Extracts of Andrographis paniculata (Burm.f.) Nees Leaves Exert Anti-Gout Effects by Lowering Uric Acid Levels and Reducing Monosodium Urate Crystal-Induced Inflammation

Andrographis paniculata (Burm.f.) Nees has been found to have anti-inflammatory and immunostimulatory effects. This study was to investigate antihyperuricemic and anti-inflammatory effects of A. paniculata leaf extracts. Andrographolide, 14-deoxy-11,12-didehydroandrographolide, and neoandrographolide were quantified in 80% ethanol (EtOH80) and water extracts using High Performance Liquid Chromatography (HPLC) analysis. Antihyperuricemic activity was evaluated using a spectrophotometric in vitro inhibitory xanthine oxidase (XO) assay. The most active extract and andrographolide were further investigated in a hyperuricemic rat model induced by potassium oxonate to determine serum uric acid levels, liver XO activity, followed by Western blot analysis for renal urate transporter URAT1, GLUT9, and OAT1 to investigate the excretion of uric acid via kidney. Anti-inflammatory activity was assessed by in vitro interleukin assay for interleukin (IL-1α, IL-1β, IL-6, IL-8), and tumor necrosis factor (TNF-α) in monosodium urate (MSU) crystal-induced human fibroblast-like synoviocyte (HFLS) cells using ELISA-kits, followed by Western blot analysis for the expression of MyD88, NLRP3, NF-κB p65, and caspase-1 proteins to investigate the inflammation pathway. In vivo assay of the most active extract and andrographolide were performed based on the swelling rate and inhibition of pro-inflammatory mediator release from synovial fluid of a rat knee joint induced by MSU crystals. The results showed that the EtOH80 extract had a greater amount of andrographolide (11.34% w/w) than the water extract (1.38% w/w). In the XO inhibitory activity, none of the samples exhibited greater than 50% inhibition. However, in a rat model, EtOH80 extract (200 mg/kg/day) and andrographolide (30 mg/kg/day) decreased serum uric acid levels and reduced liver XO activity, reduced the protein expression levels of URAT1 and GLUT9, and restored the decrease in OAT1 levels. In the in vitro anti-inflammatory study, EtOH80 extract and andrographolide significantly decreased production of IL-1α, IL-1β, IL-6, and TNF-α, as well as inhibited the synthesis of MyD88, NLRP3, NF-κB p65, and caspase-1 in a concentration-dependent manner, almost comparable to dexamethasone. The EtOH80 extract (200 mg/kg/day) and andrographolide (30 mg/kg) significantly decreased swelling rate and IL-1α, IL-1β, IL-6, and TNF-α in the synovial fluid of rat models in a time-dependent manner, comparable to indomethacin (3 mg/kg/day). In conclusion, the findings show that EtOH80 extract has a substantial anti-gout effect by lowering uric acid levels and suppressing pro-inflammatory mediator production due to the andrographolide content, that might be beneficial in the treatment of gouty-inflammation.

Application of Nanomaterial in Hydrogels Related to Wound Healing

Traditional dressings used for wound repair, such as gauze, have shortcomings; for example, they cannot provide a suitable microenvironment for wound recovery. Therefore, it is necessary to find a better dressing to overcome shortcomings. Hydrogel provides a suitable wet environment, has good biocompatibility, and has a strong swelling rate to absorb exudate. Nanomaterial in hydrogels has been used to improve their performance and overcome the shortcomings of current hydrogel dressings. Hydrogel dressing can also be loaded with nanodrug particles to exert a better therapeutic effect than conventional drugs and to make the dressing more practical. This article reviews the application of nanotechnology in hydrogels related to wound healing and discusses the application prospects of nanohydrogels. After searching for hydrogel articles related to wound healing, we found that nanomaterial can not only enhance the mechanical strength, antibacterial properties, and adhesion of hydrogels but also achieve sustained drug release. From the perspective of clinical application, these characteristics are significant for wound healing. The combination of nanomaterial and hydrogel is an ideal dressing with broad application prospects for wound healing in the future.

Superabsorbent Polymer With Excellent Water/Salt Absorbency And Water Retention, And Fast Swelling Properties For Preventing Soil Water Evaporation

Superabsorbent polymers have important applications in many fields, but insufficiency of water/salt absorbency, water retention, and swelling rate limit its application development. Herein, we fabricated HEC-g-P (AA-co-AMPS)/laterite by aqueous solution polymerization, the structure and morphology of the superabsorbent polymer were characterized by FTIR, SEM and TG/DTG. The optimal water absorbency of the superabsorbent polymer were 1294 g/g, 177 g/g, and 119 g/g in distilled water, tap water, and 0.9 wt% NaCl solution, respectively. The superabsorbent polymer had good water retention and re-swelling properties at different temperatures, and fast water absorption rate, and reached swelling equilibrium at 5 min. The swelling mechanism of the superabsorbent polymer was explained by the pseudo-second-order swelling kinetics model and Ritger-Peppas model. The effect of the amount of hydrogel on the water evaporation rate in soil was studied, and it had a good effect.

Triggering Drug Release and Thermal-Disrupting Interface Induced Mitigation of Composite Photothermal Hydrogel Treating Infectious Wounds

Introduction: With the development of photothermal technology, the appearance of composite photothermal hydrogels has increased the selectivity of treating infectious skin defects. However, how to design composite photothermal hydrogel with better antibacterial performance, reduce the resistance rate of bacteria, and the damage rate of normal tissue still needs further study.Methods: The Prussian blue and tannic acid were loaded on polyacrylamide hydrogels. Characterization of DLS, Zeta potential, UV absorption spectrum, hydrogel swelling rate, scanning electronic microscopic, drug release profile, photothermal properties, in vitro cytocompatibility, and antibacterial properties. Experiments were measured by skin defect repair, antibacterial detection, and histological staining experiments.Results: The polyacrylamide hydrogel with photothermal effect and controllable release of tannic acid was successfully prepared. The hydrogel has strong light transmittance and adhesion, and the swelling rate can reach 600%, which improves the self-cleaning ability. SEM results showed the porous structure of hydrogels, promoting cell growth. Through photothermal switches, the composite hydrogel represented adjustable and controllable drug release ability. Combined with the synergistic antibacterial effect of tannic acid, this further enhanced the antibacterial ability and reduced the probability of antibiotic resistance. The in vitro and in vivo experiments showed the hydrogel had good biocompatibility and excellent antibacterial properties, which could promote the repair of infectious skin defects in SD rats.Conclusion: We fabricated a hydrogel with a triggering drug release rate, alleviating heat damage, transparent morphology, mechanical stability, strong adhesion, good biocompatibility, and synergistic antibacterial ability, which presents new treatment options for infectious skin defect repair.

Modeling and Simulation of the Ion-Binding-Mediated Swelling Dynamics of Mucin-like Polyelectrolyte Gels

Volume phase transitions in polyeletrolyte gels play important roles in many biophysical processes such as DNA packaging, nerve excitation, and cellular secretion. The swelling and deswelling of these charged polymer gels depend strongly on their ionic environment. In this paper, we present an extension to our previous two-fluid model for ion-binding-mediated gel swelling. The extended model eliminates the assumptions about the size similarity between the network and solvent particles, which makes it suitable for investigating of a large family of biologically relevant problems. The model treats the polyeletrolyte gel as a mixture of two materials, the network and the solvent. The dynamics of gel swelling is governed by the balance between the mechanical and chemical forces on each of these two materials. Simulations based on the model illustrate that the chemical forces are significantly influenced by the binding/unbinding reactions between the ions and the network, as well as the resulting distribution of charges within the gel. The dependence of the swelling rate on ionic bath concentrations is analyzed and this analysis highlights the importance of the electromigration of ions and the induced electric field in regulating gel swelling.

Relationship of Motility Activation to Lipid Composition, Protein Profile, and Swelling Rate of Burbot Lota lota Spermatozoon Following Change of Temperature and Osmolality

Despite available information on the roles of osmotic pressure, potassium (K+), and calcium (Ca2+) in activation of Eurasian burbot spermatozoon motility, the changes in milt biochemical composition and mechanisms underlying their activation at temperatures above optimal spawning temperature is still unclear. We explored spermatozoon swelling, lipid composition and proteome in relation to osmolality and temperature of swimming medium. The result revealed that temperature increment from 4 to 30°C increases burbot spermatozoa vulnerability to osmotic pressure, decreasing motility in extremely hypotonic media, and the presence of Ca2+ decreases swelling of spermatozoa. No spermatozoon swelling was observed in non-ionic isotonic media at all studied temperatures. A role of swelling in activation of spermatozoa motility at 30°C was rejected. No differences were found in protein profile and lipid composition with respect to activation of burbot spermatozoa at 30°C. Burbot spermatozoon activation occurs at 30°C without modification of the spermatozoon membrane. Elucidation of the intrinsic signaling pathway of burbot spermatozoon spontaneous activation requires further study.

Fouling Release Coatings Based on Acrylate–MQ Silicone Copolymers Incorporated with Non-Reactive Phenylmethylsilicone Oil

Copolymers containing MQ silicone and acrylate were synthesized by controlling the additive amount of compositions. Subsequently, fouling release coatings based on the copolymer with the incorporation of non-reactive phenylmethylsilicone oil were prepared. The surface properties of the coating (CAMQ40) were consistent with that of the polydimethylsiloxane (PDMS) elastomer, which ensured good hydrophobicity. Moreover, the seawater volume swelling rate of all prepared coatings was less than 5%, especially for CAMQ40 with only 1.37%. Copolymers enhanced the mechanical properties of the coatings, while the enhancement was proportional to the molar content of structural units from acrylate in the copolymer. More importantly, the adhesion performance between the prepared coatings and substrates indicated that pull-off strength values were more than 1.6 MPa, meaning a high adhesion strength. The phenylmethylsilicone oil leaching observation determined that the oil leaching efficiency increased with the increase in the structural unit’s molar content from MQ silicone in the copolymer, which was mainly owing to the decrease in compatibility between oil and the cured coating, as well as the decrease in mechanical properties. High oil leaching efficiency could make up for the decrease in the biofouling removal rate due to the enhancement of the elastic modulus. For CAMQ40, it had an excellent antifouling performance at 30 days of exposure time with more than 92% of biofouling removal rate, which was confirmed by biofilm adhesion assay.

Development and Evaluation of Ultra-High Temperature Resistant Preformed Particle Gels for Conformance Control in North Sea Reservoirs

Preformed particle gels (PPGs), a type of hydrogel, have been widely applied to control the conformance of reservoirs owing to their robust gel chemistries. Traditional PPGs are polyacrylamide-based hydrogel compositions which can withstand neither higher temperatures nor high salinity conditions. There are many deep oilfield reservoirs worldwide which demand PPG products with a long term hydrolytic and thermal stability at the temperatures of higher than 120 °C. Current PPGs neither remain hydrated nor retain polymer integrity at these temperatures. A unique high temperature-resistant hydrogel composition (HT-PPG) was developed with exceptional thermal stability for greater than 18 months in North Sea formation temperature (~130 °C) and formation water environments. HT-PPG described herein can swell up to 30 times its initial volume in brines of different salinity for North Sea. The effects of salinity and temperature on swelling, swelling rate, and rheological behavior was studied. These HT-PPGs exhibit excellent strength with storage modulus (G’) of over 3,000 Pa at the swelling ratio of 10. Thermostability evaluations were performed in North Sea brines with variable salinity at temperatures of 130 °C and 150 °C and found to be stable for 18 months with no loss of molecular integrity at the higher temperature. Laboratory core flooding tests were conducted to test its plugging efficiency to fracture. HT-PPGs showed good plugging efficiency by reducing the permeability of open fracture and did not wash out during waterflooding. Overall, HT-PPG is a novel product with excellent hydrothermal stability that make it an ideal candidate for conformance problems associated with reservoirs of high temperature and salinity conditions.

Dual Cross-Linked Chitosan/PVA Hydrogels Containing Silver Nanoparticles with Antimicrobial Properties

Stable chitosan/PVA-based hydrogels were obtained by combining covalent and physical cross-linking methods. As covalent cross-linkers, epoxy agents with different chain lengths were used, while freeze–thaw cycles were applied for additional physical cross-linking. The chemical structure of the hydrogel was examined by FTIR spectroscopy whereas the morphology was analyzed by SEM, showing well-defined pores with dimensions of around 50 μm in diameter. It was proved that gel fraction and the network morphology were deeply influenced by the synthesis conditions. Chitosan/PVA hydrogel showed a relative high swelling rate, reaching equilibrium in the first hour. The values obtained for the elastic modulus were relatively low (3–30 kPa); as a result, these hydrogels are soft and very flexible, and are ideal candidates for medical applications as wound or oral dressings. In addition, the natural antimicrobial activity of chitosan was enhanced by in situ generation of silver nanoparticles (AgNPs) under UV irradiation. The total amount of Ag from hydrogel was determined by elemental analyses and its crystalline state was confirmed by XRD. The CS/PVA hydrogels entrapped with AgNPs exhibited high inhibitory activity against S. aureus and K. pneumonia. The vitality tests confirmed the lack of cytotoxicity of CS/PVA hydrogels without and with AgNPs.

Development and Improvement of Organic Salt Solutions of Potassium Citrate As An Environmentally Friendly Completion Fluids for Oil and Gas Wells

This article provides information on the utilization and development of colloidal formulations based on organic potassium citrate, an alternative, environmentally friendly composite fluid that can support the drilling and production of oil and gas wells. The activity started with a laboratory-scale literature study, the formulation and modification of organic potassium citrate, testing the characteristics and performance of liquids, and improving advanced formulations. This completion fluid based on organic potassium citrate has high solubility and good stability to other pollutant particles. The colloidal organic salt system based on potassium citrate is an alternative function of the replenishment fluid (pressure holding fluid) for cleaning/deepening oil and gas wells. Currently, widely used composite fluids are chloride (Cl-), bromide (Br-), nitrate (NO3-), phosphate (PO4-), and cesium formate. However, these salt solutions are highly corrosive and are not environmentally friendly. The swelling test and the corrosion rate test are carried out using different fluids (i.e., KCl slurry, NaCl polymer, and colloidal organic citrate). The test results show that when the test is performed at room temperature for 16 hours, the organic citrate fluid's swelling rate is lower than 10%, and the KCl and NaCl sludge is higher than 20%. The result of a seven days corrosion test at 350oF is that the citric acid organic liquid is lower than 10 mpy, while KCl and NaCl are higher than 50 mpy. This completion fluid formulation based on organic citrate salts is a new type of completion fluid that has the following specifications: density up to (1.80), corrosion rate (3.19 mpy) @ 248-350oF, pH (6-8), resistance to extreme temperature, turbidity (7 NTU), a swelling rate below 10%, and has good compatibility with formation water. Also, potassium citrate organic salts can be degraded efficiently, making them safe for the environment.