Search Results (126)

Background/Objectives: Solvent-intensive methods are traditionally required to extract curcumin, a potent bioactive compound from Curcuma longa, raising environmental and safety concerns. Methods: This study introduces an efficient and scalable extraction approach using microwave–ultrasound-assisted extraction (MUAE) combined with a natural deep eutectic solvent (NADES) composed of choline chloride and lactic acid. Process parameters, including solvent water content (20–30% v/v) and solid loading (4–8% w/v), were optimized using response surface methodology (RSM) to enhance curcumin yield. Results: Under optimal conditions (20% water content and 8% solid loading), the MUAE method achieved a curcumin content of 40.72 ± 1.21 mg/g, representing a 14.36% improvement over conventional ultrasound-assisted extraction (UAE), while reducing solvent usage by 50%. The quadratic model demonstrated excellent predictive capability, with an R² value of 0.98. In addition, anti-solvent precipitation using water increased curcuminoid purity from 0.31% to 20.54%, with a recovery rate of 21.49%. Conclusions: Mechanistic analysis revealed that microwave-induced cell disruption, ultrasound cavitation, and the modulation of NADES viscosity contributed synergistically to the enhanced extraction performance. This study is the first to combine MUAE with NADES for optimized curcumin extraction, delivering both high yield and reduced solvent consumption. The proposed method offers a sustainable and industrially relevant alternative for curcumin recovery in the food, nutraceutical, and pharmaceutical sectors. Full article

Alkaline treatment is well suited for extracting high-molecular-weight hemicelluloses, specifically hardwoods xylans, which, due to their polymer structure and chemical characteristics, enable the production of films with desirable mechanical, barrier, and optical properties for packaging applications. Despite its relevance, the optimization of antisolvent addition has received little attention in the literature. This study explores the use of eucalyptus industrial residue as feedstock, utilizing a statistical design to determine the optimal extraction conditions for hemicelluloses while minimizing the lignin content in the recovered liquor. The process uses alkali loads that are compatible with those in conventional Kraft pulp mills. Optimal extraction conditions involve a temperature of 105 °C, 16.7% NaOH charge, and 45 min at maximum temperature. The resulting liquor was subjected to ethanol precipitation under varying pH conditions (initial pH, 9, 7, 5, and 2) and different ethanol-to-liquor ratios (1:1 to 4:1). The acidification was performed using hydrochloric, sulfuric, and acetic acids. Ethanol served as the main antisolvent, while isopropyl alcohol and dioxane were tested for comparison. Results show that 2.3 ± 0.2% of xylans (based on oven-dry biomass) could be extracted, minimizing lignin content in the liquor. This value corresponds to the extraction of 15.6% of the xylans present in the raw material. The highest xylan precipitation yield (78%) was obtained at pH 7, using hydrochloric acid for pH adjustment and an ethanol-to-liquor ratio of 1:1. These findings provide valuable insight into optimizing hemicellulose recovery through antisolvent precipitation, contributing to more efficient biomass valorization strategies within lignocellulosic biorefineries. Full article

The antisolvent precipitation method was employed to synthesize curcumin-loaded gliadin–carboxymethyl chitosan (CMCS) composite nanoparticles (GCC NPs). When the gliadin/CMCS weight ratio was 2:1, the GCC NPs with an ideal negative charge (−27.57 ± 1.07 mV) and the minimum particle size (184.13 ± 5.49 nm) were obtained. With the addition of CMCS, the encapsulation efficiency (EE) of Cur was markedly improved from 77.46 ± 1.54% to 93.88 ± 1.31%. Under various pH values and salt concentrations, the GCC NPs displayed excellent colloidal stability. Specifically, after encapsulation within the GCC NPs, the antioxidant activity of Cur was markedly improved. In ABTS and DPPH assays, the SC₅₀ values of the GCC NPs were 4.98 ± 0.07 µg/mL and 9.86 ± 0.29 µg/mL, respectively. In summary, the GCC NPs would be an effective platform for the delivery of Cur in food and pharmaceutical preparations. Full article

In this study, an improved method combining natural surfactants with a solvent–antisolvent precipitation technique was developed to prepare highly effective nano-sized tangeretin particles. Various natural surfactants were tested and compared, and the formulation was optimized using Plackett–Burman and Box–Behnken design methodologies. The optimal preparation conditions were identified as follows: a tangeretin–dimethyl sulfoxide (DMSO) solution concentration of 5.23 mg/mL, surfactant concentration of 4.72%, and a rotor diameter of 20 mm. Under these conditions, uniform nano-tangeretin particles with an average size of 428.73 ± 30.25 nm were successfully produced. The preparation process significantly reduced particle size without chemical structure of tangeretin, as confirmed by spectral analysis. Importantly, the free radical scavenging activity of the nano-tangeretin was markedly enhanced, showing 65.4% increase in DPPH radical inhibition compared to the unprocessed powder. These results demonstrate that the proposed method can improve the bioactivity and dispersibility of tangeretin, providing a valuable strategy for the efficient utilization and industrial-scale production of bioactive compounds from natural resources. Full article

Zein was made flexible through acid-driven deamidation. This increased flexibility was confirmed by the higher release of water-soluble peptides during trypsin hydrolysis. Self-assembled flexible zein nanoparticles (FZNPs) were prepared using the anti-solvent precipitation method. To test the sensitivity of FZNPs to complex environment, ionic solutions (CaCl₂ and NaCl) at various concentrations were prepared. The morphology and particle size of FZNPs differed significantly from those of control zein nanoparticles (NZNPs). As the ionic concentration increased from 0 to 15 mmol/L, FZNPs showed higher electrical conductivity and adsorption capacity than NZNPs. This suggests that FZNPs are highly sensitive to complex environment. X-Ray Photoelectron Spectrum (XPS) results revealed that both FZNPs and NZNPs bound more Na⁺ than Ca²⁺. The enhanced sensitivity of FZNPs to complex environments may be due to their greater tendency for structural changes. These conformational changes are likely caused by the altered amino acids in flexible zein, which result from deamidation. This study offers a practical approach to designing novel nanoparticles as functional materials for delivering bioactive compounds. Full article

Background/Objectives: The co-formulation of active pharmaceutical ingredients (APIs) is a growing strategy in biopharmaceutical development, particularly when it comes to improving solubility and bioavailability. This study explores a co-precipitation method to prepare co-formulated crystals of griseofulvin (GF) and dexamethasone (DXM), utilizing nanostructured, functionalized polylactic glycolic acid (nfPLGA) as a solubility enhancer. Methods: An antisolvent precipitation technique was employed to incorporate nfPLGA at a 3% concentration into the co-formulated GF and DXM, referred to as DXM-GF-nfPLGA. The dissolution performance of this formulation was compared to that of the pure drugs and the co-precipitated DXM-GF without nfPLGA. Results: Several characterization techniques, including electron microscopy (SEM), RAMAN, FTIR, TGA, and XRD, were used to analyze the nfPLGA incorporation and the co-precipitated co-formulations. The inclusion of nfPLGA significantly enhanced the dissolution and initial dissolution rate of both GF and DXM in the DXM-GF-nfPLGA formulation, achieving a maximum dissolution of 100%, which was not attained by the pure drugs or the DXM-GF formulation. The incorporation of nfPLGA also reduced the amount of time taken to reach 50% (T₅₀) and 80% (T₈₀) dissolution. T₅₀ values decreased from 52 and 82 min (for pure DXM and GF) to 23 min for DXM-GF-nfPLGA, and the T₈₀ improved to 50 min for DXM-GF-nfPLGA, significantly outpacing the pure compounds. Furthermore, incorporating nfPLGA into the crystal structures greatly accelerated the dissolution rates, with initial rates reaching 650.92 µg/min for DXM-GF-nfPLGA compared to 540.60 µg/min for DXM-GF, while pure GF and DXM showed lower rates. Conclusions: This work demonstrates that nfPLGA incorporation enhances dissolution performance by forming water channels within the API crystal via hydrogen-bonding interactions. This innovative nfPLGA incorporation method holds promise for developing hydrophobic co-formulations with faster solubility and dissolution rates. Full article

Antioxidants are contained in fruits and vegetables and are commonly obtained through food. However, it is frequently necessary to supplement the diet with substances that are often poorly soluble in water and sensitive to light and oxygen. For this reason, in this work, luteolin (LUT) and naringenin (NAR), two compounds with antioxidant activity and potential health benefits, were precipitated through the supercritical antisolvent technique using polyvinylpyrrolidone and β-cyclodextrin as the carriers. The precipitation occurred from dimethylsulfoxide using supercritical carbon dioxide as the antisolvent. The influence of pressure (9–12 MPa), active substance/carrier concentration in the solution (20–200 mg/mL), and their ratio (1/1 and 1/2 mol/mol) on morphology, particle mean size, and distribution were investigated. Under the optimized operating conditions, spherical microparticles with a mean diameter equal to 2.7 ± 0.9 μm (for LUT) and 5.5 ± 1.9 μm (for NAR) were obtained. The active ingredients were protected from the external environment by the presence of the carrier, and the dissolution rate was notably increased by processing them with β-cyclodextrin. It was sixty times faster and three times faster than that of the antioxidant alone for LUT and NAR, respectively. Full article

Hyaluronic acid (HA) is a key component of synovial fluid as it plays a crucial role in joint physiology. Its biological activity is influenced by molecular weight, local concentration, and persistence in joints. High-molecular-weight HA has a consolidated history of clinical use, whereas little is known about the metabolic effect of low-molecular-weight hyaluronate on cartilage differentiation. This study explores the potential of HA-based nanoparticles (NPs) on chondrocytes differentiation in vitro. Starting from 25 kDa and 250 kDa sodium hyaluronate solutions, two types of NPs were prepared by antisolvent precipitation in ethanol. The resulting NPs were dried in the presence of dipalmitoyl phosphatidylcholine, a natural synovial fluid component, then applied on an in vitro model of horse articular chondrocytes: no toxicity was observed and NPs prepared from 250 kDa HA promoted chondrocyte differentiation to a larger extent with respect to corresponding HA solutions, as evidenced by increased gene expression of chondrogenic markers (Col2a1 and Sox9) and reduced expression of dedifferentiation markers (Col1a1 and Runx2). These findings suggest that HA-based NPs are more effective at promoting the cellular internalization of the molecule and the differentiation of chondrocytes in vitro and could be a promising platform for drug delivery and cartilage repair. Full article

This study investigated the valorization of Ilex guayusa leaves by producing a low-caffeine, antioxidant-rich product through the supercritical antisolvent extraction (SAE) process. The objective was to concentrate the antioxidants while selectively reducing the caffeine. The SAE treatments were conducted using an ethanolic extract of guayusa leaves under varying pressure (80 bar–150 bar) and temperature (35–45 °C) conditions to improve the recovery of chlorogenic acid (CGA) and caffeine fractionation. The co-precipitation of antioxidants with polyvinylpyrrolidone (PVP) (ratio 1:1–1:2 mass/mass) as an encapsulant was also studied. The SAE precipitates were analyzed for their recovery yield, CGA and caffeine contents, antioxidant activity, and total phenols. Based on the statistical analysis, the optimal conditions for the SAE were 120 bar and 45 °C. Under these conditions, the CGA concentration increased from 43.02 mg/g extract to 237 mg/g precipitate, while the caffeine was reduced to less than 1% mass. Co-precipitation with PVP improved the recovery yield by more than two times than the SAE alone while maintaining the caffeine content below 1% mass. Additionally, the co-precipitation with PVP facilitated the formation of spherical microparticles, indicating successful encapsulation of the bioactive compounds, with an IC₅₀ of 0.51 ± 0.01 mg/mL for DPPH and 0.18 ± 0.01 mg/mL for ABTS. These results highlight the effectiveness of the SAE co-precipitation process in developing low-caffeine functional ingredients with potential food and pharmaceutical applications. Full article

Global warming has recently intensified research interest in renewable polymer chemistry, with significant attention directed towards lignin nanoparticle (LNP) synthesis. Despite progress, LNP industrial application faces challenges: (1) reliance on kraft lignin from declining raw biomass processes, (2) sulfur-rich and condensed lignin use, (3) complex lignin macroparticles to LNP conversion, using harmful and toxic solvents, and, above all, (4) lack of control over the LNP production process (i.e., anti-solvent precipitation parameters), resulting in excessive variability in properties. In this work, eco-friendly LNPs with tailored properties were produced from a semi-industrial organosolv process by studying anti-solvent precipitation variables. Using first a parametric and then a Fractional Factorial Design, predictions of LNP sizes and size distribution, as well as zeta-potential, were derived from a model over beech by-products organosolv lignin, depending on initial lignin concentration (x₁, g/L), solvent flow rate (x₂, mL/min), antisolvent composition (x₃, H2O/EtOH v/v), antisolvent ratio (x₄, solvent/antisolvent v/v), and antisolvent stirring speed (x₅, rpm). This novel chemical engineering approach holds promise for overcoming the challenges inherent in industrial lignin nanoparticle production, thereby accelerating the valorization of lignin biopolymers for high value-added applications such as cosmetics (sunscreen or emulsion) and medicine (encapsulation, nanocarriers), a process currently constrained by significant limitations. Full article

Allicin, as a natural antibacterial active substance from plants, has great medical and health care value. However, due to its poor stability, its application in the field of food and medicine is limited. So, in this paper, allicin–zein–sodium caseinate composite nanoparticles (zein–Ali–SC) were prepared by antisolvent precipitation and electrostatic deposition. Through the analysis of the particle size, ζ-potential, encapsulation efficiency (EE), loading rate (LC) and microstructure, the optimum preparation conditions for composite nanoparticles were obtained. The mechanism of its formation was studied by fluorescence spectrum, Fourier infrared spectrum (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The stability study results showed that the particle size of composite nanoparticles was less than 200 nm and its PDI was less than 0.3 under different NaCl concentrations and heating conditions, showing good stability. When stored at 4 °C for 21 days, the retention rate of allicin reached 61.67%, which was 52.9% higher than that of free allicin. After freeze-drying and reheating, the nanoparticles showed good redispersibility; meanwhile, antioxidant experiments showed that, compared with free allicin, the nanoparticles had stronger scavenging ability of free radicals, which provided a new idea for improving the stability technology and bioavailability of bioactive compounds. Full article

Metal oxides have applications in a variety of different fields, and new synthesis methods are needed to control their properties and improve their performance as functional materials. In this study, we investigated a low-cost antisolvent precipitation method using a choline chloride-urea deep eutectic solvent to precipitate CuZnOx materials using water as the antisolvent. Using this methodology, the metal oxide materials can be precipitated directly from the deep eutectic solvent without the need for a high-temperature calcination step that can lead to a reduction in defects and surface area, which are important properties in applications such as catalysis. Full article

In recent years, concerns about the harmful effects of synthetic UV filters on the environment have highlighted the need for natural sun blockers. Lignin, the most abundant aromatic renewable biopolymer on Earth, is a promising candidate for next-generation sunscreen due to its inherent UV absorbance and its green, biodegradable, and biocompatible properties. Lignin’s limitations, such as its dark color and poor dispersity, can be overcome by reducing particle size to the nanoscale, enhancing UV protection and formulation. In this study, 100–200 nm lignin nanoparticles (LNPs) were prepared from various biomass by-products (hardwood, softwood, and herbaceous material) using an eco-friendly anti-solvent precipitation method. Pure lignin macroparticles (LMPs) were extracted from beech, spruce, and wheat straw using an ethanol–organosolv treatment and compared with sulfur-rich kraft lignin (KL). Sunscreen lotions made from these LMPs and LNPs at various concentrations demonstrated novel UV-shielding properties based on biomass source and particle size. The results showed that transitioning from the macro- to nanoscale increased the sun protection factor (SPF) by at least 2.5 times, with the best results improving the SPF from 7.5 to 42 for wheat straw LMPs and LNPs at 5 wt%. This study underscores lignin’s potential in developing high-quality green sunscreens, aligning with green chemistry principles. Full article

Curcumin is a naturally occurring hydrophobic polyphenolic compound with a rapid metabolism, poor absorption, and low stability, which severely limits its bioavailability. Here, we employed a starch–protein-based nanoparticle approach to improve the curcumin bioavailability. This study focused on synthesizing nanoparticles with a zein “core” and a carboxymethylated short-chain amylose (CSA) “shell” through anti-solvent precipitation for delivering curcumin. The zein@CSA core–shell nanoparticles were extensively characterized for physicochemical properties, structural integrity, ionic stability, in vitro digestibility, and antioxidant activity. Fourier-transform infrared (FTIR) spectroscopy indicates nanoparticle formation through hydrogen-bonding, hydrophobic, and electrostatic interactions between zein and CSA. Zein@CSA core–shell nanoparticles exhibited enhanced stability in NaCl solution. At a zein-to-CSA ratio of 1:1.25, only 15.7% curcumin was released after 90 min of gastric digestion, and 66% was released in the intestine after 240 min, demonstrating a notable sustained release effect. Furthermore, these nanoparticles increased the scavenging capacity of the 1,1-diphenyl-2-picrylhydrazyl (DPPH•) free radical compared to those composed solely of zein and were essentially nontoxic to Caco-2 cells. This research offers valuable insights into curcumin encapsulation and delivery using zein@CSA core–shell nanoparticles. Full article

Developing clinically meaningful nanomedicines for cancer therapy requires the drugs to be effective, safe, simple, cheap, and easy to store. In the present work, we report that a simple cationic Fe(III)-rich salt of [Fe^IIICl(TMPPH₂)][Fe^IIICl₄]₂ (Fe-TMPP) exhibits a superior anticancer performance on a broad spectrum of cancer cell lines, including breast, colorectal cancer, liver, pancreatic, prostate, and gastric cancers, with half maximal inhibitory concentration (IC₅₀) values in the range of 0.098–3.97 μM (0.066–2.68 μg mL⁻¹), comparable to the best-reported medicines. Fe-TMPP can form stand-alone nanoparticles in water without the need for extra surface modification or organic-solvent-assisted antisolvent precipitation. Critically, Fe-TMPP is TME-responsive (TME = tumor microenvironment), and can only elicit its function in the TME with overexpressed H₂O₂, converting H₂O₂ to the cytotoxic •OH to oxidize the phospholipid of the cancer cell membrane, causing ferroptosis, a programmed cell death process of cancer cells. Full article