RESUMEN
Vascular endothelial growth factor (VEGF), a clinically important biomarker, often plays a key role in angiogenesis, would healing, tumor growth, lung development, and in retinal diseases. Hence, detecting and quantifying VEGF is deemed medically important in clinical diagnosis for many diseases. In this report, a simple yet highly cost-effective platform was proposed for VEGF protein detection using commercially available interdigitated sensors that are surface modified to present DNA optimally for VEGF capture. The dielectric characteristics between the fingers of the sensor were modulated by the negatively charged aptamer-VEGF capture, and the impedance was estimated using an impedance analyzer. Impedance-spectra tests were compared among pristine unmodified surfaces, functionalized monolayer surfaces, and aptamer-grafted surfaces in order to evaluate the efficacy of VEGF detection. From our results, the sensitivity experiments as conducted showed the ability of the interdigitated sensor to detect VEGF at a low concentration of 5 pM (200 pg/mL). The specificity of the functionalized sensor in detecting VEGF was further examined by comparing the impedance to platelet-derived growth factor, and the results confirm the specificity of the sensor. Finally, the Nyquist plot of impedance spectra was also presented to help data visualization and the overall performance of the device was found to be a highly suitable template for a smart biosensor for the detection of VEGF.
RESUMEN
Oxidative stress generated by reactive oxygen species (ROS) plays a critical role in the pathomechanism of glaucoma, which is a multifactorial blinding disease that may cause irreversible damage within human trabecular meshwork cells (HTMCs). It is known that the transforming growth factor-ß (TGF-ß) signaling pathway is an important component of oxidative stress-induced damage related to extracellular matrix (ECM) fibrosis and activates cell antioxidative mechanisms. To elucidate the dual potential roles and regulatory mechanisms of TGF-ß in effects on HTMCs, we established an in vitro oxidative model using hydrogen peroxide (H2O2) and further focused on TGF-ß-related oxidative stress pathways and the related signal transduction. Via a series of cell functional qualitative analyses to detect related protein level alterations and cell fibrosis status, we illustrated the role of TGF-ß1 and TGF-ß2 in oxidative stress-induced injury by shTGF-ß1 and shTGF-ß2 knockdown or added recombinant human TGF-ß1 protein (rhTGF-ß1). The results of protein level showed that p38 MAPK, TGF-ß, and its related SMAD family were activated after H2O2 stimulation. Cell functional assays showed that HTMCs with H2O2 exposure duration had a more irregular actin architecture compared to normal TM cells. Data with rhTGF-ß1 (1 ng/mL) pretreatment reduced the cell apoptosis rate and amount of reactive oxygen species (ROS), while it also enhanced survival. Furthermore, TGF-ß1 and TGF-ß2 in terms of antioxidant signaling were related to the activation of collagen I and laminin, which are fibrosis-response proteins. Succinctly, our study demonstrated that low concentrations of TGF-ß1 (1 ng/mL) preserves HTMCs from free radical-mediated injury by p-p38 MAPK level and p-AKT signaling balance, presenting a signaling transduction mechanism of TGF-ß1 in HTMC oxidative stress-related therapies.
RESUMEN
The polishing process in high-tech industries produces a large amount of waste polishing slurry, which is harmful to the environment, and the solid powders in the slurry contain a lot of La and Ce, which have been widely used as catalyst materials. The aim of this study was to convert this hazardous material into hazardous material decomposition catalyst. A novel and simple approach was successfully developed for the recovery of La and Ce from hazardous waste polishing powders to synthesize a composite metal oxide catalyst for decomposition of harmful ammonia. Here, La and Ce were leached from waste polishing powder by using nitric acid, and the Ce, La, and total REE recovery rates were approximately 100%, 83.3%, and 96.4%, respectively. The elemental concentrations of leached acidic solution was analyzed, after which stoichiometry was performed to replenish elements with insufficient mole numbers. Finally, the catalyst material was prepared using the glycine-nitrate combustion process. The catalyst prepared from the recovered polishing powders achieved a 100% ammonia conversion rate at the relatively low temperature of 250 °C. The proposed environmentally friendly method does not require complex purification and separation procedures and can be used for the synthesis of catalysts for decomposing other harmful pollutants.
