Properties Of Micelles Research Articles

Deciphering supramolecular arrangements, micellization patterns, and antimicrobial potential of bacterial rhamnolipids under extreme treatments of temperature and electrolyte

The micellization properties of rhamnolipids (RLs) in extreme electrolyte concentrations and temperatures have gained considerable attention due to their broad industrial applications. In this study, the aggregation behavior, specifically the micellization pattern (critical micelle concentration (CMC)) of RLs produced from a newly isolated thermophilic strain of Pseudomonas aeruginosa from a harsh environment of an oil field, was investigated by a spectrophotometric method at various temperatures (293–393 K) and electrolyte concentrations (NaCl: 2–20%). The result indicated that the CMC values (0.267–0.140 mM⋅dm−3) were both electrolyte- and temperature-dependent exhibiting a U-shaped trend as temperature and NaCl concentration increased. Variations in NaCl concentration and temperature also affected the standard Gibbs free energy (ΔGomic), enthalpy (ΔHomic), and entropy (ΔSomic) of micellization. The molecule also showed stability at a broad range of temperatures, pH, and NaCl concentrations. Thin-layer chromatography (TLC) and Fourier-transform infrared (FTIR) analysis confirmed the similarity in composition between the crude extract and the commercial RL with Rf values of 0.72 for mono-rhamnolipids and 0.28 for di-rhamnolipids. FTIR analysis confirmed the chemical nature particularly key aliphatic functional groups present in the fatty acid tail of RLs and the -COC- bond in the structure of the rhamnose moiety. Additionally, LC-ESI-QTOF analysis confirmed corresponding ionic fragments of mono- and di-rhamnolipids congeners. Furthermore, the antimicrobial potential was determined against different human pathogens in the absence and presence of NaCl by measuring zones of inhibition. The result revealed enhanced inhibitory effects against Gram-positive pathogens (S. aureus, S. epidermidis, and L. monocytogene), with zones of inhibition of 26, 30, and 20 mm in the presence of NaCl. These findings underline the role of NaCl in the micellization of RL molecules and highlight their importance in environmental applications, pharmaceuticals, and various life science sectors.

Effect of Methyl Red on the surface properties of DTAB in CH3OH–H2O

The purpose of this study is to investigate the effect of Methyl Red (MR) on the micellization and surface properties of a cationic surfactant, dodecyl trimethylammonium bromide (DTAB), in CH3OH–H2O mixed solvent systems at varying CH3OH parts by volumes (0.1, 0.2, 0.3, and 0.4) and temperatures (298.15 K, 308.15 K and 318.15 K). Surface tension and conductivity measurements were conducted to obtain the critical micelle concentration (CMC) and various surface properties such as premicellar slope (dγdlogC), maximum surface concentration (Γmax), minimum surface area occupied (πCMC), free energy of adsorption (ΔGadso), adsorption efficiency (pC20), packing parameter (P), and aggregation number (Nagg). The results indicate that the presence of MR significantly influences the behavior of DTAB in the mixed solvent system. In the absence of MR, the CMC increased with higher CH3OH content, while MR reduced the CMC, promoting micelle formation through dye-surfactant-ion-pair (DSIP) formation. Surface properties were enhanced in the presence of MR leading to higher surface pressure. Additionally, the free energy of adsorption (ΔGadso) became more negative with MR, indicating a more favorable adsorption process. Correlations of (dγdlogC), Γmax,γ0/γcmc, pC20, Nagg, CMC/C20 with the parts by volume of CH3OH at 298.15 K, 308.15 K, and 318.15 K are discussed with and without MR. The obtained results were used to examine the effect of MR on the surface properties of DTAB in the CH3OH–H2O medium. The change in properties can be explained in terms of the change in polarity of the medium and dye-surfactant ion pair (DSIP) formation.

Multicomponent Self-Assembly and Self-Sorting of Polymer Micelles in Water: Selective and Switchable Association by Kinetic or Thermodynamic Control.

Herein, we report multicomponent self-assembly and self-sorting of polymer micelles in water using mixtures of an anionic random copolymer bearing sodium sulfonate and dodecyl groups and random copolymers carrying poly(ethylene glycol) (PEG) and alkyl groups. In pure water, the anionic copolymer is co-self-assembled with the PEG copolymers to form anion/PEG-fused micelles with a controlled aggregation number. By designing the composition or alkyl groups of PEG copolymers, the fused micelle is reversibly self-sorted into discrete anion or PEG micelles in the presence of NaCl. Co-self-assembly of the anionic copolymer and PEG copolymers is kinetically or thermodynamically controlled, depending on the dynamic properties of the PEG copolymer micelles. Thus, the selective self-assembly of ternary copolymers is also controllable and switchable by temperature: A kinetically favored anion/PEG-fused micelle is predominantly formed in the presence of a kinetically frozen PEG micelle at low temperature, whereas the fused micelle is transformed via polymer chain exchange upon heating into a thermodynamically more stable anion/PEG-fused micelle.

Surface, micellization, and thermodynamic behavior of cetyltrimethylammonium bromide in sodium polystyrene sulfonate with and without methyl red in water–ethanol mixed solvent media at varying temperatures: A tensiometric analysis

In this study, we aim to systematically investigate the surface, micellization, and thermodynamic properties of Cetyl Trimethyl Ammonium Bromide (CTAB) in Sodium Polystyrene Sulfonate (NaPSS) solutions with and without methyl red (MR) dye in water–ethanol mixed solvent media (0, 0.1, 0.2, and 0.3 vol fraction of ethanol at 298.15 ± 0.2 K, 308.15 ± 0.2 K, and 318.15 ± 0.2 K. By employing surface tension measurements, we seek to uncover the effects of solvent composition, temperature, polyelectrolyte presence, and dye addition on the Critical Micelle Concentration (CMC) and other key surface and thermodynamic parameters. The CMC, slope (dγdlnC), and γCMC values determined from γ versus ln [CTAB] for the CTAB + NaPSS + MR diminish in contrast to the CTAB + NaPSS in the chosen solvent and the temperature range studied. However, with a rising temperature and ethanol volume fraction, the CMC value rises while the obtained γCMC values fall. Various surface and thermodynamic parameters like γCMC,Amin,Γmax, ΠCMC, adsorption efficiency (PC20), packing parameter (P), aggregation number (Nagg), micellization Gibbs’ energy (ΔGm0), adsorption of Gibbs’ energy (ΔGads0), effective Gibbs’ energy (ΔGeff0), minimum Gibbs’ energy (ΔGmin), and many other parameters have been determined, comparatively discussed, and analyzed for CTAB + NaPSS and CTAB + NaPSS + MR systems. This research provides a deeper understanding of the fundamental behaviors of these complex systems, their stability, and their feasibility, with potential implications for their practical applications in fields such as drug delivery, wastewater treatment, and the formulation of personal care products.

Effect of solvent and temperature on the micellization and thermophysical properties of cetyltrimethylammonium bromide

The Micellization is the fundamental phenomenon in colloid and surface chemistry which plays a pivotal role in a multitude of industrial processes, biological systems, and everyday applications. In this study, we investigate the micellization behavior of the cationic surfactant, cetyltrimethylammonium bromide (CTAB) within aqueous and ethanol–water mixtures across a temperature range. The electrical conductivity measurements unveil insights into the critical micelle concentration (CMC) and the degree of counterion dissociation (β) at each temperature. Notably, as ethanol content increases in the solvent, both CMC and β values exhibit a corresponding uptick. These findings enable the assessment of standard Gibbs free energy (ΔGmic0). Furthermore, our investigation extends to find out the thermophysical properties (viz., density, dynamic viscosity, and kinematic viscosity) assessments across varying ethanol compositions and temperatures. These metrics facilitate the calculation of activation energy for mixed systems. The implications of these results (data) could be useful for both the fundamental as well applied research, and promise valuable insights for future endeavors.

Promoting sustainability: Micellization and surface dynamics of recycled monoethanolamine surfactants

The purpose of this work is to explore the micellization and surface characteristics of recycled monoethanolamine (MEA) surfactants, designated as MK-1, MK-2, and MK-3, and to assess their potential in promoting sustainability. Traditional surfactants contribute to environmental pollution due to their non-renewable sources and persistence in nature. This study addresses the knowledge gap in sustainable surfactant development by investigating the efficacy of recycled MEA surfactants. Its novelty lies in its innovative recycling process, which not only reduces waste, but also produces surfactants with superior properties. This study also investigates the distillation-based separation of MEA from degraded compounds, showcasing its potential in waste management. It was found that a maximum MEA separation of 17 % was achieved with a resulting purity of 83 %. Optimal conditions, including the use of catalysts and a temperature of 393K, led to enhanced oleic acid conversion. Similarly, reactions conducted with catalysts at 433K for 3 h demonstrated favorable outcomes. Surfactant MK-1 exhibited superior foam and emulsifying abilities, generating a foam height of 60 cm with only 8 cm lost after 10 min. Regarding emulsifying properties, the sunflower oil/water system with a 0.1% MK-1 solution exhibited delayed water separation from the emulsion. MK-3 displayed the highest pC20 value at 2.91. Among the MEA-based surfactants, MK-1 reduced surface tension to 33.1 mN/m. The maximum surface excess concentration (Γmax) for all surfactants was consistent. This demonstrates that recycled MEA surfactants exhibited favorable micellization properties, with a critical micelle concentration (CMC) comparable to that of virgin counterparts. Over ten cycles of use and regeneration, the performance of recycled MEA surfactants remained stable. Surface tension measurements indicated improved interfacial activity, while emulsification capacity tests revealed an enhanced performance in forming stable emulsions. This implies the potential of recycled MEA surfactants to produce high-performance surfactants, thereby promoting sustainability in the chemical industry.

Mucoadhesive and drug release of cholic acid based thiomeric micelles and encapsulated silver and gold nanoparticles for anticancer studies

Among the various drug delivery system, mucoadhesive formulation is a promising approach to deliver drugs and vaccine through close contact with the absorption site and mucous membrane. Bile acids have received considerable interest in drug delivery (DD) applications owing to their advantages of biocompatibility, ability to act as both drug solubilizing and permeation-modifying agents. In this aspects, cholic acid (CA) based thiomeric micelles with improved mucoadhesive properties have been synthesized by functionalization of thiol groups and conjugation of PEG. The synthesized CA based thiomeric micelles (TCA-PEG) were characterized by 1HNMR, ATR-IR, GPC, Zeta potential and contact angle techniques. The critical micelle concentration (CMC) of TCA-PEG was measured by a fluorescence spectrometer using pyrene as a probe. The mucoadhesive properties of TCA-PEG polymeric micelles (PMs) were examined on the goat anterior tongue mucosa with an effectively higher adhesion of 40 % up to 3 h study period. Also, curcumin loaded TCA-PEG PMs showed only 13 % of the drug released up to the period of 3 h. The TCA-PEG PMs act as reducing and stabilizing agents for the preparation of gold and silver nanoparticle (Ag and Au NPs) and were characterized by UV–visible, DLS, Zeta potential, XPS, and HR-TEM techniques. The cytotoxicity and cellular apoptosis of TCA-PEG PMs encapsulated Ag and Au NPs were examined by MTT assay and AO/PI dual staining using MCF-7 breast cancer cells wherein AgNPs showed an effective cytotoxicity than AuNPs. The developed TCA-PEG PMs act as reservoir for soubilization of hydrophobic and hydrophilic drugs and ideal template for encapsulation of silver and gold nanoparticles for mucoadhesive DD system.

High efficacy of chloroquine-derived bile salts in Pluronic F127 micelles against blood-stage Plasmodium falciparum

Colloidal nanocarriers can play a key role in the efficacious delivery of drugs, including antimalarials. Here, we investigated the ability of polymeric micelles of the block copolymer F127 to act as nanovehicles for two organic salts derived from chloroquine and human bile acids, namely, chloroquinium cholate (iCQP1) and chloroquinium glycocholate (iCQP1g). We have previously reported the strong in vitro antiplasmodial activity of these salts, which displayed IC50 values of 13 and 15 nM against blood forms of Plasmodium falciparum, respectively. By deriving from amphiphilic lipids, iCQP1 and iCQP1g also enclose the ability to act as surface-active ionic liquids (SAILs). The micellization properties of neat F127 and of the F127/SAIL mixtures were initially investigated to gain physicochemical insight into the interaction between polymer and bioactive SAILs, resorting to differential scanning calorimetry, surface tension measurements and dynamic light scattering. Micelle formation by F127 is an endothermic process strongly temperature and concentration dependent. Interestingly, this process is significantly changed when the molar fraction of SAIL (xSAIL) in the F127/SAIL mixture is varied between 0.33 and 0.90. Both SAILs favor the formation of mixed micelles by decreasing the micellization temperature, and (observed only when for xSAIL = 0.33) by synergistically decreasing the cmc. Concomitantly, the micellar size is reduced from 18 to 13 nm as xSAIL is increased from 0.33 to 0.90. Crucially, in vitro assays show that when the SAILs are loaded into F127 polymeric micelles, their antiplasmodial efficacy is substantially enhanced, with a significant drop in IC50, especially for the iCQP1/F127 system. This opens new possibilities for the nanoformulations of antimalarial compounds.

Coarse-Grained Molecular Dynamics Simulation of Heterogeneous Polysorbate 80 Surfactants and their Interactions with Small Molecules and Proteins.

Polysorbate 80 (PS80) is widely used in pharmaceutical formulations, and its commercial grades exhibit certain levels of structural heterogeneity. The objective of this study was to apply coarse-grained molecular dynamics simulations to better understand the effect of PS80 heterogeneity on micelle self-assembly, the loading of hydrophobic small molecules into the micelle core, and the interactions between PS80 and a protein, bovine serum albumin (BSA). Four representative PS80 variants with different head and tail structures were studied. Our simulations found that PS80 structural heterogeneity could affect blank micelle properties such as solvent-accessible surface area, aggregation number, and micelle aspect ratio. It was also found that hydrophobic small molecules such as ethinyl estradiol preferentially partitioned into the PS80 micelle core and PS80 dioleates formed a more hydrophobic core compared to PS80 monooleates. Furthermore, multiple PS80 molecules could bind to BSA, and PS80 heterogeneity profoundly changed the binding ratio as well as the surfactant-protein contact area.

Dissipative particle dynamics simulation and experimental studies of pseudo-gemini surfactants with different hydrophobic chain lengths

In this work new pseudo-gemini type surfactants are constructed via a simple, energy and material efficient way, using piperazine, propylene oxide and seven different fatty acids: capric, lauric, myristic, stearic, oleic and linolenic. The compounds are characterized by 1H NMR, 13C NMR and FTIR studies. Micellization and adsorption properties of the novel pseudo-gemini surfactants are investigated via surface tension and conductivity measurements. Antimicrobial properties are evaluated using the simple disk diffusion test method. Dissipative Particle Dynamics (DPD) simulations are performed to model aggregation behavior of the new pseudo-gemini surfactants. Experimental studies revealed that Critical Micelle Concentration (CMC) of the obtained pseudo-gemini surfactants are lower than 1 mmol/L. Theoretically calculated CMC values are slightly higher than experimental CMC values. However, overall, very good agreement between theoretical and experimental CMC values is observed. Radial Distribution Function (RDF) and radius of gyration (Rg) plots are analyzed to gain further insight into aggregation of the surfactant molecules in aqueous environment. The DPD model of the pseudo-gemini amphiphiles successfully predicts the most important traits of the aggregation process.

Mixed Micellar Gel of Poloxamer Mixture for Improved Solubilization of Poorly Water-Soluble Ibuprofen and Use as Thermosensitive In Situ Gel.

The aqueous solution of binary mixtures of amphiphilic copolymers is a potential platform for fabricating mixed polymeric micelles for pharmaceutical applications, particularly in developing drug delivery depots for a poorly water-soluble compound. This study fabricated and investigated binary mixtures of poloxamer 403 (P403) and poloxamer 407 (P407) at varying P403:P407 molar ratios to develop a vehicle for the poorly water-soluble compound, using ibuprofen as a model drug. The cooperative formation of mixed micelles was obtained, and the solubility of ibuprofen in the binary mixtures was enhanced compared to the solubility in pure water and an aqueous single P407 solution. The binary mixture with the P403:P407 molar ratio of 0.75:0.25 at a total polymer concentration of 19% w/v exhibited the temperature dependence of micellization and sol-to-gel characteristics of the thermosensitive mixed micellar gels. It possessed suitable micellization and gelation characteristics for in situ gelling systems. The release of ibuprofen from the thermosensitive mixed micellar depots was sustained through a diffusion-controlled mechanism. The findings can aid in formulating binary mixtures of P403 and P407 to achieve the desired properties of mixed micelles and micellar gels.

Investigation of micellization and thermodynamic properties of cationic gemini surfactant (12-2-O-2-12) in the presence of organic solvents

The micellization behaviour and thermodynamic properties of synthesized cationic gemini surfactant (12-2-O-12-12), N,N′-didodecyl-N,N,N′,N′-tetramethyl-N,N′-(oxybis(ethane-2,1-diyl))-diammonium dibromide were studied in the presence of organic solvents for four different temperatures (25, 30, 35 and 40 °C). Aqueous solutions of 10 % and 20 % methanol (MeOH), ethanol (EtOH), isopropanol (IPOH) and dimethyl sulfoxide (DMSO) were used as solvents. The critical micelle concentration (CMC) of cationic gemini surfactant and the degree of counterion dissociation (α) were determined by the conductometric method. Using the CMC and α values for each of the four temperatures, the values of the standard Gibbs free energy (ΔGmo), Gibbs free energy of transfer (ΔGm,transo), enthalpy (ΔHmo), and entropy (ΔSmo) of micellization were calculated. It was observed that the CMC and α values increased with increasing solvent percentage and temperature. It was found that in all cases, the standard Gibbs free energy and enthalpy values were negative while both the micellization entropy and the standard Gibbs free energy of transfer are positive. Negative Gibbs free energy values indicated that micellization was a spontaneous situation, while positive entropy values indicated the existence of a disordered situation. The positive ΔGm,transo values show that the presence of solvents makes the environment unfavorable for micelle formation.

Edible CO2-Responsive Wormlike Micelles with Docosahexaenoic Acid.

Due to their unique microstructure and modifiable rheological properties, wormlike micelles that respond to environmental stimulation have garnered significant interest in recent years. Among them, CO2-responsive wormlike micelles have the advantages of simple preparation and controllable properties, which have significant development potential in the food chemistry field of thickeners. In this study, CO2-responsive wormlike micelles were prepared using docosahexaenoic acid (DHA), pyridoxamine (PA), and glucosamine (GA); the stimulus-responsive behaviors and mechanisms of the two systems, namely, NaDHA/PA and NaDHA/GA, were investigated using dynamic light scattering (DLS) and cryo-transmission electron microscopy (Cryo-TEM). The nearly unaltered viscosity of the systems confirmed the cyclic reversibility of the CO2 response of the two systems when the two mixed solutions were converted back to aqueous liquids 10 times. The preparation and properties of DHA-based CO2-responsive wormlike micelles are expected to advance fundamental research and establish the theoretical groundwork for their practical application in controllable thickening agents in food chemistry.

Effects of side-chain lengths on the structure and properties of anhydrides modified starch micelles: Experimental and DPD simulation studies

Anhydride-modified starch micelles have great potential in the delivery of hydrophobic guest molecules. This study aimed to experimentally explore the effects of side-chain lengths on the structure and properties of anhydride-modified starch micelles, and to visualize the self-assembly and loading process of these micelles through Dissipative particle dynamics (DPD) simulations. Starch micelles could only form when the carbon chain length exceeded four. The highly hydrophobic C18 starch micelle exhibited the minimum particle size (65 nm) and maximum loading capability (59.10 μg/mg). For each addition carbon atom in the anhydride side chains, the critical micelle concentration (CMC) of starch micelles decreased average of 1.79 %. Thermodynamic results showed that the micellization was an entropy-dominated driven process, and longer carbon chains enhanced the stability of starch micelles. DPD results showed that the starch chains formed the small clusters then spherical aggregates and finally core-shell structure spherical micelle. Curcumin was loaded into micelles by adjoint aggregation-micellization-adsorption mechanism. Overall, this study provides microscopic insight into the micellization and drug-loading mechanisms for anhydrides modified starch micelles.

Influence of structural organization on mucoadhesive properties of poloxamer-hyaluronic acid-based micelles and hydrogels: From molecular modelling to biointerfaces interactions

New pharmaceutical formulations have been proposed as strategies to improve transport and provide best conditions to control the drug release rate in specific biological environments, such as mucosa surfaces. Herein, formulations containing binary systems Poloxamer (PL) 407 15 % and PL 338 15 %, combined with hyaluronic acid, carrying the local anesthetic bupivacaine (BVC), were studied by molecular dynamics, while other structural parameters were determined by Dynamic Light Scattering for stablishing relationships with mucoadhesive properties and cytotoxicity evaluation. The binary system PL 407 15 %/PL 338 15 % exhibited a well-organized structural morphology, with more hydrated corona, and increased mucoadhesive properties over mucin layers. After hyaluronic acid (HA) incorporation, it was observed an increase on the force of detachment, possibly due to HA role as a linker among mucin layers independently of PL supramolecular structures. On the other hand, the addition of BVC or HA/BVC into the binary system decreased the force of detachment, as a response of augmented of compactness of these hydrogels caused by desolvation of PO core, showing the influence of all components and their chemical interactions into the structural organization and their biopharmaceutical performance relationships.

Aromatic salt induced modulations in micellization behavior of amide functionalized surface-active ionic liquids: The role of cationic head group

The present study highlights the effect of aromatic salt i.e. sodium benzoate (NaBz) at fix concentration (1 mM), on the micellization behavior of four amide functionalized surface-active ionic liquids (SAILs) having different cationic head groups in aqueous medium. The adsorption behavior of the SAILs at the air-solution interface has been investigated by tensiometry, where improved surface activity was observed in all the investigated SAILs in the presence of added hydrotrope. The conductivity, steady-state fluorescence, dynamic light scattering (DLS), and zeta-potential measurements have been performed to probe the micellization of the SAILs in bulk solution. The position and orientation of aromatic anion, Bz-, at the micelle-water interface surface has been investigated by 1H NMR spectroscopy. The thermodynamic aspects of micellization have been examined by Isothermal titration calorimetry (ITC). It has been observed that the nature, geometry, and steric factor of the cationic head group of SAILs govern their interactions with Bz- and this influences the characteristic properties of micellization.

Coarse grained MD simulation of bulk and interfacial behavior of mixture of CTAB/SDS surfactants.

This study involves simulating the process of inhibiting corrosion through the formation of micelles by surfactants and their deposition on iron (Fe) surfaces. The primary focus is on examining CTAB/SDS mixtures in aqueous solutions with different concentrations. Micelle properties, including size, shape, aggregation number, cluster size, and surfactant diffusion, were calculated and validated with experimental data. The coarse-grained Fe surface was modeled and validated against experimental water contact-angle data. Subsequently, the deposition of CTAB/SDS mixtures on the Fe surface and air-water interface was studied systematically. We found that the relative ratio of CTAB/SDS in the solution directly influences surfactant deposition behavior, which might impact the corrosion inhibition efficiency. All the MD simulations were performed using the GROMACS software with MARTINI2 force field and Martini polar water. The molecules are packed using PACKMOL software. Both NVT and NPT simulations are caried out at temperature and pressure of 303 K and 1 bar respectively, with a nonbonded interaction cut-off (rcut) of 1.1 nm. The LJ potential was shifted from 0.9 nm to rcut, while the electrostatic potential was shifted from 0.0 nm to rcut. For electrostatics, reaction-field coulomb type is used, relative dielectric constant (epsilon-r) and the reaction field dielectric constant (epsilon-rf) are equal to 2.5 and infinity respectively. The dielectric constant below rcut is epsilon-r, and beyond the cut-off is epsilon-rf. Coulomb-modifier used as potential-shift which leads to shift in the coulomb potential by a constant such that it is zero at the rcut. This makes the potential of the integral of the force . The neighbor list was updated every 10 steps, employing a neighbor list cut-off equal to rcut. Using a polar water model, we used a constant time step of 0.02 ps throughout the simulation. The used epsilon-r = 2.5, is recommended for polar water.

Micellization, aggregation, interaction, and solubilization behaviors of mixed solutions of cationic gemini and nonionic surfactants

AbstractThe micellization properties of mixed aqueous solutions of a cationic gemini surfactant (CGS) and Triton X‐100, a conventional non‐ionic surfactant, with various mole fractions, were determined by measuring the surface tension at different temperatures. Various theoretical models were used to analyze the behavior of this mixed system. The interactions between CGS and Triton X‐100 were determined to be non‐ideal and synergistic. The calculated interaction parameters (βM) have negative values at all temperatures and for all mole fractions, showing attractive interactions. It was found that increasing the mole fraction of Triton X‐100 significantly increased the synergistic effect (more negative values). Micellar aggregation number (Nagg) values of pure surfactants and their mixtures in different ratios were obtained with the steady‐state fluorescence quenching method. Furthermore, the molar solubilization ratio of Sudan III organic dye in all surfactants aqueous systems was obtained using UV–Visible spectrophotometry. At concentrations above critical micelle concentration, the solubility of Sudan III in water was substantially increased linearly for all systems and it was observed that the enhancement was even more significant for mixed surfactant systems.

Development of a premix based on micellar casein for fortification of meat systems with vitamin A

A novel approach to the protection of unstable fat-soluble vitamins, using retinol as an example, is presented in this work. This method is based on introducing vitamin A molecules into casein micelles. Protective properties of micellar casein towards different forms of retinol (native vitamin and palmitic acid ester) in vitro and in emulsion-type meat products are investigated. A technology of the introduction using micellar casein concentrate (MCC) has been developed. Conditions similar to those in which vitamin molecules can be in meat emulsions during heat treatment are simulated in vitro. The optimal time of “encapsulation” (2 hours) and the need for additional surfactant (tween-80) are identified. The use of the casein micelles protection made it possible to increase the number of retinol molecules that did not undergo decomposition under model conditions (in vitro) from ~30% to ~80%. Using the vitamin premix the degree of degradation of vitamin molecules does not exceed 4% after heat treatment. Data received allowed us to determine the efficiency of the protection properties of casein micelles for unstable vitamin A molecules.

Microenvironmental Enzyme-Responsive Methotrexate Modified Quercetin Micelles for the Treatment of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease involving synovial inflammation and joint destruction. Although therapeutic drugs for RA have some efficacy, they usually cause severe side effects and are expensive. RA is characterized by synovial hyperplasia, intra-articular hypoxia, upregulated expression of matrix metalloproteinases, and excessive accumulation of reactive oxygen species. The adverse microenvironment further aggravates activated macrophage infiltration. Therefore, controlling the microenvironment of diseased tissues and targeting the activated macrophages have become new therapeutic targets in RA patients. Here, microenvironment-targeting micelles (PVGLIG-MTX-Que-Ms) were synthesized using the thin film hydration method. In the inflammatory microenvironment, PVGLIG was cleaved by the highly expressed MMP-2, PEG5000 was eliminated, MTX was exposed, macrophage activation was targeted, and Que enrichment was enhanced. The cytotoxicity, targeting, antioxidant, and anti-inflammatory properties of drug-loaded micelles were tested in vitro. The drug-loaded micelles were used to treat CIA rats. In vivo targeting, expression of serum inflammatory factors, immunohistochemistry of the articular cartilage, and changes in immunofluorescence staining were observed. The developed micelles had a particle size of (89.62 ±1.33) nm and a zeta potential of (-4.9 ±0.53) mV. The IC50 value of PVGLIG-MTX-Que-Ms (185.90 ±6.98) μmol/L was significantly lower than that of free Que (141.10 ±6.39) μmol/L. The synthesized micelles exhibited slow-release properties, low cytotoxicity, strong targeting abilities, and significant anti-inflammatory effects in vitro. In vivo, the drug-loaded micelles accumulated at the joint site for a long time. PVGLIG-MTX-Que-Ms significantly reduced joint swelling, improved bone destruction, and decreased the expression of serum inflammatory factors in CIA rats. The smart-targeting micelles PVGLIG-MTX-Que-Ms with strong targeting, anti-inflammatory, cartilage-protective, and other multiple positive effects are a promising new tool for RA treatment.