Addition Of Glycerol Research Articles

Study of a gel dosimeter based on Ag nanoparticles for applications in radiation therapy with synchrotron X-rays at ultrahigh dose rate compared to 60Co γ-rays

A silver nitrate (AgNO3) gel was developed and evaluated as a dosimeter for synchrotron X-ray-based studies in microbeam radiation therapy (MRT) and FLASH radiation therapy. The gel was irradiated at the European Synchrotron Radiation Facility (ID17 Biomedical beamline) with a continuous X-ray spectrum in the 50-600 keV range and a dose rate of 11.6kGy/s. The spectrophotometric response after irradiation at this beamline was compared with the response at a conventional 60Co γ-ray source providing a dose rate of 0.27 Gy/s. Ag+ ions in the gel dosimeter undergo reduction to Ago nanoparticles, as detected at 450 nm, which is a surface plasmon resonance band. The intensity of this band increased linearly with increasing absorbed dose up to 100 Gy, and improved with the addition of glycerol. The gel dosimeter exhibited the lowest detectable dose (LDD) of 75.9% lower and a dose deposition of 76% higher for ID17 beamline irradiation than for 60Co irradiation. The theoretical relative response HQ,Qo for the gel irradiated at the synchrotron was 1.70, which is in close agreement with the experimental relative response FQ,Qo = 1.76. These results confirm the dose enhancement in the gel irradiated with orthovoltage X-rays. The good properties of the silver nitrate gel, together with its increased sensitivity to orthovoltage X-ray irradiation and modest overall uncertainty of 5.8% (2σ), confirm that the gel is a valid dosimeter for measurements at ultrahigh dose rates for synchrotron radiotherapy. The dosimeter is also a promising candidate for dose enhancement factor measurements in nanoparticle-based radiotherapy techniques.

Mechanical and Thermal Characteristics of Films from Glycerol Mixed Emulsified Carnauba Wax/Polyvinyl Alcohol

Poly(vinyl alcohol) (PVA)-based films have drawn significant attention owing to their potential applications in various industries. The application of wax to PVA films enhanced their resistance to dissolution and water infiltration. Nevertheless, waxed PVA films often exhibit inadequate mechanical properties owing to crack formation. In this study, we evaluated the impact of glycerol as a plasticizer in varying concentrations of Carnauba wax (CW). The addition of glycerol to the PVA/CW blend led to enhanced mechanical properties compared to the blend without glycerol. The functional group and morphology of the blends confirm glycerol compatibility with PVA/CW films. Glycerol was fully dispersed to form a consistent polymer matrix and equally improved the film’s contact angle. Furthermore, the thermal property from differential scanning calorimetry and thermogravimetric analysis highlights the plasticizing effect of glycerol in PVA/CW films, potentially broadening their use in food packaging and wrapping applications.

Effect of glycerin on the physical properties of polyvinyl alcohol/sodium alginate blend

Because of the abundance of sodium resources, sodium-ion batteries (NIBs) offer a promising alternative electrochemical energy storage solution. One of the current roadblocks to the development of NIBs technology is a lack of electrode materials capable of reversibly storing/releasing sodium ions for a sufficiently long time. Thus, this work aims to study, theoretically, the effect of glycerin incorporation on polyvinyl alcohol (PVA)/sodium alginate (Na Alg) blend as electrode materials for NIBs. The electronic, thermal, and quantitative structure-activity relationship (QSAR) descriptors of polymer electrolytes based on a blend of PVA and Na Alg and glycerin are the main topics of this work. These properties are examined here using semi-empirical methods and the density functional theory (DFT). Bandgap energy (Eg) is examined because the structural analysis reveals details regarding the interactions between PVA/Na Alg and glycerin. The findings indicate that the addition of glycerin caused the Eg value to drop to 0.2814 eV. The molecular electrostatic potential surface, or MESP, shows the electron-rich and deficit regions throughout the electrolyte system as well as the distribution of molecular charges. Thermal parameters that are studied include enthalpy (H), entropy (ΔS), heat capacity (Cp), Gibbs’ free energy (G), and heat of formation. Additionally, the study examines several QSAR descriptors, such as total dipole moment (TDM), total energy (E), ionization potential (IP), Log P, and Polarizability. The results show that H, ΔS, Cp, G, and TDM increased with increasing temperature and glycerin content. Meanwhile, heat of formation, IP, and E decreased, improving reactivity and polarizability. Additionally, the cell voltage increased to 2.488 V due to glycerin addition. The overall DFT and PM6 calculations of cost-effective PVA/Na Alg based glycerin electrolytes indicate that they can partially replace lithium-ion batteries due to their multifunctionality, but requires further improvement and investigations.

Production of bioplastic films from wild cocoyam (Caladium bicolor) starch

This study tackles the pressing environmental challenges resulting from the rapid and ongoing use of conventional plastics by investigating biodegradable alternatives derived from wild cocoyam starch. The bioplastics developed from various formulations, incorporating gelatin, glycerine, vegetable oil, and vinegar, were systematically evaluated for their mechanical, chemical, microstructural and biodegradability properties. The addition of glycerine and gelatin enhanced the moisture content and flexibility of the films while vegetable oil improved water resistance, reducing water absorption. Th sample that contains 3 g of gelatin and 3 ml of glycerine exhibited the best overall performance with a tensile strength of 6.5 MPa and an elongation at break of 77 %. This sample also achieved an impressive biodegradation rate of 70 % within 7 days. Scanning Electron Microscopy revealed a uniform and smooth morphology, while Fourier Transform Infrared Spectroscopy confirmed the presence of key functional groups responsible for the material's performance. These results establish wild cocoyam starch as a promising resource for producing biodegradable bioplastics with considerable potential in various industries, particularly in packaging and agricultural applications. The excellent mechanical properties and biodegradability of the materials along with its natural abundance, offer an eco-friendly solution to the plastic waste problem. The study also opens new avenues for optimizing bioplastic formulations to enhance specific properties like thermal stability and moisture resistance, further broadening their practical applications. This research contributes to the sustainable materials landscape and represents a step toward reducing reliance on fossil-based plastics, advancing the global effort to mitigate environmental pollution.

Exploring Deep Eutectic Solvents as Pharmaceutical Excipients: Enhancing the Solubility of Ibuprofen and Mefenamic Acid.

Objectives: The study explores the potential of various deep eutectic solvents (DESs) to serve as drug delivery systems and pharmaceutical excipients. The research focuses on two primary objectives: evaluating the ability of the selected DES systems to enhance the solubility of two poorly water-soluble model drugs (IBU and MFA), and evaluating their physicochemical properties, including density, viscosity, flow behavior, surface tension, thermal stability, and water dilution effects, to determine their suitability for pharmaceutical applications. Methods: A range of DES systems containing pharmaceutically acceptable constituents was explored, encompassing organic acid-based, sugar- and sugar alcohol-based, and hydrophobic systems, as well as menthol (MNT)-based DES systems with common pharmaceutical excipients. MNT-based DESs exhibited the most significant solubility enhancements. Results: IBU solubility reached 379.69 mg/g in MNT: PEG 400 (1:1) and 356.3 mg/g in MNT:oleic acid (1:1), while MFA solubility peaked at 17.07 mg/g in MNT:Miglyol 812®N (1:1). In contrast, solubility in hydrophilic DES systems was significantly lower, with choline chloride: glycerol (1:2) and arginine: glycolic acid (1:8) showing the best results. While demonstrating lower solubility compared to the MNT-based systems, sugar-based DESs exhibited increased tunability via water and glycerol addition both in terms of solubility and physicochemical properties, such as viscosity and surface tension. Conclusions: Our study introduces novel DES systems, expanding the repertoire of pharmaceutically acceptable DES formulations and opening new avenues for the rational design of tailored solvent systems to overcome solubility challenges and enhance drug delivery.

Highly efficient coke dust suppressant with anti-freezing capabilities

Stockpiled coke is prone to wind-blowing emissions, leading to economic losses and environmental pollution which imposes severe threats to human health. While various polysaccharide-based dust suppressants have been explored to resolve this issue, they often suffer from ineffective control of wettability, poor coverage, and suppression effect in extreme weather conditions, and require additional use of cross-linking agents and surfactants due to their weak interaction with coke. Herein, we present coke dust suppressants comprising polyethyleneimine (PEI), starch, and glycerol to address these shortcomings. Our detailed investigations show that the low toxicity, cationic polymer (PEI) electrostatically interacts with the coke, increasing the wettability and promoting aggregation. Moreover, PEI hydrogen-bonds with starch to form a stable film and enhances the water-retention capability. Furthermore, the addition of glycerol lowers the freezing point to −13 °C, preventing coke loss caused by freezing during transportation and energy loss associated with dismantling the frozen coke. Wind erosion tests and bomb calorimeter results reveal that the coke dust suppressant exhibits superior wind resistance and does not interfere with the coke combustion.

Cloning of Three Aflatoxin B1 Oxidases of the Dipeptidyl Peptidase III Family and Evaluation of Their Potential for Practical Applications as Decontamination Enzymes.

Aflatoxin B1 (AFB1) produced by some Aspergillus species belongs to the most dangerous contaminants of animal feeds. Development of safe and cost efficient decontamination methods saving feed quality and nutritional value are of paramount importance. The use of recombinant AFB1-detoxifying microbial enzymes represents a promising biotechnological approach meeting the aforementioned requirements. In this study, three AFB1-degrading oxidases (AFOs) from edible basidiomycetes Cantharellus cibarius, Lentinula edodes and Pleurotus eryngii as well as AFO from Armillaria tabescens were expressed in E. coli Rosetta (DE3) and purified by immobilized metal-chelate chromatography. The stabilizing effect of the addition of glycerol and β-mercaptoethanol during protein extraction is shown. The catalytic constants of the recombinant AFOs (rAFOs) and other characteristics, which might be important for their practical application (and optimal temperature and pH, thermolability, regulation of the activity by metal ions and chelating agents, storage stability) were investigated. Among the obtained enzymes, rAFO from P. eryngii (Pe-AFO), which was characterized by the highest specific activity, thermostability and pH stability (especially at acidic pH range), the lowest Km, and relative resistance to the inhibition by phytate, showed the best AFB1-degrading efficacy. However, Pe-AFO and all other rAFOs significantly decreased the target activity during heating above 45 °C, storage frozen or lyophilization.

Crystallinity Reconstruction of Squid-Pen Chitosan into Mechanically Robust and Multifunctional Bionanocomposite Food Packaging Film.

First, we explore the effect of bioacids on the film processing of preprocessed, i.e., deacetylated, chitosan (d-chitosan with molecular weight of 1,000,000 kDa), using monocarboxylic acid (acetic acid), dicarboxylic acid (malic acid), and tricarboxylic acid (citric acid) as model weak acidic solvents to destabilize the hydrogen bonding and transform crystal structures into film. Second, we investigate the chemical and physical toughening effect in the bionanocomposite film composed of cross-linkable multicarboxilic acid, i.e., succinic acid (SA). In doing so, the addition of glycerol as a plasticizer can increase polymer chain mobility, making the biocomposite film more ductile and flexible. The addition of CNC also enhances the tensile strength (41.6%), swelling (43.47%), and oxygen barrier properties (38.81%), as well as significantly improves UV light barrier. The excellent antibacterial properties (99.9% efficiency against S. aureus and K. pneumoniae) of the prepared biocomposite films are found to be independent of the presence of glycerol or CNC. Third, the development of film processability under an industrially relevant process is also demonstrated by doctor blade method. It is found that film processability of the squid-pen's chitosan bionanocomposite can straightforwardly be compatible with and improvable in the presence of poly(vinyl alcohol) employed as a model biodegradable processing aid.

A Study on Two-Phase Flow with High Viscosity and Low Surface Tension Liquid in a 40-Degree Inclined Mini Channel

There are numerous applications of two-phase flow in mini pipes, including electronics cooling systems, microreactors in the chemical industry, and material development and manufacturing. This application requires a thorough understanding and is supported by complete data and information. However, the data and information are currently limited. Experimental research has been carried out on flow patterns, void fractions, and two-phase flow pressure gradients in small pipes. This study aims to obtain primary data on the subject. Dry air and a mixture of 67% distilled water, 30% glycerin, and 3% butanol represent the gas and liquid phases, respectively. The addition of butanol and glycerin each aims to reduce surface tension and improve the viscosity of the liquid phase, respectively. The density, kinematic viscosity, and surface tension of the liquid were 1,080.4 kg/m3, 2,368 mm2/s, and 38.6 mN/m, respectively. The test section was a 1.6 mm diameter glass pipe equipped with an optical correction box. The gas superficial velocity (JG) ranged from 0.025 to 66.3 m/s, whereas liquid superficial velocity (JL) varied from 0.033 to 4.935 m/s. The experiment was conducted under adiabatic conditions. Plug, slug-annular, annular, disperse bubbly, and churn flow patterns emerged, while separated flow was not discovered. For plug, slug-annular, and dispersed bubbly flows, the increase of JG proportionally affected the void fraction. However, for churn and annular flows, no particular relationship existed between JG and void fraction due to the slip between the real velocities of the gas and the liquid. The pressure gradient rose as JG and JL increased.

Development of fish gelatin film for anti-fogging mushroom packaging

Mushrooms are extremely perspiring and transpiring commodities. The commonly used plastic films for packaging fresh mushrooms have lower water vapour permeability compared to the rate at which mushrooms transpire, resulting in excessive moisture accumulation inside the package which leads to fogging. This study aimed to investigate the properties of a fish scale gelatin-based film and its correlation with antifogging properties. To produce the gelatin-based film, gelatin was extracted from fish scales using chemical pretreatment and thermal denaturation of collagen. A film-forming solution (FFS) was prepared by dissolving 2% (w/v) gelatin in a solvent, with the addition of glycerol. The solution was then cast to form the film, which underwent tests for mechanical strength, thermal behaviour, barrier properties, and antifogging performance. The resulting film (G-Gly) exhibited reduced tensile strength (13.21 MPa) but increased elongation at break (82.4%). Differential scanning calorimetry revealed a lower glass transition temperature (59.91 °C) for G-Gly. Both gelatin films displayed high water vapour permeability (1.69–3.09x10-6 g m/m2.day.Pa), preventing condensation. Notably, the G and G-Gly films remained fog-free even under varying temperatures, unlike linear low-density polyethylene film (LLDPE). In conclusion, the gelatin-based films demonstrated strong barrier properties and effective antifogging capabilities, making them suitable for moisture-sensitive commodities like mushrooms.

Effect of Corn Starch and Glycerol Additions on the Characteristics of Capsule Shells from Seaweed Carrageenan

Effect of Corn Starch and Glycerol Additions on the Characteristics of Capsule Shells from Seaweed Carrageenan

Development and characterization of chitosan film incorporated with additives glycerol and gel for biodegradable packaging

Development and characterization of chitosan film incorporated with additives glycerol and gel for biodegradable packaging

Evidence of isochorismate channeling between the Escherichia coli enterobactin biosynthetic enzymes EntC and EntB.

Enterobactin is a high-affinity iron chelator produced and secreted by Escherichia coli and Salmonella typhimurium to scavenge scarce extracellular Fe3+ as a micronutrient. EntC and EntB are the first two enzymes in the enterobactin biosynthetic pathway. Isochorismate, produced by EntC, is a substrate for EntB isochorismatase. By using a competing isochorismate-consuming enzyme (the E. coli SEPHCHC synthase MenD), we found in a coupled assay that residual EntB isochorismatase activity decreased as a function of increasing MenD concentration. In the presence of excess MenD, EntB isochorismatase activity was observed to decrease by 84%, indicative of partial EntC-EntB channeling (16%) of isochorismate. Furthermore, addition of glycerol to the assay resulted in an increase of residual EntB isochorismatase activity to approximately 25% while in the presence of excess MenD. These experimental outcomes supported the existence of a substrate channeling surface identified in a previously reported protein-docking model of the EntC-EntB complex. Two positively charged EntB residues (K21 and R196) that were predicted to electrostatically guide negatively charged isochorismate between the EntC and EntB active sites were mutagenized to determine their effects on substrate channeling. The EntB variants K21D and R196D exhibited a near complete loss of isochorismatase activity, likely due to electrostatic repulsion of the negatively charged isochorismate substrate. Variants K21A, R196A, and K21A/R196A retained partial EntB isochorismatase activity in the absence of EntC; in the presence of EntC, isochorismatase activity in all variants increased to near wild-type levels. The MenD competition assay of the variants revealed that while K21A channeled isochorismate as efficiently as wild-type EntB (~ 15%), the variants K21A/R196A and R196A exhibited an approximately 5-fold loss in observed channeling efficiency (~3%). Taken together, these results demonstrate that partial substrate channeling occurs between EntC and EntB via a leaky electrostatic tunnel formed upon dynamic EntC-EntB complex formation and that EntB R196 plays an essential role in isochorismate channeling.

Electrohydrodynamic Printing of Biodegradable PLGA Micro‐Patterns on 3D Polymer Structures

AbstractBiodegradable polymers such as polylactic‐co‐glycolic acids (PLGA) are used for various implantable devices such as tissue scaffolds, drug delivery devices, and biosensors in different forms. However, high‐resolution patterning of biodegradable polymers on implantable devices has not been explored much yet. While electrohydrodynamic printing (EHD) can achieve high‐resolution printing compared to other printing methods, EHD printing of PLGA solutions is rarely attempted due to unstable printing. Such printing instability originates from the volatile nature of PLGA inks, and it causes nozzle clogging or change of ink conditions during printing. Here, PLGA ink formulation and a voltage input profile are studied for stable and high‐resolution EHD printing. Addition of glycerol at an optimal ratio as well as the control of voltage pulse shape strongly influenced both the stability and resolution of EHD printing of PLGA patterns. With the optimized inks and voltage inputs, stable printing of PLGA micropatterns down to 5 µm is achieved on both conductive and insulating surfaces for controlled drug release. Furthermore, use of a ring type electrode allows for EHD printing of PLGA micropatterns on 3D surfaces of PLLA tubes and stent struts.

Production, purification, characterization, and safety evaluation of constructed recombinant D-psicose 3-epimerase

BackgroundD-psicose 3-epimerase (DPEase) is a potential catalytic enzyme for D-psicose production. D-psicose, also known as D-allulose, is a low-calorie sweetener that has gained considerable attention as a healthy alternative sweetener due to its notable physicochemical properties. This research focused on an in-depth investigation of the expression of the constructed DPEase gene from Agrobacterium tumefaciens in Escherichia coli for D-psicose synthesis. Experimentally, this research created the recombinant enzyme, explored the optimization of gene expression systems and protein purification strategies, investigated the enzymatic characterization, and then optimized the D-psicose production. Finally, the produced D-psicose syrup underwent acute toxicity evaluation to provide scientific evidence supporting its safety.ResultsThe optimization of DPEase expression involved the utilization of Mn2+ as a cofactor, fine-tuning isopropyl β-D-1-thiogalactopyranoside induction, and controlling the induction temperature. The purification process was strategically designed by a nickel column and an elution buffer containing 200 mM imidazole, resulting in purified DPEase with a notable 21.03-fold increase in specific activity compared to the crude extract. The optimum D-psicose conversion conditions were at pH 7.5 and 55 °C with a final concentration of 10 mM Mn2+ addition using purified DPEase to achieve the highest D-psicose concentration of 5.60% (w/v) using 25% (w/v) of fructose concentration with a conversion rate of 22.42%. Kinetic parameters of the purified DPEase were Vmax and Km values of 28.01 mM/min and 110 mM, respectively, which demonstrated the high substrate affinity and efficiency of DPEase conversion by the binding site of the fructose-DPEase-Mn2+ structure. Strategies for maintaining stability of DPEase activity were glycerol addition and storage at -20 °C. Based on the results from the acute toxicity study, there was no toxicity to rats, supporting the safety of the mixed D-fructose–D-psicose syrup produced using recombinant DPEase.ConclusionsThese findings have direct and practical implications for the industrial-scale production of D-psicose, a valuable rare sugar with a broad range of applications in the food and pharmaceutical industries. This research should advance the understanding of DPEase biocatalysis and offers a roadmap for the successful scale-up production of rare sugars, opening new avenues for their utilization in various industrial processes.

Dietary Supplementation of Crossbred Pigs with Glycerol, Vitamin C, and Niacinamide Alters the Composition of Gut Flora and Gut Flora-Derived Metabolites.

The addition of glycerin, vitamin C, and niacinamide to pig diets increased the redness of longissimus dorsi; however, it remains unclear how these supplements affect gut microbiota and metabolites. A total of 84 piglets (20.35 ± 2.14 kg) were randomly allotted to groups A (control), B (glycerin-supplemented), C (vitamin C and niacinamide-supplemented), and D (glycerin, vitamin C and niacinamide-supplemented) during a feeding experiment. Metagenomic and metabolomic technologies were used to analyze the fecal compositions of bile acids, metabolites, and microbiota. The results showed that compared to pigs in group A, pigs in group D had lower virulence factor expressions of lipopolysaccharide (p < 0.05), fatty acid resistance system (p < 0.05), and capsule (p < 0.01); higher fecal levels of ferric ion (p < 0.05), allolithocholic acid (p < 0.01), deoxycholic acid (p < 0.05), tauroursodeoxycholic acid dihydrate (p < 0.01), glycodeoxycholic acid (p < 0.05), L-proline (p < 0.01) and calcitriol (p < 0.01); and higher (p < 0.05) abundances of iron-acquiring microbiota (Methanobrevibacter, Clostridium, Clostridiaceae, Clostridium_sp_CAG_1000, Faecalibacterium_sp_CAG_74_58_120, Eubacteriales_Family_XIII_Incertae_Sedis, Alistipes_sp_CAG_435, Alistipes_sp_CAG_514 and Methanobrevibacter_sp_YE315). Supplementation with glycerin, vitamin C, and niacinamide to pigs significantly promoted the growth of iron-acquiring microbiota in feces, reduced the expression of some virulence factor genes of fecal pathogens, and increased the fecal levels of ferric ion, L-proline, and some secondary bile acids. The administration of glycerol, vitamin C, and niacinamide to pigs may serve as an effective measure for muscle redness improvement by altering the compositions of fecal microbiota and metabolites.

Chitosan Extracted from the Biomass of Tenebrio molitor Larvae as a Sustainable Packaging Film.

Waste from non-degradable packaging materials poses a serious environmental risk and has led to interest in developing sustainable bio-based packaging materials. Sustainable packaging materials have been made from diverse naturally derived materials such as bamboo, sugarcane, and corn starch. In this study, we made a sustainable packaging film using chitosan extracted from the biomass of yellow mealworm (Tenebrio molitor) shell waste. The extracted chitosan was used to create films, cross-linked with citric acid (CA) and with the addition of glycerol to impart flexibility, using the solvent casting method. The successful cross-linking was evaluated using Fourier-Transform Infrared (FTIR) analysis. The CA cross-linked mealworm chitosan (CAMC) films exhibited improved water resistance with moisture content reduced from 19.9 to 14.5%. Improved barrier properties were also noted, with a 28.7% and 10.2% decrease in vapor permeability and vapor transmission rate, respectively. Bananas were selected for food preservation, and significant changes were observed over a duration of 10 days. Compared to the control sample, bananas packaged in CAMC pouches exhibited a lesser loss in weight because of excellent barrier properties against water vapor. Moreover, the quality and texture of bananas packaged in CAMC pouch remained intact over the duration of the experiment. This indicates that adding citric acid and glycerol to the chitosan structure holds promise for effective food wrapping and contributes to the enhancement of banana shelf life. Through this study, we concluded that chitosan film derived from mealworm biomass has potential as a valuable resource for sustainable packaging solutions, promoting the adoption of environmentally friendly practices in the food industry.

Pyrolysis characteristics of different types of tobacco and its correlation with the released aroma components under heating condition

An in-depth insight into the pyrolysis characteristics of tobacco is of great significance for the utilization of tobacco wastes. The effects of glycerol addition on the pyrolysis characteristics and distribution of aroma components of four types of tobacco was investigated in this study by using thermogravimetry and self-built rapid heating furnace capture and GC-MS analysis. Further, correlation network analysis was used to study the correlation between pyrolysis characteristics and released aroma components. It was found that the thermal weight loss behavior of different samples exhibited both commonalities and differences, the thermal weight loss process could be divided into four stages. After the application of glycerol, the overall performance of all types of tobacco leaves at stage II showed that DTGmax2 and WL2 increased, and glycerol had a relatively obvious effect on the pyrolysis characteristic parameters of flue-cured tobacco. Pyrolysis kinetic analysis based on Coats-Redfern method showed that the activation energy and pre-exponential factor of tobacco samples were decreased after the addition of glycerol. Under the heating condition, the total amount of released aroma components from each type of tobacco followed the order of burley tobacco > flue-cured tobacco >oriental tobacco > yellow sun-cured tobacco. The release amount of heterocyclic and olefins compounds from burley tobacco were higher, while flue-cured tobacco released higher contents of esters, ketones and furans compounds. The addition of glycerol promoted the release of aroma components. In terms of correlation, Tmax2 was negatively correlated with esters, aldehydes, and furans compounds, and positively correlated with DTGmax3. Tmax3 was significantly correlated with a lot of indicators, positively with acids, aldehydes, and furans compounds, but negatively with olefins and heterocyclic compounds.

3D printing of glycerol-mediated alginate hydrogels with high strength and stiffness

As a biomass material with biodegradability and biocompatibility, sodium alginate (SA) is a good candidate for constructing hydrogels for tissue-mimicking and biomedical scaffold fabricating through extrusion-based 3D printing technology. However, the mechanical strength and stiffness of alginate hydrogels are still not comparable with biological tissues such as tendons and the printability of SA solutions is often poor. Here, a novel strategy for 3D printing of alginate hydrogels with high mechanical performance is developed by using glycerol as a co-solvent for SA solutions. The addition of glycerol (GL) enables the formation of a homogenous SA/GL solution with a high solid content of 12–20 wt.% and endows crosslinked SA hydrogels with high stretchability. By applying uniaxial stretches, hydrogel filaments prepared with concentrated SA/GL solutions reveal a high tensile strength of 36.6–161.3 MPa, Young's modulus of 59.2–1964.2 MPa, and elongation at break of 8.5 %–106.2 % due to the high orientated and closely packed SA chains. SA/GL solutions become more solid-like with increasing SA concentration, and the solution with a solid content of 16 wt.% exhibits optimal 3D printability because of the appropriate rheological properties and thixotropic behavior. By designing the deforming-and-fixing process, 3D printed high-strength alginate hydrogels with complex structures are prepared, broadening the application of alginate hydrogels in load-bearing and biomedical fields.

The role of glycerol in manufacturing freeze-dried chitosan and cellulose foams for mechanically stable scaffolds in skin tissue engineering

Various strategies have extensively explored enhancing the physical and biological properties of chitosan and cellulose scaffolds for skin tissue engineering. This study presents a straightforward method involving the addition of glycerol into highly porous structures of two polysaccharide complexes: chitosan/carboxymethyl cellulose (Chit/CMC) and chitosan/oxidized cellulose (Chit/OC); during a one-step freeze-drying process. Adding glycerol, especially to Chit/CMC, significantly increased stability, prevented degradation, and improved mechanical strength by nearly 50%. Importantly, after 21 days of incubation in enzymatic medium Chit/CMC scaffold has almost completely decomposed, while foams reinforced with glycerol exhibited only 40% mass loss. It is possible due to differences in multivalent cations and polymer chain contraction, resulting in varied hydrogen bonding and, consequently, distinct physicochemical outcomes. Additionally, the scaffolds with glycerol improved the cellular activities resulting in over 40% higher proliferation of fibroblast after 21 days of incubation. It was achieved by imparting water resistance to the highly absorbent material and aiding in achieving a balance between hydrophilic and hydrophobic properties. This study clearly indicates the possible elimination of additional crosslinkers and multiple fabrication steps that can reduce the cost of scaffold production for skin tissue engineering applications while tailoring mechanical strength and degradation.