Preparation of eco-friendly alginate-based Pickering stabilizers using a dual ultrasonic nebulizer spray method

Fabrication and evaluation of stable amorphous polymer-drug composite particles via a nozzle-free ultrasonic nebulizer

We present a promising method for producing amorphous drug particles using a nozzle-free ultrasonic nebulizer with polymers, specifically polyvinylpyrrolidone (PVP), poly(acrylic acid) (PAA), and Eudragit® S 100 (EUD). Model crystalline phase drugs-Empagliflozin, Furosemide, and Ilaprazole-are selected. This technique efficiently produces spherical polymer-drug composite particles and demonstrates enhanced stability against humidity and thermal conditions, compared to the drug-only amorphous particles. The composite particles exhibit improved water dissolution compared to the original crystalline drugs, indicating potential bioavailability enhancements. While there are challenges, including the need for continuous water supply for ultrasonic component cooling, dependency on the solubility of polymers and drugs in volatile organic solvents, and mildly elevated temperatures for solvent evaporation, our method offers significant advantages over traditional approaches. It provides a straightforward, flexible process adaptable to various drug-polymer combinations and consistently yields spherical amorphous solid dispersion (ASD) particles with a narrow size distribution. These attributes make our method a valuable advancement in pharmaceutical drug formulation and delivery.

Fabrication and Morphological Control of Nonspherical Alginate Hydrogel Particles

We report a simple platform for the fabrication of nonspherical alginate hydrogel particles using a dripping method. Hydrogel particles with novel morphologies, such as vortex ring, teardrop, disk, sphere, and mushroom, are fabricated by controlling various parameters. We monitored the deformation process of the hydrogel particles after they penetrated the crosslinking solution using a high-speed camera. Then, we proposed a mechanism showing a unique morphological transformation from a spherical to a disk shape. We demonstrated how controlling the collecting height that causes the drop impact force against the crosslinking solution surface was critical to producing hydrogel particles with these intriguing shapes. In particular, disk-shaped alginate particles show their ability as potential platforms for culturing mouse adrenocortical tumor cells (Y1) and a hippocampal neuronal cell (HT-22). To modify alginate particles, cell-adhesive gelatin is incorporated into the alginate matrix and then alginate particles are coated with poly(allylamine hydrochloride). Two modified alginate particles show good adhesion and proliferation rates on their surfaces. In particular, the hybrid hydrogel particles provide great potential to be developed into promising materials for cell culture, drug delivery, and tissue engineering.

Ni-alginate hydrogel beads for establishing breakthrough curves of lead ions removal from aqueous solutions

The scientific impact of this work is the protection of the environment from hazardous pollutants using a column technique. Besides its higher stability at working pH and its time persisting, Ni-alginate has a higher ability to remove lead ions compared to the other prepared beads (Sr-alginate, Co-alginate, and Ca-alginate). Also, Ni-alginate possessed a higher removal percent, 93.3%, toward Pb²⁺ than the other ions, taking the sorption order of Pb²⁺ > Sr²⁺ > Co²⁺ > Cd²⁺ > Zn²⁺. Therefore, this study focused on using Ni-alginate as a selective sorbent for lead ions. Fixed-bed column was employed for the sorption process. The results for that efficiency are presented as breakthrough curves in view of the impact of various parameters; influent flow rate (1.5, 3.0, and 5.0 mL/min), lead concentration (100, 150, and 200 mg/L), and bed depth of sorbent (3.0, 5.0, and 7.0 cm). Breakthrough modeling including Thomas and Yan models was employed. The outcomes indicated that Thomas theory is more applicable. The overall outcomes indicated that Ni-alginate is recommended for selective removal of Pb²⁺ from waste solutions.

A surfactant-free approach: Novel one-step ultrasonic nebulizer spray method to generate amphiphilic Janus particles

HYPOTHESIS

A solvent evaporation-induced phase separation method, which is based on the preferential partitioning of two or more immiscible materials after solvent evaporation on providing heat, has been one of the main strategies for synthesis of Janus particles (JPs). Considering this approach, it should be possible to synthesize surfactant free-JPs in continuous flow by the ultrasonic nebulizer spray method.

EXPERIMENTS

Two polymers, polystyrene and polymethylmethacrylate, were dissolved in dichloromethane, and droplets of a precursor solution generated by an ultrasonic nebulizer were then conveyed through a borosilicate glass cylinder with two heating zones. The solvent evaporation-induced phase separation occurred in a single flow process, which resulted in the preferential partitioning of two incompatible polymers in the droplets, leading to the formation of the spherical bicompartmental JPs.

FINDINGS

The successful fabrication of spherical JPs was observed at high polymer concentrations (1.5 and 2.0 wt%), and at elevated temperature (40-75 °C). The fluorescent compartmentalization of JPs was confirmed. Furthermore, the interfacial arrangement of JPs at oil-water interface was studied. A detailed explanation of theoretical prediction of interfacial configurations of JPs was provided. Lastly, the generated JPs were proved as Pickering stabilizers at the oil-water interface.

Alginate-based delivery systems for food bioactive ingredients: An overview of recent advances and future trends

Due to its advantagessuch as ionic crosslinking, pH responsiveness, excellent biocompatibility, biodegradability and low price, alginate has become one of the most important natural polysaccharides extensively used in constructing desired delivery systems for food bioactive ingredients. In this review, the fundamental knowledge of alginate as a building block for construction of nutraceutical delivery systems is introduced. Then, various types of alginate-based nutraceutical delivery systems are classified and summarized. Furthermore, the future trends of alginate-based delivery systems are highlighted. Currently, alginate-based delivery systems include hydrogel, emulsion, emulsion-filled alginate hydrogel, nanoparticle, microparticle, core-shell particle, liposome, edible film, and aerogel. Although alginate has been widely used in the fabrication of food bioactive ingredient delivery systems, further efforts and improvements are still needed. For this purpose, the future perspectives of alginate-based delivery systems are discussed. The feasible research trends of alginate-based delivery systems include the development of novel large-scale commercial preparation technology, multifunctional delivery system based on alginate, alginate oligosaccharide-based delivery system and alginate-based oleogel. Overall, the objective of this review is to provide useful guidance for rational design and application of alginate-based nutraceutical delivery systems in the future.

Metal-organic frameworks/alginate composite beads as effective adsorbents for the removal of hexavalent chromium from aqueous solution

Industrial waste discharge comprising heavy metals into potable water bodies induces many health hazards. This study investigates the role of metal-organic frameworks (MOFs) doped alginate beads (MOFs@ABs) as potential adsorbents for Cr(VI). Effects of pH, stirring rate, temperature, initial chrome concentration, and particles dosage on Cr(VI) adsorption are studied to evaluate adsorption ability of UiO-66@ABs for Cr(VI) removal from aqueous solution. The adsorption kinetics follows pseudo second order and the equilibrium isotherm is consistent with Langmuir isotherm model. The maximum adsorption capacity of UiO-66@ABs calculated from the model conforms to the experimental results. The desorption experiment of Cr(VI) adsorbed UiO-66@ABs (82%) demonstrates satisfactory regeneration efficiency. Based on our findings and comparative controlled experiments, the superiority of UiO-66@ABs promises their potential application in Cr(VI) removal from wastewater.

Interpretation of interfacial interactions between lenticular particles

HYPOTHESIS

The geometric features of charged particles at a fluid-fluid interface substantially affect their interfacial configurations and interparticle interactions (electrostatic and capillary forces). Because lenticular particles exhibit both spherical and nonspherical surface characteristics, an investigation of their interfacial phenomena can provide in-depth understanding of the relationship between the configuration and the interactions of these particles at the interface.

EXPERIMENTS

Three types of lenticular particles are prepared using a seeded emulsion polymerization method. Pair interactions at the oil-water interface are directly measured with optical laser tweezers. The numerical calculation of the attachment energy of the particle to the interface is used to predict their configuration behaviors at the interface.

FINDINGS

The lenticular particles are found to adopt either an upright or inverted configuration that can be determined stochastically. When the interface contacts the truncated boundary or the biconvex boundary, the local interface deformation-induced capillary attraction likely becomes dominant. The contact probability can be estimated on the basis of the attachment energy profile and related to the relative strengths of capillary attraction and electrostatic repulsion between two particles at the interface. Furthermore, possible artifacts in measurements of the pair interactions between nonspherical particles with optical laser tweezers are discussed, depending on their interfacial configurations.