Search Results (123)

Skin microbiome-friendly preparations are gaining increasing popularity in the cosmetics and pharmaceutical industries. Fermented plants, lysates, and heat-treated products are used as probiotic ingredients in cosmetics. This is due to the presence of Lactobacillus bacteria, such as acid or acid-rennet whey, which are natural probiotics that can positively impact the skin microbiome. However, due to technological difficulties, the direct use of whey as a cosmetic ingredient is limited. An optimized emulsification method was used to obtain alginate microspheres as carriers of whey. The process parameters were optimized using the Design of Experiments (DoEs) methodology. The effect of three key variables, including the type of probiotic raw material (whey from 1—cows, 2—goats, and 3—mixed), the alginate-to-raw material ratio (1–3%), and sonication time (0.5–1.5 min), on parameters such as encapsulation efficiency, bacterial survival, viscosity, and microspheres size was analyzed. The results obtained demonstrated that the optimal process parameters were the sonication time of 0.5 min and the alginate-to-whey mass ratio of 1.5% for all types of whey material studied. However, the most important factor influencing the properties and functionality of the microspheres was sonication time. The optimized whey-loaded microspheres were incorporated into a preservative-containing emulsion system, in which the viability of whey-derived bacteria was monitored over time. The whey encapsulation process effectively maintained the bacteria’s probiotic properties, protecting their viability despite the presence of preservatives (at a level of 4.92 ± 0.9 log CFU/g after 30 days of formulation storage), thus confirming the feasibility of incorporating liquid whey into skincare formulations. Full article

Alginate is a biomaterial that has demonstrated considerable potential and adaptability in the field of controlled drug delivery due to its unique physicochemical properties. Chemical modification of alginate has significantly enhanced its functionality, allowing the development of matrices with improved characteristics, such as increased affinity for hydrophobic drugs, sustained and controlled release, and improved cell and tissue adhesion. Hydrogels, microspheres, nanoparticles, and porous scaffolds are among the most extensively studied alginate-based drug delivery systems. It is estimated that over 50% of these systems have shown successful outcomes in in vitro testing, particularly in applications such as oral delivery of proteins and peptides, wound healing, tissue regeneration, and cancer therapy. Recent clinical advances involving alginate include the development of wound dressings, growth factor delivery systems, and cell-based therapies for treating degenerative diseases. Chemically modified alginate thus emerges as a highly adaptable and promising candidate for the design of advanced drug delivery systems across a wide range of biomedical applications. This review encompasses more than 100 research articles and aims to provide an updated overview of the current state of knowledge regarding the use of chemically modified alginate-based hydrogel systems in drug delivery. Full article

With the depletion of river sand resources and increasing environmental concerns, the development of alternative materials has become an urgent need in the construction industry. Waste concrete and non-waste concrete materials have been widely studied as alternatives to river sand. Although recycled concrete fine aggregates are close to natural sand in terms of mechanical properties, their surface cement adheres and affects the performance of cement, whereas non-recycled concrete fine aggregates perform superiorly in terms of ease of use and compressive properties, but there are challenges of supply stability and standardization. Red mud, as an industrial waste, is a potential alternative material due to its stable supply and high alkaline characteristics. In this paper, a new method is proposed for utilizing the cross-linking reaction between sodium alginate and calcium chloride by the calcium alginate-red mud microsphere preparation technique and the surface modification of red mud to enhance its bonding with cement. The experimental results showed that the mechanical properties of CMC-RM-SiO₂-2.5% were improved by 13.9% compared with those of the benchmark cement mortar, and the encapsulation of red mud by calcium alginate significantly reduced the transfer of hazardous elements in red mud. Full article

Stem cells cultured in cell aggregates exhibit higher cell survival rates and enhanced anti-inflammatory and angiogenic effects compared to single cells, constructing a stable and economical cell aggregate culture system that can accurately adjust the mass transfer distance of nutrients, which contributes to improving the therapeutic effects of stem cell aggregates. In this study, an alginate hydrogel microsphere culture system (Alg-HM) was prepared using electrostatic spraying technology and refined by optimizing the electrostatic spraying technology parameters, such as the sodium alginate concentration, voltage, electrospray injection speed, and nozzle inner diameter. Furthermore, by setting the Tip-dropped culture system (Tip-D culture system, created by dropping the resuspended hMSC aggregate–hydrogel solution with a tip to form the hydrogel microsphere) and Matrigel culture system (created by dropping the resuspended hMSC aggregates–Matrigel solution with a tip to form the Matrigel culture system) as the control group and Alg-HM as the experimental group, the culture effect of hMSC aggregates in the optimized Alg-HM culture system was tested; CCK-8 detection and Ki-67 immunofluorescence staining showed that the Alg-HM culture system significantly enhanced the cell proliferation activity of hMSC aggregates after 7 and 14 days of culture. The Calcein-AM/PI cell staining results showed that the Alg-HM culture system can significantly reduce the central necrosis of hMSC aggregates. The RNA sequencing results showed that the Alg-HM culture system can significantly activate the signaling pathways related to cell proliferation in hMSCs. This culture system is helpful for the culture of cell aggregates in vitro and efficient transplantation in vivo. Full article

Background/Objectives: Vitexin and isovitexin are bioactive flavonoids with promising pharmacological effects; however, they have poor bioavailability. Microencapsulation with biodegradable polymers is a promising strategy for improving their stability, bioavailability, and biocompatibility. This study aimed to optimize the formulation parameters to obtain microspheres with desired properties in terms of size, loading ratio, and vitexin–isovitexin release. Methods: Microspheres were prepared using alginate as the core matrix and a chitosan outer layer. A Design of Experiment approach using response surface methodology was employed. The hypoglycemic effects of the obtained microspheres were evaluated. Results: The formulation using 1.17% low-viscosity alginate, 7.60% calcium chloride, 5.78% Tween 80, and 5.00% Span 80 resulted in microspheres with optimal mean size (10.78 µm), high loading ratio (22.45%) and encapsulation efficiency (68.92%). The in vitro release of vitexin–isovitexin from microspheres was completed within 24 h in controlled manner. The microspheres were found to be non-toxic in vivo and exhibited hypoglycemic effects after 21 days at doses equivalent to 30 and 60 mg/kg of vitexin–isovitexin. The potential mechanisms might involve increasing the size of Islets of Langerhans and improving pancreatic β-cell function and insulin resistance, as observed in alloxan-induced diabetic mice. Conclusions: This work successfully developed alginate–chitosan-based microspheres for the controlled release of vitexin–isovitexin while maintaining their bioactivities. Full article

This study proposes a simple yet versatile microfluidic strategy for fabricating monodisperse alginate hydrogel microspheres using a symmetric flow-focusing device. The system integrates three key innovations: (1) Cost-effective mold fabrication: A paper-based positive master replaces conventional SU-8 photoresist, significantly simplifying device prototyping. (2) Surfactant-free droplet generation: Alginate hydrogel droplets are formed at the first flow-focusing junction without requiring interfacial stabilizers. (3) In situ solidification with coalescence suppression: Acetic acid-infused corn oil is introduced at the adjacent junction, simultaneously triggering ionic crosslinking of alginate via pH reduction while preventing droplet aggregation. Notably, the hydrogel microspheres can be efficiently harvested through oscillatory aqueous phase separation, removing post-fabrication washing steps (typically 6–8 cycles for surfactant and oil removal). This integrated approach demonstrates exceptional advantages in fabrication simplicity, process scalability, and operational robustness for high-throughput hydrogel microsphere production. Full article

Ulcerative colitis (UC) is a chronic inflammation disease with severe impact on quality of life, with limited treatment options. Ramulus Mori alkaloids (SZ-A) from Morus alba show promise for UC treatment due to their safety and pharmacological effects, including anti-inflammation and barrier repair. However, their clinical use has been limited by gastrointestinal flatulence as a side effect due to their pharmacological action as an α-glucosidase inhibitor targeting the small intestine following oral administration. Therefore, constructing a colon-targeted formulation to deliver SZ-A is an advantageous strategy to improve UC therapy. In this study, we used the complex formed by thiolated hyaluronic acid, which has mucosal adhesion and inflammation-targeting properties, and SZ-A as an intermediate carrier and prepared sodium alginate-modified PLGA microspheres (SZ-A@MSs) with the double emulsion method to achieve efficient encapsulation of SZ-A. Specifically, sodium alginate serves as a gastric acid protectant and microbiota-responsive material, enabling the precise and responsive release of microspheres in the colonic region. SZ-A@MSs have a particle size of about 30 µm, a drug loading of about 12.0%, and an encapsulation efficiency of about 31.7% and function through intestinal adhesion to and targeting of inflammatory sites. SZ-A@MSs showed antioxidant and anti-inflammatory abilities in Raw264.7 cells. In vivo imaging results suggest that SZ-A@MSs have good colon site retention and sustained-release effect. Pharmacodynamic results show that SZ-A@MSs display good efficacy, including the ability to inhibit weight loss, inhibit colonic atrophy, and inhibit the secretion of inflammatory factors. In conclusion, SZ-A@MSs have good colon-targeting properties, can improve therapeutic effects, and provide a potential treatment method for UC. Full article

Sodium alginate is a polysaccharide compound extracted from natural plants that has been successfully prepared as a hydrogel for adsorbing and removing pollutants. However, the selectivity of alginate-based hydrogels to malachite green (MG) dyes and the stability of alginate-based hydrogels in air cannot meet requirements. Herein, metal–organic frameworks (MOFs) are embedded into a magnetic hydrogel to create magnetic MOF hydrogel (MMOF hydrogel) microspheres with high adsorption capacity. The morphology and physical properties of the MMOF hydrogel microspheres were characterized by scanning electron microscopy and optical microscopy. Under optimized adsorption conditions, the adsorption rate of MG reached 96.5%. The maximum adsorption capacity of the MMOF hydrogel for MG was determined to be 315 mg·g⁻¹. This highly efficient magnetic adsorbent for dye removal has considerable potential for rapidly removing toxic contaminants from aquatic food matrices for high-throughput sampling pretreatment, which has the potential for rapid, green, large-scale environmental remediation in the future. Full article

Microfluidic granulation technology enables high-quality production of energy-containing microspheres, significantly enhancing both performance and safety. Although microfluidic methods allow control over microsphere particle size, the adjustment range remains limited; low yield and process discontinuity also restrict broader application in the synthesis of energy-containing materials. This paper presents a microfluidic granulation system for energy-containing materials utilizing pulsed pneumatic printing, co-flow, and flow-focusing techniques to achieve wide particle size adjustment, consistent particle formation, high granulation speed, and production efficiency. This system allows microsphere sizes between 110 and 2500 μm, with a coefficient of variation (CV) as low as 1.9%, a frequency exceeding 13,000 Hz, and a suspension consumption rate reaching 100 mL/h. Calcium alginate/potassium perchlorate microspheres, prepared with sodium alginate hydrogel as a binder, exhibit uniform structure, narrow size distribution, and efficient energy material loading. We anticipate further advancements in applying microfluidic technology to energy-containing microsphere production based on this system. Full article

Resorbable microparticles can be added to hydrogel-based biocompatible scaffolds to improve their mechanical characteristics and allow localised drug delivery, which will aid in tissue repair and regeneration. It is well-known that bioprinting is important for producing scaffolds personalised to patients by loading them with their own cells and printing them with specified shapes and dimensions. The question is how the addition of such particles affects the rheological responsiveness of the hydrogels (which is critical during the printing process) as well as mechanical parameters like the elastic modulus. This study tries to answer this question using a specific system: an alginate-gelatine hydrogel containing polyhydroxybutyrate-co-hydroxyvalerate (PHBV) microparticles. Scaffolds were made by bioprinting and moulding incorporating PHBV microspheres (7–12 μm in diameter) into alginate–gelatine inks (4.5 to 9.0% w/v). The microparticles (MP) were predominantly located within the polymeric matrix at concentrations up to 10 mg MP/mL ink. Higher particle concentrations disrupted their spatial distribution. Inks pre-crosslinked with 15 mM calcium and containingMPat concentrations ranging from 0 to 10 mg/mL demonstrated rheological characteristics appropriate for bioprinting, such as solid-like behaviour (G′ = 1060–1300 Pa, G″ = 720–930 Pa), yield stresses of 320–400 Pa, and pseudoplastic behaviour (static viscosities of 4000–5600 Pa·s and ~100 Pa·s at bioprinting shear rates). Furthermore, these inks allow high printing quality, assessed through scaffold dimensions, filament widths, and printability (Pr > 0.94). The modulus of elasticity in compression (E) of the scaffolds varied according to the content of MP and the manufacturing technique, with values resembling those of soft tissues (200–600 kPa) and exhibiting a maximum reinforcement effect with 3 mg MP/mL ink (bioprinted E = 273 ± 28 kPa; moulded E = 541 ± 66 kPa). Over the course of six days, the sample’s mass and shape remained stable during degradation in simulated body fluid (SBF). Thus, the alginate–gelatine hydrogel loaded with PHBV microspheres inks shows promise for targeted drug delivery in soft tissue bioengineering applications. Full article

Standard 2D cultures inadequately mimic the natural microenvironment of mesenchymal stromal cells (MSCs), compromising their properties. This study investigated the impact of 3D cultures in spheroids, alginate microspheres (AMSs), and blood plasma scaffolds on human-adipose-derived MSC behavior. The cell morphology, viability/apoptosis (6-CFDA/Annexin-Cy3.18), actin filament development (phalloidin-FITC), and metabolic activity (Alamar Blue) were assessed on the 3rd day of the generated 3D construct cultures. The abilities for adipogenic and osteogenic differentiation were evaluated after 21 days of culture in media with inducers by Nile Red and Alizarin Red staining, respectively. The 3D culture supported closer-to-physiological cell interactions and morphology and resulted in F-actin reduction compared with the 2D culture. While the metabolic activity was elevated in the scaffolds, it was significantly reduced in the spheroids and AMSs, which reflected natural-like quiescence. The differentiation was maintained across all the 3D constructs. These findings highlight the essential influence of 3D construct design on MSC function, underscoring its potential for advancing both in vitro models and cell-based therapies. Full article

Bio-based polymeric stimuli-responsive materials have attracted increasing interest, especially in the pharmacological and nutraceutical fields. These materials mainly consist of macromolecules capable of conformational and chemical changes in response to external signals. One active molecule mostly used in bio-related areas is lactoferrin (Lf), which is attracting attention due to its beneficial effects (antimicrobial, anti-inflammatory, and anti-carcinogenic) on the human body. Since pH or temperature in the human body can promote Lf degradation, encapsulation in a suitable system is required. A valid solution is to encapsulate the Lf in a polysaccharidic matrix such as alginate (ALG) thanks to its biocompatibility and easy gelation with bivalent cations. This work aims to encapsulate iron-depleted Lf in alginate gel microspheres for stability improvement by ionic cross-linking with Ca²⁺ ions. The obtained particles were characterized in terms of structure, thermal stability, and morphology, and their swelling capability was determined. Release studies were carried out on the freeze-dried particles to investigate the effect of neutral pH 7 and acidic pH 5. At last, the optimization of the loaded system was completed by developing a mathematical model able to predict the swelling behavior of the carrier particle and the subsequent Lf kinetic release over time. Full article

This work describes the immobilization and the characterization of purified Penicillium crustosum Thom P22 lipase (PCrL) using adsorption, encapsulation, and adsorption–encapsulation approaches. The maximum activity of the immobilized PCrL on CaCO₃ microspheres and sodium alginate beads was shifted from 37 to 45 °C, compared with that of the free enzyme. When sodium alginate was coupled with zeolite or chitosan, the immobilization yield reached 100% and the immobilized PCrL showed improved stability over a wide temperature range, retaining all of its initial activity after a one-hour incubation at 60 °C. The immobilization of PCrL significantly improves its catalytic performance in organic solvents, its pH tolerance value, and its thermal stability. Interestingly, 95% and almost 50% of PCrL’s initial activity was retained after 6 and 12 cycles, respectively. The characteristics of all PCrL forms were analyzed by X-ray diffraction and scanning electron microscopy combined with energy dispersive spectroscopy. The maximum conversion efficiency of oleic acid and methanol to methyl esters (biodiesel), by PCrL immobilized on CaCO₃, was 65% after a 12 h incubation at 40 °C, while free PCrL generated only 30% conversion, under the same conditions. Full article

Encapsulation in alginate hydrogel microspheres is an effective method for protecting and improving the survival of lactic acid bacteria in different environments. This research aims to expand the knowledge about the structure/property relationship of calcium alginate microspheres loaded with a mixture of autochthonous probiotic bacteria (Lactococcus lactis and Lactiplantibacillus plantarum). A novel hydrogel formulation (FORMLAB) was prepared by ionic gelation and the molecular interactions between the FORMLAB constituents, surface morphology, structure, swelling degree, and release profile were characterized. The simultaneous encapsulation of two bacterial cultures in the same compartment does not diminish their viability. The binding of calcium ions to bacterial cells creates favorable conditions for the propagation of the encapsulated bacteria. The molecular interactions between the FORMLAB constituents are complex, involving mainly hydrogen bonds and electrostatic interactions. With a very high degree of swelling followed by low crosslinking, the surface of the microspheres covered with bacterial cells and diffusion through the hydrogel matrix allow for the delivery of probiotics at the right time. The findings suggest that bacterial cells are efficiently delivered from calcium alginate microspheres, offering promising applications in the development of functional foods, especially in cheese production. Full article

Oleogels (organogels) are systems resembling a solid substance based on the gelation of organic solvents (oil or non-polar liquid) through components of low molecular weight or oil-soluble polymers. Such compounds are organogelators that produce a thermoreversible three-dimensional gel network that captures liquid organic solvents. Oleogels based on natural oils are attracting more attention due to their numerous advantages, such as their unsaturated fatty acid contents, ease of preparation, and safety of use. As a result of the research, two oleogels were developed, into which freeze-dried alginate carriers with a probiotic, L. casei, were incorporated. Two techniques were used to produce probiotic-loaded capsules—extrusion and emulsification. Alginate beads obtained by the extrusion process have a size of approximately 1.2 mm, while much smaller microspheres were obtained using the emulsification technique, ranging in size from 8 to 17 µm. The trehalose was added as a cryoprotectant to improve the survival rate of probiotics in freeze-dried alginate carriers. The encapsulation efficiency for both of the methods applied, the emulsification and the extrusion technique, was high, with levels of 90% and 87%, respectively. The obtained results showed that the production method of probiotic-loaded microspheres influence the bacterial viability. The better strain survival in the developed systems was achieved in the case of microspheres produced by the emulsification (reduction in bacterial cell viability in the range of 1.98–3.97 log in silica oleogel and 2.15–3.81 log in sucragel oleogel after 7 and 30 days of storage) than by the extrusion technique (after a week and a month of oleogel storage, the decrease in cell viability was 2.52–4.52 log in silica oleogel and 2.48–4.44 log in sucragel oleogel). Full article