scholarly journals Hydrogel Films Based on Chitosan and Oxidized Carboxymethylcellulose Optimized for the Controlled Release of Curcumin with Applications in Treating Dermatological Conditions

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2185
Author(s):  
Mohamed Dellali ◽  
Camelia Elena Iurciuc (Tincu) ◽  
Corina Lenuța Savin ◽  
Nawel Spahis ◽  
M’hamed Djennad ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Molar Ratio ◽  
Cross Linking ◽  
Oxidation Degree ◽  
Molar Ratios ◽  
Receptor Compartment ◽  
Index Value ◽  
Aldehyde Groups ◽  
Hydrogel Films

Cross-linked chitosan (CS) films with aldehyde groups obtained by oxidation of carboxymethyl cellulose (CMC) with NaIO4 were prepared using different molar ratios between the CHO groups from oxidized carboxymethyl cellulose (CMCOx) and NH2 groups from CS (from 0.25:1 to 2:1). Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy demonstrated the aldehyde groups’ presence in the CMCOx. The maximum oxidation degree was 22.9%. In the hydrogel, the amino groups’ conversion index value increased when the -CHO/-NH2 molar ratio, cross-linking temperature, and time increased, while the swelling degree values decreased. The hydrogel films were characterized by scanning electron microscopy (SEM) and FTIR analysis. The curcumin encapsulation efficiency decreases from 56.74% to 16.88% when the cross-linking degree increases. The immobilized curcumin release efficiency (REf%) and skin membrane permeability were evaluated in vitro in two different pH solutions using a Franz diffusion cell, and it was found to decrease when the molar ratio -CH=O/NH2 increases. The curcumin REf% in the receptor compartment was higher at pH = 7.4 (18%- for the sample with a molar ratio of 0.25:1) than at pH = 5.5 (16.5%). The curcumin absorption in the skin membrane at pH = 5.5 (47%) was more intense than at pH = 7.4 (8.6%). The curcumin-loaded films’ antioxidant activity was improved due to the CS presence.

scholarly journals Size-Dependent Photodynamic Activity of Gold Nanoparticles Conjugate of Water Soluble Purpurin-18-N-Methyl-D-Glucamine

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Byambajav Lkhagvadulam ◽  
Jung Hwa Kim ◽  
Il Yoon ◽  
Young Key Shim
Keyword(s):  
Gold Nanoparticles ◽  
A549 Cells ◽  
Water Soluble ◽  
Molar Ratio ◽  
Anticancer Efficacy ◽  
Molar Ratios ◽  
Size Dependent ◽  
Photodynamic Activity ◽  
Wavelength Absorption

Gold nanoparticles (GNPs) conjugates of water soluble ionic photosensitizer (PS), purpurin-18-N-methyl-D-glucamine (Pu-18-NMGA), were synthesized using various molar ratios between HAuCl4and Pu-18-NMGA without adding any particular reducing agents and surfactants. The PS-GNPs conjugates showed long wavelength absorption of range 702–762 nm, and their different shapes and diameters depend on the molar ratios used in the synthesis.In vitroanticancer efficacy of the PS-GNPs conjugates was investigated by MTT assay against A549 cells, resulting in higher photodynamic activity than that of the free Pu-18-NMGA. Among the PS-GNPs conjugates, the GNPs conjugate from the molar ratio of 1 : 2 (Au(III): Pu-18-NMGA) exhibits the highest photodynamic activity corresponding to bigger size (~60 nm) of the GNPs conjugate which could efficiently transport the PS into the cells than that of smaller size of the GNPs conjugate.

INTRAARTERIAL THROMBOLYSIS BY STREPTOKINASE-GLU-PLASMINOGEN

1987 ◽  
Author(s):  
E J Pilger ◽  
J Lammer ◽  
H Bertuch ◽  
H Steiner
Keyword(s):  
Artery Occlusion ◽  
Molar Ratio ◽  
In Vitro Test ◽  
Group Iii ◽  
Fibrinolytic Agent ◽  
Molar Ratios ◽  
Intraarterial Thrombolysis ◽  
Group I

In order to predict usefulness of streptokinase (SK), urokinase (UK) and streptokinase-glutamin-plasminogen (SK-Glu-Plg) for intraarterial fibrinolysis, an in vitro test was designed. Fibrin plates with and without plasminogen were incubated with SK, UK and SK-Glu-Plg (in molar ratios of 1:1, 2:1 and 1:2). On the fibrin plates containing plasminogen the highest fibrinolytic activity was observed with UK; on the fibrin plates without plasminogen, SK-Glu-Plg in a molar ratio of 1:2 was superior. We concluded, that plasmin would be synthesized by SK and Glu-Plg. In order to examine the in vivo efficacy of these different fibrinolytic agents, 120 patients suffering from peripheral artery occlusion were randomized into three treatment groups for local thrombolysis. The technique of Hess and coworkers was used for local thrombolytic therapy. In group I local fibrinolysis was performed with SK (2500 IU/5 min), in group II UK (4000 IU/5 min) was used and in group III the lytic agent consisted of SK-Glu-Plg (2500 IU/5 min). The primary recanalization rate was equal in all groups: 86%, 89% and 83% in group I, II and III respectively. However the duration required for the procedure and thus the total amount of fibrinolytic agent used was significantly different (p < 0,001) between the three groups: 2,3 ± 1,4; 2,1 ± 1,2 and 1,1 ±0,8 hours for groups I,II and III, respectively (mean ± SEM) . We conclude that SK-Glu-Plg or plasmin itself has the highest efficacy as a fibrinolytic agent for intraarterial thrombolysis. Since the intra-thrombotic concentration of Pig is unknown in an individual patient an empirically chosen dose of SK of UK may either be to high or to low for optimal thrombolysis.

scholarly journals Simple One Pot Preparation of Chemical Hydrogels from Cellulose Dissolved in Cold LiOH/Urea

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 373 ◽  
Author(s):  
Jiayi Yang ◽  
Bruno Medronho ◽  
Björn Lindman ◽  
Magnus Norgren
Keyword(s):  
Molar Ratio ◽  
Cross Linking ◽  
Absorption Properties ◽  
One Pot ◽  
Molar Ratios ◽  
Cellulose Pulp ◽  
Water Uptake Capacity ◽  
Swelling Capacity ◽  
Cellulose Hydrogel ◽  
Water Swelling

In this work, non-derivatized cellulose pulp was dissolved in a cold alkali solution (LiOH/urea) and chemically cross-linked with methylenebisacrylamide (MBA) to form a robust hydrogel with superior water absorption properties. Different cellulose concentrations (i.e., 2, 3 and 4 wt%) and MBA/glucose molar ratios (i.e., 0.26, 0.53 and 1.05) were tested. The cellulose hydrogel cured at 60 °C for 30 min, with a MBA/glucose molar ratio of 1.05, exhibited the highest water swelling capacity absorbing ca. 220 g H2O/g dry hydrogel. Moreover, the data suggest that the cross-linking occurs via a basic Michael addition mechanism. This innovative procedure based on the direct dissolution of unmodified cellulose in LiOH/urea followed by MBA cross-linking provides a simple and fast approach to prepare chemically cross-linked non-derivatized high-molecular-weight cellulose hydrogels with superior water uptake capacity.

scholarly journals Short-chain fatty acids produced in vitro from fibre residues obtained from mixed diets containing different breads and in human faeces during the ingestion of the diets

2000 ◽  
Vol 84 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Elisabeth Wisker ◽  
Martina Daniel ◽  
Gerhard Rave ◽  
Walter Feldheim
Keyword(s):  
Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Fibre Diet ◽  
The Difference ◽  
Wholemeal Bread ◽  
Chain Fatty Acids

It was studied whether the type of bread (i.e. a low-fibre wheat–rye mixed bread and coarse or fine wholemeal rye bread) either as part of a diet or alone, had an influence on the short-chain fatty acids (SCFA) produced during in vitro fermentation. Fermentation substrates were dietary fibre residues obtained from diets and breads. In addition, it was investigated whether the faecal SCFA pattern in the inoculum donors, who ingested the experimental diets, could be predicted by in vitro fermentation. Yields of SCFA in vitro were 0·51–0·62 g/g fermented polysaccharide. In vitro, the molar ratios of butyrate were higher for the two high-fibre diets containing coarse or fine wholemeal bread than for the low fibre diet containing wheat–rye mixed bread; the difference was significant for the coarse (P < 0·01), but not for the fine bread diet (P = 0·0678). The coarse wholemeal bread alone produced a higher molar ratio of butyrate than the fine wholemeal bread (P < 0·05) and the wheat–rye mixed bread (P < 0·01). Ingestion by the inoculum donors of the diets containing wholemeal bread led to higher faecal butyrate ratios (molar ratios: coarse bread diet 19·6, fine bread diet 17·7) compared with the wheat–rye mixed bread-containing diet (14·9), but the differences between the diets were not significant. For the diets investigated, there were no significant differences between faecal and in vitro SCFA patterns.

scholarly journals Evaluation and Characterization of Curcumin-β-Cyclodextrin and Cyclodextrin-Based Nanosponge Inclusion Complexation

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4073
Author(s):  
Hadeia Mashaqbeh ◽  
Rana Obaidat ◽  
Nizar Al-Shar’i
Keyword(s):  
In Vitro Release ◽  
Inclusion Complexation ◽  
Pharmaceutical Formulations ◽  
Cross Linking ◽  
Phase Solubility ◽  
Drug Bioavailability ◽  
Cyclodextrin Complex ◽  
Molar Ratios ◽  
Study Results

Cyclodextrin polymers and cyclodextrin-based nanosponges have been widely investigated for increasing drug bioavailability. This study examined curcumin’s complexation stability and solubilization with β-cyclodextrin and β-cyclodextrin-based nanosponge. Nanosponges were prepared through the cross-linking of β-cyclodextrin with different molar ratios of diphenyl carbonate. Phase solubility experiments were conducted to evaluate the formed complexes and evaluate the potential of using β-cyclodextrin and nanosponge in pharmaceutical formulations. Furthermore, physicochemical characterizations of the prepared complexes included PXRD, FTIR, NMR, and DSC. In addition, in vitro release studies were performed for the prepared formulations. The formation of β-cyclodextrin complexes enhanced curcumin solubility up to 2.34-fold compared to the inherent solubility, compared to a 2.95-fold increment in curcumin solubility when loaded in β-cyclodextrin-based nanosponges. Interestingly, the stability constant for curcumin nanosponges was (4972.90 M−1), which was ten times higher than that for the β-cyclodextrin complex, where the value was 487.34 M−1. The study results indicated a decrease in the complexation efficiency and solubilization effect with the increased cross-linker amount. This study’s findings showed the potential of using cyclodextrin-based nanosponge and the importance of studying the effect of cross-linking density for the preparation of β-cyclodextrin-based nanosponges to be used for pharmaceutical formulations.

scholarly journals SELECTION OF PHOSPHOLIPID AND METHOD OF FORMULATION FOR OPTIMUM ENTRAPMENT AND RELEASE OF LAMIVUDINE FROM LIPOSOME

2018 ◽  
Vol 8 (5-s) ◽  
pp. 175-183 ◽  
Author(s):  
Mangesh D Godbole ◽  
Vijay B Mathur
Keyword(s):  
Thin Film ◽  
Encapsulation Efficiency ◽  
In Vitro Release ◽  
Molar Ratio ◽  
Vesicle Size ◽  
Injection Method ◽  
Molar Ratios ◽  
Vitro Release ◽  
Selection Of

The present investigation was aimed to compare various phospholipids and different methods that would be appropriate to produce liposomes having vesicle size in the range of 200-300 nm, PDI less than 0.500, maximum entrapment and delayed release of lamivudine. The phospholipids employed were Phospholipon® 90G, Phospholipon® 90H, 1,2-Dimyristoyl-sn-glysero-3-phosphocholine (DMPC) and 1,2-Dipalmitoyl-sn-glysero-3-phosphocholine (DPPC). They were used in various molar ratio with cholesterol and blank liposomes were prepared initially by thin film hydration and ether injection method. The thin film hydration method was only found to be appropriate to produce liposome of desired size and PDI. Hence, the molar ratios of employed phospholipids:cholesterol that produced liposomes as per the expected parameters was then used to load lamivudine. The method of preparation, phospholipid: cholesterol molar ratio, hydrations above transition temperature and hydration time were showed direct influence on vesicle size, PDI, percentage encapsulation and in-vitro release. Phospholipon® 90H: cholesterol: lamivudine in the molar ratio 1:2:1 produced liposomes having desired vesicle size and PDI with maximum drug entrapment and sustained release. The encapsulation efficiency of drug in liposomes was in the order of Phospholipon® 90H> Phospholipon® 90G > DPPC > DMPC. Keywords: Liposomes, Lamivudine, Phospholipid, Thin film hydration method, Ether injection method, encapsulation efficiency

Quantitation of uncombined gonadotropin subunits within and released by the rat anterior pituitary

1988 ◽  
Vol 119 (2) ◽  
pp. 203-212
Author(s):  
H. Edward Grotjan
Keyword(s):  
Anterior Pituitary ◽  
Gel Filtration ◽  
Molar Ratio ◽  
Absolute Amount ◽  
Β Subunit ◽  
Α Subunit ◽  
Molar Ratios ◽  
Tissue Extracts ◽  
Triton X

Abstract. The release of uncombined gonadotropin subunits by rat anterior pituitaries during an in vitro incubation as well as intracellular concentrations were assessed. Uncombined subunits and native gonadotropins were quantitated by radioimmunoassays after samples were subjected to gel filtration on Sephadex G-100 Superfine. Small, but detectable, amounts of uncombined rat LH β subunit were released under basal conditions. GnRH increased the absolute amount of rLHβ released but did not alter the rLHβ/rLH molar ratio (≈ 0.02). Tissue extracts prepared in aqueous buffer (100 000 × g supernatants) and 0.5% Triton X-100 extracts of the 100 000 × g pellets from the initial homogenization ('pellet extracts') contained larger quantities of uncombined rLHβ as well as elevated rLHβ/rLH molar ratios (≈ 0.10 and ≈ 0.20, respectively). Significant amounts of uncombined rLHα were released and were present in both tissue and pellet extracts. However, when FSH β subunit was quantitated in tissue extracts after gel filtration, all of the immunoreactive materials eluted in the position of native rFSH (FSHβ/rFSH molar ratio < 0.0025). Pellet extracts contained significant amounts of rLHβ, rLH and rLHα but lesser amounts of rFSH suggesting that intracellular gonadotropins are not completely extracted when homogenization is performed in aqueous buffers. Thus, rat anterior pituitaries contain and release significant amounts of the uncombined α subunit, relatively small amounts of uncombined rLHβ and extremely small amounts of uncombined FSHβ, if any.

scholarly journals Synthesis and evaluation of B-cyclodextrin Based Nanosponges of 5- Fluorouracil by Using Ultrasound Assisted Method

2020 ◽  
Vol 29 (2) ◽  
pp. 88-98
Author(s):  
Ihsan K. Jasim ◽  
Shaimaa N. Abd Alhammid ◽  
Alaa A. Abdulrasool
Keyword(s):  
Particle Size ◽  
In Vitro Release ◽  
Particle Morphology ◽  
Entrapment Efficiency ◽  
Molar Ratio ◽  
Phase Solubility ◽  
Molar Ratios ◽  
Phase Solubility Study ◽  
Ultrasound Assisted

  CD-nanosponges were prepared by crosslinking B-CD with diphenylcarbonate (DPC) using ultrasound assisted technique. 5-FU was incorporated with NS by freeze drying, and the phase solubility study, complexation efficiency (CE) entrapment efficiency were performed. Also, the particle morphology was studied using SEM and AFM. The in-vitro release of 5-FU from the prepared nanosponges was carried out in 0.1N HCl. 5-FU nanosponges particle size was in the nano size. The optimum formula showed a particle size of (405.46±30) nm, with a polydispersity index (PDI) (0.328±0.002) and a negative zeta potential (-18.75±1.8). Also the drug entrapment efficiency varied with the CD: DPC molar ratio from 15.6 % to 30%. The SEM and AFM showed crystalline and porous nature of the nanosponges. The in vitro drug release study of the selected formula 5-FUNS2 exhibited the fastest dissolution rate which is 56% in the first hr. Different molar ratios of (cyclodextrin to crosslinker) (CD: DPC) has a proficient effect on complexation efficiency (CE), apparent stability constant (Kst) and entrapment efficiency of 5-FU. 5-FUNS2 with (1:4) molar ratio showed the best result of CE, Kst and entrapment efficiency. 5-FUNS2 gave a higher release rate than the 5-FU-BCD inclusion complex and 5-FU solution. Surface morphology of the prepared nanosponges by SEM, AFM indicate that nanosized and highly porous nanosponges was obtained. The overall results suggest that cyclodextrin nanosponges could be a promising 5-FU delivery system utilizing the suitable formula.

FK506-binding protein of the hyperthermophilic archaeum, Thermococcus sp. KS-1, a cold-shock-inducible peptidyl-prolyl cis–trans isomerase with activities to trap and refold denatured proteins

2001 ◽  
Vol 357 (2) ◽  
pp. 465-471
Author(s):  
Akira IDENO ◽  
Takao YOSHIDA ◽  
Toshii IIDA ◽  
Masahiro FURUTANI ◽  
Tadashi MARUYAMA
Keyword(s):  
Citrate Synthase ◽  
Binding Protein ◽  
Binding Pocket ◽  
Molar Ratio ◽  
Hydrophobic Region ◽  
Native Form ◽  
Ppiase Activity ◽  
Molar Ratios ◽  
Multimeric Complex

The FK506 (tacrolimus)-binding protein (FKBP) type peptidyl-prolyl cis–trans isomerase (PPIase) in the hyperthermophilic archaeum Thermococcus sp. KS-1 was shown to be induced by temperature downshift to growth temperatures lower than the optimum. This PPIase (TcFKBP18) showed chaperone-like protein refolding activity in addition to PPIase activity in vitro. It refolded unfolded citrate synthase (CS) and increased the yield of the refolded protein. At a molar ratio of 15:1 ([TcFKBP18] to [CS]) in the refolding mixture, the recovered yield of folded CS was maximal at 62%, whereas that of spontaneous refolding was 11%. Increasing FKBP above a 15:1 ratio decreased the final yield, whereas the aggregation of unfolded CS was suppressed. A cross-linking analysis showed the formation of a complex between TcFKBP18 and unfolded CS (1:1 complex) at molar ratios of 3:1 to 15:1. However, molar ratios of 15:1 or 60:1 induced the binding of multiple FKBP molecules to an unfolded CS molecule (multimeric complex). Disrupting hydrophobic interaction by adding ethylene glycol at a molar ratio of 60:1 ([TcFKBP18] to [CS]) suppressed the formation of this multimeric complex, simultaneously enhancing CS refolding. FK506 also suppressed the formation of the multimeric complex while increasing the chaperone-like activity. These results suggest that the hydrophobic region of TcFKBP18, probably the FK506-binding pocket, was important for the interaction with unfolded proteins. No cross-linked product was detected between TcFKBP18 and native dimeric CS. TcFKBP18 probably traps the unfolded protein, then refolds and releases it in a native form. This FKBP might be important at growth temperatures lower than the optimum in Thermococcus sp. KS-1 cells.

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