Complex Particles Research Articles

Solvent-Free Fabrication of Anisotropic Microparticles with Precise 3D Shape Control Using Dipping-Based Micromolding.

We present an innovative solvent-free micromolding technique for rapidly fabricating complex polymer microparticles with three-dimensional (3D) shapes utilizing a surface tension-induced dipping process. Our fabrication process involves loading a photocurable solution into micromolds through mold dipping. The loaded solution, induced by surface tension, undergoes spatial deformation upon mold removal caused by surface forces, ultimately acquiring an anisotropic shape before photopolymerization. Results show that the amount of photocurable solution loaded depends on the degree of capillary penetration, which can be adjusted by varying the dipping time and mold height. It enables the production of polymer particles with precisely controlled 3D shapes without diluting them with volatile organic solvents. Sequential micromolding enables the spatial stacking of the polymer domain through a bottom-up approach, facilitating the creation of complex multicompartmental microparticles with independently controlled compartments. Finally, we demonstrated the successful simultaneous conjugation of multiple model-fluorescent proteins through the biofunctionalization of microparticles, indicating functional stability and effective conjugation of hydrophilic molecules such as proteins. We also extend our capacity to create bicompartmental microparticles with distinct functionalities in each compartment, revealing spatially controlled functional structures. In summary, these findings demonstrate a straightforward, rapid, and reliable method for producing highly uniform complex particles with precise control over the 3D shape and compartmentalization, all accomplished without the use of organic solvents.

Fish oil encapsulation by genipin-crosslinked complex coacervation between gelatin and different anionic polysaccharides

Herein, a combination approach of bovine bone gelatin (BBG)/anionic polysaccharide (AP) complex coacervation with genipin crosslinking was developed to successfully fabricate fish oil-loaded genipin-crosslinked BBG/AP (fish oil@BBG-genipin-AP) powders. The genipin crosslinking process promoted the formation of larger fish oil@BBG-genipin-AP particles from the BBG/AP particles and fish oil@BBG/AP particles. AP types (gum Arabic, GA; sodium alginate, SA; sodium carboxymethyl cellulose, CMC) and concentrations significantly affected the critical pH to form complex coacervated particles, the powder physicochemical properties, the powder oxidative stability, and the powder in vitro digestion. The fish oil@BBG-genipin-CMC powder at the CMC preparation concentration of 17.5 mg/mL showed the highest loading capacity value (44.3% ± 0.8%), almost the highest encapsulation efficiency value (90.9% ± 0.7%), and the highest encapsulation yield (91.3% ± 2.0%). Due to the environmental pH change, the powders changed to emulsion droplets in the gastric phase and then released free fatty acids in the small intestinal phase. The highest FFA release percentages after the gastrointestinal phase (2 h in the gastric phase and 2 h in the small intestinal phase) were dependent on both AP types and their concentrations (GA: 64.8 ± 2.9%, 62.5 mg/mL; SA: 55.0 ± 3.1%, 15 mg/mL; and CMC: 48.9 ± 1.5%, 12.5 mg/mL). GA at a concentration of 62.5 mg/mL might be the best system to prepare fish oil@gelatin-genipin-anionic polysaccharide powders for fish oil digestion. This work provided useful information to develop oil-encapsulation powders for functional foods and understand the influences of wall materials on the fabrication and properties of powder foods.

COMPLEXATION OF SILVER (I) C 2-ETHYLIMIDAZOLE

The acid-base properties of 2-ethylimidazole were studied by pH-metric titration (EM). Using the literature data and our own results, a number of changes in the acid-base properties (pКa) of imidazoles have been established: ethylimidazole (7,93)> imidazole (7.05)>2-phenylimidazole (6,48)>2-aminobenzimidazole (6,11)> benzimidazole (5,53)>2-phenylbenzimidazole (5,23)>2-mercaptoimidazole (2,97)>1-methyl-2-mercaptoimidazole (2,11). Method The process of complexation of silver(I) with 2-ethylimidazole in the temperature range of 273-318K was investigated using potentiometric titration using a silver electrode. It has been established that the increase in temperature does not affect the stoichiometric composition of complex particles formed in the Ag-EM-H2O system. The results obtained show that as the temperature increases, the stability constants decrease. On the basis of diagrams, the distribution of complex particles depending on the ligand concentration is shown that in System Ag-EM-H2O is mainly dominated by the bis-substituted complex, the yield of which at EM concentrations above 1·10-2 mol/l is 100%. The thermodynamic functions of the formation of 2-ethylimidazole silver complexes have been calculated. It has been established that complexation reactions are exothermic. Spontaneous occurrence of complexation reactions in the system Ag-EM-H2O contributes to a negative change in enthalpy.

Investigation of Light-Scattering Properties of Non-Spherical Sea Salt Aerosol Particles at Varying Levels of Relative Humidity

In the marine environment, sea salt aerosol particles transition from cubic or rectangular shapes when dry to various non-spherical shapes like ellipsoids and cylinders under different humidities. The complex humidity conditions and particle morphologies pose challenges to simulating the optical scattering properties of non-spherical sea salt aerosols. This study, addressing real environmental scenarios, employs the randomly oriented T-matrix computational method to calculate the optical scattering and polarization characteristics of sea salt aerosols at a wavelength of 1.06 μm under three relative humidity conditions (50%, 80%, and 95%) and three particle morphologies (spheroid, circular cylinder, and Chebyshev particle shapes). The results show the following: (1) In terms of optical scattering properties, the greater the non-sphericity of particles under the same humidity conditions, the larger the deviation between non-spherical and spherical models. For spheroid and circular cylinder sea salt aerosols, the error in the extinction efficiency factor mainly lies within 10–30%, reaching up to 120%; the error in the asymmetry factor is primarily between 3 and 25%, with a maximum of 75%, and the error in the forward-scattering phase function is mainly within 10–60%, reaching up to 180%. Chebyshev particle-shaped sea salt aerosols exhibit smaller deviations in optical scattering properties compared to equivalent spherical models, generally within the 5–25% range. Under different humidity conditions, the scattering characteristic parameters of sea salt aerosol particles for various non-spherical models show a positive correlation with relative humidity. When relative humidity is below 70%, the optical scattering properties of differently shaped sea salt aerosols are less affected by relative humidity. Above 70% relative humidity, the optical scattering properties of sea salt aerosols of different shapes become more sensitive to changes in relative humidity. (2) Regarding polarization properties, the greater the humidity, the more significant the impact on polarization properties, and as humidity increases, sea salt aerosols with higher non-sphericity exhibit more complex changes in polarization characteristics. The differences in shapes of non-spherical models mainly affect the numerical values of polarization properties. Under the same humidity conditions, spheroid polarization characteristics are significantly different from other models. In terms of depolarization ratio for aerosols, circular cylinder sea salt aerosols show the highest depolarization ratio at various relative humidities, followed by spheroid, with Chebyshev-shaped having the least. The effect of relative humidity on the depolarization ratio varies with the scattering angle. The higher the relative humidity, the more complex the variation in the depolarization ratio with scattering angle, with more pronounced oscillations in the curve, and the less non-spherical the shape, the more intense the oscillations in the depolarization ratio curve due to humidity. In conclusion, this study calculated the optical scattering and polarization properties of sea salt aerosol particles under different relative humidities and shapes, which is of significant importance for applications like 1.06 μm laser engineering and atmospheric radiation transmission in actual marine scenarios.

Optical pulling force on a uniaxial anisotropic sphere by a high-order Bessel (vortex) beam.

Based on the generalized Lorenz-Mie theory (GLMT) and the scattering theory of uniaxial spheres, a theoretical approach is introduced to study the axial radiation force (AOF) exerted on a uniaxial anisotropic sphere illuminated by an on-axis high-order Bessel (vortex) beams (HOBVBs). Applying Maxwell's stress tensor, an analytical expression of the AOF on a uniaxial anisotropic sphere by the on-axis HOBVB is derived. The correctness of the theoretical and numerical results is verified by comparing the AOF on an isotropic sphere by a zero-order Bessel beam (ZOBB) with those results by a plane wave, Gaussian beam, and ZOBB. The focus of this study is to determine some conditions of the tractor beam, so as to realize the inverse motion of an anisotropic sphere through a Bessel beam. The range of optical pulling force (OPF) that can pull particles in reverse motion generated by zero-order and first-order Bessel beams is extended from isotropic spherical particles to anisotropic spherical particles. The effects of the sphere radius, conical angle, and especially electromagnetic anisotropy parameters on the OPF in water or a vacuum environment are discussed in detail. Moreover, the OPF exerted on the uniaxial anisotropic sphere illuminated by a HOBVB with l=2, 3, and 4 is also exhibited. It indicates that the HOBVB with l=2, 3 is also a good tractor beam for the uniaxial anisotropic sphere. The OPF generated by Bessel beams on uniaxial anisotropic spherical particles is not only affected by the conical angle and radius but is also significantly influenced by anisotropic parameters and topological charges. These properties of the OPF are different from those on an isotropic sphere. The theory and results are hopeful to provide an effective theoretical basis for the study of optical micromanipulation of biological and anisotropic complex particles by optical tractor (vortex) beams.

Preparation and characterization of sodium caseinate/xanthan gum complexes in acidic conditions and their use for the stabilization of oil‐in‐water emulsions

AbstractIn this work, complexes formed by sodium caseinate (NaCn) and xanthan gum (XG) were tested as novel natural stabilizers. They were prepared at pH 4, using a constant concentration of XG (0.4%) and different NaCn concentrations. Then, they were characterized in terms of turbidity, surface tension (ST), and rheology. The acquired results indicated that the ST of NaCn solution and NaCn/XG dispersion decreases with NaCn concentration. In addition, the ST of NaCn/XG is higher than that of NaCn solution indicating interactions between NaCn and XG. In addition, the turbidity of the dispersions increases while ST decreases with NaCn concentration. Fourier transform spectroscopy (FTIR) spectra confirmed the formation of a complex between NaCn and XG through electrostatic interactions. Structural analyses demonstrated that the morphologies of the complex particles are different compared to the pure biopolymer ones. Furthermore, the oil‐in‐water (O/W) emulsions based on NaCn/XG complexes formed into acid conditions were studied. The obtained results showed that the stability, the average diameter of the droplets, and the rheological behavior of the formulated emulsions depend on the NaCn:XG ratio. Emulsion formulated with 0.5:1, 1:1, 1.5:1, 2:1 NaCn:XG ratio presented good creaming stability during 1 month of storage at 25°C. On the other hand, samples formulated with a 1:1 ratio of NaCn/XG exhibited the best stability. Their average diameter (29.026 μm) remained constant during the storage. Emulsions formulated with higher ration PR:PS (2.5:1, 3:1) were unstable and have larger droplets. Also, all formulations showed a shear‐thinning and elastic behavior.

Pea protein isolate-zein complex particles prepared by hydrophobic interactions and their application in stable Pickering emulsions

Most of the recent studies focus on modifying hydrophobic proteins with hydrophilic components to prepare Pickering emulsion stabilizers. This study reports Pea protein isolate-Zein (PPI-Zein) complex particle prepared by hydrophobic interactions. During the formation of PPI-Zein complexes, the hydrophobic segments of two types of hydrophobic proteins interact to form the core of the particles, while the remaining hydrophilic parts tend to be exposed on the surface of the particles. Therefore, the complex particle has an improved dispersibility, the changed surface wettability and isoelectric point around 4. The diffusion coefficient of these particles is 7.1–11.4 times higher than that of pure zein and 4.0–6.3 times higher than that of pure PPI. As a result, Pickering emulsions stabilized by PPI-Zein complex particles can achieve an oil phase volume fraction of up to 60 (v/v)%, demonstrating good storage stability (up to 30 days), ionic strength resistance (up to 500 mM), high-temperature stability (80 ℃, 48 h) and pH stability (pH 2–9). And the prepared emulsion was proven to have the property of protecting active substances, such as curcumin. These findings indicate potential applications in encapsulation or carrier systems that require clean labels.

Development and characterization of novel ultra-stable high internal phase Pickering emulsions gel: Interface structure, stabilization mechanism, and applications

While both protein-polysaccharide complexes and continuous phase gelation showed great potential for stabilizing high internal phase Pickering emulsions (HIPPEs), it is not known which strategies are more effective and adaptive. In this work, HIPPEs gel was prepared by Ca2+-induced continuous phase gelation of ovalbumin (OVA)-low methoxyl pectin (LMP) electrostatic complexes particles (OLECP)-stabilized HIPPEs. The microstructure, rheological properties, stability, and application of HIPPEs and HIPPEs gel were systematically investigated and compared at different LMP concentrations. The results showed that, compared to HIPPEs, continuous phase gelation effectively improved the viscoelasticity, water binding capacity, and hardness of HIPPEs gel due to its robust and developed interface architecture. CLSM and cryo-SEM observations revealed that OLECP interconnected with each other in the continuous phase to form an advanced network architecture in HIPPEs. Whereas, a firm gel network structure and a thick interfacial layer were found in HIPPEs gel. More importantly, with increasing pectin concentration, the cross-linking phenomenon of OLECP mainly at the interface, transformed into the gelation behavior of excess pectin molecules dominating in the continuous phase. LMP contributed to the formation of a finer 3D gel network structure and a firmer interfacial layer, providing a smaller oil droplet size and superior stability for HIPPEs gel. The photochemical stability of curcumin was increased from 16.1 ± 1.5 % to 93.7 ± 2.2 % after encapsulation in HIPPEs gel. In vitro digestion results testified that HIPPEs gel (10:15, w/w) can promote fat hydrolysis (from 32.35 ± 3.06 % to 45.52 ± 2.75 %) and enhance the bioaccessibility of curcumin (from 20.1 ± 1.5 % to 32.8 ± 2.6 %) compared to bulk oil. Besides, compared with HIPPEs, HIPPEs gel showed poor printability because of improper printing adaptability and liquidity. In a nutshell, our work provides valuable information for developing novel HIPPEs gels for various food applications.

Diacylglycerols and Lysophosphatidic Acid, Enriched on Lipoprotein(a), Contribute to Monocyte Inflammation.

Oxidized phospholipids play a key role in the atherogenic potential of lipoprotein(a) (Lp[a]); however, Lp(a) is a complex particle that warrants research into additional proinflammatory mediators. We hypothesized that additional Lp(a)-associated lipids contribute to the atherogenicity of Lp(a). Untargeted lipidomics was performed on plasma and isolated lipoprotein fractions. The atherogenicity of the observed Lp(a)-associated lipids was tested ex vivo in primary human monocytes by RNA sequencing, ELISA, Western blot, and transendothelial migratory assays. Using immunofluorescence staining and single-cell RNA sequencing, the phenotype of macrophages was investigated in human atherosclerotic lesions. Compared with healthy individuals with low/normal Lp(a) levels (median, 7 mg/dL [18 nmol/L]; n=13), individuals with elevated Lp(a) levels (median, 87 mg/dL [218 nmol/L]; n=12) demonstrated an increase in lipid species, particularly diacylglycerols (DGs) and lysophosphatidic acid (LPA). DG and the LPA precursor lysophosphatidylcholine were enriched in the Lp(a) fraction. Ex vivo stimulation with DG(40:6) demonstrated a significant upregulation in proinflammatory pathways related to leukocyte migration, chemotaxis, NF-κB (nuclear factor kappa B) signaling, and cytokine production. Functional assessment showed a dose-dependent increase in the secretion of IL (interleukin)-6, IL-8, and IL-1β after DG(40:6) and DG(38:4) stimulation, which was, in part, mediated via the NLRP3 (NOD [nucleotide-binding oligomerization domain]-like receptor family pyrin domain containing 3) inflammasome. Conversely, LPA-stimulated monocytes did not exhibit an inflammatory phenotype. Furthermore, activation of monocytes by DGs and LPA increased their transendothelial migratory capacity. Human atherosclerotic plaques from patients with high Lp(a) levels demonstrated colocalization of Lp(a) with M1 macrophages, and an enrichment of CD68+IL-18+TLR4+ (toll-like receptor) TREM2+ (triggering receptor expressed on myeloid cells) resident macrophages and CD68+CASP1+ (caspase) IL-1B+SELL+ (selectin L) inflammatory macrophages compared with patients with low Lp(a). Finally, potent Lp(a)-lowering treatment (pelacarsen) resulted in a reduction in specific circulating DG lipid subspecies in patients with cardiovascular disease with elevated Lp(a) levels (median, 82 mg/dL [205 nmol/L]). Lp(a)-associated DGs and LPA have a potential role in Lp(a)-induced monocyte inflammation by increasing cytokine secretion and monocyte transendothelial migration. This DG-induced inflammation is, in part, NLRP3 inflammasome dependent.

Synthesis of patchy colloids with different chemical functionalities

Patchy particles are one of the new frontiers in developing novel functional colloids because of their similarity to molecules in terms of their potential ability to form directional bonds and give rise to complex architecture via self-assembly. Considerable challenges remain in developing effective strategies for synthesizing such complex particles. Most current works have focused on controlling the position of patches, which is already tricky. Still, very few works have tackled the problem of preparing particles with patches bearing different functionalities. In this work, we used an activated swelling method developed in our group to prepare Janus polymer particles with variable Janus balance and used them to synthesize bi-patchy particles with different chemical functionalities. We first created polystyrene/polymethyl methacrylate-glycidyl methacrylate (PS/P(MMA-GMA)) Janus particles with a small methacrylate patch. The epoxy groups were then aminated (PS/P-NH2), leading to a change in the hydrophilicity of the patch. We then used two methods to create patchy particles. In the first case, we mixed unmodified PS/P(MMA-GMA) and PS/P-NH2 Janus particles and fused them by adding THF as a plasticizer. This led to the formation of bi-patchy particles with identical patches and two patches bearing different functionalities, as proved by fluorescence microscopy. In the second case, PS/P-NH2 particles were used as seeds for an additional activated swelling polymerization step with MMA as a monomer to obtain pure bi-patchy particles with differently functionalized patches. This was possible thanks to the incompatibility between the NH2-functionalized first patch and the pure PMMA of the second one. The work opens the path to preparing colloidal molecules capable of forming multiple directional bonds through orthogonal chemical functionalization.

Mechanistic enhancement of emulsification function in zein/pectin complex nanoparticles by short linear glucan

The objective of this research was to create stable Pickering emulsions (PEs) by manipulating the structure of the interface through the control of interfacial properties, self-assembly, and packing characteristics of zein particles, utilizing the interaction between short linear glucan (SLG) and pectin. The scientists successfully synthesized ternary complex particles designated as SZPPs (abbreviated for SLG/Zein/Pectin), displaying three-phase contact angles ranging from 83.14° to 87.32°. SZPPs were effectively anchored at the oil-water interface, resulting in a robust and well-organized arrangement, as confirmed by the combination of Langmuir−Blodgett and Scanning Electron Microscope (LB-SEM) and confocal laser scanning microscopy techniques. This arrangement led to the formation of a permeating three-dimensional network of oil droplets, which greatly contributed to the creation of stable PEs. These PEs exhibited unique properties such as viscoelasticity, remarkable thixotropy, and excellent long-term storage stability. One noteworthy advantage of these engineered PEs was their ability to shield curcumin from degradation caused by UV radiation, thereby enhancing the oxidative stability of the emulsions. This protective effect ensures that the curcumin remains intact and active over time. Considering these advantageous properties, these engineered PEs hold great promise for various applications in the food and pharmaceutical industries.

Arc deposition oxide modified welding wire-effect of oxides on phase transformation

The problem in welding of high-strength steel is that it's elementary to obtain hardened microstructure in welding process, which's expected to be solved by oxide metallurgy technology. The effect of the oxides added to the welding wire on the microstructure of the deposited parts is unclear. In this work, the microstructure of the sample and morphology of the oxides were studied in deposited oxide modified H13 steel, and the solidification of the deposited oxide modified H13 steel were observed in-situ. The results show that the oxides reacted at high temperatures generated by the arc to form complex oxide particles. The complex oxide particles in molten steel also induces δ-Fe and γ-Fe nucleation and ferrite transformation in solidification process, which's conducive to alleviating the problem of excessive hardened microstructure in welding of high-strength steel.

Pickering extremulsion rich in lipophilic phytochemicals: Preparation, characterization and application

The stability and use convenience of lipophilic phytochemicals are needed in the food or medicine fields. In this work, a new and environmentally friendly process for efficient extraction and formulation of lipophilic phytochemicals from plant had been successfully developed. A medium system consisting of water, tributyrin oil and natural amphiphilic complex particles (SPICS) was established. Under the optimal conditions of the oil/water ratio 10%, the particle concentration 2%, solid-liquid ratio 35:1 (mg/mL), ultrasound time 90 s and ultrasound power 300 W, the stable and uniform Pickering extremulsion rich in phytochemical lipophilic cannabidiol（CBD）from industrial hemp leaves was prepared. The Pickering extremulsion with the highest CBD content 1.06 mg/g was obtained, which increased 1.17-fold to the traditional Soxhlet extraction. Meanwhile, the CBD-rich Pickering extremulsion had an excellent antibacterial, antioxidant activity and cell activity with bacteriostatic diameter 7.5–18 mm, DPPH clearance rate 61.8% and cell activity of more than 80%. Besides, CBD-rich Pickering extremulsion had good bioaccessibility. In conclusion, the study provided a green, efficient and low-cost approach for simultaneous extraction and preparation of lipophilic phytochemicals, and it should provide some valuable insights for its application as nutrient or active carriers in phytochemicals field.

Synthesis, characterization, antimicrobial, molecular docking simulation, and antitumor assays of nanometric complexes based on new thiazole Schiff base derivative

For further pharmaceutical applications, a novel Schiff base derivative of aminothiazole and its Co (II), Cu (II), Zn (II), and Th (IV) chelates were designed and prepared. For this purpose, 2‐aminothiazole and 2,4‐dihydroxybenzaldehyde have been coupled before the complexation reaction with the metal salts. Elemental analysis, FT‐IR, 1HNMR, UV–Vis spectra, transmission electron microscopy (TEM), X‐ray powder diffraction (XRD), molar conductance, and magnetic moment measurements were used to determine the structural formula of the ligand and its produced chelates. The acquired data pointed out that the ligand was chelated with metal through the nitrogen of azo group and deprotonated ortho phenolic oxygen atoms. In Cu (II) complex the copper ion chelated with two ligand molecules, whereas in other complexes the metal binds with one molecule only of ligand. It was shown by XRD patterns and high‐resolution TEM images that the complex particles had a uniform distribution across the chelates' surfaces and were nanometric in size. Extremely, antimicrobial and anticancer activity for the prepared ligand and complexes were investigated, which showed high activity, especially after complex formation. Docking studies have been performed to predict the compounds' efficacy as antitumor agents through their interaction with the co‐crystal structure of proteins for breast cancer cells (PDB ID: 3S7S) and protein of liver cancer 2 (PDB ID: 2JW2). The experimental results of the anticancer activity showed promising results, especially for Cu (II) compound which exhibited the greatest antitumor efficacy (IC50 = 12.81 μg/ml) contra HepG‐2 carcinoma and Mcf‐7 cells (IC50 = 18.92 ± 0.91 μg/ml). Antimicrobial activity against the strains Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), C. albicans (C. albicans), and Aspergillus niger (A. niger) also gave very promising results when it is compared with the standard drugs.

Production and investigation of Pickering emulsion stabilised by casein-Qodume Shirazi (Alyssum homolocarpum) seed gum complex particles: gastrointestinal digestion

Recently, there has been growing research interests in designing Pickering emulsions. In this work, Alyssum homolocarpum seed gum (AHSG) and casein protein (CP) nanoparticles (NPs) fabricated as Pickering stabilizers. AHSG (0.0, 0.05, 0.10, and 0.15% (w/w))-CP (2% (w/w)) nanoparticles were fabricated and their properties were investigated (mean diameter, morphology, zeta potential, Fourier transform infra-red, and contact angle). Formation and stability of Pickering emulsion (Pes) stabilized by AHSG-CP NPs were monitored by mean diameter, rheological properties, and in vitro digestion. AHSG-CP Nps exhibited a small size (107.75 ± 0.42-201.52 ± 0.70 nm) and had wettability between 64.94 ± 3.44° and 70.92 ± 7.64°. The stability of PEs was greatly improved by 0.05AHSG-CP NPs, even after 30 days of storage, centrifugation, and in vitro digestion, owing to the reinforcement of particle structure at the oil/water interfaces.This study demonstrates that 0.05% (w/w) AHSG-CP NP showed the highest stability during storage and against gastrointestinal digestion which showed its suitability as a fat reducer emulsion structure.

Effect of dynamic high-pressure microfluidization treatment on soybean protein isolate–rutin non-covalent complexes

In this investigation, soybean protein isolate–rutin (SPI–RT) complexes were treated using dynamic high-pressure microfluidization (DHPM). The effects of this process on the physicochemical and thermodynamic properties of SPI were investigated at different pressures. Fourier-transform infrared spectroscopy and fluorescence spectroscopy provided evidence that the SPI structure had been altered. The binding of SPI to RT resulted in a decrease in the percentage of α-helices and random curls as well as an increase in the percentage of β-sheets. In particular, the α-helix content decreased from 29.84 % to 26.46 %, the random curl content decreased from 17.45 % to 15.57 %, and the β-sheet content increased from 25.37 % to 26.53 %. Moreover, fluorescence intensity decreased, and the emission peak of the complex was red-shifted by 6 nm, exposing the internal groups. Based on fluorescence quenching analysis, optimal SPI–RT complexation was achieved after 120-MPa DHPM treatment, and molecular docking analysis verified the interaction between SPI and RT. The minimum particle size, maximum absolute potential, and total phenolic content of the complexes were 78.06 nm, 21.4 mV and 74.35 nmol/mg protein, respectively. Furthermore, laser confocal microscopy revealed that the complex particles had the best microstructure. Non-covalent interactions between the two were confirmed using sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Moreover, the hydrophobicity of the complex particle's surface increased to 16,045 after 120-MPa DHPM treatment. The results of this study suggest that DHPM strongly promotes the improvement of the physicochemical properties of SPI, and provide a theoretical groundwork for further research.

The relationship between the secondary structure and the emulsifying ability of protein-based particles and the Pickering emulsions stabilized by the zein-lysine complex.

Due to the sustainability and widespread use of proteins, protein-based materials are extensively utilized in the preparation of Pickering emulsions. However, the relationship between the secondary structure of proteins and their emulsifying ability has not been further investigated. This study used the addition of three different amino acids to influence the interaction between zein chains, which may induce changes in the secondary structure of the prepared zein complex particles. This study demonstrates that the emulsifying properties of proteins, such as dispersibility, zeta potential, three-phase contact angles, interfacial affinity, adsorption rates, and the volume of the stabilized oil phase, are closely related to the β-sheet content of the complex particles, providing a theoretical reference for protein-based stabilizers. Additionally, amino acids, as the blocks of proteins, have high compatibility with proteins, and using amino acids as modifiers aligns with the safety requirements for food processing. In this study, the prepared zein-lysine complex particles have good emulsifying ability, capable of stabilizing a 50 (v/v)% emulsion at a lower concentration (10 mg mL-1), and the prepared emulsion exhibits high-temperature stability and ionic resistance. This characteristic makes the emulsion potentially valuable for application in systems with high salt concentrations and those that may undergo heat treatment.

Systemic Treatment with siRNA Targeting Gamma-Secretase Activating Protein Inhibits Amyloid-β Accumulation in Alzheimer's Disease.

Amyloid-β (Aβ) peptide aggregation in the brain is a key factor in Alzheimer's disease. However, direct inhibition of β-secretase or γ-secretase proves ineffective in reducing Aβ accumulation and improving cognition in Alzheimer's. Recent findings suggest that inhibiting gamma-secretase activating protein (GSAP) can decrease Aβ generation without affecting crucial γ-secretase substrates. Dimerization of Lep9R3LC (diLep9R3LC) was confirmed by Ellman's test. The peptide-small interfering RNA (siRNA) complex ratio, particle size, and surface charge were analyzed using electrophoretic mobility shift assay, and dynamic light scattering, respectively. In a 3xTg mice model of Alzheimer's disease, diLep9R3LC:siRNA complexes were intravenously administered twice a week for 8 weeks. Assessments included gene silencing, protein expression, and behavioral improvement using reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, western blotting, Y-maze, and object recognition tests. The efficacy of Lep9R3LC dimerization was ~80% after a 3-d reaction by Ellman's test. In N2a cells, diLep9R3LC:siGSAP complexes achieved ~70% silencing at 48 h posttransfection. In 7-month-old male 3xTg mice, GSAP knockdown was ~30% in the cortex and ~50% in the hippocampus. The behavior improved in mice treated with diLep9R3LC:siGSAP complexes, showing a 60% increase in entries and an 80% increase object recognition. A novel dipeptide, diLep9R3LC, complexed with siRNA targeting GSAP (siGSAP), efficiently delivers siRNA to the mouse brain, targeting the hippocampus. The treatment inhibits Aβ accumulation, reduces GSK-3β-associated with tau hyperphosphorylation, and improves Alzheimer's behavior. Our findings highlight diLep9R3LC:siGSAP's potential for Alzheimer's and as a siRNA carrier for central nervous system-related diseases.

Targeted color design of silver-gold alloy nanoparticles.

This research article focuses on the targeted color design of silver-gold alloy nanoparticles (NPs), employing a multivariate optimization approach. NP synthesis involves interconnected process parameters, making independent variation challenging. Data-based property-process relationships are established to optimize optical properties effectively. We define a color target, employ a green chemical co-reduction method at room temperature and optimize process parameters accordingly. The CIEL*a*b* color space (Commission Internationale de l'Éclairage - International Commission on Illumination) and Euclidean distances facilitate accurate color matching to establish the property-process relationship. Concurrently, theoretical Mie calculations explore the structure-property relationship across particle sizes, concentrations, and molar gold contents. The theoretically optimal structure agrees very well with experimental particle structures at the property-process relationship's optimum. The data-driven property-process relationship provides valuable insights into the formation mechanism of a complex particle system, sheds light on the role of relevant process parameters and allows to evaluate the practically available property space. Model validation beyond the original grid demonstrates its robustness, yielding colors close to the target. Additionally, Design of Experiments (DoE) methods reduce experimental work by threefold with slight accuracy trade-offs. Our novel methodology for targeted color design demonstrates how data-based methods can be utilized alongside structure-property relationships to unravel property-process relationships in the design of complex nanoparticle systems and paves the way for future developments in targeted property design.

Co-assembly of cellulose nanocrystals and gold nanorods: insights from molecular dynamics modelling.

A coarse-grained molecular dynamics model is developed to explore the co-assembly of cellulose nanocrystals (CNCs) and gold nanorods (AuNRs) under sedimentation conditions with varying volumetric concentration and particle-size ratios. Simulations and statistical analysis reveal a noticable preferential attachment of AuNRs on the surface of CNC clusters as the solid fraction of AuNRs was increased when the volumetric fraction of the AuNRs was low. Density-driven self-assembly under sedimentation forces is primarily driven by the AuNRs. This shift in the dominant mechanism from CNCs to AuNRs reveals the limits of multi-particle interactions and formation of ordered structures in binary particle systems. The fundamental insights provided in this work into the self-assembly process in complex particle systems are valuable for the design and control of the physical conditions to achieve desired ordered structures.