effects of skeletonization on carotid artery biomechanics and microanatomy in a rabbit model. Six carotid arteries were surgically skeletonized. To support healing, three of these received polyethylene glycol hydrogel injected along their exterior surfaces. M-mode ultrasonography was used to track circumferential cyclic strain in the skeletonized, hydrogel-treated, and contralateral vessels. On day 21, the arteries were harvested, and vessel structure was assessed by histology, immunofluorescence microscopy, two-photon elastin autofluorescence, and second harmonic generation (SHG) microscopy. Intimal-medial thickness appeared unaffected by skeletonization, but the SHG signals indicated significant changes in collagen turnover in the adventitia. Skeletonized arteries also exhibited significantly decreased radial compliance (circumferential cyclic strain dropped ∼30%) and decreased numbers of elastic laminae (9.1 ± 2.0 to 2.3 ± 1.4). Hydrogel treatment protected against these effects with treated vessels maintaining normal mechanical properties. These results indicate that arterial skeletonization triggers immediate effects on vessel remodeling and reduced vessel compliance resulting in specific tissue alterations within 21 days, but that these effects can be attenuated by the placement of hydrogel on the exterior surface of the skeletonized vessel.