Versatile conductometric biosensors for rapid and selective detection of inflammatory and cardiac biomarkers in saliva.

Biosensors have become promising alternatives to the conventional methods in early identification of diseases. However, translation of biosensors from lab to commercial products have challenges such as complex sensor fabrications and complicated detection, and inadequate sensitivity and selectivity. Here, we introduce simple and low-cost fabricated conductometric sensors based on high resistivity silicon wafers (HR-Si) which can be adopted to functionalise with both natural and synthetic antibodies in detecting five biomarkers including interleukin-6, C reactive protein, cardiac troponin I, brain natriuretic peptide, and N terminal-probrain natriuretic peptide. All five biomarkers show selective and rapid (10 min sample incubation and <1 min of reading time) detection in both media of phosphate buffer saline and saliva with the detection limits lower than that of reported healthy levels in saliva. This work highlights the versatility of HR-Si sensors in functionalisation of both natural and synthetic antibodies in sensitive and selective biomarker detection. As these miniaturised conductometric biosensors can be easily modified with on-demand biomaterials to detect corresponding target biomarkers, they enable a new category of compact point-of-care medical devices.

Colocalization of Galectin-3 With CD147 Is Associated With Increased Gelatinolytic Activity in Ulcerating Human Corneas.

Purpose: Galectin-3 is a carbohydrate-binding protein known to promote expression of matrix metalloproteinases, a hallmark of ulceration, through interaction with the extracellular matrix metalloproteinase inducer CD147. The aim of this study was to investigate the distribution of galectin-3 in corneas of patients with ulcerative keratitis and to determine its relationship to CD147 and the presence of gelatinolytic activity. Methods: This was an observational case series involving donor tissue from 13 patients with active corneal ulceration and 6 control corneas. Fixed-frozen sections of the corneas were processed to localize galectin-3 and CD147 by immunofluorescence microscopy. Gelatinolytic activity was detected by in situ zymography. Results: Tissue from patients with active corneal ulceration showed a greater galectin-3 immunoreactivity in basal epithelia and stroma compared with controls. Immunofluorescence grading scores revealed increased colocalization of galectin-3 and CD147 in corneal ulcers at the epithelial-stromal junction and within fibroblasts. Quantitative analysis using the Manders' colocalization coefficient demonstrated significant overlap in corneas from patients with ulcerative keratitis (M1 = 0.29; M2 = 0.22) as opposed to control corneas (M1 = 0.01, P < 0.01; M2 = 0.02, P < 0.05). In these experiments, there was a significant positive correlation between the degree of galectin-3 and CD147 colocalization and the presence of gelatinolytic activity. Conclusions: Our results indicate that concomitant stimulation and colocalization of galectin-3 with CD147 are associated with increased gelatinolytic activity in the actively ulcerating human cornea and suggest a mechanism by which galectin-3 may contribute to the degradation of extracellular matrix proteins during ulceration.