scholarly journals THE EFFECT OF A CARBOXYMETHYLCELLULOSE SODIUM SALT ON THE PROPERTIES OF HYDROPHILIC POWDERS CONTAINING A LACTIC ACID-CHITOSAN COMPLEX

Author(s):  
Katarzyna Małolepsza-Jarmołowska

The investigated powders on a methylcellulose base revealed good adhesion to the vaginal mucosa and were present on it throughout the daily activities of the patient. This property enabled the continuity of the 24-hour action of the drug. The treatment of vagina inflammatory conditions is usually long and difficult because of the frequent relapse. Powders were transformed into gels and were tested for their properties. Formulations were prepared with varying pH and rheological properties. The test showed the work of adhesion of gels. All gels with ratios of lactic acid to chitosan of 1:1 and 2:1 showed a pH in the physiological range at 37°C. Additionally, carboxymethylcellulose sodium salt and excipients allow various formulations with a wide range of pH to be obtained. Rheological investigation revealed an increase in the dynamic viscosity of preparations containing lactic acid complexed with chitosan and carboxymethylcellulose sodium salt in comparison to gels without carboxymethylcellulose sodium salt.

2018 ◽  
Vol XXIII ◽  
pp. 130-139
Author(s):  
Katarzyna Małolepsza-Jarmołowska

The insufficient duration of the drug’s contact with the vaginal mucosa does not provide adequate pH, conditioning the physiological biocenosis of the organ. This effect is hampered by numerous anatomic and physiological conditions which do not facilitate prolonged contact of the drug with the application site. This study has shown the impact of the used excipients and the ratio of lactic acid to chitosan on pH, dynamic viscosity and adhesiveness of methylcellulose gels obtained from powders. The addition of sodium alginate and excipients to these complexes allows various formulations to be obtained over a wide range of pH. Rheological investigations revealed an increase in the dynamic viscosity of preparations containing lactic acid complexed with chitosan and sodium alginate in comparison to gels without sodium alginate. Studies of the work of adhesion showed the effect of glycerol, 1,2-propylene glycol and their concentrations on the value of the work of adhesion.


Author(s):  
Katarzyna Małolepsza-Jarmołowska

Gynecological scientific journals report that traditional therapeutic regimens used to treat vaginal inflammation recommended by global treatment centers and health organizations are not producing satisfactory results. Insufficient duration of the drug’s contact with vaginal mucosa does not provide adequate pH conditioning the physiological biocenosis of the organ. The conducted research and obtained positive results encourage further research possibilities in the field of optimization of pharmaceutical properties of the examined gynecological preparations. Assuming the above assumptions tested impact of polyvinylpyrrolidone K-15, polyvinylpyrrolidone K-30 and polyvinylpyrrolidone K-90 in the properties of the globules. The study was prepared formulations with different pH and rheological properties. The device simulating the conditions in the vagina, studied the adhesion and movement of the gel on the mucosa of the organ. Globules after application of the apparatus simulates the natural conditions in the gel passes and cover the surface. A wide range of pH of the gels allows the selection of the optimum formulation


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Miriam Zacchia ◽  
Emanuela Marchese ◽  
Marianna Caterino ◽  
Margherita Ruoppolo ◽  
Giovambattista Capasso

Abstract Background and Aims Bardet Biedl Syndrome (BBS) is a rare genetic disorder characterized by a wide range of organ dysfunction, including kidney disease. The severity of renal dysfunction is highly variable in this setting, ranging from tubular defects to the end stage renal disease, with poor genotype-phenotype correlation. Proteomics and metabolomics are powerful tools able to contribute to the better understanding of molecular basis of disease conditions. Our previous studies demonstrated that the urinary proteomic pattern of BBS patients differed from that of healthy subjects, with a set of deregulated proteins including cell adhesion and extracellular matrix organization proteins (1). The present study aims to characterize urine metabolomic profile of BBS patients, in order to identify both 1) potential disease biomarkers and 2) aberrant metabolic pathways underlying renal disease Method To this end, in the pilot study urine samples have been collected from 14 adult BBS patients and have been compared with healthy volunteers, using an untargeted strategy. In the confirmation study, 24 BBS patients with wide range of kidney dysfunction have been enrolled, and additional control groups, besides healthy subjects, were included: 1) age-gender-matched chronic kidney disease patients by other causes and 2) obese individuals. Results Several metabolites were de-regulated in BBS patients compared with normal subjects (lactic acid, glycolic acid,3-Hydroxypropionic acid, pyruvic acid, 3-hydroxyisobutyric acid, 2-ethyl-3-hydroxy-propionic acid, succinic acid, fumaric acid, erythropentonic acid, 2-hydroxyglutaric acid, 4-hydroxyphenyllactic acid, 3,4-pyridinedicarboxylic acid, retinoic acid, 4-hydroxyphenylacetic acid, palmitic acid, 9-Hexadecenoic acid, oleic acid and 9-Octadecenoic acid). The clusterization performed by MetaboAnalyst tool, revealed a possible deregulation of different metabolic pathways, including glycolysis, TCA cycle, pyruvate metabolism, lipids biosynthesis and glutamate metabolism (p-value <0.01) (figure 1); some of these pathways were described as de-regulated in other ciliopathies (2). In the confirmation study (on-going studies) some metabolites, including lactic acid and intermediates of Krebs cycle, correlated with kidney dysfunction only in the BBS group. Conclusion These findings suggest that urine metabolomic fingerprint of BBS patients is different from that of healthy subjects and indicate a possible deregulation of several metabolic pathways; some urinary molecules correlated with kidney dysfunction only in BBS patients, suggesting the specificity of these results.


2011 ◽  
Vol 233-235 ◽  
pp. 1906-1910
Author(s):  
Ying Mo Hu ◽  
Qing Ling Wang ◽  
Jian Hua Zhu ◽  
Yang Liu ◽  
Xue Yang ◽  
...  

A convenient method to synthesize starch/lactic acid copolymer was studied in this work. Copolymer of starch graft with lactic acid (LA) was directly prepared by reaction of cornstarch with lactic acid in sodium hydroxide (NaOH) aqueous solution as a catalyst. The product was characterized by IR and WAXD, and the good adhesion between the two components has been observed by SEM. The results showed that the highest grafting degree could reach 33.60% when the graft copolymerization was carried in 0.40 mol·L-1 NaOH aqueous for 9 h at 90°C with the 1: 5~6 ratio of starch and lactic acid.


2016 ◽  
Vol 94 (8) ◽  
pp. 680-686
Author(s):  
Huiqing Li ◽  
Jing Wei ◽  
Youming Dong ◽  
Zhiyue Yu

The major bovine milk protein β-lactoglobulin (β-LG), a member of the lipocalin superfamily, can bind a wide range of ligands and act as a transporter. In the present study, the combination of the hydrophobic molecule 2-(p-toluidino)-6-naphthalenesulfonic acid sodium salt (TNS) with β-LG was analyzed using fluorescence spectroscopy and AutoDock modeling to discern the major binding sites of the protein and to determine the capacity of other small ligands to bind with β-LG by utilizing TNS as a reference. The experimental data indicate that in a neutral pH environment, TNS is located in the hydrophobic domain of the protein, 2.5 nm away from the Trp19 residues of β-LG. The binding constant of the small molecule to β-LG is (3.30 ± 0.32) × 106 (mol L–1)−1. An interaction model between the ligand and β-LG was developed, and AutoDock modeling also demonstrates that the ligand is located in the central hydrophobic calyx of β-LG within the regions covered by the Förster radius of the Trp19–ligand pair. Although the interaction between the ligand and β-LG is affected by increasing ion strength, pH change, and heat treatment, the complex is maintained until the secondary structure of β-LG is destroyed. Additionally, the ligand binding stabilizes the folding of β-LG. The binding constants of sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) to β-LG were obtained using competitive ligand binding measurements. With a sensitive fluorescence signal and stable complex, the ligand could be utilized as a reference to detect the binding of other small ligands to β-LG.


2021 ◽  
Vol 10 (14) ◽  
pp. 3116
Author(s):  
Florence Lai ◽  
Nathaniel Mercaldo ◽  
Cassandra M. Wang ◽  
Giovi G. Hersch ◽  
Herminia Diana Rosas

Adults with Down syndrome (DS) have an exceptionally high prevalence of Alzheimer disease (AD), with an earlier age of onset compared with the neurotypical population. In addition to beta amyloid, immunological processes involved in neuroinflammation and in peripheral inflammatory/autoimmune conditions are thought to play important roles in the pathophysiology of AD. Individuals with DS also have a high prevalence of autoimmune/inflammatory conditions which may contribute to an increased risk of early AD onset, but this has not been studied. Given the wide range in the age of AD onset in those with DS, we sought to evaluate the relationship between the presence of inflammatory conditions and the age of AD onset. We performed a retrospective study on 339 adults with DS, 125 who were cognitively stable (CS) and 214 with a diagnosis of AD. Data were available for six autoimmune conditions (alopecia, celiac disease, hypothyroidism, psoriasis, diabetes and vitamin B12 deficiency) and for one inflammatory condition, gout. Gout was associated with a significant delay in the age of AD onset by more than 2.5 years. Our data suggests that inflammatory conditions may play a role in the age of AD onset in DS. Further studies are warranted.


2000 ◽  
Vol 15 (12) ◽  
pp. 2758-2769 ◽  
Author(s):  
Michael Lane ◽  
Reinhold H. Dauskardt ◽  
Anna Vainchtein ◽  
Huajian Gao

The effects of plasticity in thin copper layers on the interface fracture resistance in thin-film interconnect structures were explored using experiments and multiscale simulations. Particular attention was given to the relationship between the intrinsic work of adhesion, Go, and the measured macroscopic fracture energy, Gc. Specifically, the TaN/SiO2 interface fracture energy was measured in thin-film Cu/TaN/SiO2 structures in which the Cu layer was varied over a wide range of thickness. A continuum/FEM model with cohesive surface elements was employed to calculate the macroscopic fracture energy of the layered structure. Published yield properties together with a plastic flow model for the metal layers were used to predict the plasticity contribution to interface fracture resistance where the film thickness (0.25–2.5 μm) dominated deformation behavior. For thicker metal layers, a transition region was identified in which the plastic deformation and associated plastic energy contributions to Gc were no longer dominated by the film thickness. The effects of other salient interface parameters including peak cohesive stress and Go are explored.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 466
Author(s):  
Kaixin Chang ◽  
Qianjin Zhu ◽  
Liyan Qi ◽  
Mingwei Guo ◽  
Woming Gao ◽  
...  

Nitrogen-doped carbon quantum dots (N-CQDs) were synthesized in a one-step hydrothermal technique utilizing L-lactic acid as that of the source of carbon and ethylenediamine as that of the source of nitrogen, and were characterized using dynamic light scattering, X-ray photoelectron spectroscopy ultraviolet-visible spectrum, Fourier-transformed infrared spectrum, high-resolution transmission electron microscopy, and fluorescence spectrum. The generated N-CQDs have a spherical structure and overall diameters ranging from 1–4 nm, and their surface comprises specific functional groups such as amino, carboxyl, and hydroxyl, resulting in greater water solubility and fluorescence. The quantum yield of N-CQDs (being 46%) is significantly higher than that of the CQDs synthesized from other biomass in literatures. Its fluorescence intensity is dependent on the excitation wavelength, and N-CQDs release blue light at 365 nm under ultraviolet light. The pH values may impact the protonation of N-CQDs surface functional groups and lead to significant fluorescence quenching of N-CQDs. Therefore, the fluorescence intensity of N-CQDs is the highest at pH 7.0, but it decreases with pH as pH values being either more than or less than pH 7.0. The N-CQDs exhibit high sensitivity to Fe3+ ions, for Fe3+ ions would decrease the fluorescence intensity of N-CQDs by 99.6%, and the influence of Fe3+ ions on N-CQDs fluorescence quenching is slightly affected by other metal ions. Moreover, the fluorescence quenching efficiency of Fe3+ ions displays an obvious linear relationship to Fe3+ concentrations in a wide range of concentrations (up to 200 µM) and with a detection limit of 1.89 µM. Therefore, the generated N-CQDs may be utilized as a robust fluorescence sensor for detecting pH and Fe3+ ions.


Author(s):  
М.И. Пряжников ◽  
А.В. Минаков

Data on the bulk viscosity of an aqueous suspension of SiO2 nanoparticles (Ludox TM-50) were obtained using an acoustic spectrometer for the first time. A wide range of mass concentrations of nanoparticles (from 1 to 50 wt.%) was considered. The spectra of the attenuation coefficient of ultrasound and the coefficients of longitudinal and dynamic viscosity were measured. The dependences of the dynamic and bulk viscosity coefficients of the suspensions on the nanoparticle concentration were obtained.


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