DEV Community

Kloster Sheppard
Kloster Sheppard

Posted on

Id associated with successful top features of LFP sign to make closed-loop heavy brain arousal within parkinsonian rats.

Burn injuries are the most prevalent and devastating form of skin trauma. Current study aimed to fabricate novel chitosan-based composite films of vancomycin for wound healing applications. The developed vancomycin-chitosan films were evaluated for various quality attributes and were subjected to anti-bacterial activity against methicillin resistant Staphylococcus aureus (MRSA) and wound healing efficacy study in rat model. The prepared vancomycin-chitosan film 2 (VCF2) physically displayed a substantial tensile strength and swelling ratio. Pharmacologically, VCF2 exhibited sustained vancomycin release, excellent antibacterial activity and improved wound healing efficacy in rats. The superior wound healing potential was ascribed to the enhanced levels of reduced glutathione, glutathione-S-transferase, catalase and decreased lipid peroxidation. Furthermore, improved angiogenesis, granulation, epidermal regeneration and down regulation in the expressions of tumor necrosis factor, cyclooxygenase-2 and nuclear factor kappa B were the reasons of improved wound healing as confirmed by histopathological and molecular techniques. Thus, it is plausible to say that VCF2 could provide a potential therapeutic approach in burn wounds.Superior mechanical properties, high adsorption capacity, and excellent regeneration property are crucial design criterions to develop a new-type aerogel for adsorptive applications towards heavy metal removal from water. Herein, chitosan and melamine not only introduced abundant functional groups to increase adsorbing sites for lead ions, but also reinforced the three-dimensional network skeleton structure of absorbents to improve the service life in adsorption applications. As-fabricated alginate/melamine/chitosan aerogel can extract Pb (II) from aqueous solution efficiently, i.e., the optimum adsorption quantity of 1331.6 mg/g at pH 5.5, which exhibited excellent and selective adsorption capacity for Pb (II) against the competition of coexisting divalent metal ions. More importantly, alginate/melamine/chitosan aerogel could be regenerated using dilute acidic solution and recovered well after eight adsorption-desorption cycles. This work might offer a new idea for design and preparation of biomass-based aerogel sorbents with promising prospect in the remediation of Pb (II)-contaminated wastewater.Hydrogels that exhibit properties such as ultra-elongation, self-recovery, and self-healing have applications in sensors and many other fields. With these properties and applications in mind, we hypothesised that we could develop a strain-sensing hydrogel based on acrylic acid, stearyl methacrylate, cationic guar gum, and hexadecyl trimethyl ammonium bromide, without any covalent crosslinker. The hydrogels are instead held together by physical, non-covalent interactions such as ionic interactions, hydrogen bonding, and the hydrophobic effect, as suggested by spectroscopy and swelling experiments. The hydrogels exhibit many useful properties, such as excellent stretching-up to 4267%-and almost complete reversion to their original state at a large strain of 500%, even after 20 successive cycles; temperature-dependent self-healing and self-recovery; and strain-sensitive conductivity that is attributable to the directional migration of ions. Because of these outstanding features, such as notch-insensitivity and the ability to withstand knotting under high strain, our hydrogels will be useful as flexible sensors.Carboxymethyl cellulose (CMC) is a water-soluble derivative of cellulose and a major type of cellulose ether prepared by the chemical attack of alkylating reagents on the activated non-crystalline regions of cellulose. It is the first FDA approved cellulose derivative which can be targeted for desired chemical modifications. In this review, the properties along with current advances in the physical and chemical modifications of CMC are discussed. Further, CMC and modified CMC could be engineered to fabricate scaffolds for tissue engineering applications. In recent times, CMC and its derivatives have been developed as smart bioinks for 3D bioprinting applications. From these perspectives, the applications of CMC in tissue engineering and current knowledge on peculiar features of CMC in 3D and 4D bioprinting applications are elaborated in detail. Lastly, future perspectives of CMC for wider applications in tissue engineering and 3D/4D bioprinting are highlighted.The recent progress in the manufacturing of new functional cellulose-derived materials shows that the renewable side of these materials does not ensure sustainable development. In contrast, reaction/process design and waste minimization play a key role here. Herein, reactive extrusion was used as a fast method for cellulose transesterification with vinyl laurate in 1-ethyl-3-methylimidazolium acetate (EmimOAc)/DMSO system. It was demonstrated that cellulose laurate can be synthesized with high reaction efficiency (91 %). The low amount of solvent during the process provides high cellulose concentration (20 wt%) mild chemical modification within minutes and without any depolymerization. Temperature has a significant influence on the reaction kinetics. To examine the sustainability of the process E-factor was employed. Processing properties of obtained cellulose laurates were investigated. Samples with DS of 2.5 and higher can be easily extruded showing low melt viscosity. EmimOAc was recovered and reused for subsequent cellulose transesterification exhibiting high catalytic activity.Water-extracted polysaccharides from Russula vinosa Lindblad (WRP) were separated into three fractions (WRP-1, WRP-2 and WRP-3) by gradient ethanol precipitation and gel chromatography. Structural characterization indicated that WRP-1 was a branched β-(1→3)-glucan and exhibited rigid helical conformation in aqueous solution with Mw of 2,180 kDa and radius of gyration (Rg) of 123.4 nm. The galactoglucan of WRP-2 and WRP-3 were mainly composed of →6)-Galp-(1→ and →4)-Glcp-(1→ terminated by glucose and mannose, presenting much lower Mw (392 and 93.6 kDa) and Rg (57.6 and 42.6 nm), and more incompact flexible conformation than WRP-1. All fractions showed potential immunostimulatory activity by promoting macrophage proliferation, phagocytosis, as well as the release of nitric oxide and cytokines (TNF-α and IL-1β). WRP-1 with unique structure and conformation showed the best immunostimulatory effects among them. This study suggests that WRP could be explored as natural immunostimulator used in the food and pharmaceutical industry.Searching for green, recyclable and highly efficient catalyst for the synthesis of cyclic carbonates from CO2 is of great importance because it is profitable for reducing the greenhouse effects and meets the principles of green chemistry. Herein, a series of cellulose nanocrystals, either the pristine or modified ones (TEMPO oxidized and Co(III)salen immobilized), were explored as catalysts for cycloaddition of epoxides and carbon dioxide. The impact of surface properties on the performance of the as-made catalysts was investigated. Co(III)-salen grafted cellulose nanocrystals was proven to be the most effective catalyst in this study, which could afford excellent yield up to 99 % after 24 h even under low CO2 pressures of 0.1 MPa. They can be easily recovered and reused for at least 4 times, demonstrating their excellent stability. We found that the surface functional groups such as enriched sulfate or carboxylic groups could also account for the enhanced catalytic activity. This work highlights the applications of green and sustainable nanoparticles in a cycloaddition reaction and offers a sustainable solution in industrial catalysis related to CO2 conversions.Acute kidney injury (AKI) is a common and serious clinical syndrome of acute renal dysfunction in a short period. One of therapeutic interventions for AKI is to reduce ROS massively generated in the mitochondria and then ameliorate cell damage and apoptosis induced by oxidative stress. In this study, stepwise-targeting chitosan oligosaccharide, triphenyl phosphine-low molecular weight chitosan-curcumin (TPP-LMWC-CUR, TLC), was constructed for sepsis-induced AKI via removing excessive ROS in renal tubular epithelial cells. Benefiting from good water solubility and low molecular weight, TLC was rapidly and preferentially distributed in the renal tissues and then specifically internalized by tubular epithelium cells via interaction between Megalin receptor and LMWC. The intracellular TLC could further delivery CUR to mitochondria due to high buffering capacity of LMWC and delocalized positive charges of TPP. Both in vitro and in vivo pharmacodynamic results demonstrated the enhanced therapeutic effect of TLC in the treatment of AKI.Limited options for the treatments of diseases triggered through viral infections revealed the quest for novel antiviral drugs. Polysaccharide sulfates owing to their unique mode of action are prominent antiviral drug candidates. Herein, the arabinoxylan of Plantago ovata seed husk was simultaneously extracted and chemically sulfated using sulphur trioxide-pyridine reagent in N,N-dimethylformamide solvent (SO3⋅Py/DMF). Thus, three arabinoxylan sulfates (IS1201-IS1203) holding variable degrees of sulfation (DS 0.1-0.9), molar masses (18.4-31.3 kDa) and glycosyl makeup (Ara Xyl10-1981-90; molar ratio) were produced and then characterized. According to the results, these polymers displayed anti-herpes simplex virus type 1 activity and their potency depends upon DS. The utmost effective compound (IS1203, IC50 2.9 μg mL-1) was a 18.4 kDa arabinoxylan possessing sulfate groups at O-3 and O-2,3 positions of xylopyranosyl (Xylp), and O-5 of arabinofuranosyl (Araf) residues. Besides, this polymer showed no cytotoxicity at concentration up to 1000 μg mL-1. Given that polysaccharide sulfates have antiviral activities, synthesis of new molecules possessing diverse structures will be a useful addition to the arsenal of antivirals.In recent years, many studies have been conducted on the production of edible films from emerging gums, which are mostly made from botanical sources. However, each one interacts differently with the film compounds, producing films with different properties that may improve or hinder their utilization in food packaging. Therefore, the aim of this review was to investigate and compare the physical, mechanical, thermal and structural properties of edible films produced with these emerging gums. The results of this review showed that it is possible to produce edible films with desirable physical, mechanical and thermal properties by optimizing the amounts and type of compounds in film formulations such as plasticizers, nanoparticles, lipid compounds, crosslinkers and combination of gums with other biopolymers. The future trends of this research include the deepening of knowledge to understand the molecular structures of emerging gums and to address the shortcomings of films based on these gums for their industrial-scale application in food packaging.Citrate-based thermoset bioelastomer has numerous tissue engineering applications. learn more However, its insoluble and unmeltable features restricted processing techniques for fabricating complex scaffolds. Herein, direct ink writing (DIW) was explored for 3D printing of poly(1, 8-octanediol-co-Pluronic F127 citrate) (POFC) bioelastomer scaffolds considering that POFC prepolymer (pre-POFC) was waterborne and could form a stable emulsion. The pre-POFC emulsion couldn't be printed, however, chitin nanocrystal (ChiNC) could be as a rheological modifier to tune the flow behavior of pre-POFC emulsion, and thus DIW printing of POFC scaffolds was successfully realized; moreover, ChiNC was also as a supporting agent to prevent collapse of filaments during thermocuring, and simultaneously as a biobased nanofiller to reinforce scaffolds. The rheological analyses showed the pre-POFC/ChiNC inks fulfilled the requirements for DIW printing. The printed scaffolds exhibited low swelling, and good performances in strength and resilence.learn more

Top comments (0)