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These results demonstrate that PVA/keratin/chitosan 3DENS have the potential for biomedical applications.Circular dichroism (CD) and small-angle X-ray scattering (SAXS) measurements were made for three xanthan samples, a double helical polysaccharide, in 5 or 10 mM aqueous NaCl after rapid temperature change to investigate the kinetics of the conformational change between the ordered and disordered states. After the rapid heating, the CD signal mainly reflecting the carbonyl groups on the side chains quickly changed ( less then 150 s) while the scattering intensity from SAXS around q (magnitude of the scattering vector) = 1 nm-1 changed more gradually, reflecting the main-chain conformation. The difference between CD and SAXS implies us the intermediate conformation which can be regarded as a loose double helix. The SAXS profile in the rapid cooling process showed that the loose double helical structure was constructed within 150 s, but the CD signal slowly changed with around 2 days to recover the native tight double helix.As a natural polymer, chitin has excellent biological properties such as biodegradability and immunological, antibacterial, and wound-healing activities and has numerous applications in cosmetics, drug delivery, and pharmaceuticals. Organic polymer monoliths have also drawn significant attention, owing to their high permeability, large surface area, and high mechanical strength. They are usually applied to separation, ion exchange, catalysis, and chromatography. We have previously prepared cellulose monoliths using biopolymers; however, because chitin possesses amide groups on its side chain, it is superior to cellulose for further chemical modification and applications. However, the utilization of chitin is restricted by its insolubility in water and common organic solvents. In this study, for the first time, a monolith was prepared by chemical modification of chitin using a thermally induced phase separation (TIPS) method. First, we prepared dibutyrylchitin (DBC) as a starting polymer that is soluble in organic solvents. To prepare the monolith, DBC was dissolved completely in dimethyl sulfoxide (DMSO) while heating, and deionized water was added to the solution. It was then cooled at 20 °C to form a monolith via phase separation. The porous morphology of the DBC monolith was altered by regulating the DBC concentration, DMSO/H2O ratio, and aging temperature. The DBC monolith was converted to a chitin monolith by the alkaline hydrolysis of butyryl ester. The successful hydrolysis of butyryl ester was confirmed by the disappearance of the peak at 1735 cm-1 in the FT-IR spectra, which is related to the ester moiety of DBC. The chitin monolith has the potential to be utilized under water flow for catalysis, metal capture from wastewater, dye sorption, and drug delivery systems.Chitosan oligosaccharides (COS) are a derivative of low molecular weight chitosan and are potent natural antimicrobial agents. selleck products The antimicrobial activity of COS against Aspergillus flavus and Aspergillus fumigatus was evaluated by minimum inhibitory concentration (MIC) and inhibition of mycelial growth. The MICs of COS against these two fungi were 31.2 and 15.6 mg/mL, respectively. COS treatment rendered fungal mycelia wrinkled and deformed with a fractured appearance. COS also increased cellular permeability leading to a significant leakage of cellular components indicating membrane damage. This compound also dose-dependently reduced chitin production and enhanced chitinase activity while enhancing the accumulation of reactive oxygen species (ROS). These characteristics suggested that COS has inhibitory effects against food spoilage fungi and acts on the cell wall and membrane and alters cellular metabolism. COS shows promise for food industry applications since it is non-toxic to higher organisms.Cellulose was treated with supercritical water at 668 K and 25 MPa for 0.04 s in this study. The cellulose/water system was transparent at room temperature for a while after supercritical water treatment before a precipitate gradually appeared over several hours. The precipitation process was monitored by synchrotron X-ray scattering. The scattering functions of fractal systems and flat-like structures were utilized to explain the experimentally observed small-angle scattering profiles. Immediately after supercritical water treatment, the cellulose appeared to dissolve with a fractal dimension D of approximately 1, indicating that the cellulose molecules were rigid, followed by aggregation into a 5-nm-thick flat-like structure. The flat-like structure was determined to be similar to the molecular sheets observed during the early stages of precipitation in the cellulose/aqueous sodium hydroxide and cellulose/aqueous lithium hydroxide/urea systems. Resultant regenerated cellulose had high crystallinity, large crystal size, and a low degree of polymerization.The present review explores the recent developments of cellulose nanocrystals, a class of captivating nanomaterials in variety of applications. CNCs are made by acid hydrolysing cellulosic materials like wood, cotton, tunicate, flax fibers by sonochemistry. It has many desirable properties, including a high tensile strength, wide surface area, stiffness, exceptional colloidal stability, and the ability to be modified. CNCs are colloidally stable, hydrophilic, and rigid rod-shaped bio-based nanomaterials in the form of rigid rods with high strength and surface area that has a diverse set of applications and properties. The intriguing features emerging from numerous fibers studies, such as renewable character and biodegradability, piqued the curiosity of many researchers who worked on lowering the size of these fibers. Physicochemical properties such as rheological, mechanical, thermal, lipid crystalline, swelling capacity, microstructural properties result in affecting surface-area to volume ratio and crystallinity of cellulose nanocrystals. The present article highlights the fundamentals of cellulose nanocrystals such as sources, isolation, fabrication, properties and surface modification with an emphasis on plethora of biomedical applications. Selected nanocellulose studies with significant findings on cellular labelling and bioimaging, tissue engineering, biosensors, gene delivery, anti-viral property, anti-bacterial property, ocular delivery, modified drug release, anti-cancer activity and enzyme immobilization are emphasized.In the search for photosensitizers with chemical handles to facilitate their integration into complex drug delivery nanosystems, new, unsymmetrically substituted, water insoluble meso-tetraphenylporphyrin and meso-tetra(m-hydroxyphenyl)porphyrin derivatives bearing one carboxyalkyl side chain were synthesized. Permethyl-β-cyclodextrin (pMβCD) was their ideal monomerizing host and highly efficient shuttle to transfer them into water. New assembly modes of the extremely stable (Kbinding > 1012 M-2) 21 complexes were identified. The complexes are photostable and do not disassemble in FBS-containing cell culture media for 24 h. Incubation of breast cancer MCF-7 cells with the complexes results in intense intracellular fluorescence, strongly enhanced in the endoplasmic reticulum (ER), high photokilling efficiency (~90%) and low dark toxicity. pMβCD stands out as a very capable molecular isolator of mono-carboxyalkyl-arylporphyrins that increases uptake and modulates their localization in the cells. The most efficient porphyrins are envisaged as suitable photosensitizers that can be linked to biocompatible drug carriers for photo- and chemo-therapy applications.The biodegradability and mechanical properties of polysaccharides are dependent on their architecture (linear or branched) as well as their crystallinity (size of crystals and crystallinity percent). The amount of crystalline zones in the polysaccharide significantly governs their ultimate properties and applications (from packaging to biomedicine). Although synthesis, characterization, and properties of polysaccharides have been the subject of several review papers, the effects of crystallization kinetics and crystalline domains on the properties and application have not been comprehensively addressed. This review places focus on different aspects of crystallization of polysaccharides as well as applications of crystalline polysaccharides. Crystallization of cellulose, chitin, chitosan, and starch, as the main members of this family, were discussed. Then, application of the aforementioned crystalline polysaccharides and nano-polysaccharides as well as their physical and chemical interactions were overviewed. This review attempts to provide a complete picture of crystallization-property relationship in polysaccharides.Previous researches suggested that polysaccharides from brown algae had anti-virus activity. We hypothesized that nature polysaccharide from marine plants might have the effect on anti-SARS-CoV-2 activity. By high throughput screening to target 3CLpro enzyme using polysaccharides library, we discover a crude polysaccharide 375 from seaweed Ecklonia kurome blocked 3CLpro enzymatic activity and shows good anti-SARS-CoV-2 infection activity in cell. Further, we show that homogeneous polysaccharide 37502 from the 375 may bind to 3CLpro well and disturb spike protein binding to ACE2 receptor. The structure characterization uncovers that 37502 is alginate. These results imply that the bioactivities of 375 on SARS-CoV-2 may target multiple key molecules implicated in the virus infection and replication. The above results suggest that 375 may be a potential drug candidate against SARS-CoV-2.Here, Cotton fabric was functionalized via hybrid coating including 2D MgAl LDH (layered double hydroxide) and SA (stearic acid). The urea hydrolysis was employed for construction of vertically aligned LDH on surface of cellulose fibers under hydrothermal condition. The in situ formation mechanism of LDH on cotton surface was nucleation, growth, and interaction with activated cellulose chains. The partial cellulose ionization in the alkaline solution led to nucleophilic behavior towards electron deficient atom. The effect of different ageing, synthesis temperature, and amount of SA were investigated and optimized at 100 °C for 24 h with 0.05 M. The superhydrophobic surface architecture of treated cotton with hierarchical micro/nanostructure was inspired from the Taro leaf structure with continuous contact line presented WCA of 154 ° and CAH of 9 °. The Cotton@LDH@SA exhibited efficient oil/water separation after several washes (>90%) with good stain resistant. Also, the physico-mechanical properties were studied.Engineered promoters are key components that allow engineered expression of genes in the cell-factory design. Promoters having exceptional strength are attractive candidates for designing metabolic engineering strategies for tailoring de novo production strategies that require directed evolution methods by engineering with de novo synthetic biology tools. Engineered promoter variants (EPVs) of naturally occurring promoters (NOPs) can be designed using metabolic engineering strategies and synthetic biology tools if the genes encoding the activating transcription factors (TFs) exist in the genome and are expressed and synthesized at non-limiting concentrations within the cell. The hybrid-architectured EPV design method targets an essential and predetermined part of the general transcription machinery. That is cis-acting DNA site(s) in coordination with the trans-acting factor(s) that must bind for the regulated transcription machinery activation. The method needs genomic and functional information that can lead to the discovery of the master TF(s) and synthetic cis-acting DNA elements, enabling the engineering of binding of master regulator TF(s).