Microenvironment-regulated dual-hydrophilic coatings for glaucoma valve surface engineering.

Glaucoma valves (GVs) play an essential role in treating glaucoma. However, fibrosis after implantation has limited their long-term success in clinical applications. In this study, we aimed to develop a comprehensive surface-engineering strategy to improve the biocompatibility of GVs by constructing a microenvironment-regulated and dual-hydrophilic antifouling coating on a GV material (silicone rubber, SR). The coating was based on a superhydrophilic polydopamine (SPD) coating with good short-range superhydrophilicity and antifouling abilities. In addition, SPD coatings contain many phenolic hydroxyl groups that can effectively resist oxidative stress and the inflammatory microenvironment. Furthermore, based on its in situ photocatalytic free-radical polymerization properties, the SPD coating polymerized poly 2-methylacryloxyethylphosphocholine, providing an additional long-range hydrophilic and antifouling effect. The in vitro test results showed that the microenvironment-regulated and dual-hydrophilic coatings had anti-protein contamination, anti-oxidation, anti-inflammation, and anti-fiber proliferation capabilities. The in vivo test results indicated that this coating substantially reduced the fiber encapsulation formation of the SR material by inhibiting inflammation and fibrosis. This design strategy for dual hydrophilic coatings with microenvironmental regulation can provide a valuable reference for the surface engineering design of novel medical implantable devices. STATEMENT OF SIGNIFICANCE: Superhydrophilic polydopamine (SPD) coatings were prepared on silicone rubber (SR) by a two-electron oxidation method. Introduction of pMPC to SPD surface using photocatalytic radical polymerization to obtain a dual-hydrophilic coating. The dual-hydrophilic coating effectively modulates the oxidative and inflammatory microenvironment. This coating significantly reduced protein contamination and adhesion of inflammatory cells and fibroblasts in vitro. The coating-modified SR inhibits inflammatory and fibrosis responses in vivo, promising to serve the glaucoma valves.

Electrocatalytic Degradation of Rhodamine B on the Sb-Doped SnO2/Ti Electrode in Alkaline Medium.

To realize efficient electrocatalytic degradation of organic compounds in alkaline wastewater, an Sb-doped SnO2/Ti electrode was fabricated and employed for the removal of Rhodamine B (RhB), and the electrocatalytic oxidation performance of this electrode was assessed in an alkaline medium. In an alkaline solution (pH 11), the complete fading of 50 mg·L-1 RhB could be achieved after 150 min of degradation, the removal efficiency of the chemical oxygen demand reached 56.1% at 300 min, and the degradation process of RhB followed the pseudo-first-order kinetic model very well. Under the attack of hydroxyl radicals, partial RhB was degraded to low-molecular-weight organic acids through N-demethylation and the destruction of the conjugated chromophore. Various techniques including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and cycle voltammetry were used to examine the changes in the morphology and structure, as well as the activity of the Sb-doped SnO2/Ti electrode before and after use. The Sb-doped SnO2/Ti electrode could be reproduced in batches, and each electrode was reused up to eight times without a significant decrease in degradation ability; the leaching amount of antimony was significantly lower than the national emission standard. The electrocatalytic oxidation of the dye wastewater sample was also performed with the desired results, indicating that electrochemical oxidation is a very promising technology for the treatment of alkaline dye wastewater using a Sb-doped SnO2/Ti electrode.

Enhanced Reactive Brilliant Blue Removal Using Chitosan-Biochar Hydrogel Beads.

To address the challenges associated with the weak affinity and difficult separation of biochar, we developed chitosan-biochar hydrogel beads (CBHBs) as an efficient solution for removing reactive brilliant blue (RBB KN-R) from wastewater. The adsorption behavior and mechanism of RBB KN-R onto CBHBs were extensively studied. Notably, the adsorption capacity of RBB KN-R showed pH-dependence, and the highest adsorption capacity was observed at pH 2. The adsorption process was well fitted with the pseudo-second-order kinetic model and the intraparticle diffusion model. Film diffusion and intraparticle diffusion were both responsible for the adsorption of RBB KN-R onto CBHBs. At 298.15 K, the maximum adsorption capacity qm was determined to be 140.74 mg/g, with higher temperatures favoring the adsorption process. A complex mechanism involving π-π interactions, electrostatic attraction, hydrophobic interaction, and hydrogen bonding was found to contribute to the overall adsorption process. The experimental data discovered the coexisting substances and elevated ionic strength hindered the adsorption capacity. Significantly, after three cycles of adsorption-desorption, the CBHBs maintained an adsorption capacity above 95% for RBB KN-R. These promising results imply that CBHBs are a durable and cost-effective adsorbent for efficient removal of dyes from wastewater.