Sodium Carboxymethyl Cellulose Solution Research Articles

Preparation of CMC-poly(N-isopropylacrylamide) semi-interpenetrating hydrogel with temperature-sensitivity for water retention

The CMC-PNIPAM hydrogel with semi-interpenetrating structure and temperature-sensitivity was prepared by in-situ polymerization of N-isopropylacrylamide (NIPAM) in sodium carboxymethylcellulose (CMC) solution at room temperature. The mass ratio of CMC to NIPAM was a key factor influencing the network structure and property of CMC-PNIPAM hydrogel. The low critical phase transition temperature (LCST) of CMC-PNIPAM hydrogels increased from 34.4 °C to 35.8 °C with the mass ratio of CMC to NIPAM rising from 0 to 1.2. The maximum compressive stress of CMC-PNIPAM hydrogel reached to 26.7 kPa and the relaxation elasticity was 52 % at strain of 60 %. The viscoelasticity of CMC-PNIPAM hydrogel was consistent with the generalized Maxwell model. The maximum swelling ratio in deionized water was 170.25 g·g−1 (dried hydrogel) with swelling rate of 2.57 g·g−1·min−1 at 25 °C. CMC-PNIPAM hydrogel hardly absorbed water above LCST, but the swollen hydrogel could release water at the rate of 0.36 g·g−1·min−1 once exceeding LCST. The test of water retention showed that soil mixed with 2 wt% dried CMC-PNIPAM hydrogel could retain 13.08 wt% water after 30 days at 25 °C that was 4.4 times than that of controlled soil without CMC-PNIPAM hydrogel. The semi-interpenetrating CMC-PNIPAM hydrogel showed a potential to conserve water responding to temperature.

Dehydration of collagen hydrogel simply by immersion in sodium carboxymethylcellulose solution

Pre-dehydration of collagen-based hydrogel can result in reduced energy consumption in their large-scale production. This article reported a method to dehydrate collagen hydrogel by simply immersing hydrogel into sodium carboxymethylcellulose (CMC) solution, and the dehydration regularity and possible dehydration mechanisms were investigated. Collagen hydrogel was dehydrated in CMC solution with a dehydration rate of up to 68%, which favored the subsequent drying process as the drying time reduced by at least 18%. The CMC concentration, degree of substitution (DS), molecular weight (MW), and immersion time were all important factors affecting dehydration performance. The main dehydration mechanism was shown to be the Donnan equilibrium, which was attributed to the semi-permeability of the collagen hydrogel and the osmotic pressure difference at the interface induced by the CMC. Low MW CMC was able to penetrate into collagen hydrogel while high MW CMC was still difficult in penetrating into collagen hydrogel even in prolonged immersion time. Moreover, CMC-induced dehydration did not change the collagen fiber structures. This study provides a new pathway for the pre-dehydration of collagen-based materials, and also can help the design of collagen gel materials.

Physicochemical characteristics of a nanocomposite film based on purified sodium carboxymethylcellulose and selenium nanoparticles

AbstractIn this study, selenium nanoparticles (SeNPs) were synthesized and stabilized by reducing sodium selenite using ascorbic acid in an aqueous solution of sodium carboxymethylcellulose (Na‐CMC) with a degree of substitution of 0.97 and a degree of polymerization of 810. IR‐Fourier spectroscopy revealed that coordination bonds between functional groups in Na‐CMC and SeNPs resulted in the development of polymer‐metal complexes. UV–Vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic light scattering (DLS) methods were used to determine the SeNP sizes in the structure of the nanocomposite film. Investigation of the stabilization and nonstabilization of SeNPs over several cycles has shown that the effect of the polymer matrix of Na‐CMC on the stabilization of nanoparticles was achieved for 672 h, which was confirmed by the unchanged size distribution and resistance to change of the SeNPs synthesized in Na‐CMC solutions.

Hyperuricemia Induces Reproductive Damage in Male Rats through Zinc Homeostasis Imbalance and Oxidative Stress

Studies have reported the adverse effects of hyperuricemia on male reproduction, but the mechanism is still unclear. The purpose of this study is to explore the mechanism of hyperuricemia on reproductive system damage in male rats. The rats were divided into a control group and a model group. Rats were given hypoxanthine and potassium oxonate dissolved in 0.5% (w/v) sodium carboxymethyl cellulose solution to induce the hyperuricemia (HUA) model. After 6 weeks, the blood, testis, and epididymis tissues of the anesthetized rats were collected for further experiments and analysis. Compared with the control rats, the serum uric acid of HUA rats was significantly increased, and the serum testosterone, sperm count, and motility were significantly decreased. The protein expression of testosterone-related molecules CYP11A1, 3β-HSD, and StAR was downregulated in the testis of HUA rats. The protein expression of blood–testis barrier (BTB) related molecules ZO-1 and Connexin43 was downregulated in the testis of HUA rats. Compared with the control group, the zinc content and zinc-containing enzymes (ALP and LDH) were decreased, and the mRNA and protein expression of zinc transporters (ZnT4 and ZIP7) were downregulated in the testis of HUA rats. Furthermore, the level of MDA increased and the activities of CAT, GSH-PX, and SOD decreased in the testicular tissue of HUA rats. The PI3K/AKT/mTOR pathway in the testis of HUA rats was activated. However, there was no significant change in the protein expression of autophagy associated molecules LC3, Beclin1, and ATG5 in the testis of HUA rats. Thus, the conclusion is that hyperuricemia can lead to the destruction of BTB, impaired testosterone synthesis, and decreased sperm count and motility in male rats, mainly by inducing zinc homeostasis imbalance and oxidative stress, rather than autophagy.

Protective role of hesperidin in finasteride-induced testicular toxicity in adult male Wistar rats: Insights into oxidative stress, apoptosis, and ultrastructure of seminiferous tubules

A negative impact of finasteride on fertility has been reported, in which over production of reactive oxygen species and apoptosis were implicated. Hesperidin, a plant-derived bioflavonoid with antioxidant and anti-apoptotic effects, may mitigate these adverse effects. In order to investigate the possible protective role of hesperidin against finasteride-induced seminiferous tubules toxicity in adult male Wistar rats, 60 rats were randomized into five groups (I-V) receiving distilled water, 0.5% sodium carboxymethylcellulose solution, hesperidin, finasteride, and combined hesperidin and finasteride respectively. Testicular weight, sperm count and motility were determined. Testicular tissue homogenates were prepared to measure the level of malondialdehyde (MDA), total antioxidant capacity (TAC), reduced glutathione (GSH) and the gene expression of caspase-3 and B-cell lymphoma 2 (Bcl2). Testes were processed for light and electron microscopic evaluation. Johnsen score was calculated. Administration of finasteride resulted in significantly decreased testicular weights, sperm count and motility, Johnsen score, tissue levels of TAC and GSH together with significant increase in tissue MDA. Gene expression revealed significantly increased caspase-3 and decreased Bcl2. Furthermore, finasteride disrupted the seminiferous tubules, causing degenerative changes affecting Sertoli cells and spermatogenic cells. Co-administration of hesperidin with finasteride resulted in improvement in testicular weights, TAC, GSH, Bcl2, Johnsen score, sperm count and motility as well as preservation of the structure of the seminiferous tubules. To conclude, hesperidin was found to have a protective potential on finasteride-induced oxidative stress, apoptosis and testicular structural damage.

Pharmacological Evaluation of Ovulation Inducing Potential of Siddha Herbomineral Formulation Arputha Mathirai on Estradiol Valerate Induced Poly Cystic Ovarian Syndrome Wistar Albino Rat Model

Aim: The aim of this study is to examine the potential of Arputha Mathirai, a tablet-based Siddha herbomineral formulation, in promoting ovulation in Wistar Albino rats with polycystic ovary syndrome (PCOS) induced by Estradiol Valerate (EV).
 Place of Study: The study took place at C.L. Baid Metha College of Pharmacy located in Thorapakkam, Chennai - 600 092, Tamil Nadu.
 Methodology: Arputha Mathirai, the Siddha herbomineral formulation, was prepared in accordance with Good Manufacturing Practices (GMP) guidelines. Prior to conducting the study, approval was obtained from the Institutional Animal Ethics Committee (IAEC). The research adhered to ethical principles and guidelines established by the committee responsible for overseeing and regulating animal experimentation, ensuring proper control and supervision.
 Female Wistar Albino rats were selected as the preferred rodent species for the study. Polycystic ovary syndrome (PCOS) was induced in the animals by administering subcutaneous injection of 100μg Estardiol valerate (EV). The reproductive cycles of the rats were synchronized to ensure consistency.
 The rats were divided into four groups, each containing six rats, as follows:
 
 Group I: Normal Control animals received 1 ml/kg of Sodium Carboxymethyl Cellulose (CMC) solution.
 Group II: Rats were orally administered Arputha Mathirai at a dosage of 100 mg/kg for 10 days.
 Group III: Rats were orally administered Arputha Mathirai at a dosage of 200 mg/kg for 10 days.
 Group IV: Received Clomiphene at a dosage of 10 mg/kg and served as the standard group.
 
 At the end of the study, blood samples were collected from the rats through retro-orbital and cardiac puncture. The levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone were estimated using ELISA method. Ovaries from the experimental rats were dissected out for histopathological studies.
 Results: The results consistently showed that the higher dosage of the drug (group III) had a more pronounced effect in normalizing hormone levels compared to the lower dosage group. However, it is important to note that the lower dosage group also exhibited effectiveness. While the results in both groups did not closely match those of the standard group (group IV), the drug Arputha Mathirai demonstrated significant potential in the experimental groups, supporting its efficacy in inducing ovulation.
 Furthermore, the histopathological analysis confirmed the drug's potential in inducing ovulation, particularly in the higher dosage group (group III) compared to the lower dosage group (group II).
 Overall, the findings suggest that Arputha Mathirai has promising ovulation-inducing activity, with the higher dosage showing more pronounced effects.
 Conclusion: It is hypothesized that the bioactive phytocompounds present in Arputha Mathirai may exert their effects at various stages to restore hormone levels and reverse the pathological condition associated with PCOS. These natural compounds have the potential to regulate hormone levels and promote ovulation. However, it is important to acknowledge that there is a scarcity of published evidence regarding the specific ability of these phytochemicals to address the underlying causes of the condition. Further research is needed to explore the mechanisms by which these compounds act and their potential in addressing the root causes of PCOS.

Pressure drop and bubble length prediction for gas-non-newtonian fluid two-phase flow in a curved microchannel

The control mechanism of the pressure drop and bubble size has a guiding significance for selecting the micropump, the pressure resistance design, and the precise control of the microfluidics. In this study, single-phase flows and gas-non-Newtonian fluid two-phase flows are studied in a microchannel containing curved structures. Sodium carboxymethyl cellulose solutions are used as the non-Newtonian fluids; water and nitrogen are used as Newtonian fluid and gas phases, respectively. The pressure drop and the bubble length are measured. The influences of operating conditions are discussed. The non-Newtonian properties of the solutions are found to affect the parameters measured significantly. The experimental results are compared with the existing models, and the fanning friction factor is used to evaluate the pressure drop. The two-phase flow pressure drop can be predicted by the Lockhart-Martinelli method with a newly developed C-coefficient as a function of the fluid characteristic parameters and microchannel structure parameters. The new correlation for two-phase pressure drop prediction has an error within 18%, smaller than existing models. A new prediction method for the dimensionless bubble length containing the two-phase friction multiplier is also given with an error of 16%.

Effect on the Viscometric Properties of Sodium Carboxymethylcellulose in a Dimethylacetamide and Acetone Mixture

The main objective of our research described here was to determine the viscometric properties of polysaccharide solutions of sodium carboxymethyl cellulose (CMC) in dimethylacetamide (DMA)/acetone (A) mixtures. The evolution of the dynamic and intrinsic viscosities and the effect of the intrinsic Gibbs energy of CMC in DMA/A (44 ml/6 ml) were characterized as a function of the temperature (293.15 to 318.15) K, and concentration (1 to 10) g/l. We identified four main concentration regimes, corresponding to an absorption regime, a dilute regime, a critical regime, and the semi-dilute regime. The thermodynamic parameters of the viscosity also supported the obtained results. Exploiting our results, CMC/DMA/A is a promising solvent mixture for use in pharmaceutical and antibacterial applications.

30-LB: Study on the Mechanism of Calycosin in Promoting Wound Healing in Diabetic Foot Ulcers

Objective: To investigate the effect of calycosin in promoting wound healing of foot ulcers and explore the regulation on vascular endothelial growth factor (VEGF). Methods: 8-week-old male C57BL/6J mice were injected intraperitoneally with 1% streptozotocin 120 mg/kg for 3 consecutive times, and the mice with random blood glucose > 16.7 mmol/L were used and randomly divided into model group and calycosin suspension groups (30 mg/kg, 60 mg/kg, 90 mg/kg). Mice were pretreated for 30 days at a dose of 10 mL/kg of the corresponding drugs once a day, and the control group was given the same dose of 0.5% sodium carboxymethyl cellulose solution. At the end of administration, the animals were anesthetized with isoflurane and the whole layer of skin with diameter 10 mm was removed on the back to establish the wound model of diabetic foot ulcer as day 0. The wound healing was observed and photographed with a camera on the day 0, 2, 4, 6, 8, 10 and 12, respectively. At the end of the day 12, the new tissues around the wound were taken for the detections of the growth of new granulation tissue, VEGF, CD31 and the content of sorbitol. Results: Compared with the model group, the wound healed faster in calycosin groups. It closed on the 12th day, but the wound in the model group did not heal completely. However, there was no obvious dose-effect relationship between different dose groups. The mice in treatment groups showed a better structural integrity of epidermis, and a more expression of VEGF and CD31 in the newborn tissue. And the protein level of VEGF of the calycosin (60 mg/kg) group increased. And the sorbitol content in calycosin (90 mg/kg) group reduced significantly (P<0.05), while in 30 mg/kg and 60 mg/kg changed slightly. Conclusion: Calycosin could promote the wound healing of diabetic foot ulcer, which may be related to the effect of increasing the level of VEGF and reducing the accumulation of sorbitol in tissues. And further research was needed for fully exploration on the mechanism. Disclosure Y. Xu: None. J. Ke: None. L. Yang: None. D. Zhao: None. Funding Tongzhou District Science and Technology Plan Project (KJ2022CX024)

Phosphorylated PKM2 regulates endothelium-dependent vasodilation in diabetes.

Endothelium-dependent vasodilation dysfunction is the pathological basis of diabetic macroangiopathy. The utilization and adaptation of endothelial cells to high glucose determine the functional status of endothelial cells. Glycolysis pathway is the major energy source for endothelial cells. Abnormal glycolysis plays an important role in endothelium-dependent vasodilation dysfunction induced by high glucose. Pyruvate kinase isozyme type M2 (PKM2) is one of key enzymes in glycolysis pathway, phosphorylation of PKM2 can reduce the activity of pyruvate kinase and affect the glycolysis process of glucose. TEPP-46 can stabilize PKM2 in its tetramer form, reducing its dimer formation and phosphorylation. Using TEPP-46 as a tool drug to inhibit PKM2 phosphorylation, this study aims to explore the impact and potential mechanism of phosphorylated PKM2 (p-PKM2) on endothelial dependent vasodilation function in high glucose, and to provide a theoretical basis for finding new intervention targets for diabetic macroangiopathy. The mice were divided into 3 groups: a wild-type (WT) group (a control group, C57BL/6 mice) and a db/db group (a diabetic group, db/db mice), which were treated with the sodium carboxymethyl cellulose solution (solvent) by gavage once a day, and a TEPP-46 group (a treatment group, db/db mice+TEPP-46), which was gavaged with TEPP-46 (30 mg/kg) and sodium carboxymethyl cellulose solution once a day. After 12 weeks of treatment, the levels of p-PKM2 and PKM2 protein in thoracic aortas, plasma nitric oxide (NO) level and endothelium-dependent vasodilation function of thoracic aortas were detected. High glucose (30 mmol/L) with or without TEPP-46 (10 μmol/L), mannitol incubating human umbilical vein endothelial cells (HUVECs) for 72 hours, respectively. The level of NO in supernatant, the content of NO in cells, and the levels of p-PKM2 and PKM2 protein were detected. Finally, the effect of TEPP-46 on endothelial nitric oxide synthase (eNOS) phosphorylation was detected at the cellular and animal levels. Compared with the control group, the levels of p-PKM2 in thoracic aortas of the diabetic group increased (P<0.05). The responsiveness of thoracic aortas in the diabetic group to acetylcholine (ACh) was 47% lower than that in the control group (P<0.05), and that in TEPP-46 treatment group was 28% higher than that in the diabetic group (P<0.05), while there was no statistically significant difference in the responsiveness of thoracic aortas to sodium nitroprusside (SNP). Compared with the control group, the plasma NO level of mice decreased in the diabetic group, while compared with the diabetic group, the phosphorylation of PKM2 in thoracic aortas decreased and the plasma NO level increased in the TEPP-46 group (both P<0.05). High glucose instead of mannitol induced the increase of PKM2 phosphorylation in HUVECs and reduced the level of NO in supernatant (both P<0.05). HUVECs incubated with TEPP-46 and high glucose reversed the reduction of NO production and secretion induced by high glucose while inhibiting PKM2 phosphorylation (both P<0.05). At the cellular and animal levels, TEPP-46 reversed the decrease of eNOS (ser1177) phosphorylation induced by high glucose (both P<0.05). p-PKM2 may be involved in the process of endothelium-dependent vasodilation dysfunction in Type 2 diabetes by inhibiting p-eNOS (ser1177)/NO pathway.

Heat transfer characteristics in turbulent flow and flow patterns of PCM slurry using super-hydrophobic gel particles

An experimental study on the characteristics of heat transfer in turbulent flow and the flow patterns of an organic phase change marerial (PCM) slurry was conducted to investigate the latent heat transportation. As a PCM slurry, the particles of the super-hydrophobic marshmallow-like gel, adsorbing hexadecane on their surface, were dispersed in sodium carboxymethyl cellulose (CMC) solution. Hexadecane is a PCM with a melting point of 17.5 °C, and latent heat of 226.5 kJ·kg−1. For the heat transfer measurement, a double-tube heat exchanger with an inner tube with an inner diameter of 8 mm was used. The results demonstrated that the heat transfer of the marshmallow-like slurry with hexadecane was 1.5 times higher than that of Newtonian fluids. From the pressure drop in the test section, the heat transport efficiency was calculated, which was also higher than that of Newtonian fluids. Furthermore, the flow patterns of the marshmallow-like gel slurries were investigated by varying the CMC concentration and flow velocity. From the results, four patterns of particle dispersion in the flow were observed. The most dispersed flow pattern was observed with all CMC concentrations when the flow velocity was sufficiently high. Based on these results, it was concluded that heat transportation by the marshmallow-like gel slurry is promising.

Synthetic method to improve adhesion of sodium carboxymethyl cellulose solutions and its application to reconstituted tobacco for improved processability

Sodium carboxymethyl cellulose (Na-CMC) binds tobacco powder, additives, and other components together during the rolling moulding of reconstituted tobacco. Due to its insufficient bonding, the product has low tensile strength and a high shredding rate. The standard preparation of Na-CMC solutions suffers from long preparation times and low adhesion. This research used glycerol as a co-solvent, quickly dissolved Na-CMC solutions and increased adhesive solution adherence. When the glycerol/Na-CMC ratio was more significant than or equal to 11:1, the adhesive solution’s adhesion was enhanced by more than 100% compared to conventional Na-CMC solutions at equivalent concentrations. When the highly adhesive Na-CMC solution was applied to reconstituted tobacco, the tension index increased by 192.59%, and the elongation at break increased by 147.14%. The shredding rate decreased by 61.83%. This method should help various Na-CMC industries obtain excellent adhesion at lower adhesive solution concentrations.

An intelligent label using sodium carboxymethyl cellulose and carrageenan for monitoring the freshness of fresh-cut papaya

A novel intelligent label (CNCB) was prepared by casting and drying a mixed solution of sodium carboxymethyl cellulose (CMC-Na) and carrageenan, to which bromothymol blue (BTB) was fixed as the pH indicator. The CNCB label can reply the freshness of fruit through color changes according to the CO2 concentration inside the package. Variations in the three label components were investigated using Fourier transform infrared spectroscopy. Furthermore, the label morphology and structure were evaluated using scanning electron microscopy and X-ray diffractometry. Lastly, the thermal stability of the labels was analyzed using a synchronous thermal analyzer. Carrageenan enhanced the water resistance of the CMC-Na label and improved the mechanical properties. Moreover, while the BTB dye was added to visually indicate color change, its addition improved not only the physical properties but also the thermal stability of the label. The CNCB label showed different color changes in response to different CO2 concentrations. When the CNCB label was stored with fresh-cut papaya, its color changed from blue to green, yellow-green, and eventually yellow-brown as the fruit lost its freshness, displaying a strong correlation with the CO2 concentration in the package. This label prepared from CMC-Na, carrageenan, and BTB, can be used as intelligent label in monitoring the freshness of fresh-cut papaya for the excellent pH sensitivity.

Natriy-karboksimetilsellüloza ERITMACIDA SELENIY NANOZARRALARINING SINTEZI VA XUSUSIYATLARINI QAYTA QILISh.

This work explores feasibilities of forming selenium nanoparticles of different sizes and shapes by means of chemical reduction from a solution of sodium selenite salt of different concentrations in a polymer matrix of purified sodium-carboxymethyl cellulose with the degrees of substitution and polymerization (0.97; 810, accordingly); and determines reaction conditions. It has been experimentally proven that negatively charged carboxyl groups (-СН2СОО-) in the macromolecules of sodium-carboxymethyl cellulose interact with selenium ions to form polymer-metal complexes. Homogenous stable selenium nanoparticles with dimensions of 60–90 nm were synthesized in purified sodium-carboxymethyl cellulose solutions, and optimal conditions for synthesis have been determined. Physicochemical research methods have been applied in order to study the properties of solution of sodium-carboxymethyl cellulose containing stable selenium nanoparticles of different sizes and shapes. In particular, the research has made use of physicochemical methods such as IRFure spectroscopy, atomic force microscope (AFM), X-ray diffractometer analysis (XRD) and dynamic light scattering (DLS). The shape and size of the selenium nanoparticles formed in the polymer matrix were studied using the AFM research method. Crystal level of selenium nanoparticles was determined by the X-ray structural analysis method. The chemical bonds formed in the synthesized polymer metal complex [Se(С5H7O4 -CH2OCH2COO)4 ]4-n were determined by IR-fure spectroscopy studies. The size of the selenium particles formed in the polymer matrix was determined by the dynamic light scattering method.

Short-term exposure to gossypol causes reversible reproductive toxicity and nephrotoxicity in mice

To study the toxic effects of short-term exposure to gossypol on the testis and kidney in mice and whether these effects are reversible. Twenty 7 to 8-week-old male mice were randomized into blank control group, solvent control group, gossypol treatment group and drug withdrawal group. In the former 3 groups, the mice were subjected to daily intragastric administration of 0.3 mL of purified water, 1% sodium carboxymethylcellulose solution, and 30 mg/mL gossypol solution for 14 days, respectively; In the drug withdrawal group, the mice were treated with gossypol solution in the same manner for 14 days followed by treatment with purified water for another 14 days. After the last administration, the mice were euthanized and tissue samples were collected. The testicular tissue was weighed and observed microscopically with HE and PAS staining; the kidney tissue was stained with HE and examined for mitochondrial ATPase activity. Compared with those in the control group, the mice with gossypol exposure showed reduced testicular seminiferous epithelial cells with rounded seminiferous tubules, enlarged space between the seminiferous tubules, interstitium atrophy of the testis, and incomplete differentiation of the spermatogonia. The gossypol-treated mice also presented with complete, non-elongated spermatids, a large number of cells in the state of round spermatids, and negativity for acrosome PAS reaction; diffuse renal mesangial cell hyperplasia, increased mesangial matrix, and adhesion of the mesangium to the wall of the renal capsule were observed, with significantly shrinkage or even absence of the lumens of the renal capsules and reduced kidney mitochondrial ATPase activity. Compared with the gossypol-treated mice, the mice in the drug withdrawal group showed obvious recovery of morphologies of the testis and the kidney, acrosome PAS reaction and mitochondrial ATPase activity. Shortterm treatment with gossypol can cause reproductive toxicity and nephrotoxicity in mice, but these toxic effects can be reversed after drug withdrawal.

CsxWO3 nanorods with broadband nonlinear response for Q-switched and mode-locked pulse generation

Nano-CsxWO3 with broadband local surface plasmon resonance is the promising candidate for nonlinear photonics applications. In this work, Q-switched and mode-locked pulses were generated from Er- and Tm- doped fiber lasers by using CsxWO3 nanorods (NRs) as saturable absorbers (SAs). The CsxWO3 NRs were synthesized by a water controlled-release solvothermal process. Then they were mixed with sodium carboxymethylcellulose (NaCMC) solution to fabricate a SA film and deposited onto a d-shaped fiber to fabricate a d-shaped fiber SA. These SAs exhibited excellent nonlinear optical properties at 1.5- μm and 2- μm. A ∼ 1560 nm Q-switched fiber laser with the shortest pulse width of 3.8 µs, the maximum average power of 10 mW, a pulse energy of 0.35 μJ was obtained by using the filmy CsxWO3 SA. A stable soliton mode-locked fiber laser at ∼ 1943 nm was realized based on the d-shape fiber CsxWO3 SA, it had a maximum average output power of ∼ 50 mW, a pulse duration of ∼ 292 fs, and a repetition rate of 25.5 MHz. Our results show that the CsxWO3 NRs are potential nonlinear materials for broadband ultrafast response and Q-switched/mode-locked pulse generation.

Rheological Properties of Sodium Carboxymethylcellulose Solutions in Dihydroxy Alcohol/Water Mixtures.

The aim of the research presented in this paper was to determine the effect of dihydroxy alcohols on the rheological properties of sodium carboxymethylcellulose (Na-CMC) solutions with different degrees of substitution and different average molecular masses. Rheological measurements were carried out with a rotational rheometer in continuous and oscillatory flows. Two dihydroxy alcohols were used in the study: butane-1,3-diol and propane-1,2-diol. The concentration of Na-CMC in the solutions was 1.6% and 2.2%, while the concentration of the dihydroxy alcohols ranged from 10% to 60%. The measurements show that the viscoelastic properties of Na-CMC solutions are strongly linked to the type of solvent used. The application of low-substituted high-molecular-mass Na-CMC makes it possible to obtain fluids with the properties of weak physical gels. On the other hand, the dissolution of Na-CMC with a high degree of substitution (>1) and low molecular mass in dihydroxy alcohol/water mixtures yields a viscoelastic fluid. Based on oscillatory measurements, increasing concentrations of polyhydroxy alcohols in Na-CMC solutions were found to induce an increase in the strength of the network structure. At the same concentrations of polyhydroxy alcohols in solutions containing butane-1,3-diol, a stronger network structure is formed compared to solutions containing propane-1,2-diol. The rheological measurement results presented in this paper may be useful in the formulation of drug carriers and cosmetics in which rheological properties are a significant factor.

Development, Quality by Design-Based Optimization, and Stability Assessment of Oral Liquid Formulations Containing Baclofen for Hospital Use.

The absence of oral liquid pharmaceutical forms appropriate for use in pediatric and adult patients with difficulty swallowing is a public health problem, especially in the hospital context. Baclofen is a muscle relaxant of choice for treating spasticity, generally marketed only in tablet form, highlighting the need for liquid formulations to facilitate dose adjustment, administration, and swallowing. The present study aimed to develop oral liquid formulations containing baclofen, optimize them through the quality by design approach, and evaluate their physicochemical and microbiological stability. Preformulation and preliminary stability studies were carried out for the development of formulations. Experimental screening and optimization designs resulted in eleven experiments for each step that were evaluated for 28days. A stability-indicating method by high-performance liquid chromatography presented linearity, low limits of detection and quantification, precision, accuracy, and robustness. The experimental design led to two optimized formulations containing baclofen, glycerin, potassium sorbate, citric acid, ultrapure water, flavor, and sucrose syrup or sodium carboxymethylcellulose solution as a vehicle, the last one with sucralose as a sweetener. The formulations were placed in amber glass flasks and subjected to a physicochemical and microbiological stability study. Both formulations showed physicochemical and microbiological stability when stored at room temperature and refrigerated for 84days. The results of this study may serve as a reference in the preparation of liquid oral formulations containing baclofen in the hospital routine and collaborate with the safety and adherence to the treatment of adult and pediatric patients.

Complex ink flow mechanisms in micro-direct-ink-writing and their implications on flow rate control

Despite its simplicity, low cost, and ability to process a wide range of materials, direct-ink-writing (DIW) is an additive manufacturing process with low resolution and accuracy, in the multiple hundred microns to millimeter range. One of the main sources for this issue is the difficulty with accurately controlling ink flow rate at smaller size scales. Towards addressing this limitation, this paper elucidates complex ink flow mechanisms that renders flow rate control difficult and explores printing implementations to increase flow rate accuracy in direct-ink-writing at the micro scale. To this end, a DIW system utilizing hybrid pressure and velocity-controlled extrusion is used to obtain pressure-flow rate relationships for a water-based sodium carboxymethyl cellulose (NaCMC) solution ink, as a function of printing nozzle diameter (510–100 µm). These studies showed that the transient response of piston velocity-controlled extrusion significantly slows down with decreasing nozzle diameter. For pressure-controlled extrusion, the wall slip increases with decreasing nozzle diameter and the constant slip velocity assumption no longer holds as nozzle size decreases below a certain diameter. To contextualize the influence of such behavior on flow rate accuracy, temperature-controlled parallel plate rheometry was performed on the inks and rheological ink models were accordingly determined. It was shown that the associated flow rate predictions under predicted flow rates due to lack of wall-slip consideration, particularly for smaller nozzle sizes. Lastly, an iterative pressure-controlled DIW implementation was explored to address the accuracy issues for micro-DIW. Our results indicated significant improvement in the transient response and flow rate accuracy for nozzle diameters as small as 100 µm using this approach compared to both of the conventional pressure and velocity control approaches.

Pharmacokinetics of Herb-Drug Interactions of Plumbagin and Tazemetostat in Rats by UPLC-MS/MS.

ObjectiveA sensitive and rapid UPLC-MS/MS method for determination of tazemetostat in rat plasma was developed, and the pharmacokinetics of herb-drug interactions (HDIs) of plumbagin (PLB) and tazemetostat was investigated.MethodsAfter the rat plasma samples were precipitated by acetonitrile, tazemetostat and verubecestat (ISTD) were detected. Gradient elution was performed with 0.1% formic acid and acetonitrile as mobile phases. The multi-reaction monitoring was used with ESI+ source, and the ion pairs for tazemetostat and ISTD were m/z 573.12→135.99 and m/z 410.10→124.00, respectively. 12 SD rats were randomly divided into the control group and the experimental group, 6 rats in each group. The rats in the experimental group were given PLB 100 mg/kg by gavage once a day for 7 consecutive days. The rats in the control group were given the same amount of 0.1% sodium carboxymethyl cellulose solution by gavage once a day for 7 consecutive days. At the seventh day, tazemetostat (80 mg/kg) was given and the blood was collected at different time points. The main parameters of pharmacokinetics were calculated and the herb-drug interactions (HDIs) were evaluated.ResultsIn the calibrated range of 1–1000 ng/mL, tazemetostat had a good linearity. The extraction recovery was more than 84%, and the RSD of intra-batch and inter-batch precision were both less than 15%. The Cmax of tazemetostat in the experimental group was 32.48% higher than that in the control group, and the AUC(0-t) and AUC(0−∞) of tazemetostat in the experimental group were 46.24% and 46.67% higher than that in the control group, respectively, and the t1/2 was prolonged from 10.56 h to 11.73 h.ConclusionA simple, rapid and sensitive UPLC-MS/MS method for the determination of tazemetostat in rat plasma was established. PLB can inhibit the metabolism of tazemetostat and increase the plasma exposure of tazemetostat in rats.