Solubility In Aqueous Solutions Research Articles

Curcumin copolymerized drugs mediated by enteric-coated polymers: Their design, synthesis and biocompatibility cell imaging studies

Curcumin has anticancer, anti-inflammatory, antioxidant, antibacterial and other pharmacological activities with less side effects, which has been widely studied. However, due to the low oral bioavailability, poor solubility in aqueous solution and easy degradation under physiological conditions, the application of curcumin is limited. In this paper, curcumin and acrylic resin were combined by chemical bond to obtain four curcumin-eudragit polymers, which has excellent photophysical properties. The maximum emission wavelengths of the four polymers are concentrated between 546 and 596 nm. In addition, four polymers were applied to cell imaging. They can enter and be well absorbed by L02, HeLa and HCT-116 cells. Overall, the polymers synthesized in this paper can be used as a drug fluorescence agent, at the same time, the experiment has great reference value in loading drugs with polymer materials to realize the slow and controlled release of drugs.

Prediction of hydrogen solubility in aqueous solutions: Comparison of equations of state and advanced machine learning-metaheuristic approaches

Hydrogen is the primary carrier of renewable energy stored underground. Understanding the solubility of hydrogen in water is critical for subsurface storage. Accurately measuring the hydrogen solubility in water has implications for monitoring, control, and storage optimization. In this study, two intelligent systems of Radial Basis Function (RBF) and Least Square Support Vector Machine (LSSVM) were used to precisely predict hydrogen solubility in water. These models were optimized using metaheuristic algorithms, namely biogeography-based optimization (BBO), cultural algorithm (CA), imperialist competitive algorithm (ICA), and teaching-learning-based optimization (TLBO). Quantitative and illustrative evaluations revealed that the RBF paradigm optimized using the CA algorithm with a root mean square error of 0.000176 and a correlation coefficient of 0.9792 is the best model for predicting hydrogen solubility in water. Also, to estimate hydrogen solubility in water, the four well-known equations of state (EoSs) of Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), Redlich-Kwong (RK), and Zudkevitch-Joffe (ZJ) were utilized. The results indicated that the SRK has the best performance among EoSs. However, the intelligent models outperformed the EoSs in terms of accuracy. Considering independent factors, pressure and temperature had the greatest effect on hydrogen solubility in water, respectively. The Leverage technique typified that the RBF + CA model has a good degree of validity for forecasting hydrogen solubility in pure and saline water. Finally, the findings of this investigation demonstrated that the RBF + CA model can have industrial applications and accurately predicts the solubility of hydrogen in pure water and saline water under underground storage conditions (high pressure and temperature).

Hydrolysis of cellulose to fermentable sugars by using 2,5-furandicarboxylic acid as a recyclable catalyst in green solvent of GVL/ H2O

Hydrolysis of cellulose into C6 sugars is the starting point and entry point for biomass refining and is an important pathway for biofuel production. However, biomass-based 2,5-furandicarboxylic acid (FDCA) is a highly catalytic promising but underutilized organic carboxylic acid. In this paper, we investigated the use of easily recoverable FDCA as a catalyst for the hydrolysis of cellulose to produce C6 sugars in a γ-valerolactone/water (GVL/H2O) green solvent system. FDCA has high inherent acidity (pKa = 2.76) and stability with unique solubility in aqueous solutions and many solvents. These properties allows it to meet both high temperature solubility for efficient homogeneous hydrolysis reactions and low temperature crystallization catalysts for high purity recovery. This process not only solves the problem of solid-solid mass transfer between solid acid and cellulose which limits the hydrolysis rate, but also eliminates the problem of difficult separation and recovery of liquid acid catalysts. The results showed when initial concentration of microcrystalline cellulose was 0.7 wt%（equivalent to 7 g/L）, and the initial dosage of FDCA was 2.0 wt%, the maximum yield of C6 sugars reached 72.9% (40.1% glucose and 32.8% fructose) in GVL/H2O (60/40, V/V) with a reaction at 200 °C for 30 min. More importantly, FDCA can achieve 80% recovery and ＞99% spectroscopic purity recovery. This study reveals the potential of FDCA as a catalyst in the catalytic conversion of biomass, which provides a new pathway for the green and efficient conversion of biomass resources.

The effects of conjugation of walnut protein isolate with polyphenols on protein solubility, antioxidant activity, and emulsifying properties

Alkaline-extracted walnut protein isolate (AWPI) shows poor solubility in aqueous solutions, resulting in relatively low emulsion capacity. This work investigated the influence of ellagic acid (EA) or epigallocatechin-3-gallate (EGCG) conjugation on the solubility and emulsifying properties of AWPI. The increase in polyphenol content and decrease in free amino and thiol groups of walnut proteins confirmed successful conjugation. AWPI polyphenol conjugates showed significantly reduced surface hydrophobicity, greatly enhanced surface charge, and consequently improved solubility. Circular dichroism (CD) results indicated that the polyphenol-conjugated AWPI contained relatively higher α-helical and lower β-sheet contents than AWPI. The antioxidant capacity of the polyphenol-conjugated AWPI was significantly enhanced. Additionally, polyphenol conjugation resulted in decreased mean particle sizes and increased surface charges of the walnut protein-covered oil droplets. The emulsions stabilized by AWPI-polyphenol conjugates were relatively more stable over a range of pH values (7.0–11.0) and thermal treatments (25 °C–90 °C). Moreover, they exhibited greater storage stability than those stabilized by unmodified AWPI.

Enhanced Photocatalytic Efficiency in Visible-Light-Induced NADH Regeneration by Intramolecular Electron Transfer.

Inspired by natural photosynthesis, photocatalytic NADH regeneration has drawn increasing interest in the recent decade as it provides a perfect approach for NAD+ reduction into NADH, which can be further consumed by oxidordeuctase for enzymatic redox reactions. However, two issues still remain unsolved in this procedure. First, the photocatalytic efficiency in NAD+ hydrogenation requires further improvement. Second, the rhodium electron mediator [Cp*Rh(bpy)H2O]2+ (M), which is always required for selective 1,4-NADH regeneration, is difficult to recover because of its good solubility in aqueous solution. Given the high price of M, it is highly wasteful and inefficient if it only spends once. Here, we report a Cp*Rh(bpy)Cl implanted conjugated microporous polymer DTS/Rh@CMPs which can be employed as a highly effective visible light photocatalysts for in situ NADH regeneration without using additional M. In addition, the insertion of Rh complex into a polymer skeleton, as demonstrated in UV-vis, fluorescence, photocurrent and electrochemical impedance, dramatically improves the light absorption capacity and the electron separation and transfer efficiency. Compared with that of DTS@CMP-1 with M, an enhanced reaction yield of 33% was determined in DTS/Rh@CMP-1 suggesting that intramolecular electron transfer has a better activity than that of intermolecular electron transfer in photocatalytic NAD+ reduction. Moreover, as the Rh complex is rooted firmly in a polymer framework, negligible Rh loss and conversion decrease in NADH regeneration are observed. When the DTS/Rh@CMP-1 was coupled with yeast alcohol dehydrogenase (YADH, from Saccharomyces cerevisiae), 1.36 mM of methanol was accumulated, implying an excellent biocompatibility of DTS/Rh@CMP-1 and a high feasibility of photobiocatalysis for formaldehyde hydrogenation.

Caffeine solubility in aqueous solutions of polyethylene glycol dimethyl ether 250: measurement and thermodynamic modeling

ABSTRACT Molar solubility of caffeine in polyethylene glycol dimethyl ether 250 (PEGDME 250) + water mixtures over all mass fractions of PEGDME 250 were determined at 293.15–313.15 K under atmospheric pressure (≈ 85 kPa). The crystal forms of the caffeine in equilibrium with neat solvents of PEGDME 250 and water were analysed using X-ray powder diffraction and the results compared with the original caffeine. Also, the Hansen solubility parameters of caffeine and PEGDME 250 + water mixtures in the absence of caffeine were predicted. The studies of apparent thermodynamic analysis presented an endothermic and enthalpy-driven dissolution of caffeine. Moreover, the solubility of caffeine were correlated using various models; the van’t Hoff, mixture response surface, Jouyban–Acree, Jouyban–Acree–van’t Hoff, the modified version of Jouyban–Acree–van’t Hoff, the CNIBS/R-K, the Buchowski–Ksiazczak, the modified Wilson and modified Wilson–van’t Hoff models, acquiring average relative deviation values that were lower than 14.7%.

Prediction of CO2 solubility in NaCl brine under geological conditions with an improved binary interaction parameter in the Søreide-Whitson model

The accurate prediction the CO2 solubility in the aqueous NaCl solution under geological conditions is essential in CO2 geo-energy resources recovery and CO2 geological storage practices, therefore has attracted extensive academic interests. In this paper, comprehensive thermodynamical calculations are performed concerning the CO2 solubility in aqueous solutions with various sodium chloride concentrations of 1–6 m (mol/kgw) at the geological pressure and temperature conditions of 313–433 K and 0.5–30 MPa. A new binary interaction parameter (BIP) in Søreide-Whitson (SW) model is proposed to improve the calculation accuracy in the wide salinity, temperature and pressure ranges. Through systematic comparisons with the 42 experimental sets and 206 measurement points on the solubility of CO2 in NaCl brine, the employed thermodynamic model as well as the modeling results is well validated based on the satisfactory Average Absolute Deviation (AAD) value of 3.77%. At last, detailed analysis on effects of salinity, temperature and pressure are carried out based on the calculation results. It is found the solubility of CO2 decreases with increasing salinity and decreasing pressure. There are oversteps for the CO2 solubility under different temperatures when the system pressure is higher than 20 MPa.

CO2 solubility modelling in Non-Precipitating aqueous solutions of potassium lysinate

Modelling of CO2 solubility in aqueous solutions of potassium lysinate (LysK) is mainly hindered by scarcity of experimental vapor–liquid equilibrium data and lack of chemical equilibrium constants associated to the reaction mechanism for the CO2/LysK/H2O system. Therefore, Kent-Eisenberg (KE) correlation stands out from the literature, being among the most used approaches for the description of the equilibrium CO2 partial pressure at different loadings. In this work, a Kent-Eisenberg-like approach has been developed, enhancing the empirical Kent-Eisenberg with Debye-Hückel activity coefficients in order to guide model calibration with reference to selected experimental data for CO2 solubility in 33.1 and 33.5 %w/w aqueous LysK solution; moreover, the KE edition provides an estimation of the missing equilibrium constants. This information has been embedded in a first thermodynamically sound and predictive Deshmukh-Mather (DM) model (average absolute deviation equal to 7 %) validated against additional experimental data in a wide temperature and concentration range.

Thermodynamic properties data of ternary system NH4Cl-NH4H2PO4-H2O at 298.15 K including the solubility data

• Determination of the thermodynamic properties of the system {yNH4Cl+(1-y)NH4H2PO4}(aq) at 25 °C. • Application of the PSC model to describe the thermodynamic behavior of aqueous solutions. • Calculation of NH4Cl and NH4H2PO4 activity coefficients in the system {yNH4Cl+(1-y)NH4H2PO4}(aq). • Prediction of NH4Cl and NH4H2PO4 solubilities in aqueous solution. The mixed aqueous electrolyte system ammonium chloride and ammonium di-hydrogen phosphate has been studied with the hygrometric method at the temperature 298.15 K. The water activities, osmotic coefficient and solubilities are deduced from measurements of relative humidities of this system against total molality ranging from 0.4 mol . kg −1 to about saturation, and for different ionic-strength fractions y of NH 4 H 2 PO 4 ( y = I N H 4 H 2 P O 4 / [ I N H 4 H 2 P O 4 + I N H 4 C l ]) of 0, 1/4, 1/3, 1/2, 2/3, 3/4 and 1. Experimental results are compared to Dinane rule by the Extended Compound Additivity Law (ECA), Leitzke-Stoughton (LS II) and Lin et al. equation. The obtained results were correlated using the PSC model to predict the solute activity coefficients in the mixture for different compositions of the system and are also used to calculate the solubility and excess Gibbs energy in the studied molality range.

Dendrimeric micelles composed of polyamidoamine dendrimer-peptide-cholesterol conjugates as drug carriers for the treatment of melanoma and bacterial infection

Skin cancer is a serious health concern posing an economic burden. Phytochemicals isolated from plants have attracted the attention of researchers as potential therapeutic agents against skin cancer. Paclitaxel and curcumin are effective anticancer agents. However, their poor solubility in aqueous solutions results in low bioavailability, limiting their therapeutic applications. In this study, we developed dendrimeric micelles to encapsulate paclitaxel and curcumin for the treatment of melanoma. The antibacterial activity of curcumin-loaded dendrimeric micelles was evaluated. Dendrimeric micelles were prepared using PAMAM dendrimers conjugated with histidine-arginine dipeptides and cholesterol (PHRC). Different amounts of cholesterol (6 % or 23 %) were conjugated to the surface of PAMAM dendrimer generation 2 derivatives (PAMAM G2-HR) to evaluate the effects of cholesterol on the drug encapsulation efficiency and bioactivity. The critical aggregation concentration (CAC) value of PHRC6 and PHRC23 was 0.14 mg/mL and 0.09 mg/mL, respectively. The size of the dendrimeric micelles was confirmed using dynamic light scattering (DLS). Furthermore, the cytotoxicity of PHRC amphiphiles was measured in B16F10 melanoma cells. Both PHRC6 and PHRC23 were combined with TPGS to prepare functional mixed dendrimeric micelles, including PHRC6/TPGS and PHRC23/TPGS. The encapsulation efficiency was higher for curcumin than paclitaxel (80.2 % and 76.3 % for curcumin and 30.7 % and 38.2 % for paclitaxel in PHRC6/TPGS and PHRC23/TPGS, respectively). Based on these results, PHRC/TPGS dendrimeric micelles displayed a high potential for the nano-formulation of hydrophobic drugs and good bioavailability and bioactivity against skin cancer.

Cinnamomum: The New Therapeutic Agents for Inhibition of Bacterial and Fungal Biofilm-Associated Infection.

Due to the potent antibacterial properties of Cinnamomum and its derivatives, particularly cinnamaldehyde, recent studies have used these compounds to inhibit the growth of the most prevalent bacterial and fungal biofilms. By inhibiting flagella protein synthesis and swarming motility, Cinnamomum could suppress bacterial attachment, colonization, and biofilm formation in an early stage. Furthermore, by downregulation of Cyclic di‐guanosine monophosphate (c‐di‐GMP), biofilm-related genes, and quorum sensing, this compound suppresses intercellular adherence and accumulation of bacterial cells in biofilm and inhibits important bacterial virulence factors. In addition, Cinnamomum could lead to preformed biofilm elimination by enhancing membrane permeability and the disruption of membrane integrity. Moreover, this substance suppresses the Candida species adherence to the oral epithelial cells, leading to the cell wall deformities, damage, and leakages of intracellular material that may contribute to the established Candida’s biofilm elimination. Therefore, by inhibiting biofilm maturation and destroying the external structure of biofilm, Cinnamomum could boost antibiotic treatment success in combination therapy. However, Cinnamomum has several disadvantages, such as poor solubility in aqueous solution, instability, and volatility; thus, the use of different drug-delivery systems may resolve these limitations and should be further considered in future investigations. Overall, Cinnamomum could be a promising agent for inhibiting microbial biofilm-associated infection and could be used as a catheter and other medical materials surface coatings to suppress biofilm formation. Nonetheless, further in vitro toxicology analysis and animal experiments are required to confirm the reported molecular antibiofilm effect of Cinnamomum and its derivative components against microbial biofilm.

Development of Heteroarene-Fused Quinones As Rapidly Dissoluble and Stable Biosensors

Aqueous electron mediators for point-of-care testing require a variety of properties, such as rapid dissolubility, high stability, and moderate formal potential (near 0 V). Using the redox-active properties of quinone derivatives, various quinone-containing electron mediators have been developed for electrochemical sensors. However, most quinone derivatives exhibit very low solubility in aqueous solutions and instability in the presence of nucleophilic species. Herein, we report a strategic design for quinones incorporating sulfonated thioether and nitrogen-containing heteroarene moieties as solubilizing, stabilizing, and formal potential-modulating groups. Systematic investigations found that di(thioether sulfonate)-substituted quinoline-1,4-dione (QLS) and quinoxaline-1,4-dione (QXS) displayed high water solubility and rapid dissolubility. By finely balancing the electron-donating effect of the thioethers and the electron-withdrawing effect of the nitrogen atom, formal potentials suitable for electrochemical biosensors are achieved with QLS and QXS (−0.15 and −0.09 V vs Ag/AgCl, respectively, at pH 7.4). QLS is stable for >1 d in PBS (pH 7.4) and for 1 h in tris buffer (pH 9.0), which is sufficient for point-of-care testing. Furthermore, QLS, with its high electron mediation ability, is successfully used in biosensors for sensitive detection of glucose and parathyroid hormone. This strategy provides organic electron mediators that exhibit rapid dissolution and high stability and will find broad applications beyond quinone-based biosensors. Figure 1

Enhancement in aqueous solubility of sulindac medicine by using the micellar solution of ionic and non-ionic surfactants

In the science of pharmacology, solubility plays a crucial role in the efficacy and bioavailability of the drug. Utilizing solubility features to improve the bioavailability and pharmacological effect of diverse weakly soluble substances, is an arduous task for pharmaceutical experts and researchers. Particle size, surface area, physicochemical qualities, physical forms of drugs, solvents and surfactant usage are parameters that influence solubility. The objective of the current study was to enhance the solubility of the non-steroidal anti-inflammatory drug (NSAID): Sulindac. The micellar solutions method was employed with different surfactants to increase the efficiency. Both nonionic (Tween 20, 40, 60 and 80 with Brij 30, 35 and 56) and ionic (SDS, SDBS, CTAB, TTAB and DTAB) surfactants were investigated for their effect on drug solubility in aqueous solution. Various parameters of surfactant solutions such as aggregation number, micelle-water partition coefficient (KM), molar solubilization ratio (MSR), Gibbs energy of solubilization (∆Gº s), size of micelle and binding constant of the drug micelles were measured. Finding reveals that the use of mentioned surfactant is an excellent approach to enhancing the solubility of sulindac. Furthermore, the present work provides an understanding of the relation of aqueous solubility with aggregation number and structure of surfactants used.

PLGA-Based Nanoplatforms in Drug Delivery for Inhibition and Destruction of Microbial Biofilm.

The biofilm community of microorganisms has been identified as the dominant mode of microbial growth in nature and a common characteristic of different microorganisms such as Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The biofilm structure helps in the protection from environmental threats including host immune system and antimicrobial agents. Thus, the biofilm community has led to a higher prevalence of multidrug-resistant (MDR) strains in recent years. In this regard, the use of a new class of antibiotics, natural compounds, and anti-biofilm enzymes has been considered for the destruction of the microbial biofilm. However, different drawbacks such as low penetration, high susceptibility to degradation, instability, and poor solubility in aqueous solutions limit the use of anti-biofilm agents (ABAs) in a clinical setting. As such, recent studies have been using poly lactic-co-glycolic acid (PLGA)-based nanoplatforms (PLGA NPFs) for delivery of ABAs that have reported promising results. These particles, due to proper drug loading and release kinetics, could suppress microbial attachment, colonization, and biofilm formation for a long time. Additionally, PLGA NPFs, because of the high drug-loading efficiencies, hydrophilic surface, negative charge, and electrostatic interaction, lead to effective penetration of antibiotics to the deeper layer of the biofilm, thereby eliminating the microbial biofilm. Thus, PLGA NPFs could be considered as a potential candidate for coating catheters and other medical material surfaces for inhibition and destruction of the microbial biofilm. However, the exact interaction of PLGA NPFs and the microbial biofilm should be evaluated in animal studies. Additionally, a future goal will be to develop PLGA formulations as systems that can be used for the treatment of the MDR microbial biofilm, since the exact interactions of PLGA NPFs and these biofilm structures are not elucidated. In the present review article, we have discussed various aspects of PLGA usage for inhibition and destruction of the microbial biofilm along with different methods and procedures that have been used for improving PLGA NPF efficacy against the microbial biofilm.

Aqueous solubility of high concentrated caffeine using hydrotrope and the application to the anti-cellulite cosmetics

This study presents measurements of the aqueous solubility of caffeine at a temperature ranging from 5 to 40°C. And the low water solubility of caffeine was increased by using a hydrotropic solubilization system. Solubility was measured with a single hydrotropic system of niacinamide or betaine and a mixed hydrotropic system of niacinamide and betaine. As a result, it was possible to prepare a high-concentration aqueous caffeine solution of about 4% at 5.9°C and about 25% at 39.9°C. The modified Apelblat equation was applied to predict the temperature dependence of caffeine solubility in aqueous solutions containing niacinamide, and our experimental data showed good agreement with the correlated values. We propose the results of this study as basic data for the development of anti-cellulite cosmetics.

Pharmacokinetics of asciminib in the presence of CYP3A or P-gp inhibitors, CYP3A inducers, and acid-reducing agents.

Asciminib is a first‐in‐class inhibitor of BCR::ABL1, specifically targeting the ABL myristoyl pocket. Asciminib is a substrate of CYP3A4 and P‐glycoprotein (P‐gp) and possesses pH‐dependent solubility in aqueous solution. This report summarizes the results of two phase I studies in healthy subjects aimed at assessing the impact of CYP3A and P‐gp inhibitors, CYP3A inducers and acid‐reducing agents (ARAs) on the pharmacokinetics (PK) of asciminib (single dose of 40 mg). Asciminib exposure (area under the curve [AUC]) unexpectedly decreased by ~40% when administered concomitantly with the strong CYP3A inhibitor itraconazole oral solution, whereas maximum plasma concentration (Cmax) decreased by ~50%. However, asciminib exposure was slightly increased in subjects receiving an itraconazole capsule (~3%) or clarithromycin (~35%), another strong CYP3A inhibitor. Macroflux studies showed that cyclodextrin (present in high quantities as excipient [40‐fold excess to itraconazole] in the oral solution formulation of itraconazole) decreased asciminib flux through a lipid membrane by ~80%. The AUC of asciminib was marginally decreased by concomitant administration with the strong CYP3A inducer rifampicin (by ~13–15%) and the strong P‐gp inhibitor quinidine (by ~13–16%). Concomitant administration of the ARA rabeprazole had little or no effect on asciminib AUC, with a 9% decrease in Cmax. The treatments were generally well tolerated. Taking into account the large therapeutic window of asciminib, the observed changes in asciminib PK following multiple doses of P‐gp, CYP3A inhibitors, CYP3A inducers, or ARAs are not considered to be clinically meaningful. Care should be exercised when administering asciminib concomitantly with cyclodextrin‐containing drug formulations.

Cografting of Zwitterionic Sulfobetaines and Cationic Amines on β-Cyclodextrin-Threaded Polyrotaxanes Facilitates Cellular Association and Tissue Accumulation with High Biocompatibility.

β-Cyclodextrins (β-CDs) and β-CD-containing polymers have attracted considerable attention as potential candidates for the treatment of cholesterol-related metabolic and intractable diseases. We have advocated the use of β-CD-threaded acid-degradable polyrotaxanes (PRXs) as intracellular delivery carriers for β-CDs. As unmodified PRXs are insoluble in aqueous solutions, chemical modification of PRXs is an essential process to improve their solubility and impart novel functionalities. In this study, we investigated the effect of the modification of zwitterionic sulfobetaines on PRXs due to their excellent solubility, biocompatibility, and bioinert properties. Sulfobetaine-modified PRXs were synthesized by converting the tertiary amino groups of precursor 2-(N,N-dimethylamino)ethyl carbamate-modified PRXs (DMAE-PRXs) using 1,3-propanesultone. The resulting sulfobetaine-modified PRXs showed high solubility in aqueous solutions and no cytotoxicity, while their intracellular uptake levels were low. To further improve this system, we designed PRXs cografted with zwitterionic sulfobetaine and cationic DMAE groups via partial betainization of the DMAE groups. Consequently, the interaction with proteins, intracellular uptake levels, and liver accumulation of partly betainized PRXs were found to be higher than those of completely betainized PRXs. Additionally, partly betainized PRXs showed no toxicity in vitro or in vivo despite the presence of residual cationic DMAE groups. Furthermore, partly betainized PRXs ameliorated the abnormal free cholesterol accumulation in Niemann-Pick type C disease patient-derived cells at lower concentrations than β-CD derivatives and previously designed PRXs. Overall, the cografting of sulfobetaines and amines on PRXs is a promising chemical modification for therapeutic applications due to the high cholesterol-reducing ability and biocompatibility of such modified PRXs. In addition, modification with both zwitterionic and cationic groups can be used for the design of various polymeric materials exhibiting both bioinert and bioactive characteristics.

Synergistic inhibition of the urinary tract pathogen Staphylococcus saprophyticus by curcumin and berberine

Staphylococcus saprophyticus is a Gram-positive pathogen that is most commonly associated with community-acquired urinary tract infections in adolescent and adult women. While antibiotics can be used to treat these infections, they often reoccur and there has been increased interest in using herbal preparations to treat them. Curcumin has been promoted as a treatment for a variety of diseases, but its effectiveness is limited by its low solubility in aqueous solutions and poor bioavailability. The sensitivity of S. saprophyticus to curcumin and berberine was determined by plate count assays, minimum inhibitory concentrations in microtiter plates, and growth kinetics. When 100 µg ml-1 berberine was combined with 20 µg ml-1 curcumin, there was a large increase in the lag phase and a decrease in the growth rate and final yield of bacteria. There was complete inhibition of growth in normal human urine. These studies indicate that a combination of curcumin with berberine allows curcumin to be used at much lower concentrations.

CO2/N2 separation by glycerol aqueous solution in a hollow fiber membrane contactor module: CFD simulation and experimental validation

In this paper, CO2 separation from CO2/N2 mixed gas was experimentally and theoretically investigated inside a gas–liquid hollow fiber membrane contactor (HFMC) module along with developing and validation of a comprehensive computational fluid dynamic (CFD) model. An aqueous solution of glycerol (10 wt%) (C3H8O3), a green and cost-effective physical solvent, was employed as the liquid absorbent, flowing in the shell side of the hollow fibers. To attain a better insight into the membrane wetting effects on separation performance, all non-wetting, partially-wetting, and completely-wetting conditions were investigated. Moreover, a correlation for CO2 Henry’s law constant was developed to estimate the CO2 solubility in aqueous solutions of glycerol via adopting the literature data. The CFD simulation results revealed that the gas to absorbent flow rate ratio (Fg/Fa) is a dominant parameter in controlling the CO2 removal efficiency. CO2 separation performance was augmented via decreasing the gas flow rate, absorption temperature and increasing the membrane porosity to tortuosity ratio as well as glycerol concentration. In contrast, by increment of the membrane wettability from non-wetting to completely-wetting condition, the CO2 removal percentage was dramatically reduced from 72.5 to 18.5%. A fair agreement between the CFD simulation results and experimental data with an absolute average relative error percentage (AARE%) of 2.7% was achieved, confirming the validity of the developed model.

A Tumor-Homing Peptide Platform Enhances Drug Solubility, Improves Blood-Brain Barrier Permeability and Targets Glioblastoma.

Simple SummaryGlioblastoma (GBM) is a fatal and incurable brain cancer, and current treatment options have demonstrated limited success. Here, we describe the use of a dg-Bcan-Targeting-Peptide (BTP-7) that has BBB-penetrating properties and targets GBM. Conjugation of BTP-7 to an insoluble anti-cancer drug, camptothecin (CPT), improves drug solubility in aqueous solution, retains drug efficacy against patient-derived GBM stem cells (GSC), enhances BBB permeability, and enables therapeutic targeting to intracranial patient-derived GBM xenograft in mice, leading to higher toxicity in GBM cells compared to normal brain tissues and prolonged animal survival. This work demonstrates a proof-of-concept for BTP-7 as a tumor-targeting peptide for therapeutic delivery to GBM. Background: Glioblastoma (GBM) is the most common and deadliest malignant primary brain tumor, contributing significant morbidity and mortality among patients. As current standard-of-care demonstrates limited success, the development of new efficacious GBM therapeutics is urgently needed. Major challenges in advancing GBM chemotherapy include poor bioavailability, lack of tumor selectivity leading to undesired side effects, poor permeability across the blood–brain barrier (BBB), and extensive intratumoral heterogeneity. Methods: We have previously identified a small, soluble peptide (BTP-7) that is able to cross the BBB and target the human GBM extracellular matrix (ECM). Here, we covalently attached BTP-7 to an insoluble anti-cancer drug, camptothecin (CPT). Results: We demonstrate that conjugation of BTP-7 to CPT improves drug solubility in aqueous solution, retains drug efficacy against patient-derived GBM stem cells (GSC), enhances BBB permeability, and enables therapeutic targeting to intracranial GBM, leading to higher toxicity in GBM cells compared to normal brain tissues, and ultimately prolongs survival in mice bearing intracranial patient-derived GBM xenograft. Conclusion: BTP-7 is a new modality that opens the door to possibilities for GBM-targeted therapeutic approaches.