Gelatin/carboxymethyl chitosan/aloe juice hydrogels with skin-like endurance and quick recovery: Preparation, characterization, and properties.

Gelatin-based hydrogels have gained considerable attention due to their resemblance to the extracellular matrix and hydrophilic three-dimensional network structure. Apart from providing an air-permeable and moist environment, these hydrogels optimize the inflammatory microenvironment of the wounds. These properties make gelatin-based hydrogels highly competitive in the field of wound dressings.

N-lauric-O-carboxymethyl chitosan: Synthesis, characterization and application as a pH-responsive carrier for curcumin particles.

A pH-responsive amphiphilic chitosan derivative, N-lauric-O-carboxymethyl chitosan (LA-CMCh), is synthesized. Its molecular structures are characterized by FTIR, H NMR, and XRD methods. The influencing factors are investigated, including the amount of lauric acid (LA), carboxymethyl chitosan (CMCh), N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS), and their molar ratio, reaction time, and reaction temperature on the substitution.

Acyl-protein thioesterase1 alleviates senile osteoporosis by promoting osteoblast differentiation via depalmitoylation of BMPR1a.

Objective: Senile osteoporosis (SOP) is an aging-related disease. The depalmitoylating enzyme Acyl-protein thiesterase1 (APT1) is involved in disease regulation. This study explored the mechanism of APT1 in SOP.

Effects of Chitosan and Cellulose Derivatives on Sodium Carboxymethyl Cellulose-Based Films: A Study of Rheological Properties of Film-Forming Solutions.

Bio-based packaging materials and efficient drug delivery systems have garnered attention in recent years. Among the soluble cellulose derivatives, carboxymethyl cellulose (CMC) stands out as a promising candidate due to its biocompatibility, biodegradability, and wide resources. However, CMC-based films have limited mechanical properties, which hinders their widespread application.

Studies on Intermolecular Interaction of -Glycidyltrimethyl Ammonium Chloride Modified Chitosan/,-Dimethyl--dodecyl--(2,3-epoxy propyl) Ammonium Chloride and Curcumin Delivery.

Chitosan has potential applications in many fields, due to its biocompatibility, biodegradability and reproducibility. However, the insolubility in water restricts its wide application. In order to expand the application of chitosan in the delivery of oil-soluble drugs and improve the efficacy of oil-soluble drugs, -Glycidyltrimethyl ammonium chloride-modified chitosan (GTA-m-CS) and ,-Dimethyl--dodecyl--(1,2-epoxy propyl) ammonium chloride (DDEAC), a kind of reactive surfactant, were synthesized and characterized by FTIR, NMR and XRD methods.

Porphyriynes: 18-π-Conjugated Macrocycles Incorporating a Triple Bond.

Tetraphenylporphyriyne (), a novel porphyrin analogue with a C≡C bond incorporated into an 18-π-conjugated system, has been created via cleavage of the N-confused pyrrolic ring in Ag(III) N-confused tetraphenylporphyrin. The structure of was confirmed by X-ray crystallography and H NMR, IR, and UV-vis spectroscopy. The mechanism of cleavage of the N-confused pyrrolic ring was investigated by theoretical calculations.

N-(2-hydroxyl)-propyl-3-trimethylammonium chitosan chloride/carboxymethyl cellulose films filled with in-situ crystallized calcium carbonate.

The research and development of substitutes for petroleum-based plastics has become a hot topic. The N-(2-hydroxyl)-propyl-3-trimethylammonium chitosan chloride (HTCC, 10 wt%)/sodium carboxymethyl cellulose (CMC) films have showed enhanced mechanical properties, which also provide a potential substitute to petroleum-based plastics. In this paper, calcium carbonate was crystallized (cry-CaCO) in HTCC/CMC film-forming solutions, and the effects of the cry-CaCO particles on HTCC/CMC film properties including microstructures, mechanical properties, thermal stability, whiteness, and wettability were characterized.

Solution properties of N-(2-allyl-butyl ether)-O-carboxymethyl chitosan and N-(2-allyl-isooctyl ether)-O-carboxymethyl chitosan.

pH-sensitive and amphiphilic chitosan derivatives can be used as hydrophobic drug carriers, and their rheological properties play a key role in their performance. In this paper, two pH-responsive and amphiphilic chitosan derivatives, N-(2-allyl-butyl glycidyl ether)-O-carboxymethyl chitosan (HBCC) and N-(2-ethylhexyl glycidyl ether)-O-carboxymethyl chitosan (H2ECC) were synthesized, and their rheological properties were studied. The influence of parameters including concentrations of HBCC and H2ECC, the degree of substitution, solution pH, and [Ca] on the rheological properties were investigated.

O-Carboxymethyl chitosan-based pH-responsive amphiphilic chitosan derivatives: Characterization, aggregation behavior, and application.

Chitosan has attracted much attention in drug delivery, however, carboxymethyl chitosan (CMC)-based self-aggregated nanocarriers are seldom reported. In this paper, two kinds of CMC-based pH-responsive amphiphilic chitosan derivatives, N-2-hydroxylpropyl-3-butyl ether-O-carboxymethyl chitosan (HBCC) and N-2-hydroxylpropyl-3-(2-ethylhexyl glycidyl ether)-O-carboxymethyl chitosan (H2ECC), have been synthesized by the homogeneous reaction. The molecular structures were characterized by FTIR, H NMR and C NMR.

Synthesis, structure, and properties of N-2-hydroxylpropyl-3-trimethylammonium-O-carboxymethyl chitosan derivatives.

N-2-hydroxylpropyl-3-trimethylammonium-O-carboxymethyl chitosan (HTCMCh) was synthesized through homogeneous reaction. The effects of different reaction condition on the properties of HTCMCh were characterized by FTIR, NMR, SEM, TEM, DLS, XRD, TGA, and DSC. The results of FTIR spectra, H NMR, and C NMR proved the successful synthesis of HTCMCh.

Effects of chitosan quaternary ammonium salt on the physicochemical properties of sodium carboxymethyl cellulose-based films.

The effects of N-(2-hydroxyl)-propyl-3-trimethylammonium chitosan chloride (HTCC) on the physicochemical properties of sodium carboxymethyl cellulose (CMC)-based films were investigated. The prepared HTCC/CMC film-forming solutions (FFSs) with varying mass ratios exhibited shear-thinning behavior and typical pseudo-plasticity. The highest apparent viscosity and lowest crossover frequency was obtained for the HTCC/CMC FFS with a mass ratio of 10%, due to the formation of the strongest intermolecular interactions, which also led to the best mechanical properties.

Flavobacterium phocarum sp. nov., isolated from soils of a seal habitat in Antarctica.

A Gram-stain-negative, yellow-pigmented, non-flagellated, gliding, rod-shaped, oxidase-negative and catalase-positive bacterium, designated SE14, was isolated from soil on King George Island, South Shetland Islands, Antarctica. Strain SE14 grew at 4-25 °C (optimum, 20 °C), at pH 6.0-9.

Flavobacterium ardleyense sp. nov., isolated from Antarctic soil.

A Gram-stain-negative, aerobic, yellow-pigmented, non-flagellated, non-gliding, rod-like, oxidase- and catalase-positive bacterium, designated A2-1, was isolated from soil on Ardley Island, South Shetland Islands, Antarctica. Strain A2-1 grew at 4-22 °C (optimum, 10 °C), at pH 6.0-8.

Rheological properties of N-[(2-hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride.

N-[(2-hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride (HTCC) was synthesized using 1-allyl-3-methylimidazole chloride (AmimCl) as a homogeneous green reaction media. The effects of polymer concentration, temperature, cation valence, anion type and concentration of inorganic salt, and degree of substitution (DS) on the rheological properties of HTCC were investigated. The apparent viscosity indicated that HTCC solution was a typical pseudoplastic fluid, which could be described by Ostwald de Waele and Cross-empirical models.

Theoretical study of the reaction of chitosan monomer with 2,3-epoxypropyl-trimethyl quaternary ammonium chloride catalyzed by an imidazolium-based ionic liquid.

The molecular mechanism of the graft reaction of 2,3-epoxypropyl-trimethyl quaternary ammonium chloride with chitosan monomer was investigated by performing density functional theory (DFT) calculations. The calculated results show that the -NH2 group of chitosan monomer is more reactive than its -OH and -CH2OH groups, and the graft reaction on the -NH2 group is calculated to be exothermic by 20.5kcal/mol with a free energy barrier of 42.

A simple and convenient method to synthesize N-[(2-hydroxyl)-propyl-3-trimethylammonium] chitosan chloride in an ionic liquid.

N-[(2-Hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride (HTCC) was synthesized through nucleophilic substitution of 2,3-epoxypropyltrimethyl ammonium chloride (EPTAC) onto chitosan using ionic liquid of 1-allyl-3-methylimidazole chloride (AmimCl) as a homogeneous and green reaction media. The chemical structure of HTCC was confirmed by FTIR, (1)H NMR and (13)C NMR. The FTIR peak intensity of amino group at 1595 cm(-1) decreased and that of [Formula: see text] at 1475 cm(-1) increased with the increase of reaction time, confirming the substitution of EPTAC on CS.

Effect of amino acids on aggregation behaviour of sodium deoxycholate in solution: a fluorescence study.

The influence of three alkaline amino acids, L-lysine (L-Lys), L-arginine (L-Arg) and L-histidine (L-His), on the aggregation behaviour of sodium deoxycholate (NaDC) in phosphate buffer, pH 7.0, was studied at 25 °C. The fluorescence probe technique based on pyrene was employed to determine accurately the critical aggregation concentration (cac), polarity of the microenvironment and aggregation numbers for the NaDC aggregates.

Phase behavior studies of quaternary systems containing N-lauroyl-N-methylglucamide/alcohol/alkane/water.

The three-phase behavior of quaternary systems comprising N-lauroyl-N-methylglucamide (MEGA-12)/alcohol/alkane/water has been studied using epsilon-beta fishlike phase diagrams. From the epsilon-beta fishlike phase diagrams a series of phase inversions Winsor I (2) --> III (3) --> II (2) were observed, and the hydrophilic-lipophilic balanced (HLB) plane equation for the quaternary system was deduced. Some physicochemical parameters, such as the mass fraction of alcohol in the HLB interfacial layer, A S, the coordinates of the start (beta B, epsilon B) and end points (beta E, epsilon E) of the middle-phase microemulsion, the mass fractions of MEGA-12 and alcohol in the total system (C S and C A), and the solubilities of MEGA-12 and alcohol in oil phase (S O and A O), were calculated.