Search Results (1,385)

Background: Hydrolyzed collagen peptides (HCP) are widely used as bioactive ingredients in anti-aging and skin rejuvenation formulations due to their role in supporting skin hydration, elasticity, and extracellular matrix integrity. However, their high hydrophilicity limits effective incorporation into lipid-based systems, and restricts controlled release from formulations. Objective: In this study, ethosomal nanocarriers were designed as a phospholipid–ethanol-based system to promote favorable molecular interactions with hydrophilic peptides, aiming to enhance the encapsulation, stability, and controlled release of HCP for dermocosmetic applications. Methods: HCP-loaded ethosomes were prepared using phospholipid (Lipoid P75) and ethanol and optimized by varying high-pressure homogenization cycles. Physicochemical properties, including vesicle size, distribution uniformity, zeta potential, pH, and long-term stability, were monitored for up to 180 days. Vesicle morphology and peptide–lipid interactions were characterized using cryo-scanning electron microscopy and FTIR spectroscopy. Encapsulation efficiency was determined by ultrafiltration, while cytocompatibility was assessed in HaCaT keratinocyte cells. In vitro release behavior was investigated using Franz diffusion cells and compared with aqueous HCP solutions. Results: All formulations exhibited nanoscale size distribution and high colloidal stability, with negative zeta potentials ranging from −42.9 to −76.7 mV. The optimized formulation demonstrated sustained encapsulation efficiency (73% after 180 days) and preservation of peptide structure, as confirmed by FTIR, indicating effective chemical stabilization within the ethosomal matrix. Cytotoxicity studies confirmed good skin cell compatibility. In vitro release studies revealed a controlled and prolonged release profile from ethosomal carriers compared with free HCP solutions, suggesting improved topical bioavailability of collagen peptides. Conclusions: To the best of our knowledge, this work provides one of the first systematic investigations of optimized ethosomal systems for the stabilization of hydrophilic collagen peptides as anti-aging dermocosmetic ingredients. These findings demonstrate that optimized HCP-loaded ethosomes represent a promising ingredient formulation platform enabling bioactive preservation, formulation stability, and controlled topical performance for collagen-based skin rejuvenation applications. Full article

Metastatic breast cancer remains a significant therapeutic challenge due to its high invasiveness and resistance to conventional treatments. In this study, an ultrasound-responsive copper-calcium phosphate (Ca₁₉Cu₂(PO₄)₁₄) nanomaterial is developed for synergistic ion-mediated tumor therapy. The Ca₁₉Cu₂(PO₄)₁₄ nanomaterials exhibit a uniform morphology and crystalline structure, as well as good colloidal stability. Upon ultrasound irradiation, the release of Cu²⁺ and Ca²⁺ is spatiotemporally controlled via mechanical and cavitation effects. In vitro studies using highly metastatic 4T1 cells demonstrate that a combination of Ca₁₉Cu₂(PO₄)₁₄ and ultrasound significantly enhances apoptosis to 37.56%, while inducing 41.37% cell viability at 20 μg/mL of Ca₁₉Cu₂(PO₄)₁₄+ US. In contrast, Ca₁₉Cu₂(PO₄)₁₄ alone exhibits negligible cytotoxicity. Mechanistic investigations reveal that the combined release of Cu²⁺ and Ca²⁺ induces pronounced mitochondrial stress by suppressing the mitochondrial copper/redox regulator FDX1 and the PDH complex E2 subunit DLAT, thereby impairing mitochondrial metabolic homeostasis and promoting mitochondrial dysfunction. Overall, this study presents an ultrasound-triggered Ca₁₉Cu₂(PO₄)₁₄ nanoplatform for the effective ablation of tumor cells. Full article

Phytopathogenic fungi pose a critical threat to global food security through substantial pre- and post-harvest crop losses, intensified by climate change and fungicide resistance. To address this, we synthesized low-concentration chitosan–inorganic oxide nanocomposites (CS-SiO₂, CS-ZnO, CS-CuO) via ionic gelation, a green and scalable method. Comprehensive characterization (DLS, UV-Vis, FTIR, XRD, SEM) confirmed nanocomposite formation, CS-SiO₂ exhibited uniform particle sizes (200–250 nm), while CS-CuO showed slightly larger particles, all with excellent dispersity. Zeta potential analysis confirmed strong colloidal stability, with pure chitosan nanoparticles (CSNPs) displaying a surface charge of +12.9 mV, while all nanocomposites retained positive charges, enhancing adhesion to negatively charged fungal membranes. In vitro antifungal assays against Alternaria alternata, Botrytis cinerea, Colletotrichum graminicola, and Fusarium graminearum demonstrated hierarchical efficacy: CS-CuO > CS-ZnO > CS-SiO₂, with CS-CuO achieving >80% growth inhibition against B. cinerea and A. alternata. SEM revealed severe hyphal damage and spore collapse in CS-CuO-treated fungi, attributed to synergistic reactive oxygen species (ROS) generation and chitosan-mediated membrane disruption. In vivo trials on B. cinerea-infected apples showed CS-CuO reduced lesion area by 81% and elevated host defense markers, including a 1.5-fold increase in total phenolic content and higher DPPH radical scavenging activity compared to controls. These nanocomposites, particularly CS-CuO, offer a sustainable, dual-action solution direct antifungal activity and enhanced host resilience while minimizing environmental impact. By integrating scalable synthesis, eco-compatibility, and efficacy, this work advances chitosan–inorganic oxide nanocomposites as viable alternatives to conventional fungicides, with immediate potential for agricultural and postharvest applications. Full article

The term “pristine emulsion” is used for differentiating emulsions that consist of only water and oil with no surfactant from the Pickering emulsions, which are also surfactant-free but stabilized with colloidal particles. We review 22 papers dedicated to such emulsions prepared from a wide variety of liquids. We studied here the evolution of one such emulsion, hexadecane-in-water at 4% vl, over a long period of time, from days to weeks. We discovered that the droplet size grows with time, with a rate that depends on mixing conditions, which supports a coalescence hypothesis. However, this coalescence is unusual because the size reaches a certain constant value, which contradicts typical coalescence behavior. To explain this peculiarity and such emulsification in general, we employ a theoretical model that was developed for explaining pristine nano-bubble stability. We hypothesize the existence of a layer of structured water molecules at the interface, following Eastoe and Ellis (Adv in Colloid and Interface Sci., 134–135, 89–95, 2007) and others. We point out that the Electric Double Layer exerts a force on the water dipole moments in this layer (dielectrostatic force) that compensates Kelvin’s pressure. The droplet size calculated using this model is close to the measured size. The second factor associated with this layer is the repulsion of the water dipole moments, which we show can compensate for the surface tension tangential to the interface. After ruling out alternative hypotheses with our data, we conclude that the model suggested for explaining the stability of nano-bubbles is also consistent with our results for these “pristine emulsions”. Full article

Background: Artesunate (ART), a natural product derivative of artemisinin, exhibits striking antitumor activity. However, the clinical translation of ART is limited by rapid clearance, poor tumor selectivity, and severe off-target toxicity. To address these limitations, we developed an unsaturated aliphatic chain-driven nanoassembly strategy to optimize the therapeutic performance of ART. Methods: We designed and synthesized two ART derivatives by conjugating saturated aliphatic chains (ART-SAs) or unsaturated aliphatic chains (ART-LAs) to ART, which subsequently self-assembled into carrier-free nanoassemblies (NAs). These NAs were characterized for their self-assembly capacity and colloidal stability. Biological evaluations included studies on cellular uptake efficiency, in vivo pharmacokinetics, and antitumor efficacy in a tumor-bearing mouse model. Results: The saturated aliphatic chain is found to drive nanoassembly of ART-SA but significantly shields the antitumor activity of ART. Interestingly, the conjugate of an unsaturated aliphatic chain to ART (ART-LA) not only shows outstanding self-assembly capacities but also retains the native antitumor activity of ART. The P-AL NAs with improved pharmacokinetics and tumor-specific biodistribution exert potent antitumor activity and favorable safety. Conclusions: We successfully applied ART for highly effective antitumor therapy by employing an unsaturated aliphatic chain-driven strategy. This study is conducive to promoting the clinical application of ART. Full article

This study focuses on the synthesis and characterization of buckwheat husk-derived activated carbon, chemically activated with potassium hydroxide (KOH) and subsequently modified with urea and Prussian Blue (PB). The obtained carbons were evaluated in terms of particle-size distribution, surface morphology, structural features, and electrokinetic properties using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and electrophoresis, as well as N₂ adsorption–desorption (BET surface area and porosity analysis). The results confirmed that both pyrolysis conditions and the type of modifier significantly affect the physicochemical properties of the activated carbon and its behavior in electrolyte solutions. Colloidal stability and particle size were strongly dependent on pH and the type of anions present in solution, with sodium nitrate (NaNO₃) systems showing higher stability than sodium chloride (NaCl). Modification with KOH and urea imparted a more basic surface character, whereas PB introduced more acidic properties. All samples exhibited predominantly negative surface charges and mesoporous structures, which are favorable for adsorption processes and enhance affinity for heavy-metal cations. Among the tested materials, BH-KOH-Fe (Fe-modified KOH-activated carbon) showed the most favorable performance for the targeted application, while BH-KOH (KOH-activated buckwheat husk-derived carbon) exhibited high surface area and good colloidal stability. The prepared materials show promising applicability for water purification, including the removal of organic pollutants and radionuclides (e.g., ¹³⁷Cs and ⁹⁰Sr), as well as metal cations (K⁺, Na⁺, and Li⁺). Full article

Mineral oils are increasingly being replaced by plant-based insulating liquids, known as natural esters, because of their biodegradability and high fire safety characteristic. However, their wider use in high-voltage and unsealed transformer applications is still limited due to concerns about thermo-oxidative stability and the relatively limited long-term performance data available compared to mineral oils. This study investigates improving the oxidation stability of natural esters through nanotechnology. A canola-based insulating liquid was used as the base fluid and modified with TiO₂ and SiO₂ nanoparticles of different sizes. Nanoparticle concentrations ranged from 0.05 to 0.25 wt.%, while Span 80 (sorbitan monooleate, non-ionic surfactant) served as a surfactant to ensure uniform dispersion and long-term colloidal stability. The nanofluids were subjected to accelerated aging to evaluate oxidation resistance, and key properties such as acidity, viscosity, and dissipation factor were monitored throughout the process. Dielectric performance was assessed using AC breakdown voltage testing, with results interpreted through two-parameter Weibull statistics. The TiO₂-based nanofluids demonstrated superior thermo-oxidative stability compared to both the base oil and the SiO₂-modified samples. Formulations containing smaller TiO₂ nanoparticles (5 nm) exhibited the lowest increases in viscosity, acid value, and dissipation factor, indicating strong resistance to degradation under thermal stress. In dielectric performance, SiO₂ nanofluids reached 65.8 kV, while TiO₂ nanofluids achieved a higher value of 72.4 kV, confirming their greater effectiveness. Although the nanoparticles are not biodegradable, their use at low concentrations significantly enhances the oxidative and dielectric stability of natural esters, helping extend fluid life and reduce dependence on petroleum-based insulating liquids. Full article

The highly chitinolytic marine bacterium Vibrio jasicida KMM 6832, which exhibits potent antifungal activity, possesses an atypical Glycosyl Hydrolase family 19 (GH19) chitinase (ChitVjs). This is the first report of a GH19 gene in V. jasicida, an enzyme generally absent in this species and rare within the Harveyi clade. Phylogenetically, ChitVjs-like enzymes from the genera Vibrio and Aeromonas form a distinct cluster, separate from typical plant and bacterial GH19 counterparts. Despite high sequence identity (80–94%) with characterized homologs from V. parahaemolyticus and V. cholerae, ChitVjs is distinguished by its obligate halophilicity (optimum 0.3–0.4 M NaCl), an acidic isoelectric point (pI 4.72), and a broader cation-activation profile (K⁺, Ni²⁺, Ca²⁺, Cu²⁺, Co²⁺). The recombinant ChitVjs was produced in E. coli as a soluble 63 kDa protein. It functions as a stable, salt-dependent endo-chitinase/chitosanase, exhibiting optimal activity at 40 °C and pH 7.0. The enzyme displays high affinity for colloidal chitin (K_M 0.377 mg·mL⁻¹), is activated by DTT and Tween 80, and shows moderate stability in organic solvents. Furthermore, unlike its primarily catabolic relatives, ChitVjs suppresses conidial germination in marine-derived Aspergillus strains. These findings suggest that ChitVjs significantly contributes to the competitive fitness of V. jasicida KMM 6832 in high-salinity marine environments through both nutrient acquisition and antagonism. Full article

Fine-denier silicone emulsions play an important role in the polyacrylonitrile (PAN) precursor treatment process by reducing surface tension and preventing fiber fusion during thermal stabilization and carbonization. These emulsions are typically prepared by dispersing polydimethylsiloxane (PDMS) polymers with various functional groups into water through different emulsification methods. In this study, two types of silicone emulsions—one prepared using a mechanical disperser and the other using a high-shear colloid mill—were manufactured on a pilot scale and systematically compared. Thermal aging was conducted at 50 °C and 70 °C for approximately one month, and changes in particle size, dispersion stability, and physicochemical properties were evaluated. The colloid-mill emulsification method produced smaller and more uniform silicone particles and exhibited superior thermal and dispersion stability relative to the mechanically dispersed emulsion. NMR relaxation, Turbiscan multiple light scattering, and viscosity measurements confirmed that the colloid-mill emulsion maintained a stable microstructure with minimal aggregation even under elevated-temperature storage. These results demonstrate that high-shear emulsification is an effective approach for producing fine-denier silicone emulsions with enhanced stability, making the colloid-mill method a more reliable and practical route for preparing silicone-based oiling agents used during PAN precursor processing in carbon fiber manufacturing. Full article

The inadequate biosafety of MRI contrast agents (CAs) remains a challenging issue. Both increasing the magnetic relaxivity of CAs and targeting them through conjugation with folates are promising approaches to addressing this issue. Silica nanoparticles (SNs) with Mn²⁺ ions specifically localized in the outer layer were selected as the target for further surface modification for the covalent attachment of folates. It was shown that when Mn-containing SNs are conjugated with folates via preliminary amino modification of the surface silanol groups, the folate-conjugated SNs suffer from colloidal instability. Thus, precoating Mn-containing SNs with unfolded BSA exposes surface amino groups that successfully conjugate with folates without loss of colloidal stability. Partial washout of surface-localized Mn²⁺ follows folate conjugation of Mn-containing SNs, although residual Mn²⁺ ions provide r₁₍₂₎ relaxivities of 62.1 (160.4) mM⁻¹s⁻¹ at 0.47 T. Full article

The oral delivery of polyphenolic compounds such as rosmarinic acid (Ros) is limited by poor gastrointestinal stability and early release, resulting in low bioaccessibility. Herein, carboxymethylated guar gum (cmGG)-based nanoparticles were developed as a pH-responsive colloidal delivery system to enhance Ros stability, prevent early release, and improve intestinal bioaccessibility. In this context, pH-responsiveness refers to pH-dependent modulation of degradation, and stabilization along the gastrointestinal tract, rather than an abrupt pH-triggered burst release. Guar gum was chemically modified to different degrees of carboxymethylation to enhance its colloidal stability under gastrointestinal conditions, reduce polymer degradation, and enable a more controlled release of the phenolic compound Ros. Comparative evaluation of cmGG systems with varying degrees of carboxymethylation revealed that nanoparticles prepared from highly substituted cmGG exhibited superior colloidal stability and acid resistance, contributing to effective protection of Ros under gastric conditions. Ros-loaded guar gum nanoparticles effectively suppressed release at acidic pH while enabling controlled and sustained release at intestinal pH. Simulated gastrointestinal digestion studies demonstrated that Ros-loaded carboxymethylated guar gum nanoparticles significantly enhanced the gastrointestinal stability and bioaccessibility of Ros compared with non-carboxymethylated guar gum nanoparticles. Overall, these findings indicate that the degree of carboxymethylation is a critical design parameter for tuning colloidal behavior and release performance under the varying pH conditions encountered throughout the gastrointestinal tract in guar gum-based nanoparticle systems. Full article

Hypoxia and nutrient-deprived microenvironments pose significant challenges to the survival of transplanted human umbilical cord mesenchymal stem cells (UC-MSCs), necessitating the development of controllable oxygen delivery strategies. In this study, we engineered fluorosurfactant-coated oxygen nanobubbles (Tivida^®-stabilized; TONBs) and assessed their cytoprotective effects in a two-dimensional (2D) ischemia-mimetic model (1% O₂ and 1% FBS). The TONBs were characterized by nanoparticle tracking analysis and zeta potential, while dissolved oxygen (DO) release was quantified in DMEM culture media. TONBs formed stable sub-200 nm populations with high colloidal stability (−58 mV) and demonstrated elevated DO levels up to ~18 ppm, compared to DMEM control (~ 8 ppm). Under hypoxic stress, TONB treatment preserved metabolic activity and viability, reduced mitochondrial ROS levels by ~20% and resulted in an ~8–9 fold downregulation of HIF-1α expression relative to untreated hypoxic controls. These results indicate that TONBs provide oxygen buffering to mitigate hypoxia-driven metabolic stress, supporting their potential as an oxygen delivery adjunct for regenerative medicine applications and tissue engineering applications. Full article

The surface decoration techniques, such as incising-filling, glaze spraying, wood firing, and secondary low-temperature refiring, etc., have been widely used for traditional potteries, such as Jianshui purple pottery. These surface modifications are mainly for artistic expression, whereas functional surface modification has barely been reported. The development of novel coating materials and processes is an alternative path for the innovation of traditional pottery. However, the surface functional materials often peel or detach from the pottery body after high-temperature sintering. It is thus imperative to develop coating materials and processes with robust adhesion and accommodation for secondary functional materials. Through the screening of different ZrO(OH)₂ sols and coating processes, the coating of ZrO(OH)₂ sol on the 800 °C baked Jianshui purple pottery achieved uniform and tight surface coating. Reducing the colloidal particle size and particle concentration in the sol, as well as Y³⁺ doping, is also conductive to the structural stability of the coatings. Additional loading of silver nanoparticles onto the ZrO₂ coating layer effectively endows the pottery with antibacterial performance. The coated samples loaded with silver nanoparticles exhibited an antibacterial rate of 32.7% after accelerated desorption, demonstrating potential for functional pottery applications. Full article

Severe fluid loss in fractured, depleted reservoirs usually defeat conventional water-based drilling fluids (WBDFs), and rigid lost-circulation materials (LCMs) struggle to form durable, conformal seals. We report an eco-oriented colloidal gas aphron (CGA) fluid built from a nanostructured corn biopolymer (NCBP) and a biodegradable peanut-oil-derived surfactant, benchmarked against a reference fluid (RF) and aphron-only baselines (aphron based fluid, ABF). NCBP, produced by ball milling, was confirmed nanostructured by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), electron and atomic microscopies. Performance was evaluated from 25 to 90 °C for rheology, aphron stability and filtration at low temperature and low pressure (LTLP) of 100 psi and 25 °C, with post-test mud cake imaging. The optimized formulation, NCBP-2, showed stronger shear-thinning and higher gel strengths with heat, sustained stable and uniform aphrons for at least 120 min with foam persistence beyond 24 h, and delivered 3.0 mL filtrate with a 0.8 mm mud cake. These outcomes correspond to 60% less filtrate and approximately 73% thinner mud cakes than RF (7.5 mL; 3.0 mm), and about 14% and 33% improvements over the best ABF (3.5 mL; 1.2 mm). Micrographs revealed denser, finer-pored mud cakes, consistent with a mechanism in which deformable aphrons bridge micro-fractures while nano-scale polymeric fillers tighten the mud cake network. The results demonstrate decisive loss-control gains with temperature-tolerant rheology, supporting bio-based CGA fluids for depleted and fractured formations. Full article

Electrical spark discharge was used to prepare nano Ag–Cu colloids with an electrical discharge machine, deionized water (DW) as the dielectric fluid (DF), and at room temperature and normal pressure. The upper and lower electrodes of the electrical discharge machine were pure Ag and Cu wires or composite metal wires with an Ag–Cu ratio of 92.5:7.5 or 72:28. The optimal T_on–T_off, process time, and current for colloid production were identified as 30–30 µs, 5 min, and approximately 11 A, respectively. The absorbance, characteristic wavelength, particle size distribution, and suspension stability were, respectively, 0.586, 406 nm, 101 nm, and 28.1 mV for the colloids prepared using pure Ag and Cu wires; 0.509, 419 nm, 197.5 nm, and −6.67 mV for the 92.5:7.5 composite wires; and 1.479, 407 nm, 85.27 nm, and14.8 mV for the 72:28 composite wires. The diffraction peaks of the Ag and Cu particles shifted for the composite-produced colloids; this was likely caused by internal structural defects in the composite metal wires. Transmission electron microscopy was used to analyze the nanomaterials. The average Ag and Cu lattice widths, respectively, were 0.234 nm and 0.207 nm for the pure-metal wires, 0.243 nm and 0.210 nm for the 92.5:7.5 composite wires, and 0.243 nm and 0.210 nm for the 72:28 composite wires. X-ray diffraction (XRD) analyses were conducted to determine the crystal orientations of the nano Ag–Cu particles and revealed that nano Ag–Cu colloids prepared using pure Ag and Cu wires had an Ag–Cu particle ratio of approximately 97:3. Full article