Chitosan-Based Charge-Controllable Supramolecular Carrier for Universal Immobilization of Enzymes with Different Isoelectric Points.

Electrostatic adsorption is an enzyme immobilization method that effectively maintains enzyme activity and exhibits considerable binding efficiency. However, enzymes carry different charges at their respective reaction pH levels, which prevents the use of the same carrier to immobilize enzymes with different charges. In this study, we employed a template-mediated polysaccharide-enzyme coupling self-assembly strategy to develop a charge-controllable supramolecular immobilization carrier by regulating the charge properties of carboxymethyl chitosan, enabling the universal immobilization of enzymes with different charge levels across a range of reaction pH values.

Switchable CO-Responsive Janus Nanoparticle for Lipase Catalysis in Pickering Emulsion.

The use of convertible immobilized enzyme carriers is crucial for biphasic catalytic reactions conducted in Pickering emulsions. However, the intense mechanical forces during the conversion process lead to enzyme leakage, affecting the stability of the immobilized enzymes. In this study, a CO-responsive switchable Janus (CrSJ) nanoparticle (NP) was developed using silica NP, with one side featuring aldehyde groups and the other side adsorbing ,-dimethyldodecylamine.

A chitosan-based antibacterial hydrogel with injectable and self-healing capabilities.

Unlabelled: The presence of bacteria directly affects wound healing. Chitosan-based hydrogel biomaterials are a solution as they offer advantages for wound-healing applications due to their strong antimicrobial properties. Here, a double-cross-linking chitosan-based hydrogel with antibacterial, self-healing, and injectable properties is reported.

Characterization and comparison of carboxymethylation and TEMPO-mediated oxidation for polysaccharides modification.

In this study, carboxymethylation and TEMPO-mediated oxidation were compared for their ability to introduce carboxyl groups to polysaccharides, using cellulose and chitin as model polysaccharides. The carboxyl group contents and changes in the molecular weight of carboxymethylated and TEMPO-oxidized cellulose/chitin were measured. The results revealed that carboxymethylation achieved higher carboxyl group contents, with values of 4.

Magnetic macroporous chitin microsphere as a support for covalent enzyme immobilization.

In this study, a novel magnetic macroporous chitin microsphere (MMCM) was developed for enzyme immobilization. Chitin nanofibers were prepared and subsequently subjected to self-assembly with magnetic nanoparticles and PMMA (polymethyl methacrylate). Following this, microspheres were formed through spray drying, achieving a porous structure through etching.

An efficient method for chitin production from crab shells by a natural deep eutectic solvent.

Crab shells are an important feedstock for chitin production. However, their highly compact structure significantly limits their use for the production of chitin under mild conditions. Here, a green and efficient approach using a natural deep eutectic solvent (NADES) to produce chitin from crab shells was developed.

Preparation and comparison of dialdehyde derivatives of polysaccharides as cross-linking agents.

Dialdehyde-based cross-linking agents are widely used in the cross-linking of amino group-containing macromolecules. However, the most commonly used cross-linking agents, glutaraldehyde (GA) and genipin (GP), have safety issues. In this study, a series of dialdehyde derivatives of polysaccharides (DADPs) were prepared by oxidation of polysaccharides, and their biocompatibility and cross-linking properties were tested using chitosan as a model macromolecule.

A Biodegradable Multifunctional Film as a Tissue Adhesive for Instant Hemostasis and Wound Closure.

Here, a multifunctional film (MFF) as an alternative tissue adhesive in the form of an interpenetrating network consisting of self-crosslinked aldehyde-functionalized chitosan (AC) and crosslinked poly(acrylic acid) (PAA) further coordinated with Ag is reported. The MFF combines enhanced toughness and stretchability, which is attributed to the synergistic effects of the double-network design. Covalent crosslinking maintains the overall integrity of the MFF matrix, while noncovalent crosslinking dissipates energy under deformation.

Design, Preparation, and Evaluation of Enteric Coating Formulation of HPMC and Eudragit L100 on Carboxylated Agarose Hydrogel by Using Drug Tartrazine.

Enteric-coated application on drug is used to prevent the drug from inactivation which are degraded by gastric enzyme. The present study is aimed at achieving controlled drug delivery in acidic medium of gastrointestinal tract (GIT) by enteric coating of hydroxy propyl methylcellulose (HPMC) and Eudragit L100 on carboxylated agarose hydrogel, creating a pH-dependent delivery system. Fourier-transformed infrared spectroscopy (FTIR) was for the detection of carboxylic group on agarose hydrogel, and scanning electron microscope (SEM) was used for the determination surface of prepared formulation.

Synthesis of Agarose-Based Multistimuli-Responsive Hydrogel Dressing for Accelerated Wound Healing.

Stimuli-responsive hydrogels have drawn increasing research interest in regenerative medicine due to their tunable molecular structures and functional properties for both providing a suitable microenvironment for wound healing and to serve as a sustainable therapeutic. Hence, we developed a stimuli-responsive drug-loaded hydrogel wound dressing for sustained, controlled release of the drug and accelerating wound healing. Hydrogel dressings with stimuli-responsive properties were prepared using carboxymethyl agarose (CMA) with various degrees of substitution and calcium ion crosslinking, followed by the loading of recombinant human epidermal growth factor (Rh-EGF) on the CMA hydrogel.

Characterization of TEMPO-oxidized chitin nanofibers with various oxidation times and its application as an enzyme immobilization support.

Chitin nanofibers have recently received increased attention and are considered to be a promising material for a wide range of applications because of their excellent characteristics. In this study, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized chitin nanofibers (CNFs) with various oxidation times were prepared and characterized. CNFs with different oxidation times were then utilized for enzyme immobilization, using chymotrypsin as a model enzyme.

A Novel Soluble Squalene-Hopene Cyclase and Its Application in Efficient Synthesis of Hopene.

Hopene is an important precursor for synthesizing bioactive hopanoids with great commercial value. However, the chemical methods for synthesizing hopene are not efficient to date. Hopene is commonly obtained by extracting from plants or bacteria like other terpenoids, but the complicated extraction process is inefficient and unfriendly to the environment.

New type of green extractant for oil production: Citric acid/citric acid sodium extraction system.

Developing green solvents with low toxicity and low energy consumption is an important issue for edible oil production. In this study, a novel extraction system, specifically a citric acid/citric acid sodium mixture, was developed for oil extraction from seed crops. Peanut and pumpkin seeds were used to evaluate extraction efficiency and more than 70% and 57% oils, respectively, were extracted from peanut and pumpkin seeds at 4 °C.

Combining Cell Surface Display and DNA-Shuffling Technology for Directed Evolution of Phospholipase D and Synthesis of Phosphatidylserine.

Phospholipids have been widely used in food, medicine, cosmetics, and other fields because of their unique chemical structure and healthcare functions. Phospholipase D (PLD) is a key biocatalyst for the biotransformation of phospholipids. Here, an autodisplay expression system was constructed for rapid screening of mutants, and PLD variants were recombined using DNA shuffling technology and three beneficial mutations were obtained.

Effects of Comedication and Genetic Factors on the Population Pharmacokinetics of Lamotrigine: A Prospective Analysis in Chinese Patients With Epilepsy.

Lamotrigine (LTG) is a second-generation anti-epileptic drug widely used for focal and generalized seizures in adults and children, and as a first-line medication in pregnant women and women of childbearing age. However, LTG pharmacokinetics shows high inter-individual variability, thus potentially leading to therapeutic failure or side effects in patients. This prospective study aimed to establish a population pharmacokinetics model for LTG in Chinese patients with epilepsy and to investigate the effects of genetic variants in uridine diphosphate glucuronosyltransferase (UGT) 1A4, UGT2B7, MDR1, ABCG2, ABCC2, and SLC22A1, as well as non-genetic factors, on LTG pharmacokinetics.

A novel autolysis system for extracellular production and direct immobilization of a phospholipase D fused with cellulose binding domain.

Background: Several types of phospholipases have been described in phospholipids modification. The majority of phospholipase D (PLD) superfamily members can catalyze two separate reactions: the hydrolysis of phospholipids to produce phosphatidic acid (PA) and the transphosphatidylation of phosphatidyl groups into various phosphatidyl alcohols to produce modified phospholipids. Transphosphatidylation is a useful biocatalytic method for the synthesis of functional phospholipids from lecithin or phosphatidylcholine (PC), which are both easily accessible.

Two-Step Separation of Chitin from Shrimp Shells Using Citric Acid and Deep Eutectic Solvents with the Assistance of Microwave.

In this research, a two-step extraction approach was developed for chitin preparation from shrimp shells by utilizing citric acids and deep eutectic solvents (DESs), which effectively removed minerals and proteins. In the first step, minerals of shrimp shells were removed by citric acid, and the demineralization efficiency reached more than 98%. In the second step, the removal of protein was carried out using deep eutectic solvents with the assistance of microwave, and the deproteinization efficiency was more than 88%.

Efficient enzymatic hydrolysis of ionic liquid pretreated chitin and its dissolution mechanism.

Colloidal chitin, the substrate of chitinase with an open hydrated gel-like structure, can be obtained by treatment using either traditional hydrochloric acid (HCl) or ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]). IL-pretreated chitin provided an efficient production of N-acetylglucosamine (175.62 mg g chitin) and N,N'-diacetylchitobiose (341.

Conformational changes of proteins and oil molecules in fish oil/water interfaces of fish oil-in-water emulsions stabilized by bovine serum albumin.

This study investigated the conformational changes in proteins and oil molecules at fish oil/water interfaces. Results of FT-IR indicate that α-helical content of bovine serum albumin decreased (from 46.1% to 28.

Green and Facile Production of Chitin from Crustacean Shells Using a Natural Deep Eutectic Solvent.

Natural deep eutectic solvents (NADESs) are sustainable, nontoxic, and biodegradable solvents, which are composed of natural primary metabolites. A green and efficient approach based on choline chloride-malic acid, a NADES, was developed for extracting chitin from crustacean shells, and its effectiveness for demineralization and deproteinization was determined. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to investigate changes in the chemical composition of extracted chitin.

Simultaneous cell disruption and lipid extraction in a microalgal biomass using a nonpolar tertiary amine.

A simultaneous cell disruption and lipid extraction method is developed for microalgal biodiesel production using a triethylamine/methanol solvent system. Individually, the pure solvents, i.e.

A novel microalgal lipid extraction method using biodiesel (fatty acid methyl esters) as an extractant.

Although microalgae are considered promising renewable sources of biodiesel, the high cost of the downstream process is a significant obstacle in large-scale biodiesel production. In this study, a novel approach for microalgal biodiesel production was developed by using the biodiesel as an extractant. First, wet microalgae with 70% water content were incubated with a mixture of biodiesel/methanol and penetration of the mixture through the cell membrane and swelling of the lipids contained in microalgae was confirmed.

Nickel oxide nanoparticle-based method for simultaneous harvesting and disruption of microalgal cells.

Microalgae biodiesel is considered one of the most promising renewable fuels. However, the high cost of the downstream process is a major barrier to large-scale microalgal lipid production. In this study, a novel approach based on nickel oxide nanoparticles (NiO NPs) was developed and its effectiveness for simultaneous harvesting and cell disruption in microalgal lipid production was determined.

Pharmacokinetic Properties of Peramivir After Single and Multiple Intravenous Infusions in Healthy Chinese Volunteers.

Background And Objectives: Peramivir, an antiviral agent for intravenous administration, is used to treat progressive influenza in patients with serious complications. The present study was designed to determine the pharmacokinetics of single and multiple intravenous infusions of peramivir in healthy Chinese subjects.

Methods: Single (150, 300 and 600 mg) and multiple (600 mg) doses of peramivir were intravenously administered to 12 healthy Chinese subjects.

Cationic surfactant-based method for simultaneous harvesting and cell disruption of a microalgal biomass.

Microalgae are one of the most promising sustainable energy sources for biodiesel production. However, the high costs of the downstream process are a major bottleneck for commercial-scale production of biodiesel from a microalgal biomass. A novel approach called the cationic surfactant-based harvesting and cell disruption (CSHD) method was studied to determine its effectiveness in simultaneous microalgal biomass harvesting and cell disruption.