The electrical properties of pristine fluoropolymers are inferior due to their low polar crystalline phase content and rigid dipoles that tend to retain their fixed moment and orientation. Several strategies, such as electrospinning, electrohydrodynamic pulling, and template-assisted growing, have been proven to enhance the electrical properties of fluoropolymers; however, these techniques are mostly very hard to scale-up and expensive. Here, a facile interfacial engineering approach based on amine-functionalized graphene oxide (AGO) is proposed to manipulate the intermolecular interactions in poly(vinylidenefluoride-trifluoroethylene) (PVDF-TrFE) to induce β-phase formation, enlarge the lamellae dimensions, and align the micro-dipoles.
View Article and Find Full Text PDFBackground Diabetic nephropathy is a common diabetes mellitus complication associated with hypertension, proteinuria, and excretion of urinary plasmin that activates the epithelial sodium channel, ENaC, . Here we hypothesized that the deletion of plasminogen and amiloride treatment protect against hypertension in diabetes mellitus. Methods and Results Male plasminogen knockout (plasminogen-deficient [Plg]) and wild-type mice were rendered diabetic with streptozotocin.
View Article and Find Full Text PDFCreating strong joints between dissimilar materials for high-performance hybrid products places high demands on modern adhesives. Traditionally, adhesion relies on the compatibility between surfaces, often requiring the use of primers and thick bonding layers to achieve stable joints. The coatings of polymer brushes enable the compatibilization of material surfaces through precise control over surface chemistry, facilitating strong adhesion through a nanometer-thin layer.
View Article and Find Full Text PDFAm J Physiol Renal Physiol
December 2019
The present study tested the hypotheses that nephrotic syndrome (NS) leads to renal K loss because of augmented epithelial Na channel (ENaC) activity followed by downregulation of renal K secretory pathways by suppressed aldosterone. The hypotheses were addressed by determining K balance and kidney abundance of K and Na transporter proteins in puromycin aminonucleoside (PAN)-induced rat nephrosis. The effects of amiloride and angiotensin II type 1 receptor and mineralocorticoid receptor (MR) antagonists were tested.
View Article and Find Full Text PDFStainless steel (SS) surfaces were grafted with poly(glycidyl methacrylate) (PGMA) brushes that were post-modified using allylamine, diallylamine, and propylamine as reagents. Likewise, poly[2-(diethylamino)ethyl methacrylate] brushes were synthesized. All samples were compression molded with uncured ethylene-propylene-diene M-class rubber and dicumyl peroxide and vulcanized for 12 min at 170 °C.
View Article and Find Full Text PDFPreeclampsia is characterized by hypertension, proteinuria, suppression of plasma renin-angiotensin-aldosterone, and impaired urine sodium excretion. Aberrantly filtered plasmin in urine may activate proteolytically the γ-subunit of the epithelial sodium channel (ENaC) and promote Na reabsorption and urine K loss. Plasma and urine was sampled from patients with preeclampsia, healthy pregnant controls and non-pregnant women, and from patients with nephrostomy catheters.
View Article and Find Full Text PDFIn nephrotic syndrome, aberrant glomerular filtration of plasminogen and conversion to active plasmin in preurine are thought to activate proteolytically epithelial sodium channel (ENaC) and contribute to sodium retention and edema. The ENaC blocker amiloride is an off-target inhibitor of urokinase-type plasminogen activator (uPA) in vitro. It was hypothesized that uPA is abnormally filtered to preurine and is inhibited in urine by amiloride in nephrotic syndrome.
View Article and Find Full Text PDFIn conditions with albuminuria, plasminogen is aberrantly filtered across the glomerular barrier and activated along the tubular system to plasmin. In the collecting duct, plasmin activates epithelial sodium channels (ENaC) proteolytically. Hyperactivity of ENaC could link microalbuminuria/proteinuria to resistant hypertension.
View Article and Find Full Text PDFBackground: Aberrant filtration of plasminogen from plasma and subsequent activation to plasmin in the urinary space may activate proteolytically the epithelial sodium channel, ENaC. In conditions with chronic albuminuria, this may cause hypertension. It was hypothesized that patients with type 2 diabetes mellitus (T2DM) and treatment-resistant hypertension excrete plasmin(ogen) in urine in proportion to albumin and that plasmin confers to urine the ability to activate ENaC.
View Article and Find Full Text PDFBackground: Urinary plasmin activates the epithelial Na(+) channel (ENaC) in vitro and may possibly be a mechanism of sodium retention in nephrotic syndrome (NS). This study used a paired design to test the hypothesis that remission of NS is associated with a decreased content of urinary plasmin and reduced ability of patients' urine to activate ENaC.
Methods: Samples were collected during active NS and at stable remission from 20 patients with idiopathic NS, aged 9.
In nephrotic syndrome, plasminogen is aberrantly filtered from plasma to the urinary space and activated along the tubular system. In vitro, plasmin increases ENaC current by proteolytic cleavage of the γ-subunit. It was hypothesized that preeclampsia is associated with plasmin-dependent ability of tubular fluid to activate ENaC.
View Article and Find Full Text PDFCurr Opin Nephrol Hypertens
September 2011
Purpose Of Review: Activation of epithelial sodium channel (ENaC) by proteolysis appears to be relevant for day-to-day physiological regulation of channel activity in kidney and other epithelial tissues. Pathophysiogical, proteolytic activation of ENaC in kidney has been demonstrated in proteinuric disease.
Recent Findings: A variation in sodium and potassium intake or plasma aldosterone changes the number of cleaved α and γ-ENaC subunits and is associated with changes in ENaC currents.