Mixture Of Chitosan Research Articles

Effect of Incorporating Chitosan to Resin Modified Glass Ionomer Cement on Shear Bond Strength to Dentin (An In vitro Comparative Study).

Resin-modified glass ionomer cement tends to shrink due to polymerization of the resin component. Additionally, they are more prone to syneresis and imbibition during the setting process. This in vitro study evaluates the impact of chitosan, a biopolymer that is, both biomaterial and biocompatible, on the strength of dentin bonding and compares it with ACTIVA Bio-ACTIVE Restorative. The present study was aimed to assess the impact of including chitosan into Fuji II on the shear bond strength between. the restoration material and tooth dentin, in contrast to Bioactiva in permanent teeth. A total of 30 premolar teeth were recently extracted. The study involved three distinct sample groups. Group 1 (10 teeth) is the negative control (Fuji II), Group 2 (10 teeth) is the positive control (ACTIVA Bio-ACTIVE Restorative), and Group 3 (10 teeth) is treated with a mixture of Chitosan and Fuji II (CH-Fuji II). Each tooth's buccal and palatal cusps were eliminated to achieve a horizontal surface. Using a periodontal probe, 1.5 mm from the mesial pit to the mesial marginal ridge were removed. Restoration was implemented in all groups following manufacturer directions. Thermocycling the teeth by immersing them in a water bath with temperatures ranging from 5°C to 55°C (± 1-2°C) for 30 s (500 cycles). Each sample was attached to the universal testing machine's jig at a cross-head speed of 1 mm/min. Shear force was used until breakage, and the bond's adhesive strength was then calculated. Statistical analysis using ANOVA with Dunnett's T3 post hoc test. Results were significant at P < 0.05. Statistically significant difference was present between Chitosan and Fuji II and between Chitosan and Activa by reducing the shear bond strength. Addition of chitosan to Fuji II had a negative effect on the shear bond with a significant difference while Activa and Fuji II exhibited favorable shear bond strength.

Advancing oral health: Harnessing the potential of chitosan and polyphenols in innovative mouthwash formulation

This paper explores the therapeutic perspectives of polyphenols and chitosan as potential anticancer agents in the mouthwash formulations. Taking into account the high incidence of squamous cell carcinoma (SCC) among oral cancers, this discussion will concentrate on the potential advantages of these compounds in oral care, focusing on their impact on improving oral health and cancer prevention. According to the data, it appears that the mixture of BACs extract and chitosan may increase the efficiency of the apoptosis of cancer cells while reducing the undesired side effects. The cytotoxicity assays demonstrate a significant reduction in squamous carcinoma cell viability after incubation with BACs extract, with a marked decrease observed over 24–72 hours up to 76%. The anti-cancer properties of the BAC extract are related to luteolin, which is a predominant compound. The addition of 0.025% chitosan reduced the metabolic activity of cancer cells by 37.5%, suggesting a synergistic interaction between the compounds. This research highlights the potential of BACs and chitosan in modulating important molecular targets associated with cancer cell.

A NEW NATURAL FOOD DYE: MICROENCAPSULATED CORNELIAN CHERRY BIOACTIVE COMPOUNDS

Cornus mas (CM) is one of the four edible fruits of the Cornus genus, a rich source of biologically active compounds (BACs) such as vitamins (like vitamin C), carotenoids, iridoids, and phenolics (phenolic acids, anthocyanins, and other flavonoids). This study aimed to analyse the improvement of the stability of CM anthocyanins by microencapsulation, in order to propose a new natural food dye. Microencapsulation using a mixture of whey protein isolate (WPI) and chitosan (CH) as wall materials has been applied to protect anthocyanins against external factors (e.g., light, temperature, storage, etc.). Two experimental variants of microencapsulated powders, WPI:CH = 1:1 (CH1) and WPI:CH = 1:2 (CH2), were realised by varying the wall materials ratio. The cornelian cherry fruit concentrated extract was evaluated for its phytochemical, colourimetric, and antioxidant capacities. Due to the excellent anthocyanin encapsulation effectiveness (74.29 – 88.71%), the wall materials utilised for both powders can be considered effective choices to safeguard the anthocyanins. All tests performed on the microencapsulated powders demonstrated that both suggested experimental forms can serve as a healthy substitute for artificial food additives. The incorporation of cornelian cherry fruit extract and microencapsulated powders into a food matrix (jelly candies) allowed examination of their effectiveness. The colour analysis rigorously characterised all the colour parameters related to red nuances (due to anthocyanins content, such as cyanidin-3-glucoside) and yellow nuances (associated with carotenoids content).

Degradation of chitosan–gelatin and chitosan–gelatin–β-tricalcium phosphate scaffolds

Background: Fabrication of the composite scaffold was carried out by combining chitosan, gelatin, and β-tricalcium phosphate (βTCP) derived from limestone. The extraction of βTCP was based on the abundance of limestone containing calcium carbonate, which can be a source of βTCP synthesis. Purpose: This study evaluates the degradation of the combination of chitosan–gelatin (ChG) and chitosan–gelatin–βTCP (ChG-βTCP) composite scaffolds. Methods: The freeze-drying method was used to obtain the composite scaffold, which was a mixture of chitosan, gelatin, and βTCP. Degradation was measured by immersing the samples in a simulated body fluid solution at 37°C for 3, 7, 14, and 21 days. For statistical analysis, one-way analysis of variance (ANOVA) and post hoc Fisher’s least significant difference were performed. Results: The ChG scaffold shows better degradability than the ChG-βTCP scaffold. The ChG scaffold shows higher weight degradation than the ChG-βTCP scaffold up to 21 days. Conclusion: In conclusion, the scaffold containing βTCP has lower degradation than the ChG scaffold.

Functionalization of Technical Textiles with Chitosan

Textiles are used for many different applications and require a variety of properties. Wet functionalization improve textiles’ properties, such as hydrophilicity or antimicrobial activity. Chitosan is a bio-based polymer widely investigated in the textile industry for this purpose. A weaving comprising a cotton/polyester mix and a pure-polyester weaving was functionalized with different concentrations of chitosan to determine the most robust method for chitosan detection in both cotton- and polyester-containing materials. Additionally, mixtures of chitosan with 3-glycidyloxypropyltriethoxy silane (GLYEO) or 3-aminopropyltriethoxy silane (AMEO) were applied in a one-step or two-step procedure on the same fabrics. Scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS) and dyeing with Remazol Brilliant Red F3B demonstrated the presence of chitosan and silanes on the textiles’ surfaces. While non-functionalized textiles were not stained, the dependency of the dyeing depths on the chitosan concentrations enabled us to infer the efficacy of the very short processing time and a mild dyeing temperature. The one-step application of AMEO and chitosan resulted in the highest presence of silicon on the textile and the greatest color intensity. The functionalization with GLYEO reduced the water sink-in time of polyester, while chitosan-containing solutions increased the hydrophobicity of the material. Washing experiments demonstrated the increasing hydrophilicity of the cotton/polyester samples, independent of the type of functionalization. These experiments show that chitosan-containing recipes can be used as part of a useful method, and the type of functionalization can be used to adjust the hydrophilic properties of polyester and cotton/polyester textiles. Via this first step, in the future, new combinations of bio-based polymers with inorganic binder systems can be developed, ultimately leading to sustainable antimicrobial materials with modified hydrophilic properties.

Therapeutic Effects of Esomeprazole, Curcumin, Chitosan, and Curcumin-Chitosan Mixture on Ethanol-Induced Gastric Ulcer in Female Rats

Introduction: Gastric ulcer (GU) is a prevalent health issue linked to alcohol consumption, smoking, and physiological stress. This study aims to assess the therapeutic effects of esomeprazole (40 mg), curcumin (40 mg/kg), chitosan (150 mg/kg), and a mixture of curcumin (40 mg/kg) and chitosan (150 mg/kg) on ethanol-induced gastric ulcers in female rats. Method: The study involved 30 female rats with an average weight ranging from 179.1 to 180.3 gm. Rats were divided into two control groups and four treated groups (esomeprazole, curcumin, chitosan, and mixture), each containing 5 rats. Gastric ulcers were induced by orally administering 2 ml of absolute ethanol to All groups, except the negative control, after a 19-hour fasting period. Therapeutic effects were evaluated by assessing gastric juice volume and pH, ulcer index, curative index, and through morphological and histological examination of the stomach. Results: The study revealed a significant decrease (p≤0.05) in body weight percentage change in the curcumin-treated group compared to the positive control. Esomeprazole, chitosan, and the mixture showed mixture showed no significant change (p&gt;0.05). Additionally, esomeprazole, curcumin, chitosan, and the mixture demonstrated a significant decrease (p≤0.05) in ulcer index and gastric juice volume, with a significant increase (p≤0.05) in pH compared to the positive control. Conclusion: In conclusion, esomeprazole, chitosan, and the mixture demonstrated notable protective effects and therapeutic effects by reducing ulcer index and gastric juice volume in ethanol-induced gastric ulcers in female rats.

Encapsulation of grape seed oil in oil-in-water emulsion using multilayer technology: Investigation of physical stability, physicochemical and oxidative properties of emulsions under the influence of the number of layers

Many studies have shown that grape seed oil (GSO) is one of the vegetable fats that are plentiful in essential fatty acids and can be used as a fat substitute or to modify fat in food products to reduce saturated fatty acids. However, due to its low solubility and high sensitivity to oxidation, it is necessary to develop delivery systems that can distribute GSO in food more effectively. Recently, the preparation of emulsions using the layer-by-layer (LBL) method has many advantages in delivering lipid-soluble functional compounds. This research was used to check the formation of GSO oil-loaded primary, secondary and tertiary multilayer emulsions stabilized by mixture of anionic gelatin, cationic chitosan, and anionic basil seed gum (BSG) as the aqueous phase at pH 5, prepared using a layer-by-layer electrostatic deposition technique. Multilayer emulsions prepared by GSO and a mixture of gelatin, chitosan, and BSG as the aqueous phase at pH 5. Finally, the effect of the number of layers on the physicochemical properties (particle size, viscosity, turbidity, refractive index, and physical stability) and oxidative stability (peroxide value, thiobarbituric acid value, and fatty acid profile) during the storage time (30 days) at two temperatures 25 °C & 4 °C was investigated. Also, the zeta potential and Fourier transform infrared spectroscopy (FTIR) of mono-layer and multi-layer emulsions were investigated. The results revealed that by increasing the number of layers of multi-layer emulsion of GSO, the stability has improved. Thus, the tertiary emulsion has been more effective than the other two emulsions in maintaining the physicochemical characteristics and stability over time (P < 0.001). Morphological characterization and FTIR spectroscopy results confirmed that gelatin, chitosan, and BSG were successfully loaded into the LBL emulsions. This study can improve the original percept of multilayer emulsions and promulgate their potential applications for the entire encapsulation of essential fatty acids to enrich and prevent peroxide attack.

Chitosan/Alginate nanocomposites containing magnetic nanoparticles and multi-wall carbon nanotubes for efficient iron sorption

The widespread presence of iron pollution in groundwater is a major global worry, as increased levels can lead to severe health hazards. To tackle this urgent problem, we engaged in a synthesis procedure where magnetic nanoparticles (MNPs) and multi-wall carbon nanotubes (CNTs) were combined with a mixture of chitosan (CS) and sodium alginate (Alg) to produce a magnetic composite material. This novel composite, known as CS/Alg/MNPs/CNTs, was crafted with the primary aim of effectively removing iron from groundwater through adsorption. A thorough physicochemical analysis using FTIR, SEM, PSA, XRD, DSC, and TGA confirmed the composition's characteristics. The study delved into the influence of parameters such as retention time, sorbent dose, initial Fe concentration, pH, agitation rate, and temperature on the adsorption process. The Langmuir isotherm model fittingly represented the adsorption data, indicating a monolayer coverage of 12.43 mg/g and aligning with the pseudo-second-order kinetic model. Additionally, the adsorption of iron ions by the composite material was identified as a endothermic process. Furthermore, the study highlights the sorption process's inherent spontaneity and survivability, as demonstrated by the negative ΔG value. In conclusion, the results of this study indicate that the magnetic composite adsorbent (CS/Alg/MNPs/CNTs) holds considerable promise for effectively removing iron ions from groundwater, making it a viable and attractive choice for use in water purification applications.

Formulation and Characterization of Blend Microspheres of Anti Diabetic Drug Glimepiride

The objective of the present investigation was to prepare polymeric blend microspheres of glimepiride for improving its half-life using chitosan and gelatin as the two polymers for preparing the blend. The blend microspheres of chitosan and gelatin were prepared by using different ratios of both the polymers as well as cross-linking agent, glutaraldehyde (GA), by emulsion cross-linking method. The optimum formulation was one which exhibited the lowest particles size and it was used to load glimepiride (20% by weight) of the polymers. The glimepiride loaded blend microspheres were evaluated for yield, drug polymer interaction, entrapment efficiency, surface study and in vitro release. The particle size of the blend microspheres was found to be in the range of 126.8 µm to 371.3 µm. The lowest particle size (126.8 ± 6.11 µm) was obtained in AF5 containing 50% of gelatin and 50% of chitosan. The FTIR spectra of the physical mixture of glimepiride, gelatin and chitosan displayed all the characteristic peaks of glimepiride, thus indicating that no incompatibility was present between the drug and the polymer. The SEM image of the drug loaded blend microsphere revealed spherical particles of irregular size with smooth surface. The average particles size of the glimepiride loaded blend microspheres was obtained to be 131.4 ± 9.7 µm with a yield of 91.6% by weight of the drug and polymers used for formulation of the microspheres. It was found that 82.4 ± 6.8% of glimepiride was found to be entrapped in the particles. The results of the in vitro release studies of the glimepiride loaded blend microsphere revealed that 71.49 ± 0.74 % glimepiride was released from the particles at the end of 12th hour of study.

Synthesis of chitosan based new material for recovery of Pt (IV)

In this study a new type of adsorbent bead precursor was reached using chitosan and pretreated clay. The pretreated clay was produced from the clay of the "Tsogt-Ovoo" deposit in the Umnugovi province of Mongolia. It was produced by acid and heat treatment to remove its mechanical impurities. The mixtures of chitosan and pretreated clay were taken with various ratios (8:1, 8:2, and 8:3) for chemical processing to obtain a chitosan-based adsorbent bead for recovery of (Pt(IV)) from aqueous solution. It was examined that the adsorption capacity of the adsorbent bead when the chitosan and pretreated clay mass ratio 8:2 was the highest for platinum ion (Pt (IV)). The adsorption properties of Pt (IV) were studied depending on the solution pH, contacting time, temperature, initial concentration of platinum ion solution, and amount of adsorbent material. The adsorption efficiency was the highest (93.29%) when the initial concentration of the platinum ion was 50 mg/l at the following condition; pH=3, temperature 250C, time 3 hours, and the amount of the adsorbent material 0.1 g. It represents that the chitosan clay bead can be applied for the recovery of platinum (Pt (IV)) from aqueous solution.

PFAS-Free Carbon Electrodes for Efficient Micropollutants Removal through Heterogeneous Electro-Fenton: From Material Synthesis to Module Design

Emerging micropollutants (MPs) in water bodies such as pharmaceuticals, pesticides, personal care products, and per-and poly-fluoroalkyl substances (PFAS) have posed environmental, ecological, and anthropological issues since MPs are too persistent to be degraded by conventional biological treatment. On the other hand, electrochemical advanced oxidation processes (EAOPs) have proved themselves as efficient and robust techniques to unselectively degrade MPs by forming OH radicals (•OH). Among EAOPs, electro-Fenton, or more specifically heterogeneous electro-Fenton (HEF), suggests an eco-friendly and energy-efficient treatment technique with a wide pH range for removing persistent MPs. In HEF, hydrogen peroxide (H2O2) is electrochemically produced on the cathode surface, which can react with immobilized, adjacent Fe catalysts for •OH generation. Yet, one challenge for HEF is that most of the studies have primarily focused on synthesizing Fe-containing carbons as a catalyst that suffers from several delicate preparation steps, which are time-, chemical-, and energy-consuming and lack reusability over consecutive runs [1].Additionally, these catalysts are usually powders, entailing adding polymeric binders for the immobilization of the catalyst layer on electrodes. The presence of polymeric binders, e.g., polytetrafluoroethylene (PTFE)—as PFAS-containing compounds on the electrode surface—enhances the risk of PFAS contamination during the HEF process due to mechanical wear-off or degradation under the harsh oxidative condition caused by the formation of unselective •OH. Therefore, developing PFAS-free carbon electrodes for the HEF process offering facile fabrication and good reusability with a scaling-up perspective is imperative to enable decentralized solutions for MPs removal, especially highly recalcitrant PFAS. In this work, freestanding carbons made of bio-based precursors, chitosan and sucrose, serve as electrodes for the HEF process. Chitosan is the backbone for the self-standing feature and a nitrogen-rich biopolymer, while sucrose serves as a carbon-rich compound. The mixture of chitosan and sucrose undergoes silica- and ice-templating to make a hierarchically porous carbon [2]. Bio-based carbons illustrated their capability for oxygen reduction reactions, particularly the electro-generation H2O2 [3]. As-synthesized carbons proved to remove carbamazepine and sulfamethoxazole as two persistent MPs at pH 3 and pH 7 [3]. Moreover, a novel flow-through electrolysis module equipped with as-synthesized carbons has been designed and operated to remove 20 mg/L CBZ solution at a current density of 20 mA/cm2. This module design demonstrates the ease of scaleup for a decentralized water/wastewater treatment unit to remove highly recalcitrant MPs.

Effect of carrageenan addition on the characteristic of chitosan-based bioplastic

Synthetic plastic is a product that widely used in daily life. However, the use of plastic has a negative impact that is very difficult to decompose by nature, so it is necessary to find other alternatives by switching to bioplastics. Chitosan is a polysaccharide that can be used as raw material for bioplastics because of its good plastic-forming ability. On the other hand, it has poor elasticity so it is necessary to add carrageenan which can improve the mechanical properties of bioplastics. The purpose of this research is to determine the characteristics of bioplastics made from a mixture of chitosan and carrageenan. The concentration of chitosan used was 2%, glycerol was 0.5%, and carrageenan concentrations were varied from 0%, 0.25%, 0.5%, 0.75%, and 1%. Characteristic tests carried out were film thickness, density, moisture content, solubility, tensile strength, elongation, FTIR, and antibacterial activity. The result showed that the addition of 0.5% of carrageenan resulted in better bioplastic with film thickness of 0.06 mm, density of 0.85 g/cm3, water content of 17.27%, solubility of 36.89%, the tensile strength of 13.72 mPa, the elongation of 46.03%, inhibition zone of the antibacterial activity of 2.66 mm and a new group is formed in the FTIR test.

Physical Properties and Release Profiles of Chitosan Mixture Films Containing Salicin, Glycerin and Hyaluronic Acid

Chitosan (CS) has gained considerable attention due to its distinctive properties and its broad spectrum of potential applications, spanning cosmetics, pharmaceuticals, and biomedical uses. In this study, we characterized thin films comprising chitosan mixtures containing salicin (SAL) and glycerin (GLY), both with and without hyaluronic acid (HA) as active ingredients. Characterization was achieved through release studies of SAL, infrared spectroscopy, microscopy techniques (AFM and SEM), and thermogravimetric analysis (TGA). CS/GLY/SAL and CS/GLY/SAL/HA mixture films were fabricated using the solvent evaporation technique. We probed interactions between the components in the chitosan mixtures via infrared analysis. The concentration of released salicin was monitored at various time intervals in a phosphate buffer (PBS) at pH 5.5 using HPLC. The linear regression analysis for the calibration graph showed a good linear relationship (R2 = 0.9996) in the working concentration range of 5–205 mg/dm3. Notably, the release of SAL reached its peak after 20 min. Furthermore, the introduction of HA caused changes in the films’ morphology, but their roughness remained largely unchanged. The results obtained were compared, indicating that the release of SAL in the CS mixture films is sufficient for diverse applications, including wound-healing materials and cosmetic beauty masks.

Polydopamine modified cerium-based MOFs/ chitosan aerogel beads for the efficient phosphate removal

The metal organic frameworks (MOFs) are considered as the effective adsorbents for phosphate removal, while their ultrafine powders limit their practical application. In this study, we fabricate two chitosan (CS) gel beads added with different cerium-based MOFs and coated with PDA for phosphate adsorption. The MOFs doped in beads are CM1 and CM2, in which the Ce(III)/Ce(IV) ratio is 0.36 and 1.46, indicating CM2 is Ce(III) dominated and more suitable for phosphate removal. However, during the process of preparing gel beads, the mixture of chitosan and CM1/CM2 are added drop-by-drop to NaOH solution, leading to the decrease of Ce(III) contents in both of the two beads on account of oxidization. On this basis, in order to improve the phosphate uptake performance and enhance the mechanical strength, polydopamine (PDA) is applied to be coated on the outside. The adsorption capacities of CS-CM1 and CS-CM2 are no more than 20 mg/g higher than that of pure CS, which is also quite equal with the phosphate uptake of CS@PDA (63 mg/g). Due to the reduction of PDA, the content of Ce(III) increasing evidently in the two adsorbents. The maximum phosphate adsorption capacities are 146.8 mg/g and 114.8 mg/g for CS-CM1@PDA and CS-CM2@PDA, respectively. CS-CM2@PDA exhibits the largest treatment volume of ∼1166 BV in the fix-bed column study, much higher than that of CS-CM1@PDA (976 BV). The main reason is that Ce(III) could form binding with phosphate through ligand exchange and precipitation. Those inner-sphere interactions are much stronger than the electrostatic attraction between Ce(IV) and phosphate. Thus, due to this strong affinity, CS-CM2@PDA possessing a higher content of Ce(III) can capture phosphate more easier at low concentration. In summary, owing to reduction of PDA, the Cerium-based MOFs are successfully introduced in CS to realize excellent phosphate removal and exhibit a great prospect in application.

Iron-loading N and S heteroatom doped porous carbon derived from chitosan and CdS-Tetrahymena thermophila for peroxymonosulfate activation

Transforming waste into resources is an important strategy to enhance the economic efficiency and reduce the waste entering the environment. In this work, iron-loading N and S co-doped porous carbon materials, as peroxymonosulfate (PMS) activator for pollutants degradation, were prepared by pyrolysis of the mixture of iron loading chitosan and CdS-Tetrahymena thermophila under N2 flow. Chitosan is mainly derived from the shell waste of shrimp and crab, and CdS-Tetrahymena thermophila is produced in the removing process of Cd2+ pollution bioremediation using Tetrahymena thermophila. The synergistic effects of iron related species and heteroatoms (S/N) co-doped porous carbon in the obtained carbon materials improved the performance for activating PMS. The prepared Fe-S-CS-1-900 exhibited high performance for the degradation of Rhodamine B (RhB) by activating PMS. Radical quenching tests and electron paramagnetic resonance measurements suggested that superoxide radical (O2−) and singlet oxygen (1O2) were the primary reactive oxygen species in RhB degradation. These results propose new insights of using biomass waste to derive Fe-loading N and S heteroatom co-doping carbon as PMS activator applied in the removal of organic pollutants.

Development of a membrane and a bilayer of chitosan, gelatin, and polyhydroxybutyrate to be used as wound dressing for the regeneration of rat excisional wounds.

The skin is the largest organ in the human body that acts as a protective barrier from the outside environment. Certain dermatological pathologies or significant skin lesions can result in serious complications. Several studies have focused on the development of tissue-engineered skin substitutes. In this study, a new bilayer scaffold composed of a chitosan-gelatin membrane and a chitosan-polyhydroxybutyrate (PHB) porous matrix was synthesized and populated with human adipose-derived mesenchymal stem cells (hASCs) to be potentially used for wound dressing applications. By combining this membrane and porous matrix with the stem cells, we aimed to provide immunomodulation and differentiation capabilities for the wound environment, as well as mechanical strength and biocompatibility for the underlying tissue. The membrane was prepared from the mixture of chitosan and gelatin in a 2:1 ratio and the porous matrix was prepared from the mixture of chitosan and PHB, in equal proportions to form a final solution at 2.5% (m/v). Fourier transform infrared spectroscopy analysis showed the formation of blends, and micro-computed tomography, scanning electron microscopy and atomic force microscopy images demonstrated membrane roughness and matrix porosity. The MTT assay showed that the scaffolds were biocompatible with hASC. The membrane and the bilayer were used as dressing and support for cell migration in the dorsal excisional wound model in Wistar rats. Histological and gene transcriptional analyses showed that the animals that received the scaffolds regenerated the hair follicles in the deep dermis in the central region of the wound. Our results demonstrate the potential of these new biomaterials as dressings in wound healing studies, favoring tissue regeneration.

Evaluation of antibacterial of newly innovated mixture of stevia and chitosan as an intracanal medicaments on Enterococcus Faecalis.

Evaluation of antibacterial of newly innovated mixture of stevia and chitosan as an intracanal medicaments on Enterococcus Faecalis.

Biofabricated graphene-magnetite nanobioaerogel with antibiofilm property: Response surface methodology based optimization for effective removal of heavy metal ions and killing of bacterial pathogens

Fabrication of mechanically stable porous materials with excellent adsorption capacity for different types of heavy metal ions simultaneously is still scientifically and technically challenging. Herein, the Response Surface Methodology (RSM) was employed to statistically fabricate the biological materials (collagen, chitosan) functionalized graphene–magnetite (BGM) hybrid nanobioaerogel. RSM statistically predicted the concentration of GO, Fe2+, collagen–chitosan mixture and glutaraldehyde as 6.78 mg/mL, 0.20 M, 61.39 mg/mL and 68.63 µM, respectively, for the maximum responses of Young’s modulus (5.26 kPa) and adsorption capacity. Various spectroscopic and microscopic techniques demonstrated the porous interconnected network structure and superparamagnetic behavior of BGM hybrid nanobioaerogel with a saturation magnetization value of 19.34 emu/g. The nanobioaerogel exhibited fast and high adsorption for Cu(II) (183.96±5.68 mg/g, 29 min), Cd(II) (67.04±1.53 mg/g, 36 min), Cr(VI) (134.49±5.21 mg/g, 45 min) and As(III) (64.62±2.40 mg/g, 40 min) at optimum pH 5.0 and 60 °C in multicomponent system, which is almost four times higher than commercially available activated carbon and other reported literatures. The adsorption process follows the Langmuir isotherm suggesting the monolayer chemisorption, follows pseudo–second order (Cu(II)) and intraparticle diffusion (Cd(II), Cr(VI) and As(III)) models and suggesting rate–limiting step is surface binding and internal pores. ATR–FTIR spectrum revealed that hydroxyl, amine, carboxylate, carbohydrate and iron functional groups in hybrid BGM nanobioaerogel interacted with the heavy metals in a multicomplex manner. It was easily regenerated and reused for multiple adsorptions–desorption cycles. In addition, it also showed >5 log reduction in 4 h against different pathogens and antibiofouling agents.

Effect of storage temperature transfer on the internal browning and other fruit qualities of GP3 and MD2 pineapple clones after postharvest applications of ABA, chitosan and decrowning

Changes in pineapple storage temperature accelerate the increase in internal browning (IB) incidence. This study aims for postharvest applications with changes in storage temperature affecting IB incidence and severity. This research was conducted on ‘GP3’ and ‘MD2’ pineapple clones when they were ripe for export. The experimental were a completely randomized design of storage temperatures (T1: at 7°C for 30 days and T2: at 7°C for 28 days followed by 16°C for 2 days), clones (‘GP3’ and ‘MD2’), decrownings (crown and crownless), and coatings [chitosan 1%, ABA 50mg/L, ABA+chitosan mixture, and control (H2O)]. The results showed that T2 had a significant effect on the increase IB incidence in ‘MD2’ and IB severity in ‘GP3’ compared to T1. Ascorbate acid decreased in ‘MD2’ stored at T2, but had no effect on ‘GP3’. Soluble solid content (SSC) of ‘MD2’ was higher than ‘GP3’. Titratable acidity (TA), SSC/TA ratio, and mold severity were not significantly affected by treatments. The T2 had a significant effect on fruit temperature (FT), with an increase of 2.77-2.88ºC. An increase in FT was positively correlated with maturity, fruit weight loss, and skin dehydration. During the 28 to 30 days of storage, the T2 treatment increased in ripeness by 81.25%.

LDH-doped gelatin-chitosan scaffold with aligned microchannels improves anti-inflammation and neuronal regeneration with guided axonal growth for effectively recovering spinal cord injury

Spinal cord injury (SCI) causes immune cell infiltration, neuronal death and permanent motor dysfunction. Effective treatment for SCI requires simultaneous suppression of the inhibitory and inflammatory microenvironment and enhancement of the pro-regenerative potential at SCI sites. However, realizing neuronal regeneration with guided axon growth and anti-inflammation simultaneously is currently challenging. In this study, a layered double hydroxides (LDH)-doped gelatin-chitosan scaffold with aligned microchannels (GC-LDH/A scaffold) combined with chemical and structural repair effects was developed to regulate immune microenvironment and promote directional neurogenesis. The GC-LDH/A scaffold was prepared by anisotropic freezing of a mixture of Mg-Fe layered double hydroxides (Mg-Fe LDH), gelatin and chitosan. The LDH, gelatin and aligned microchannel structure work together to promote neuronal regeneration. Chitosan and the aligned microchannel structure have a function of anti-inflammation while the latter also guides axonal growth. The repair effect of this scaffold was assessed by restoring a completely transected spinal cord injury, and the results showed that the GC-LDH/A scaffold effectively activated the anti-inflammatory polarization of macrophages and microglia, promoted neurogenesis and guided axonal growth from the rostral to caudal of the lesion site. The key mediator of functional recovery in SCI is Myosin II, which negatively regulates axonal growth; however, the aligned microchannel structure inhibits its activity and reverses the repair effect. This study provides a promising strategy for addressing the repair challenges for effective SCI treatment.