Absolute Zeta Potential Research Articles

Thermal-assisted stirring as a new method for manufacturing o/w emulsions stabilized by gelatin-arginine complexes

Effects of pH (5, 7, or 9) and arginine level (0, 0.6%, 1.2%, or 1.8%, w/v) on the stabilization of emulsions prepared by a novel thermal-assisted stirring method were evaluated. The results of physical stability showed that thermal-assisted stirring was effective in manufacturing heat-insensitive o/w emulsions. As the arginine level increased, the emulsifying ability and the absolute zeta potential of each pH-treated group first increased significantly and then decreased significantly, reaching a maximum at 1.2% (w/v) addition. When pH increased, the emulsifying ability and the absolute zeta potential of each arginine-treated group increased significantly. The results of particle size, storage modulus, and loss modulus were in accordance with changes in the emulsifying ability and the zeta potential, which were confirmed by the microstructure. As a result, the emulsion prepared at pH 9 with 1.2% (w/v) arginine had the largest levels of emulsion stability and surface protein load (145.69 mg/m2). In conclusion, the major reason for the formation of heat-insensitive emulsions by thermal-assisted stirring might be attributed to a high level of surface protein load, and increasing pH and arginine addition might enhance the adsorption of gelatin-arginine complexes on the surface of oil droplets, thereby improving the stability of emulsions.

Surface physicochemical characteristics for sodium ion removal with sodium silicate modified magnetite core-shell nanoparticles and activation of their plasmid DNA purification ability

In this study, it is investigated the elimination of residual sodium ions from sodium silicate (Na2SiO3) modified Fe3O4@SiO2 nanoparticles, via the additional acidic treatment. Residual sodium ions are generated from the Na2SiO3 precursor during the titration for the fabrication of the Fe3O4@SiO2 core-shell structure; however, they were entirely removed after the in situ additional titration at pH 3 using a 1 M of hydrochloric acid (HCl). The thickness of the SiO2 shell layer of each nanoparticle was measured to 10 nm and the morphology of SiO2 shell on the Fe3O4 core were not significantly different after acid treatment to remove the residual sodium ions. However, the absolute zeta potential of the Na2SiO3-modified Fe3O4@SiO2 was decreased about 20% after HCl treatment (−52.5 ± 3.0 mV). In addition, the mean particle size of the Na2SiO3-modified Fe3O4@SiO2 was increased (363.98 nm) and the polydispersity index, which indicates dispersibility was increased (0.23) since residual sodium ions were eliminated by the acid treatment. It is assumed that the reducing anions in the diffuse layer of the particle due to the elimination of the residual sodium, as the counter ion, decreased the surface charge, thereby reducing the repulsive force between the Fe3O4@SiO2 nanoparticles. Then Fe3O4@SiO2 nanoparticles were utilized for separating plasmid DNA and separated plasmid DNA was measured with agarose gel electrophoresis and the absorbance monitoring. The efficiency of the DNA purification of the Na2SiO3-modified Fe3O4@SiO2 measured to 43.3 ± 5.2 ng/μl which was 58% increased after acid treatment. As a result, the dispersion/magnetic properties and DNA purification efficiency of the Na2SiO3-modified Fe3O4 became equivalent to the characteristics of the TEOS-modified Fe3O4@SiO2 using the additional acid treatment for sodium ions removal.

Comparative study on the mechanical and thermal properties of polycarbonate composites reinforced by KH570/SA/SDBS modified wollastonite fibers

AbstractIn order to increase the applicability of wollastonite (Wo) in polycarbonate (PC) polymer, surface modification of Wo was carried out using different modifiers containing silane coupling agent KH570, stearic acid (SA), and sodium dodecylbenzene sulfonate. The physical, physic‐chemical, and application properties of modified Wo were evaluated. Results showed that KH570 modified Wo had narrower particle size distribution, higher absolute zeta potential and were more evenly distributed. Scanning electron microscope study confirmed their changes in morphology and aspect ratio during the modification process. The tensile strength of Wo/PC composites, in which KH570‐modified Wo was used were superior to those in which original Wo or other modifiers modified samples were used. The maximum tensile strength of 65 ± 1 MPa was obtained by adding 15 wt% KH570‐modified Wo. Thermal analysis indicated that adding Wo to the polycarbonate increased the residue content but decreased the thermal decomposition temperature and glass transition temperature slightly, regardless of unmodified or modified Wo. These results indicated that the well‐modified Wo mineral had the potential to replace expensive carbon and glass fibers as fillers in polycarbonate products.

Tuning liquid aggregation of zwitterionic chitin nanocrystals by graphene oxide planar catchers via electrostatic regulation

As important structural units, biomass nanomaterials have exhibited great potentials to construct high-performance macroscopic materials for broad applications by liquid assembly. However, the liquid aggregation of nanomaterials was less investigated. Here, we demonstrate that the one-dimensional (1D) zwitterionic chitin nanocrystals (ZChNCs) can be reversibly captured and released by two-dimensional (2D) planar catchers of graphene oxide (GO) sheets. The dominant electrostatic regulation strategy by pH variation drives that there are three reversible changes for the liquid aggregation of ZChNCs and GO, which were the isolated dispersion state (pH > 7), homogeneous hybridization state (7 ≥ pH ≥ 5), and partially stacked hybridization state (pH < 5), respectively. We found there are no sedimentation during the change of liquid aggregation with the higher absolute Zeta potentials (almost>30 mV). Moreover, the ZChNCs-GO nanohybrids have reached a maximum Zeta potential up to −80 mV, which can be explained by the ionization of excess carboxyl groups on the surface of ZChNCs. Besides, the electrostatic regulation endows the nanohybrids with rheological behavior, which is beneficial to the macro assembly of liquid nanomaterials. This work provides a new class of hybrid colloidal nanomaterials, opens the structural design dimension of macro assembly and holds great potentials in high-performance biodegradable material.

A novel aquatic worm (Limnodrilus hoffmeisteri) conditioning method for enhancing sludge dewaterability by decreasing filamentous bacteria

In this study, a novel aquatic worm conditioning method was proposed to enhance sludge dewaterability by reducing filamentous bacteria. The optimal treatment time was 4 days and the optimal sludge concentration was 5000 mg/L. Under these conditions, the sludge dewaterability was improved with CST of 16.69 s, reduction in sludge SRF of 48.95 %, and reduction in LfA of 58.23 %. After bio-conditioning, sludge flocs broke up by the aquatic worm predation. The absolute zeta potential decreased to −8.27 mV, and the particle size increased from 36.64 μm to 48.05 μm. Proteins, polysaccharides and other organic substances in sludge EPS and microbial cells were released, with the viscosity reduced to 1.16 mPa·s and the bound water converted into free water. Besides, the number and abundance of representative filamentous Chloroflexi decreased, resulting in the enhancement of sludge dewatering performance. Overall, the aquatic worm conditioning process can be divided into two steps: Sludge destruction by the aquatic worm predation and sludge re-coagulation by filamentous bacteria as a skeleton.

Phase inversion emulsification of paraffin oil/polyethylene wax blend in water: A comparison between mixed monomeric and monomeric/gemini surfactant systems

• Natural-based gemini surfactant (GS) reduced water surface tension more than Tween80. • Using GS reduced water phase volume fraction at phase inversion point (f w,inv ). • Change in f w,inv with polyethylene was alike change in phases interfacial tension. • Rheological properties of emulsions highly depended on crystallinity of oil phase. • Higher stability of emulsions was achieved by GS due to their higher zeta potential. Despite the environmental attractiveness of phase inversion emulsification, polyethylene wax-based emulsions are prepared by high-energy emulsification methods. In this research, phase inversion emulsification of paraffin oil/high density polyethylene wax (PEW) blend in water was conducted using mixed surfactants systems. Sorbitan monooleate (Span 80) was used as the oil-soluble surfactant, while either polysorbate 80 (Tween 80) or a synthesized sunflower oil-based gemini surfactant (SF6) was utilized as the water-soluble surfactant. In order to conduct phase inversion emulsification, the 85 °C water phase containing 5 wt% Tween 80 or SF6 was added to the melted oil phase containing 30 to 60 wt% PEW in the blend and 5 wt% Span 80 at 120 °C with the addition rate of 5 mL/min. Phase inversion point was detected by monitoring the dissolution of the emulsion in water during emulsification and proved by electrical conductivity measurements. A lower effectiveness was found for the mixed monomeric surfactant system compared to the gemini surfactant-containing system. For each surfactant system, the trend of change in water phase volume fraction at phase inversion point upon increase in the PEW content in the oil phase was in accordance with the trend of change in the interfacial tension between the water phase and the oil phase. Using the mixed monomeric/gemini surfactant system resulted in emulsions with larger values of absolute zeta potential and drop sizes comparable to their monomeric surfactant-containing counterparts. The absolute zeta potential of the emulsions containing 30, 50, and 60 wt% PEW in the blend was about 70, 54, and 13 mV higher in case of using the mixed monomeric/gemini surfactant system. The gemini surfactant-containing emulsions demonstrated less shear-thinning behavior and the general trend of change in their viscosity and storage modulus with formulation was in agreement with that in the enthalpy of melting of the dried emulsions. Usage of the mixed monomeric/gemini surfactant system led to higher long-term stability of the emulsions, revealed by lower rate of water evaporation from the emulsions. The results of the current study can be applied for preparation of non-polar polyethylene wax-based emulsions using phase inversion emulsification technique. This investigation also opens up the opportunity to use efficient gemini surfactants in low-energy phase inversion emulsification.

Alendronate modified mPEG-PLGA nano-micelle drug delivery system loaded with astragaloside has anti-osteoporotic effect in rats

Astragaloside (AS) has an anti-osteoporotic effect, but its poor water solubility and low bioavailability limit its application. In this study, a novel nano-carrier with bone targeting was prepared by modifying mPEG-PLGA with alendronate (AL) before incorporation into astragaloside nano-micelles (AS-AL-mPEG-PLGA) to enhance the oral bioavailability, bone targeting and anti-osteoporosis effect of AS. The release behavior of AS-AL-mPEG-PLGA in vitro was investigated via dialysis. The pharmacokinetics of AS-AL-mPEG-PLGA was studied in Sprague-Dawley (SD) rats. The cytotoxicity of AS-AL-mPEG-PLGA in vitro (via MTT method), coupled with bone targeting ability in vitro and in vivo were evaluated. The therapeutic effects of free AS and AS-AL-mPEG-PLGA (ELISA, micro-CT, H&E staining) were compared in osteoporotic rats. AS-AL-mPEG-PLGA with smaller particle size (45.3 ± 3.8 nm) and high absolute zeta potential (−23.02 ± 0.51 mV) were successfully prepared, wherein it demonstrated higher entrapment efficiency (96.16 ± 0.18%), a significant sustained-release effect for 96 h and acceptable safety within 10–200 μg/mL. AS-AL-mPEG-PLGA could enhance the hydroxyapatite affinity and bone tissue concentration of AS. The relative bioavailability of AS-AL-mPEG-PLGA was 233.90% compared with free AS. In addition, the effect of AS in reducing serum levels of bone metabolism-related indicators, restoring the bone microarchitecture and improving bone injury could be enhanced by AS-AL-mPEG-PLGA. AS-AL-mPEG-PLGA with small particle size, good stability, remarkable sustained-release effect, safety and bone targeting was successfully constructed in this experiment to potentially improve the oral bioavailability and anti-osteoporosis effect of AS. Thus, AS-AL-mPEG-PLGA may be a promising strategy to prevent and treat osteoporosis.

Physicochemical, functional and antioxidant properties of mung bean protein enzymatic hydrolysates

This study aimed to investigate physicochemical, functional and antioxidant properties of mung bean protein (MBP) enzymatic hydrolysates (MBPEHs) by alcalase, neutrase, protamex, flavourzyme and papain. Physicochemical properties were evaluated by SDS-PAGE, particle size distribution, FTIR, ultraviolet visible and fluorescence spectrophotometries. ABTS, hydroxyl scavenging, Fe2+ chelating activity were used to evaluate antioxidant activity. Enzymolysis with five proteases decreased average particle size, α-helix, β-sheet, surface hydrophobicity of hydrolysates. Alcalase hydrolysate had the highest degree of hydrolysis (23.55%), absolute zeta potential (33.73 mV) and the lowest molecular weight (<10 kDa). Protamex and papain hydrolysates had higher foaming capacities, emulsification activity indexes, emulsion stability indexes (235.00%, 123.07 m2/g, 132.54 min; 200.10%, 105.39 m2/g, 190.67 min) than MBP (135.03%, 20.03 m2/g, 30.88 min). Alcalase hydrolysate demonstrated the lowest IC50 (mg/mL) in ABTS (0.12), hydroxyl (2.98), Fe2+ chelating (0.22). These results provide support for application of MBPEHs as foaming agent, emulsifier and antioxidant in food industry.

Modification of Ovalbumin by Maillard Reaction: Effect of Heating Temperature and Different Monosaccharides.

Glycosylation is considered to be an effective way to improve the performance of protein emulsification. This study focused on the effects of the molecular structure and emulsifying properties of ovalbumin (OVA) by wet heating Maillard reaction with three types of monosaccharides (i.e., xylose, glucose, and galactose). Results showed that increasing reaction temperature from 55°C to 95°C could significantly improve the degree of grafting (DG), while glycosylated OVA conjugate with xylose at 95°C processed the highest DG of 28.46%. This reaction was further confirmed by the browning intensity determination. Analysis of Fourier transform infrared spectrophotometer, circular dichroism, and fluorescence spectra indicated that there were slight changes in the subunits and the conversion of α-helices to β-sheets, as well as the unfolded structures, thereby increasing the surface hydrophobicity and absolute zeta potential of obtained glycosylated OVA. Glycosylation endowed OVA with better emulsifying properties, especially the xylose glycosylated OVA was superior to that of glucose and galactose glycosylated OVA, which was mainly due to its shorter molecular chains with smaller steric hindrance for reaction. Furthermore, the enhancement of emulsifying properties may be attributed to the synergistic effect of stronger electrostatic repulsion of larger absolute zeta potential and the steric hindrance from thicker adsorbed layer, thereby inhibiting aggregation and flocculation of emulsion droplet.

Ultrasound accelerates pickling of reduced-sodium salted duck eggs: An insight into the effect on physicochemical, textural and structural properties

In this work, high-intensity ultrasound (HIU) was used to accelerate the pickling of the reduced-sodium salted duck eggs (RSSDE). Meanwhile, it was evidenced that HIU treatment was also helpful to improve the overall quality of RSSDE. When the optimized HIU at 80 W was used, it resulted in favorably higher hardness (1.83 N), springiness (4.20 mm), and chewiness (4.83 mJ) of RSSDE whites, while the lowest hardness (1.12 N) of RSSDE yolks. The average particle size of RSSDE whites was significantly reduced (230.37 nm, 7.14%) as well. Apart from that, the absolute zeta potential and hydrophobicity were increased to −8.63 mV by 14.30% and 164.70 μg by 3.12%, respectively, attributed to the destruction of protein aggregation by cavitation effects. The oil exudation showed an obvious rising during the 14 days of the salting. HIU treatment at 80 W destroyed the emulsification state of lipid droplets and led to higher oil exudation (39.30%). The structural analysis of RSSDE proteins revealed marked alterations following HIU, with a reduction in α-helix and an increase in β-turn and random coil. The highest r-value reached 1.32 after HIU treatment at 80 W, which was attributed to the exposure of both tyrosine and tryptophan residues caused by the hydrophobic rearrangement of RSSDE protein. Scanning electron microscopy revealed that HIU altered the architecture of RSSDE proteins, resulting in more irregular pores. This work proved that HIU was a promising tool to shorten the salting period of RSSDE with much better quality.

The Promotion Effect of Ionic Liquids on Polymer-Driven Recovered Water by Microwave Treatment

SummaryIn view of the difficulties in breaking emulsions and removing oil from polymer-produced water, this study systematically analyzes the promotion effect of anion type, cation type, and concentration of ionic liquid on polymer-driven water produced by microwave treatment. First, when the microwave power is 400 W and the radiation time is 40 seconds, the oil removal rate is only 34.95%. Second, when the anion of the ionic liquid is Br−, the oil/water interfacial tension (IFT) reaches the lowest value. During microwave radiation, the ionic liquid adsorbed on the oil/water interface converts more electromagnetic energy to heat energy owing to dipole polarization and interfacial polarization. In addition, bromine salts have the lowest absolute zeta potential; thus, the electroneutralization effect is the largest. Third, as the length of the cationic alkyl chain of the ionic liquid increases, its synergistic effect with the microwaves first decreases and then increases. Finally, during microwave irradiation, as the concentration of 1-hexadecyl-3-methylimidazole bromide salt increases, the oil removal rate first increases rapidly and then decreases slightly. When the concentration of 1-hexadecyl-3-methylimidazole bromide is 1 mmol/L, the oil removal rate reaches the highest value of 90.31%.

Effect of short-term frozen storage of raw meat on aroma retention of chicken broth: A perspective on physicochemical properties of broth

The effect of short-term frozen storage (0, 2, 4, 6, and 8 wk) of raw meat on the aroma retention of chicken broth was discussed from a perspective on physicochemical properties of broth. With the increased storage time of frozen chicken, the protein concentration of the broth first increased and then decreased significantly due to changes in the small-molecule protein fractions (<10 kDa), as determined by SDS-PAGE. The volume fraction of oil droplets and the particle size increased significantly. Meanwhile, the absolute zeta potential decreased. The result from the circular dichroism spectrum showed that gelatin, the major structural protein in chicken broth, tended to depolymerize. In general, when the storage time of frozen chicken increased, the depolymerization of gelatin in the broth could enhance its emulsifying ability, resulting in the increases in the fat content and particle size of chicken broth, which enhanced the aroma retention of chicken broth. The information obtained could be used to explain the enhanced aroma strength of the broth prepared from chicken following short-term frozen storage.

D-optimal mixture design for optimization of topical dapsone niosomes: in vitro characterization and in vivo activity against Cutibacterium acnes

This study aimed to illustrate the use of D-optimal mixture design (DOMD) for optimization of an enhancer containing Dapsone niosomal formula for acne topical treatment. Mixture components (MixCs) studied were: Span 20, Cholesterol, and Cremophor RH. Different responses were measured. Optimized formula (OF) was selected to minimize particle size and maximize absolute zeta potential and entrapment efficiency. Optimized formula gel (OF-gel) was prepared and characterized. OF-gel in vivo skin penetration using confocal laser scanning microscopy and activity against Cutibacterium acnes in acne mouse model were studied. Based on DOMD results analysis, adequate models were derived. Piepel and contour plots were plotted accordingly to explain how alteration in MixCs L-pseudo values affected studied responses and regions for different responses’ values. The OF had suitable predicted responses which were in good correlation with the actually measured ones. The OF-gel showed suitable characterization and in vivo skin penetration up to the dermis layer. In vivo acne mouse-model showed that OF-gel-treated group (OF-gel-T-gp) had significantly better recovery (healing) criteria than untreated (UT-gp) and Aknemycin®-treated (A-T-gp) groups. This was evident in significantly higher reduction of inflammation percent observed in OF-gel-T-gp than both UT-gp and A-T-gp. Better healing in OF-gel-T-gp compared with other groups was also verified by histopathological examination. Moreover, OF-gel-T-gp and A-T-gp bacterial loads were non-significantly different from each other but significantly lower than UT-gp. Thus, DOMD was an adequate statistical tool for optimization of an appropriate enhancer containing Dapsone niosomal formula that proved to be promising for topical treatment of acne.

Study on the mechanism of enhanced gel strength of heat-induced egg white by shikimic acid braising

This study evaluated the effects and mechanism of shikimic acid braising on the gelling characteristics of heat-induced egg white gel (HEWG). The results indicated that, during braising, soluble protein and hardness showed an overall increasing trend. The absolute Zeta potential value showed a decreasing trend; however, T2 and free sulfhydryl group showed an increasing trend first and decreasing trend later, and surface hydrophobicity showed a decreasing trend. Microstructure analysis showed that protein gel aggregation increased and that holes and cracks formed first, and then the cracks decreased. Fourier transform infrared spectrometry showed that shikimic acid could strengthen the polarity of HEWG, and a mutual transformation occurred between intramolecular β-sheets, intermolecular β-sheets, and intermolecular antiparallel β-sheets, as well as a slight blue-shift, in the α-helices. In general, the addition of shikimic acid could alter the HEWG structure and improve its gel strength, polarity, and aggregation. Moreover, the higher the concentration of shikimic acid, the greater the influence on HEWG. Therefore, shikimic acid could be used as a new type of gel enhancer for the modification of egg white gel.

Effect of modification by Gemini cationic surfactant on the properties of slurries prepared with petroleum coke: Experiments and molecular dynamics simulation

In order to improve the properties of petroleum coke water slurry (PWS), a quaternary ammonium Gemini cationic surfactant, 14-3(OH)-14(2Cl) (G14), was chosen to modify the surface chemistry of Lanqiao petroleum coke (LQ). Compared with the single additive of naphthalene sulfonate-formaldehyde condensate (NSF), the compound additive G14&NSF greatly decreased the apparent viscosity of PWS prepared with 73% solid loading of LQ from 789 mPa.s to 623 mPa.s at 25 °C. However, with the increase in temperature, the viscosity-reducing effect of G14 decreased. At the temperature range of this experiment, the static stability of PWS was enhanced remarkably to 7 d, without any deterioration of its rheological behavior. The modification mechanism of G14 on the properties of PWS was ascribed to the apparently strengthened NSF adsorption and the increased absolute zeta potential of LQ particles after pre-adsorption of G14. The adsorption mechanism of the compound additive G14&NSF on LQ particles was investigated by both experiments and MD simulations. The results showed that G14 was adsorbed on LQ particles by a lateral horizontal adsorption mode, which provided more active adsorption sites for NSF mainly via electrostatic interaction, cation-π interaction or the synergistic effect of these two interactions.

Modification of emulsifying properties of mussel myofibrillar proteins by high-intensity ultrasonication treatment and the stability of O/W emulsion

The purpose of this research was to investigate the effects of high-intensity ultrasonication (HIUS) treatment at different ultrasonic powers (0, 150, 300, 450, 600 W) on the emulsifying properties of mussel myofibrillar protein (MMP). The changes in fourier infrared spectroscopy, fluorescence spectroscopy, free sulfhydryl groups and surface hydrophobicity, indicated that HIUS treatment changes the structure of MMP. HIUS treatment could significantly improve the emulsifying properties of MMP by affecting its physicochemical properties. HIUS treatment improved the emulsification activity index, emulsification stability index, adsorption protein percentage, creaming index, interfacial tension, rheology and other emulsifying properties of O/W emulsion. HIUS treatment at 600 W had the best effect on the solubility of MMP. Solubility, compared to control, increased from 11.1% to 33.4%; and the change in molecular structure of MMP was characterized by smaller particles (from 48.64 to 20.60 µm), lager absolute zeta potential (from 56.24 to 79.92 mV), and decreased turbidity (from 1.68 to 0.97). The emulsion stabilized by MMP ultrasonicated at 600 W showed the best storage stability, with the lowest particle size, the lowest surface tension (11.83 mN/m) and the largest absolute value of zeta potential (31.78 mV), which was confirmed in the microstructure photos. The results of this research provide theoretical basis for the application of ultrasonic modified MMP as functional protein ingredients to control emulsion-type seafood products or design of MMP-based emulsion delivery systems for functional material in the food industry.

Structural and interfacial characteristics of ultrasonicated lipophilic-protein-stabilized high internal phase Pickering emulsions

Soybean lipophilic protein (LP) can stabilize high internal phase Pickering emulsions (HIPPE) under acidic conditions (pH 2.0); thus, it is vital for the targeted release of functional nutrients. However, the high fat content and low solubility of LP under acidic conditions hinder the functional properties of HIPPEs. We explored the effect of ultrasonic compound acid treatment on the structure and functional properties of LP. The effects of varying ultrasonication power (0, 150, 250, 350, and 450 W) for 10 min on the freeze–thaw stability and interfacial characteristics of the modified LP-stabilized HIPPE were evaluated using particle size, rheological, and differential scanning calorimetry. The results showed that LP sonicated at 350 W exhibited a small particle size (minimum 250 nm), high absolute zeta potential (maximum 28 mV), and the maximum solubility. Following ultrasonication, LP covered the oil–water interface more uniformly, and the adsorbed protein percentage increased significantly (p < 0.05) to 53%. LP-stabilized HIPPE possessed a stronger gel-like network and exhibited significantly increased freeze–thaw stability (p < 0.05). Our results indicate that ultrasonication can change the structural and functional properties of LP, providing a theoretical reference for further applications of acid emulsions in the food industry.

Nanostructured lipid carriers for delivery of free phytosterols: Effect of lipid composition and chemical interesterification on physical stability

The objective of this study was to develop new nanostructured lipid carrier (NLC) formulations loaded with free phytosterols (FPs) using interesterified and simple lipid phases. The simple and interesterified lipid phases were composed of soybean oil as liquid lipid and fully hydrogenated palm (HPO) and crambe (HCO) oils s solid lipids. High-pressure homogenization was the preparation method, with soy lecithin as a natural emulsifier. The characteristics of NLCs were influenced by chemical interesterification and the composition of solid lipid, mainly with respect to the fatty acid chain size. All developed FP-loaded NLCs displayed an appropriate nanoscale size from approximately 167 to 330 nm (d32) and appropriate physical stability with zeta potential values ranging from − 29.83 to − 43.70 mV after 30 days of storage. The changes observed in these parameters were influenced by the lipid phase of the NLCs and the crystallization of FP on the surface of the NLCs. FP-loaded NLCs formulated with interesterified blends displayed smaller particle size values, with less evidence of particle agglomeration and higher absolute zeta potential values than NLCs formulated with simple blends. These results indicated that NLCs developed with interesterified lipid blends were more stable than those developed with single blends NLCs produced from solid lipids with fatty acids with larger chain sizes (HCO) had larger particle sizes but were less likely to flocculate and coalesce. Thermal behavior study revealed that interesterification caused a reduction in the melting temperature and recrystallization index of the NLCs. These findings indicated decreased crystallinity and a less organized structure. This behavior favored the highest encapsulation efficiency and load capacity observed for NLCs developed with interesterified blends.

Structure and rheological studies of phosphorylated cellulose nanofibrils suspensions

Cellulose nanofibrils (CNFs) are normally handled in the form of aqueous suspensions. Therefore, their rheology and intrinsic flow features in an aqueous state also fascinated the researchers. However, understanding the structure-rheology relationship remains a profound challenge to design CNFs with desirable properties. For that purpose, jute fibers were used as source material (Corchorus olitorius) to produce CNFs, and pretreatment using phosphorylation was applied to facilitate the fibrillation during ultra-sonication. This study aims to investigate the relationship between the microstructure and their rheology for CNF aqueous suspensions as influenced by the temperature and concentration of CNF. The surface chemistry, fiber diameter distribution, crystalline structure, thermal stability, and rheological properties of the obtained CNFs were characterized and compared. The grafting of phosphorous moieties on the surface of the fibers was confirmed by the FTIR, XPS analyses, elemental analyses, and zeta potential. Despite influencing crystallinity, phosphorylation enhanced the diameter of nanofibers. The results demonstrated that phosphorylation did not alter the main chemical structure of cellulose. The crystallographic form of the obtained CNFs remained cellulose I. The resulting fibers have nanometric dimensions (<100 nm) with high absolute zeta potential values (>30 mV). A substantial improvement in flame retardancy has also been noted for CNF due to the presence of phosphate groups. Both steady-state and dynamic rheological measurements were improved significantly upon increasing concentration from 0.5 to 2.5 wt%. All the CNF suspensions demonstrated typical shear-thinning behavior and gel-like viscoelastic character even at low concertation (0.5 wt%) due to the construction of a wire-like matrix structure. The frequency and temperature alteration, however, do not affect the viscoelastic gel-like properties of the CNF suspensions.

Study on the Preparation and Characterization of Glycyrrhizic Acid Liposomes

The purpose of this study was to prepare glycyrrhizic acid nanoliposomes and evaluate the encapsulation efficiency and other properties of glycyrrhizic acid nanoliposomes, which would provide a reference for further research on Glycyrrhizic Acid in the treatment of liver diseases. Firstly, the preparation conditions of glycyrrhizic acid liposomes were optimized by the orthogonal design method. Then, glycyrrhizic acid liposomes were prepared by ultrasonic-film dispersion method and the encapsulation efficiency was determined by the HPLC method. Finally, the properties of glycyrrhizic acid nanoliposomes were also studied. The results showed that the optimal preparation conditions of liposomes were as follows: the ratio of drug to lipid was 1:30; Lecithin: cholesterol = 1:1; Hydration medium: pure water; Ultrasonic time: 120 s. The encapsulation efficiency of liposomes was about 90%. The final liposomes were round and uniform in distribution, with an average particle size of about 50 nm and absolute zeta potential of −28.9 mV. In this study, glycyrrhizic acid liposomes were prepared and the optimal preparation conditions were optimized. The encapsulation efficiency of the liposomes under the optimized conditions was determined. The evaluation of the morphology, size, particle size and stability of the liposomes was completed.