Gel Solution Research Articles

INFLUENCE OF THICK EXTRACT FROM MAITAKE MUSHROOMS ON SIGNS OF INFLAMMATORY PROCESS IN EXPERIMENTAL TOXIC HEPATITIS

Background. The priority of the contemporary pharmaceutical industry is to create effective, safe and inexpensive drugs to ensure the highest quality of care and optimal use of available raw materials. Objective. The aim of our study was to investigate anti-inflammatory properties of the Maitake mushrooms thick extract in the experiment on rats with paracetamol(acetaminophen)-induced hepatitis. Methods. 60 white male rats, weighing 180-210 g, randomized into 10 groups of 6 animals in each, were used for the experiment. Paracetamol hepatitis was simulated by acetaminophen intragastric administering in a dose of 1250 mg/kg 1 time per day (for 2 days) as a suspension in 2% starch gel solution. Maitake mushrooms thick extract, which was administered intragastrically 2 hours before the administration of acetaminophen and daily after the lesion in a dose of 150 mg/kg of the animal’s body weight, was used for the toxic lesion correction. “Silibor” was selected as the comparison drug, which was administered according to the same scheme as the investigated extract in a dose of 20 mg/kg of the animal’s body weight. Euthanasia was conducted on the 3rd, 7th and 10th day of the experiment with sodium barbamyl. Liver homogenate and animal serum were used for the studies. The development of inflammatory processes was studied by the content of pro-inflammatory and anti-inflammatory cytokines, as well as C-reactive protein in the serum of rats with toxic hepatitis and after the application of Maitake mushroom extract and the comparison drug. Results. It was found that the introduction of acetaminophen to animals for the acute hepatitis simulation is accompanied by changes in the cytokine profile, i.e. an increase in the level of IL-6 and a decrease in the level of IL-4 in the serum of rats. Inflammatory development is evidenced by the content of C-reactive protein increase in the blood of the affected animals. The application of Maitake mushroom extract facilitated bringing the studied indicators almost to the level of intact control. Conclusions. Reduction of inflammation signs in rats with the simulated paracetamol hepatitis under the influence of Maitake mushrooms thick extract confirms its anti-inflammatory properties. Objective. The aim of our study was to investigate anti-inflammatory properties of the Maitake mushrooms thick extract in the experiment on rats with paracetamol(acetaminophen)-induced hepatitis. Methods. 60 white male rats, weighing 180-210 g, randomized into 10 groups of 6 animals each, were used for the experiment. Paracetamol hepatitis was simulated by acetaminophen intragastric administering in a dose of 1250 mg/kg 1 time per day (for 2 days) as a suspension in 2% starch gel solution. Maitake mushrooms thick extract, which was administered intragastrically 2 hours before the administration of acetaminophen and daily after the lesion in a dose of 150 mg/kg of the animal’s body weight, was used for the toxic lesion correction. "Silibor" was selected as the comparison drug, which was administered according to the same scheme like the investigated extract in a dose of 20 mg/kg of the animal’s body weight. Euthanasia was conducted on the 3rd, 7th and 10th day of the experiment with sodium barbamyl using. Liver homogenate and animal serum were used for the studies. The development of inflammatory processes was studied by the content of pro- and anti-inflammatory cytokines, as well as C-reactive protein in the serum of rats with toxic hepatitis and after the application of Maitake mushroom extract and the comparison drug. Results. It was found that the introduction of acetaminophen to animals for the acute hepatitis simulation is accompanied by changes in the cytokine profile, namely, an increase in the level of IL-6 and a decrease in the level of IL-4 in the serum of rats. The inflammatory process development is evidenced by the content of C-reactive protein increasing in the blood of affected animals. The application of Maitake mushroom extract helped to bring the studied indicators closer to the level of intact control. Conclusions. The application of the Maitake mushrooms thick extract as a corrective factor at the simulated paracetamol hepatitis confirms its anti-inflammatory properties. KEYWORDS: Maitake mushrooms, paracetamol, hepatitis, inflammatory processes, thick extract, anti-inflammatory properties.

Harnessing of Doxylamine Succinate/Pyridoxine Hydrochloride-Dual Laden Bilosomes as a Novel Combinatorial Nanoparadigm for Intranasal Delivery: In Vitro Optimization and In Vivo Pharmacokinetic Appraisal

The present work is concerned with tailoring and appraisal of a novel nano-cargo; bilosomes (BLS) dual laded with doxylamine succinate (DAS) and pyridoxine hydrochloride (PDH), the first treatment option against gestational nausea and vomiting, for intranasal delivery. This bifunctional horizon could surmount constraints of orally-commercialized platforms both in dosage regimen and pharmacokinetic profile. For accomplishing this purpose, DAS/PDH-BLS were elaborated integrating phospholipid, sodium cholate and cholesterol applying thin-film hydration method based on Box-Behnken design. Utilizing Design-Expert® software, the effect of formulation variables on BLS physicochemical features alongside the optimal formulation selection were investigated. Then, the optimum DAS/PDH-BLS formulation was incorporated into a thermally-triggered in situ gelling base. The in vivo pharmacokinetic studies were explored in rats for intranasal DAS/PDH-BLS in situ gel compared with analogous intranasal free in situ gel and oral solution. The optimized BLS disclosed vesicle size of 243.23 nm, ζ potential of -31.33 mV, entrapment efficiency of 59.18 and 41.63%, accumulative % release within 8 h of 63.30 and 85.52% and accumulative permeated amount over 24 h of 347.92 and 195.4 µg/cm2 for DAS/PDH, respectively. Following intranasal administration of the inspected BLS in situ gel, pharmacokinetic studies revealed a 1.64- and 2.3-fold increment in the relative bioavailability of DAS and a 1.7- and 3.73-fold increase for PDH compared to the intranasal free in situ gel and oral solution, respectively besides significantly extended mean residence times for both drugs. Thus, the intranasally exploited DAS/PDH-BLS could be deemed as a promising hybrid nanoplatform with fruitful pharmacokinetics and tolerability traits.

Iron Encapsulation by Deacetylated Glucomannan as an Excipient Using the Gelation Method: Characteristics and Controlled Release.

SUMMARYResearch backgroundDeacetylation and the use of CaCl2 as a gelation agent improve the performance of glucomannan as iron encapsulant. This study was conducted to investigate the effects of deacetylation degree and pH of gelation on the characteristics of encapsulated iron using gelation in CaCl2 solution.Experimental approachGlucomannan was deacetylated at various NaOH concentrations and was subsequently utilized as an iron excipient using the pipette-dropped gelation method in CaCl2 solution to directly investigate the process of encapsulation by gelation. The pH of the gelation solution was also changed. The beads were subsequently vacuum-dried.Results and conclusionsDeacetylation led to lower endothermic peak of the glucomannan than that of the native one. The deacetylation degree and pH of gelation did not significantly affect the diameter of the beads but influenced their appearance and physical characteristics. The backbone of glucomannan was not changed by either the deacetylation degree or the pH of the gelation. The highest encapsulation efficiency (73.27%) was observed in the encapsulated iron using the glucomannan matrix of the highest deacetylation degree (82.56%) and gelated in the solution at pH=10. The highest deacetylation degree of glucomannan caused the highest swelling of the beads, which led to the release of a higher amount of iron. Glucomannan deacetylation improves the iron encapsulation and enables higher iron release at pH=6.8 than at pH=1.2. The Weibull model was the best-fitting model to represent the profile of iron release from the deacetylated glucomannan matrix using the gelation method (R2>0.93) at pH=6.8 and pH=1.2.Novelty and scientific contributionThis result supports the application of deacetylated glucomannan using NaOH as a pH-sensitive matrix for iron encapsulation and CaCl2 solution as gelation agent. A higher deacetylation degree leads to the release of a higher amount of iron from the matrix. The encapsulation does not only protect the iron but also delivers it to the absorption site and controls its release, which is useful in supplement formulation or food fortification. The results show that the deacetylated glucomannan as the matrix holds more iron in encapsulation process.

Inhibition of browning via aqueous gel solution of Aloe vera: a new method for preserving fresh fruits as a case study on fresh kernels of Persian walnut.

Aloe Vera (AV) gel is commonly used as a natural, inexpensive, edible coating that can improve the quality and shelf life of fruits. The objective of this study was to evaluate how two methods of applying AV, i.e. as an edible coating (dry environment) and as a gel solution (aqueous environment: a new method), prevent browning and maintain quality characteristics of fresh kernels of Persian walnut for 60days during cold storage. Distilled water was used as a control group for both environments. In general, AV caused a reduction in the peroxide value (POV) of kernels, while preserving Total Phenolic Compound and Total Antioxidant Activity (TAA). The AV treatment slowed down the process of color change and maintained sensory properties during storage, compared to the control groups of both methods. The AV gel solution performed better than the AV edible coating in terms of POV, color (L* and h°) and microbial growth. In contrast, the AV edible coating was more effective in preserving TPC and TAA. Also, TAA was found to have a significant, positive correlation with L* and, simultaneously, a negative correlation with POV. As far as we know, this is the first instance that the AV gel was used as a formulated solution and as an edible coating on fresh fruits. This innovative method can be used in commercial practice, while being ecofriendly and non-chemical as a treatment for the maintenance of postharvest quality in fruits.

Glyceraldehyde as an Efficient Chemical Crosslinker Agent for the Formation of Chitosan Hydrogels.

The rheological changes that occur during the chemical gelation of semidilute solutions of chitosan in the presence of the low-toxicity agent glyceraldehyde (GCA) are presented and discussed in detail. The entanglement concentration for chitosan solutions was found to be approximately 0.2 wt.% and the rheological experiments were carried out on 1 wt.% chitosan solutions with various amounts of GCA at different temperatures (25 °C and 40 °C) and pH values (4.8 and 5.8). High crosslinker concentration, as well as elevated temperature and pH close to the pKa value (pH ≈ 6.3–7) of chitosan are three parameters that all accelerate the gelation process. These conditions also promote a faster solid-like response of the gel-network in the post-gel region after long curing times. The mesh size of the gel-network after a very long (18 h) curing time was found to contract with increasing level of crosslinker addition and elevated temperature. The gelation of chitosan in the presence of other chemical crosslinker agents (glutaraldehyde and genipin) is discussed and a comparison with GCA is made. Small angle neutron scattering (SANS) results reveal structural changes between chitosan solutions, incipient gels, and mature gels.

Experimental study on an oil‐based polymer gel for lost circulation control in high‐temperature fractured formation

AbstractAiming at the lack of plugging agent for oil‐based drilling fluid leakage in fractured formation, an oil‐based gel‐plugging agent with high structural strength and strong thermal stability was synthesized based on monomer polymerization and crosslinking. According to the preparation experiment, when the total concentration of methyl methacrylate (MMA) and butyl acrylate (BA) is 30% and the ratio is 6:4, the oil‐based gel solution can be completely gelatinized from 80 to 200°C, which has high gel strength and controllable gelation time. The effects of total concentration of BA and MMA, the ratio of BA and MMA, synthesis temperature, oil‐based drilling fluid invasion, shear effect, and fiber concentration on gelling performance were systematically studied. Fourier transform infrared molecular structure analysis showed that the oil‐based gel contained benzene ring group and ester characteristic group. From the rheological properties of oil‐based gel with 30% gelling agent at 160°C, it could be seen that the elastic modulus G′ of 10 Hz is 232 kPa, which is much larger than the storage modulus G″ is 99 kPa, which reflects the solid properties and has good elasticity and high strength. The displacement experiment of sand filling pipe and dynamic and static plugging experiment of high temperature and high pressure shows that the oil‐based gel has high bearing capacity in fractures and sand filling pipe. The bearing pressure is 3.01 MPa in 6 mm fractures, and the bearing pressure gradient is 0.602 MPa/cm.

Flexible and Ultrathin Metal-Oxide Films for Multiresonance-Based Sensors in Plastic Optical Fibers

We have exploited a laser-based integration process of ultrathin metal-oxide (MO) films to improve the plasmonic effect in sensors based on D-shaped plastic optical fibers (POFs). More specifically, using ultrathin MO films, the performances of the surface plasmon resonance (SPR) phenomenon improve and a lossy mode resonance (LMR) can occur. Although the role of this kind of materials has been already presented, when they are deposited as overlayer (upside the thin metal film), we have used a different approach by depositing MOs, especially zirconium oxide (ZrO2) and titanium oxide (TiO2), as flexible intermediate layers between the exposed core of POFs and the gold film. The MO layer is prepared from sol–gel solution, and deep-UV laser curing allows us to densify the thin film and tune the refractive index, with a room-temperature process fully compatible with the flexible polymer substrates. In a preliminary step, we have carried out numerical results, based on transfer matrix formalism, to predict the SPR response. Subsequently, we have experimentally characterized the developed sensor configurations. Numerical and experimental results have shown above all an enhancement of the sensor performances, in terms of SPR sensitivity, with respect to a reference sensor based on a polymer instead of MOs. Moreover, in some proposed sensor configurations, together with the SPR phenomenon, an LMR phenomenon was observed. It occurred in a different wavelength range, for a typical refractive index range present when considering receptors for biochemical sensing applications. Therefore, both resonances (SPR and LMR) could be used in several application fields.

Intracellular polyphosphate length characterization in polyphosphate accumulating microorganisms (PAOs): Implications in PAO phenotypic diversity and enhanced biological phosphorus removal performance

Polyphosphate (polyP) accumulating organisms (PAOs) are the key agent to perform enhanced biological phosphorus removal (EBPR) activity, and intracellular polyP plays a key role in this process. Potential associations between EBPR performance and the polyP structure have been suggested, but are yet to be extensively investigated, mainly due to the lack of established methods for polyP characterization in the EBPR system. In this study, we explored and demonstrated that single-cell Raman spectroscopy (SCRS) can be employed for characterizing intracellular polyPs of PAOs in complex environmental samples such as EBPR systems. The results, for the first time, revealed distinct distribution patterns of polyP length (as Raman peak position) in PAOs in lab-scale EBPR reactors that were dominated with different PAO types, as well as among different full-scale EBPR systems with varying configurations. Furthermore, SCRS revealed distinctive polyP composition/features among PAO phenotypic sub-groups, which are likely associated with phylogenetic and/or phenotypic diversity in EBPR communities, highlighting the possible resolving power of SCRS at the microdiversity level. To validate the observed polyP length variations via SCRS, we also performed and compared bulk polyP length characteristics in EBPR biomass using conventional polyacrylamide gel electrophoresis (PAGE) and solution 31P nuclear magnetic resonance (31P-NMR) methods. The results are consistent with the SCRS findings and confirmed the variations in the polyP lengths among different EBPR systems. Compared to conventional methods, SCRS exhibited advantages as compared to conventional methods, including the ability to characterize in situ the intracellular polyPs at subcellular resolution in a label-free and non-destructive way, and the capability to capture subtle and detailed biochemical fingerprints of cells for phenotypic classification. SCRS also has recognized limitations in comparison with 31P-NMR and PAGE, such as the inability to quantitatively detect the average polyP chain length and its distribution. The results provided initial evidence for the potential of SCRS-enabled polyP characterization as an alternative and complementary microbial community phenotyping method to facilitate the phenotype-function (performance) relationship deduction in EBPR systems.

Research of a Surfactant Gel with Potential Application in Oilfield

Abstract In this study, a viscoelastic surfactant gel was composed using erucoylamine propyl betaine and other additives. The formulation of this viscoelastic surfactant gel solution was determined as: erucamide propyl betaine:oleic acid amide propyl betaine:octadecyl hydroxyl sulfonate betaine = 1.7%:1.36%:0.01%. Then the performance of viscoelastic surfactant gel fluid was evaluated. The results showed that the viscoelastic surfactant gel has good temperature resistance and salt resistance. At 50°C, the apparent viscosity reaches the maximum value, 37 mPa · s, and it displays high shear resistance under the shear rate of 170 s–1, with the viscosity retention of 83.3%. Kerosene (1%) can completely break the gel within 2 h, which can convert the gel into a surfactant solution soon. Also the gel shows high emulsion ability, which can benefit the oil displacement in oilfield. Finally this gel can enhance the oil displacement rate as high as 28%.

Incorporation of 45S5 bioglass via sol-gel in β-TCP scaffolds: Bioactivity and antimicrobial activity evaluation

In this work, β-TCP (β-tricalcium phosphate) bioresorbable scaffolds were prepared by the gel casting method. Then, they were impregnated with a 45S5 bioglass sol gel solution to improve biocompatibility and promote bioactivity and antimicrobial activity. The β-TCP scaffolds had an apparent porosity of 72%, and after the incorporation of the bioglass, this porosity was maintained. The elements of the bioglass were incorporated into β-TCP matrix and there was a partial transformation from the β-TCP phase to the α-TCP (α-tricalcium phosphate) phase, besides the formation of bioactive calcium and sodium‑calcium silicates. The scaffolds β-TCP with 45S5 bioglass incorporated (β-TCP/45S5) did not show a reduction in their values of mechanical strength and Weibull modulus, despite the partial transformation to the α-TCP phase. Bioactivity, cell viability, and antimicrobial activity improved significantly for the β-TCP/45S5 scaffold comparing to the scaffold without the bioglass. The mineralization of carbonated hydroxyapatite was verified in Simulated Body Fluid (SBF). The cell viability, evaluated by the reduction of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide – MTT in MG63 cells, increased by 178%, and β-TCP/45S5 scaffold also enhanced cell activity and osteoblast differentiation observed by means of total protein contend and alkaline phosphatase activity, respectively. The formation of growth inhibition zones was also observed in the disk diffusion assay for three tested microorganisms: Staphylococcus aureus, Escherichia coli and Candida albicans. To conclude, the vacuum impregnation method in 45S5 bioglass sol gel solution was effective in penetrating all the interconnected macroporosity of the scaffolds and covering the surface of the struts, which improved their biological properties in vitro, bioactivity and antibacterial activity, without reducing mechanical strength and porosity values. Thus, the β-TCP/45S5 scaffolds are shown as potential candidates for use in tissue engineering, mainly in bone tissue regeneration and recovery.

Influence of non-ionic, ionic and lipophilic polymers on the pH and conductivity of model ointments, creams and gels.

The pH of the skin surface is usually between 5.4 and 5.9 and functions as a barrier against bacteria and fungi; thus, the composition of the topically applied drug form may be of high importance for proper medication. To evaluate the influence of the measurement conditions in aqueous solutions of ointments, creams, and gels, which include polymeric components, on the pH and conductivity results. The pH and electrolytic conductivity of aqueous dispersions of commercially available ointments, creams and gels were tested and compared to reference vehicles. The results of the dilution method measurements of the pH and electrolytic conductivity of the ointment preparations are highly diverse, ranging from 5.88 to 6.27, whereas the reference pH for Unguentum simplex was between 5.40 and 5.43. Furthermore, the measurements of the pH and electrolytic conductivity with the dilution method for creams did not provide repeatable results with a small sample size, and the pH of commercial preparations was in the range between 5.79 and 6.37, compared to the reference pH of 5.23-5.46. However, the dilution method for measurements of the pH and electrolytic conductivity was suitable for hydrogel preparations and the obtained results were repeatable in the range of 6.11-6.90, while the reference preparations were in the range of 5.19-5.62. Evaluation methods of the electrolytic conductivity and pH of the preparations applied on the skin should be further evaluated; however, the pH of the commercial preparation seems to differ from the physiological skin pH, which covers the range of reference preparations.

Urea induces (unexpected) formation of lamellar gel-phase in low concentration of cationic surfactants

HypothesisThe unexpected formation of a lamellar structure with concomitant gelation in solutions containing high urea concentration (40 wt%) and relatively low amount of cationic surfactant (3 wt%), indicates that a hierarchically structured complex is formed by both molecules. ExperimentsGels formed by combination of aqueous solutions of urea and C12TAB, C14TAB or C16TAB were prepared in different proportions and their structures at microscopic and mesoscopic levels were investigated using XRD and SAXS, respectively. The elastic and viscous moduli and yield stress of the samples were determined and correlated with the composition and structuration of the gels. The lamellar structure is reversibly thermically destroyed and this process was investigated using DSC. FindingsXRD revealed that, at microscopic scale, the gels are formed through crystallization of adducts containing surfactant molecules loaded into the cavities of honeycomb-like urea assemblies. Such crystalline phase arranges itself in lamellae with interplanar distance around ∼20–30 nm, which were observed by SAXS. This hierarchical structure is independent of the chain length of the cationic surfactants. The blocks of lamellae dispersed in the continuous phase form a three-dimensional rigid particulate network structure, giving the characteristic rheological behavior of a hydrogel. DSC revealed a reversible thermal transition at around 20–25 °C, beyond which the adducts and the lamellar phase are destroyed and micelles are formed. The characteristic transition temperature is independent of the chain length of the surfactant, and thus, it is not associated with their Krafft temperatures. The structures of the gels indicate that they resemble alpha-gels formed by fatty-alcohols and surfactants, although they self-assemble by different driving forces.

Slow-release lubrication of artificial joints using self-healing polyvinyl alcohol/polyethylene glycol/ graphene oxide hydrogel

New fabrication methods and lubrication materials must be developed to improve the lubrication performance of artificial joints and increase the lubrication duration. Herein, a novel polyvinyl alcohol/polyethylene glycol/graphene oxide (PVA/PEG/GO) hydrogel was prepared by a physical cross-linking method, and then the hydrogel and its sustained-release solution were used as lubricant for friction evaluation. The results demonstrated that the slow-release gel solution has good lubrication performance, and coefficient of friction (COF) is only 0.04, which is much lower than the COF of distilled water (about 0.08) under the same conditions. The structure characterization results revealed that no new materials are formed in the gel. The results of thermogravimetric analyses and differential scanning calorimetry demonstrated that the addition of GO may improve the network crosslinking structure of the PVA/PEG hydrogel and improve its mechanical strength. In addition, PVA/PEG/GO hydrogel has superior self-healing function. The self-healing hydrogel did not break again after being pulled under 200 G of weights. The PVA/PEG/GO hydrogel with excellent slow-release lubricating performance and self-healing properties provides a novel candidate for design of long-term lubricating artificial joints, and is expected to promote the progress of artificial joint lubrication applications.

Development, characterization and in vitro–in vivo evaluation of Farnesol loaded niosomal gel for applications in oral candidiasis treatment

ObjectivesThe aim of the study was to formulate and characterize the farnesol loaded niosomes comprising gel formulation and perform their in vitro–in vivo evaluation for applications in the treatment of oral candidiasis infections. MethodsVarious gelling systems were evaluated for their rheological and stability properties. The formulation was statistically optimized using experimental design method (Box-Behnken). Transmission electron microscopy (TEM) and Atomic force microscopy (AFM) were used to observe the niosomal surface morphology. Centrifugation method and dialysis method were used to find out the % entrapment efficiency (%EE) and in-vitro release of Farnesol, respectively. In-vitro antifungal effect and cell biocompatibility of the Farnesol loaded niosomal gel was also performed using Candida albicans (C. albicans) as the model organism and epithelial cell line (SW480) by MTT cytotoxicity assay. In-vivo skin irritation test was performed on rabbit skin. Key findingsFarnesol loaded niosomes were integrated into polymeric gel solution. The optimized formulation demonstrated acceptable % EE (>80%) and an optimum particle size (168.8 nm) along with a sustained release and a long-term storage stability for up to a period of 6 months. TEM and AFM observations displayed a spherical niosome morphology. Farnesol niosomal gel showed a higher antifungal efficacy, ex-vivo skin permeation and deposition in comparison to plain farnesol solution. The niosomal gel also showed negligible cytotoxicity to normal cells citing biocompatibility and was found to be non-toxic and non-irritant to rabbit skin. ConclusionsThis novel niosome loaded gel-based formulation could make the oral candidiasis healing process more efficient while improving patient compliance. With the optimized methodology used in this work, such formulation approaches can become an efficient, industrially scalable, and cost-effective alternatives to the existing conventional formulations.

Experimental investigation of a unique solar photoelectrochemical hydrogen generating reactor for clean fuels

A new photoanode configuration utilizes the maximum light over daytime at any angle of the delivered rays due to its meshy dome design. This specific dome design of the photoanode is unique and helps increase the illumination electrode area, and the mesh type of configuration makes the rays reach inside the dome body better to increase the received sunlight at any angle of the solar rays. The mesh dome photoanode is manufactured of stainless steel and coated with titanium dioxide sol–gel solution using the dip-coating method. This photoanode is immersed in 0.1 M potassium dioxide solution with titanium mesh dome cathode and examined under the solar simulator at vertical light and 45° tilted light conditions. The present experimental measurements indicate that the highest hydrogen mass generation rate produced under the vertical light condition is 5.58 µg/s occuring at the photocurrent density of 1.62 mA/cm2. Moreover, the exergy and energy efficiencies that could be achieved at the vertical light condition are 0.81% and 1.17%, respectively. The enhancement of the hydrogen mass production rates that happens at tilted light conditions is varied between 75% and 80% of the enhancement by vertical light conditions. According to the experimental results, this photoanode design is effective during the daytime considering the angle of sun rays.

3 D printing technology and experimental study of chitosan gel using atomized solidification liquid-assisted extrusion molding

PurposeThis paper aims to propose a suitable atomizing solidification chitosan (CS) gel liquid extrusion molding technology for the three dimensional (3D) printing method, and experiments verify the feasibility of this method.Design/methodology/approachThis paper mainly uses experimental means, combined with theoretical research. The preparation method, solidification forming method and 3D printing method of CS gel solution were studied. The CS gel printing mechanism and printing error sources are analyzed on the basis of the CS gel ink printing results, printing performance with different ratios of components by constructing a gel print prototype, experiments evaluating the CS gel printing technology and the effects of the process parameters on the scaffold formation.FindingsCS printing ink was prepared; the optimal formula was found; the 3 D printing experiment of CS was completed; the optimal printing parameters were obtained; and the reliability of the forming prototype, printing ink and gel printing process was verified, which allowed for the possibility to apply the 3 D printing technology to the manufacturing of a CS gel structure.Originality/valueThis study can provide theoretical and technical support for the potential application of CS 3 D printed gels in tissue engineering.

Exploration of collagen cavitation based on peptide electrolysis

Electrochemical modification of animal skin is a new material preparation method and new direction of research exploration. In this study, under the action of the electric field using NaCl as the supporting electrolyte, the effect of electrolysis on Glycyl-glycine(GlyGl), gelatin(Gel) and Three-dimensional rawhide collagen(3DC) were determined. The amino group of GlyGl is quickly eliminated within the anode region by electrolysis isolated by an anion exchange membrane. Using the same method, it was found that the molecular weight of Gel and the isoelectric point of the Gel decreased, and the viscosity and transparency of the Gel solution obviously changed. The electrolytic dissolution and structural changes of 3DC were further investigated. The results of TOC and TN showed that the organic matter in 3DC was dissolved by electrolysis, and the tissue cavitation was obvious. A new approach for the preparation of collagen-based multi-pore biomaterials by electrochemical method was explored.

Decisive Influence of Hydrophobic Side Chains of Polyesters on Thermoinduced Gelation of Triblock Copolymer Aqueous Solutions

A series of amphiphilic triblock copolymers composed of poly(ethylene glycol) (PEG) and poly(ε-caprolactone-co-5-alkyl δ-lactone)s bearing distinct alkyl side groups were synthesized via ring-opening copolymerization of ε-caprolactone and a small amount of various 5-alkyl δ-lactones using PEG as the macroinitiator and metal-free diphenyl phosphate as the catalyst. The analysis of 1H NMR, GPC, DSC, and XRD confirmed that the synthetic copolymers had similar molecular weights and bulk properties; nevertheless, they exhibited quite different aqueous behaviors in response to temperature variations. While the polyesters without side chains simply presented a free-flowing sol over the entire examined temperature range, those bearing methyl or n-propyl side groups underwent a sol–gel transition upon heating and harvested a reversed thermosensitive hydrogel (T-Gel). Meanwhile, the sol–gel transition temperature of the polymer/water system could be easily tailored by adjusting the content of the n-propyl side group. In contrast, the polyesters containing longer n-amyl side groups formed a normal hydrogel (N-Gel) exhibiting a gel–sol (suspension) transition upon heating. Their different aqueous behaviors stemmed from the difference in the hydrophilic–hydrophobic equilibrium of the amphiphilic copolymers. The sol–gel transitions of the thermosensitive hydrogels were attributed to the aggregation of micelles and the dehydration of PEG. The copolymers bearing n-propyl side groups had good cytocompatibility and were fairly stable in a phosphate buffered saline for 80 days, whereas the formed thermosensitive hydrogel (20 wt %) was rapidly degraded via surface erosion within half a month after subcutaneous injection into mice. Consequently, this study indicates that subtle variation in the length of hydrophobic side chains plays a decisive role in the physical gelation of PEG/polyester copolymers. In addition, the thermosensitive hydrogels have the potential for drug and cell delivery based on their good biocompatibility and biodegradability.

Preparation and Characterization of a Hard Capsule Based on Oxidized Rice Starch and Cellulose Nanocrystals

AbstractA hard capsule based on oxidized rice starch (ORS) and cellulose nanocrystals (CNC) is prepared by a dipping method and the glycerol and carrageenan are used as a plasticizer and gelling agent in the ORS/CNC gel solution, respectively. The viscosity of gel solution that is suitable for film‐forming/capsule‐forming is analyzed. When the content of CNC is 8.0%, the tensile strength of the ORS/CNC composite film is 10.09 MPa and increased by 196.0%. The loss on drying and the disintegration time of the ORS/CNC capsules are also investigated. The ORS/CNC capsules are analyzed by Fourier Transform Infrared spectroscopy (FTIR), X‐Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The results show that the ORS and CNC have good compatibility and good film‐forming ability and can be used as excipients to prepare the hard capsules.

Soil organic carbon, physical fractions of the macro-organic matter, and soil stability relationship in lacustrine soils under banana crop.

Banana is a staple food and a major export commodity in the tropics. However, banana production systems are affected by the plant-soil relationships, where properties such as quality and quantity of soil organic matter play an important role in the dynamics of soil physical properties. In order to evaluate the effect of the soil organic carbon (SOC) content and its distribution in the water-stable of soil aggregates (WAS), and the physical fractions of the macro-organic matter, a study was conducted in lacustrine soils under Banana cv. 'Grand Nain' in Venezuela. Soil sampling was carried out in two batches differentiated by their textural class and crop production. A completely randomized design under a directed random sampling technique was carried out. In each condition, 12 composite samples were taken at depths 0-5 and 5-10 cm, respectively. WAS were separated into micro (< 250 μm) and macroaggregates (> 250 μm). Also, physical fractionation by size-density of the macro-organic matter into light (LF), intermediate (IF), and heavy (HF) fraction using a silica gel solution, and SOC, were determined and correlated with banana yield and other agronomic traits. A major proportion of aggregates > 250 μm were found in both conditions and depths. Organic Carbon within soil aggregates ranged between 29.7 and 35.3 g kg-1. The HF was superior to IF and LF; however, its C content was higher in the LF. The results allow inferring that the stability conferred to these soils is primarily associated with the presence of the snail, which shares the same size as the aggregates studied. High yields are associated with high C content in stable aggregates, as well as in the most labile fractions of macro-organic matter. These results highlight the importance of the use of organic fertilizers less recalcitrant as a strategy for sustainable management of banana cultivation.