Search

Spheroids exhibit enhanced cell-cell interactions that facilitate improved survival and mimic the physiological cellular environment in vivo. Cell spheroids have been successfully used as building blocks for engineered tissues, yet the viability of this approach with skeletal muscle spheroids is poorly understood, particularly when incorporated into three-dimensional (3D) constructs. Bioprinting is a promising strategy to recapitulate the hierarchical organization of native tissue that is fundamental to its function. However, the influence of bioprinting on skeletal muscle cell spheroids and their function are yet to be interrogated. Using C2C12 mouse myoblasts and primary bovine muscle stem cells (MuSCs), we characterized spheroid formation as a function of duration and cell seeding density. We then investigated the potential of skeletal muscle spheroids entrapped in alginate bioink as tissue building blocks for bioprinting myogenic tissue. Both C2C12 and primary bovine MuSCs formed spheroids of similar sizes and remained viable after bioprinting. Spheroids of both cell types fused into larger tissue clusters over time within alginate and exhibited tissue formation comparable to monodisperse cells. Compared to monodisperse cells in alginate gels, C2C12 spheroids exhibited greater MyHC expression after 2 weeks, while cells within bovine MuSC spheroids displayed increased cell spreading. Both monodisperse and MuSC spheroids exhibited increased expression of genes denoting mid- and late-stage myogenic differentiation. Together, these data suggest that skeletal muscle spheroids have the potential for generating myogenic tissue via 3D bioprinting and reveal areas of research that could enhance myogenesis and myogenic differentiation in future studies.

All-liquid molding can be used to transform a liquid into free-form solid constructs, while maintaining internal fluidity. Traditional biological scaffolds, such as cured pre-gels, are normally processed in solid state, sacrificing flowability and permeability. However, it is essential to maintain the fluidity of the scaffold to truly mimic the complexity and heterogeneity of natural human tissues. Here, this work molds an aqueous biomaterial ink into liquid building blocks with rigid shapes while preserving internal fluidity. The molded ink blocks for bone-like vertebrae and cartilaginous-intervertebral-disc shapes, are magnetically manipulated to assemble into hierarchical structures as a scaffold for subsequent spinal column tissue growth. It is also possible to join separate ink blocks by interfacial coalescence, different from bridging solid blocks by interfacial fixation. Generally, aqueous biomaterial inks are molded into shapes with high fidelity by the interfacial jamming of alginate surfactants. The molded liquid blocks can be reconfigured using induced magnetic dipoles, that dictated the magnetic assembly behavior of liquid blocks. The implanted spinal column tissue exhibits a biocompatibility based on in vitro seeding and in vivo cultivating results, showing potential physiological function such as bending of the spinal column.

Background: Advances in regeneration methods have brought us improved vascular scaffolds with small diameters (φ < 6 mm) for enhancing biological suitability that solve their propensity for causing intimal hyperplasia post‐transplantation. Methods: The correlation between the rehydration ratio of the hydrogel and its material concentration is obtained by adjusting the material ratio of the hydrogel solution. The vascular model with helical structure has been established and analyzed to verify the effect of helical microvascular structure on thrombosis formation by the fluid simulation methods. Then, the helical structure vascular has been fabricated by self‐developed 3D bioprinter, the vascular scaffolds are freeze‐dried and rehydrated in polyethylene glycol (PEG) solution. Results: The experimental results showed that the hybrid hydrogel had a qualified rehydration ratio when the content of gelatin, sodium alginate, and glycerol was 5, 6, and 3 wt%. The established flow channel model can effectively reduce thrombus deposition and improve long‐term patency ratio. After PEG solution modification, the contact angle of the inner wall of the vascular scaffold was less than 30°, showing better hydrophilic characteristics. Conclusion: In study, a small‐diameter inner wall vascular scaffold with better long‐term patency was successfully designed and prepared by wrinkling and PEG modification of the inner wall of the vascular scaffold. This study not only creates small‐diameter vascular scaffolds with helical structure that improves the surface hydrophilicity to reduce the risk of thrombosis but also rekindles confidence in the regeneration of small caliber vascular structures. [ABSTRACT FROM AUTHOR]

The flotation behavior of apatite, a main mineral source of phosphorus, is strongly affected by the dissolved ionic species from gangue minerals. In this study, the effect of calcium ions on the fluorapatite flotation using the extracted sodium alginate E.SA depressant was investigated through microflotation tests, adsorption experiments, zeta potential measurements, and FTIR analyses. Although the amount of NaOL collector adsorbed on fluorapatite increased with increasing calcium concentrations, microflotation results reveal that adding calcium ions could deteriorate the fluorapatite recovery. More significant depression of fluorapatite could be achieved when Ca2+ and E.SA co-existed in the system. Zeta potential measurements and FTIR analyses showed that the addition of Ca2+ hardly affected the adsorption of E.SA onto fluorapatite surface, which can be due to the formation and precipitation of calcium alginate. In contrast, NaOL remained weakly adsorbed on the fluorapatite surface even the presence of Ca2+ and E.SA. [ABSTRACT FROM AUTHOR]

The bottom‐up assembly of premagnetized microgels offers remarkable flexibility in programmability, material selection, and complexity for fabricating programmable magnetic soft machines with discrete 3D magnetization profiles. However, the current microgel bonding encounters challenges due to the utilization of adhesives for attachment, biocompatibility for in vivo applications, and the need for elevated temperature for self‐healing materials. Here, an approach is presented that leverages N‐hydroxysuccinimide ester‐activated sodium alginate (SA‐NHS) and chitosan (CS) to form modular gels for on‐demand assembly through covalent bonding, yielding a tough and durable interface. Photolithography‐based patterning and magnetic maneuverability are imparted by introducing poly(ethylene glycol) diacrylate and ferromagnetic particles into SA‐NHS or CS, resulting in the creation of modularized magnetic or nonmagnetic microgels. Different magnetization profiles of the modular microgel can be achieved by magnetizing the ferromagnetic particles inside the microgel. To prove the versatility of the proposed method, several programmable magnetic soft machines are developed for various application scenarios, including heterogeneous cell‐laden hydrogel assemblies, multisegmented magnetic soft swimmers, programmable magnetic switches for electric circuits, and magnetically triggered release from drug‐encapsulated magnetic capsules. This proposed approach holds great potential to engineer highly intricate and hierarchical architectures, enhancing the functionality, versatility, and adaptability of programmable soft machines. [ABSTRACT FROM AUTHOR]

Tetracycline (TC) is a common antibiotic; when untreated TC enters the environment, it will cause a negative impact on the human body through the food chain. In the present study, MnO2/MCM-41@Fe3O4 (FeMnMCM) prepared using a hydrothermal and redox method and Camellia oleifera shell-activated carbon (COFAC) prepared through alkali activation were encapsulated using alginate (ALG) and calcium chloride as a cross-linking matrix to give the composite beads COFAC–FeMnMCM–ALG. The resultant COFAC–FeMnMCM–ALG composite beads were then carefully characterized, showing a high immobilization of MnO2/MCM-41@Fe3O4, with porous COFAC as an effective bioadsorbent for enriching the pollutants in the treated samples. These bead catalysts were subsequently applied to the oxidative degradation of TC in a Fenton oxidation system. Several parameters affecting the degradation were investigated, including the H2O2 concentration, catalyst dosage, initial TC concentration, and temperature. A very high catalytic activity towards the degradation of TC was demonstrated. The electron paramagnetic resonance (EPR) and quenching results showed that ·OH and ·O2− were generated in the system, with ·OH as the main radical species. In addition, the COFAC–FeMnMCM–ALG catalyst exhibited excellent recyclability/reusability. We conclude that the as-prepared COFAC–FeMnMCM–ALG composite beads, which integrate MnO2 and Fe3O4 with bioadsorbents, provide a new idea for the design of catalysts for advanced oxidation processes (AOPs) and have great potential in the Fenton oxidation system to degrade toxic pollutants. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) bioprinting opens up many possibilities for tissue engineering, thanks to its ability to create a three-dimensional environment for cells like an extracellular matrix. However, the use of natural polymers such as silk fibroin in 3D bioprinting faces obstacles such as having a limited printability due to the low viscosity of such solutions. This study addresses these gaps by developing highly viscous, stable, and biocompatible silk fibroin-based inks. The addition of 2% carboxymethyl cellulose sodium and 1% sodium alginate to an aqueous solution containing 2.5 to 5% silk fibroin significantly improves the printability, stability, and mechanical properties of the printed scaffolds. It has been demonstrated that the more silk fibroin there is in bioinks, the higher their printability. To stabilize silk fibroin scaffolds in an aqueous environment, the printed structures must be treated with methanol or ethanol, ensuring the transition from the silk fibroin's amorphous phase to beta sheets. The developed bioinks that are based on silk fibroin, alginate, and carboxymethyl cellulose demonstrate an ease of printing and a high printing quality, and have a sufficiently good biocompatibility with respect to mesenchymal stromal cells. The printed scaffolds have satisfactory mechanical characteristics. The resulting 3D-printing bioink composition can be used to create tissue-like structures. [ABSTRACT FROM AUTHOR]

The present study reports an environmentally friendly in‐situ synthesis of novel antibacterial copper‐based MOFs within the hydrogel network of sodium alginate. Two different copper‐based MOF/sodium alginate composite beads were prepared via the post‐treatment of copper‐ion‐crosslinked alginate hydrogels with two different ligand solutions, namely, tartaric acid and oxalic acid, at 100 °C for 24 h. The structural, thermal, and morphological properties of the prepared samples were investigated using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), and their antibacterial activities against gram‐positive (Staphylococcus aureus and Bacillus) and gram‐negative (Escherichia coli and Pseudomonas aeruginosa) strains were examined using the conventional disc diffusion method. The results demonstrated the success of the in‐situ synthesis of two distinct copper‐based MOFs with FTIR spectra, confirming the existence of characteristic bands of the ligands complexed to the sodium alginate matrix. Moreover, the XRD diffractograms revealed the formation of two distinct crystalline structures with well‐defined morphologies observed in the SEM images. In addition, thermal analysis showed that the prepared composite beads had enhanced thermal stability compared to the copper‐ion‐crosslinked alginate beads. Antibacterial testing revealed the strong capacity of the copper‐based MOFs/sodium alginate composite beads to deactivate the growth of all the bacterial strains used, with a minimum inhibition zone of 23 mm, which highlights the potential of the synthesized materials as highly potent antibacterial agents. [ABSTRACT FROM AUTHOR]

Selection of adjuvant to be combined with the antigen is an extremely important point for formulating effective vaccines. The aim of this study was to evaluate reactogenicity, levels of IgM, IgG and subclasses (IgG1, IgG2b and IgG3), and protection elicited by vaccine formulations with association of chitosan coated alginate or Montanide ISA 61 with γ-irradiated Brucella ovis. The alginate/chitosan biopolymers as well as the Montanide ISA 61 emulsion elicited intense and long-lasting local response, especially when associated with the antigen. However, Montanide ISA 61 induced less intense reactogenicity when compared to alginate/chitosan. Furthermore, γ-irradiated B. ovis with Montanide ISA 61 induced higher levels of IgG2b an important marker of cellular immune response. In conclusion, Montanide ISA 61 resulted in milder reactogenicity when compared to the alginate/chitosan, while it induced a high IgG2b/IgG1 ratio compatible with a Th1 profile response. [ABSTRACT FROM AUTHOR]

Background: This work studies emulsion gel (EG) formulation with quinoa proteins (QP), high‐oleic sunflower oil and alginate, and the effect of QP concentration (0.5–1–2%) and the oil volume fraction (10–30–50%) on the physicochemical and mechanical properties of EG systems. EGs were tested for their microstructural and textural attributes, color, and water holding capacity as well as for their thermal, physical, and oxidative stability. Results: The microstructure of EG showed that with increasing QP concentrations, the gel structure tended to be much denser, with oil droplets entrapped within the network. A significant decrease in droplet diameter with increasing QP concentration (p = 0.015) and oil volume fraction (p < 0.000) was observed. Hardness mean value was 2.8 N ± 0.5, reaching the highest value with 1 and 2% QP and 30% oil (p < 0.000). Cohesiveness shows a similar trend to that observed for hardness, while springiness showed the opposite behavior. As for adhesiveness, there were no significant differences between samples. EG have high lightness with slight yellow and green contributions. The mean water holding capacity was 88 ± 4%, and after heat treatment all samples exhibited a good fluid retention, significantly lower for the lower oil volume fraction (p = 0.001). EG, also proved to be highly stable against creaming and oxidative damage. Conclusion: Results suggest that EG could be useful to create a new generation of healthier and innovative products that could substitute animal fat and deliver nutrients and biological compounds, thus improving food quality. [ABSTRACT FROM AUTHOR]

Nanosized alginate-based particles (NAPs) were obtained in a one-pot solvent-free synthesis procedure, achieving the design of a biocompatible nanocarrier for the encapsulation of IbM6 antimicrobial peptide (IbM6). IbM6 is integrated in the nascent nanosized hydrogel self-assembly guided by electrostatic interactions and by weak interactions, typical of soft matter. The formation of the nanogel is a dynamic and complex process, which presents an interesting temporal evolution. In this work, we optimized the synthesis conditions of IbM6-NAPs based on small-angle X-ray scattering (SAXS) measurements and evaluated its time evolution over several weeks by sensing the IbM6 environment in IbM6-NAPs from photochemical experiments. Fluorescence deactivation experiments revealed that the accessibility of different quenchers to the IbM6 peptide embedded in NAPs is dependent on the aging time of the alginate network. Lifetimes measurements indicate that the deactivation paths of the excited state of the IbM6 in the nanoaggregates are reduced when compared with those exhibited by the peptide in aqueous solution, and are also dependent on the aging time of the nanosized alginate network. Finally, the entrapment of IbM6 in NAPs hinders the degradation of the peptide by trypsin, increasing its antimicrobial activity against Escherichia coli K-12 in simulated operation conditions. [ABSTRACT FROM AUTHOR]

Naturally derived biopolymers modifying or combining with other components are excellent candidates to promote the full potential of additive manufacturing in biomedicine, cosmetics, and the food industry. This work aims to develop new photo-cross-linkable alginate-based inks for extrusion 3D printing. Specifically, this work is focused on the effect of the addition of cross-linkers with different chemical structures (polyethylene glycol diacrylate (PEGDA), N,N′-methylenebisacrylamide (NMBA), and acrylic acid (AA)) in the potential printability and physical properties of methacrylated alginate (AlgMe) hydrogels. Although all inks showed maximum photo-curing conversions and gelation times less than 2 min, only those structures printed with the inks incorporating cross-linking agents with flexible and long chain structure (PEGDA and AA) displayed acceptable size accuracy (~0.4–0.5) and printing index (Pr ~1.00). The addition of these cross-linking agents leads to higher Young's moduli (from 1.6 to 2.0–2.6 KPa) in the hydrogels, and their different chemical structures results in variations in their mechanical and rheological properties. However, similar swelling ability (~15 swelling factor), degradability (~45 days 100% weight loss), and cytocompatibility (~100%) were assessed in all the systems, which is of great importance for the final applicability of these hydrogels. [ABSTRACT FROM AUTHOR]

Seafood is highly perishable and has a short shelf‐life. This study investigated the effect of chitosan and alginate (CH‐SA) coating combined with the cell‐free supernatant of Streptococcus thermophilus FUA329 (CFS) as a preservative on the quailty of white shrimp (Litopenaeus vannamei) refrigerated at 4° for 0, 3, 6, 9, 12, 15 days. Freshly shrimps were randomly divided into four groups: the CFS group (400 mL); the CH‐SA group (1% chitosan/1% alginate); the CFS‐CH‐SA group (1% chitosan/1% alginate with 400 mL CFS) are treatment groups, and the control group (400 mL sterile water). The CFS–CH–SA coating effectively suppressed microbial growth total viable count and chemical accumulation (pH, total volatile basic nitrogen, thiobarbituric acid reactive substance) compared with the control. Additionally, the CFS–CH–SA coating improved the texture and sensory characteristics of shrimp during storage. The coated shrimp exhibited significantly reduced water loss (p < 0.05). The combination of CH–SA coating with CFS treatment can extend the shelf life of shrimp. Practical Application: Recently, edible films have received more consideration as a promising method to enhance the shelf life of seafood. The presence of Lactic acid bacteria metabolites in edible films reduces spoilage and improves consumer health. Our findings encourage the application of edible coating incorporated with cell‐free supernatant of Streptococcus thermophilus FUA 329 to design multifubctional foods and preserve the qualities of shrimp. [ABSTRACT FROM AUTHOR]

Double‐network hydrogels based on calcium alginate are extensively exploited. Unfortunately, their low strength and unstable constitution to open environments limit their application potential. Herein, a new type of double‐network organohydrogel (OHG) is proposed. By solvent exchange, a stable physical network is established based on dimethyl sulfoxide (DMSO)‐alginate in the presence of a polyacrylamide network. The DMSO content endows tunable mechanical properties, with a maximum tensile strength of ≈1.7 MPa. Importantly, the OHG shows much better environmental stability compared to the conventional double‐network hydrogels. Due to the reversible association of hydrogen bonds, the OHG possesses some unique properties, including free‐shapeability, shape‐memory, and self‐adhesion, that offers several promising ways to utilize alginate‐based gels for wide applications. [ABSTRACT FROM AUTHOR]

Purpose: Particles are of the controlled release delivery systems. Also, topically applied olive oil has a protective effect against ultraviolet B (UVB) exposure. Due to its sensitivity to oxidation, various studies have investigated the production of olive oil particles. The purpose of this study was to use chitosan and sodium alginate as the vehicle polymers for olive oil. Design/methodology/approach: The gelation method used to prepare the sodium alginate miliparticles containing olive oil and particles were coated with chitosan. Morphology and size, zeta potential, infrared spectrum of olive oil miliparticles, encapsulation efficiency and oil release profile were investigated. Among 12 primary fabricated formulations, formulations F5 (olive oil loaded alginate miliparticles) and F11 (olive oil loaded alginate miliparticles + chitosan coat) were selected for further evaluations. Findings: The size of the miliparticles was in the range of 1,100–1,600 µm. Particles had a spherical appearance, and chitosan coat made a smoother surface according to the scanning electron microscopy. The zeta potential of miliparticles were −30 mV for F5 and +2.7 mV for F11. Fourier transform infrared analysis showed that there was no interaction between olive oil and other excipients. Encapsulation efficiency showed the highest value of 85% in 1:4 (olive oil:alginate solution) miliparticles in F11. Release study indicated a maximum release of 68.22% for F5 and 60.68% for F11 in 24 h (p-value < 0.016). Therefore, coating with chitosan had a marked effect on slowing the release of olive oil. These results indicated that olive oil in various amounts can be successfully encapsulated into the sodium-alginate capsules cross-linked with glutaraldehyde. Originality/value: To the best of the authors' knowledge, no study has used chitosan and sodium alginate as the vehicle polymers for microencapsulation of olive oil. [ABSTRACT FROM AUTHOR]

Mesoporous polysaccharide aerogels are versatile functional materials for drug delivery and wound dressing devices. The hydration and wetting of these aerogels control their application‐related performance, e.g. the release of encapsulated drugs. Reported here is a detailed small‐angle neutron scattering (SANS) analysis of the hydration mechanism of a calcium alginate aerogel, based on mathematical modelling of the scattering. The model accounts for the hierarchical structure of the material comprising a mesoporous structure, the solid skeleton of which is made up of water‐swollen polymers. At large scale, the mesoporous structure is modelled as a random collection of elongated cylinders, which grow in size as they absorb water and aggregate. The small‐scale inner structure of the skeleton is described as a Boolean model of polymer coils, which captures the progressive transition from a dense dry polymer to a fully hydrated gel. Using known physico‐chemical characteristics of the alginate, the SANS data are fitted using the size of the cylinders as the only adjustable parameter. The alginate aerogel maintains a nanometre‐scale, albeit altered, structure for low water contents but it collapses into micrometre‐sized structures when the water content approaches one gram of water per gram of alginate. In addition to the wetting of aerogels, the model might be useful for the small‐angle scattering analysis of the supercritical drying of gels. [ABSTRACT FROM AUTHOR]

Herein, a semi-interpenetrating network (semi-IPN) hydrogel (SH/PNA) was prepared by simple free radical polymerization using N-isopropylacrylamide and 2-acrylamide-2-methylpropanesulfonic acid as monomers, poly(ethylene glycol) dimethacrylate as a crosslinking agent, and sodium alginate and humic acid as filled biomolecules. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and rheometer were used to characterize the structure and properties of the samples. The effect of feeding ratios on the gel mass fraction and swelling properties of the SH/PNA hydrogel was explored to optimize its preparation conditions. The swelling behavior under different pH and temperatures was investigated. The experimental result showed that the SH/PNA hydrogel had excellent water absorption capacity and pH/temperature dual responsiveness. Moreover, SH/PNA hydrogel was used as a carrier of urea to prepare slow-release and water-retention fertilizer by in situ loading method, and slow-release properties of urea in water and soil were measured. Taking into account its good ability for controlled release and water retention, the WSRF was expected to be a promising low-cost, environmentally friendly fertilizer that can be used in agriculture and horticulture. [ABSTRACT FROM AUTHOR]

The Cell Dome is a dome-shaped structure (diameter: 1 mm, height: 270 μm) with cells enclosed within a cavity, covered by a hemispherical hydrogel shell, and immobilized on a glass plate. Given that the cells within Cell Dome are in contact with the inner walls of the hydrogel shell, the properties of the shell are anticipated to influence cell behavior. To date, the impact of the hydrogel shell properties on the enclosed cells has not been investigated. In this study, we explored the effects of the cell adhesiveness of hydrogel shell on the behavior of enclosed cancer cells. Hydrogel shells with varying degrees of cell adhesiveness were fabricated using aqueous solutions containing either an alginate derivative with phenolic hydroxyl moieties exclusively or a mixture of alginate and gelatin derivatives with phenolic hydroxyl moieties. Hydrogel formation was mediated by horseradish peroxidase. We used the HeLa human cervical cancer cell line, which expresses fucci2, a cell cycle marker, to observe cell behavior. Cells cultured in hydrogel shells with cell adhesiveness proliferated along the inner wall of the hydrogel shell. Conversely, cells in hydrogel shells without cell adhesiveness grew uniformly at the bottom of the cavities. Furthermore, cells in non-adhesive hydrogel shells had a higher percentage of cells in the G1/G0 phase compared to those in adhesive shells and exhibited increased resistance to mitomycin hydrochloride when the cavities became filled with cells. These results highlight the need to consider the cell adhesiveness of the hydrogel shell when selecting materials for constructing Cell Dome. [ABSTRACT FROM AUTHOR]

This work presents the synthesis of alginate-coated magnetite nanoparticle (MNP) containing aminoenriched moieties for the immobilization of palladium (Pd), and its use as a recyclable catalyst for the reduction of 4-nitrophenol (4NP) in water. The alginate grafted onto the surface of MNP contained carboxylate anions that served as coordination sites for Pd. Additionally, the incorporation of aminoenriched components, such as poly(vinyl amine) (PVAm) and 2-(dimethyl amino)ethyl methacrylate (DMAEMA), onto the alginate-coated MNPs resulted in additional interactions, including the formation of carboxylate-ammonium salts. In this study, the influence of these amino groups on the efficiency of Pd immobilization, catalytic activity and reusability of nanosorbents for 4NP reduction was investigated. The existence of Pd in the nanosorbents was detected by inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, and energy-dispersive X-ray techniques. The average size of MNPs was approximately 12.3 ± 2.9 nm, and for Pd, it was about 3.9 ± 0.8 nm. It was found that the incorporation of these amino-enriched moieties into the particles significantly enhanced the catalytic activity of the nanosorbents. Notably, MNP containing extended DMAEMA units exhibited excellent tolerance to 4NP reduction, with an insignificant loss of catalytic performance even after 20 consecutive reuses, maintaining a conversion of over 98 %. [ABSTRACT FROM AUTHOR]

The synthesis of butyl butyrate, medium chain flavored esters by green chemistry is of immense importance to the food industry. In the present work, green synthesis of iron-alginate nanogels is done using a water-in-oil microemulsion method using food-grade oil for immobilization of Candida rugosa lipase (CrL). The morphological characterization of Fe-Alg nanogels was accomplished using dynamic light scattering (DLS) and scanning electron microscopy (SEM). Elongated tube-shaped Fe-Alg showed a hydrodynamic diameter of 100 ± 2 nm and a zeta potential of − 28 ± 4 mV. The nanogels exhibit an immobilization efficiency of 98%. Taguchi design-assisted immobilization of CrL onto Fe-Alg was effective in predicting the maximum response against immobilization parameters (0.7 µgm/ml of substrate, 20 min immobilization, 53⁰ C and pH 8.5). The esterification of butyl butyrate (∼90%) was completed in 6 h, which is confirmed by gas chromatography. The application of food-grade oil in the microemulsion method (water-in-oil) of nanogel synthesis is an attractive improvement for the development of support matrix in enzyme immobilization and ester synthesis. [Display omitted] • Iron-alginate nanogel synthesized using food-grade materials. • Iron-alginate support matrix used for immobilization of Candida rugosa lipase. • Optimization of immobilization parameters by Taguchi method. • Under optimized conditions, the yield of butyl butyrate reached 90%. [ABSTRACT FROM AUTHOR]

Interactions between sodium dodecyl sulfate (SDS) and sodium alginate (NaAlg) in aq. salts/hydrotrope (HDT) media have been investigated using conductivity method with changing the micellar parameters (e.g., critical micelles concentration (CMC), extent of micelle ionization (α), and bound counterions (β)) and thermodynamics of the micellization of SDS + NaAlg mixtures. CMC values and α were assessed from the plots of conductivity versus [SDS]. The micellization of SDS + NaAlg was enhanced in aq. electrolyte and aq. HDTs media. The formation of SDS + NaAlg micelles was found to happen delayed with an increase in temperature in water and aq. 10% (w/w) glycerol (GLY) solution, while in other employed solvents, micelle creation was observed to favor with an upsurge of working temperature. Thermodynamics of SDS + NaAlg mixtures were computed from temperature dependency of CMC. The values of ΔG0m were found negative for all the experiments, thereby, examined. The values of Δ H m 0 in the micellization of SDS + NaAlg mixtures in H2O, H2O + sodium acetate (NaOAc), H2O + sodium benzoate (NaBenz), and H2O + 4-amino benzoic acid (4-ABA) media were observed positive, and, hence, the process was endothermic in these solvents. Micellization of SDS + NaAlg was exothermic in 10% (w/w) glycerol (GLY) solutions at all temperatures and in H2O + NaCl at 298.15 and 303.15 K. The values of Δ H m 0 and Δ S m 0 for SDS + NaAlg show that the hydrophobic, van der Waals and exothermic interactions are the driving forces between SDS and NaAlg in electrolytes and HDT media. [ABSTRACT FROM AUTHOR]

Acne is a prevalent dermatological disease, with high global incidence, and is a health menace. The current study aimed to isolate and characterize the anaerobic bacteria responsible for the condition. Causes of a total of 70 acne-based bacterium isolates obtained from patients of mild, moderate, and severe acne, 24 were Clostridium innocuum, 21 were Lactobacillus plantarum, 13 were Anaerococcus prevotii, and 12 were Peptoniphilus asaccharolyticus. Nearly 69% of males were suffering, while the rest were females at 31%. The 15–30 years old age group was the most affected. The gold/alginate nanoparticles' nanopreparation (GANPs) produced from chloroauric acid and sodium alginate was an effective treatment against the acne conditions under the experimental conditions. The nanopreparation exhibited significant inhibitory activity against anaerobic bacterial isolates, with a minimum inhibitory concentration of 200 µg/ml for A. prevotii and P. asaccharolyticus, and 400 µg/ml for C. innocuum and L. plantarum. The in vitro efficacy of the GANPs on human blood parameters was also assessed. The concurrent results suggested potential antibacterial activity and hemocompatibility of the product, which has promise to be used as a successful antibacterial agent for acne. [ABSTRACT FROM AUTHOR]

There is a strong need to develop an insulin delivery system suitable for oral administration and preserving natural (α-helix) insulin conformation. In this work, we fabricated alginate–gelatin hydrogel beads for insulin encapsulation. Altering matrix composition and crosslinking agents has resulted in various surface morphologies and internal spatial organization. The structures of the insulin-loaded matrices were studied using optical and field emission electronic microscopy. We use FTIR spectroscopy to identify insulin conformation changes as affected by the hydrogel matrices. It was found that blended alginate–gelatin matrices demonstrate better encapsulation efficiency and stronger swelling resistance to a simulated gastric environment than sodium alginate beads crosslinked with the CaCl2. FTIR measurements reveal conformation changes in insulin. It is also confirmed that in the presence of gelatin, the process of insulin fibrinogenesis ceases due to intermolecular interaction with the gelatin. Performed molecular modeling shows that dipole–dipole interactions are the dominating mechanism that determines insulin behavior within the fabricated matrix. [ABSTRACT FROM AUTHOR]

BACKGROUND: Calcium alginate gels are widely used to encapsulate active compounds. Some characteristic parameters of these gels are necessary to describe the release of active compounds through mechanistic mathematical models. In this work, transport and kinetics properties of calcium alginate gels were determined through simple experimental techniques. RESULTS: The weight‐average molecular weight (M¯w = 192 × 103 Da) and the fraction of residues of α‐l‐guluronic acid (FG = 0.356) of sodium alginate were determined by capillary viscometry and 1H‐nuclear magnetic resonance at 25 °C, respectively. Considering the half egg‐box model, both values were used to estimate the molecular weight of calcium alginate as Mg = 2.02 × 105 Da. An effective diffusion coefficient of water (Deff,w = 2.256 × 10−9 m2 s−1) in calcium alginate was determined using a diffusion cell at 37 °C. Finally, a kinetics constant of depolymerization (km = 9.72 × 10−9 m3 mol−1 s−1) of calcium alginate was obtained considering dissolution of calcium to a medium under intestinal conditions. CONCLUSION: The experimental techniques used are simple and easily reproducible. The obtained values may be useful in the design, production, and optimization of the alginate‐based delivery systems that require specific release kinetics of the encapsulated active compounds. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Butter has been widely used in bakery products and it contains high level of saturated fats. However, excessive consumption of saturated fats would increase the risk of chronic disease. This study was to fabricate water‐in‐oil (W/O) type bigels as butter replacers to improve the quality attributes of breads. RESULTS: A stable water‐in‐oil (W/O) type bigel system was fabricated based on mixed oleogelators (rice bran wax and glycerol monostearate) and sodium alginate hydrogel. The ratios of oleogel to hydrogel could significantly affect the stability, microstructure and rheological properties of bigels. All of the bigels exhibited solid‐like properties, with increased oleogel fractions, and the network structure of bigel became more compact and orderly with smaller sodium alginate gel particles. Meanwhile, the viscoelastic modulus and firmness of bigel increased, contributing to a higher stability. The bigel dough exhibited lower gel strength and relatively higher extensibility compared to the butter dough. Regardless of oleogel fractions, all the bigel produced bread with a higher specific volume and softer texture than the butter bread. When the oleogel fractions was less than 80%, increasing the oleogel fractions was more beneficial for improving the specific volume, softness and fluffy structure of bread. CONCLUSION: W/O type bigel as butter replacers showed great potential in improving the appearance, structure and textural properties of bread. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Laser-induced graphene (LIG) possesses desirable properties for numerous applications. However, LIG formation on biocompatible substrates is needed to further augment the integration of LIG-based technologies into nanobiotechnology. Here, LIG formation on cross-linked sodium alginate is reported. The LIG is systematically investigated, providing a comprehensive understanding of the physicochemical characteristics of the material. Raman spectroscopy, scanning electron microscopy with energy-dispersive x-ray analysis, x-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy and x-ray photoelectron spectroscopy techniques confirm the successful generation of oxidized graphene on the surface of cross-linked sodium alginate. The influence of laser parameters and the amount of crosslinker incorporated into the alginate substrate is explored, revealing that lower laser speed, higher resolution, and increased CaCl2 content leads to LIG with lower electrical resistance. These findings could have significant implications for the fabrication of LIG on alginate with tailored conductive properties, but they could also play a guiding role for LIG formation on other biocompatible substrates. [ABSTRACT FROM AUTHOR]

Selenium nanoparticles (SeNPs) have recently garnered substantial attention in drug delivery due to their unique properties. The present study focused on synthesizing SeNPs, utilizing sodium selenite as a template and ascorbic acid as the reducing agent. This was followed by sodium alginate-decorated selenium nanoparticles (SA-SeNPs) and pectin-decorated selenium nanoparticles (PET-SeNPs). These nanoparticles were subjected to UV–vis spectrophotometry, Fourier infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (RS), and dynamic light scattering (DLS) for characterization. The UV–vis spectroscopy results indicate a peak absorption spectrum at 266 nm for SeNPs, SA-SeNPs, and PET-SeNPs. The FTIR spectrum of SeNPs, SA-SeNPs, and PET-SeNPs was recorded within the wavenumber range of 400–4000 cm−1. XRD analysis confirmed the crystalline nature of SeNPs and SA-SeNPs, while PET-SeNPs were amorphous. SEM analysis revealed spherical morphology for SeNPs, spherical fibrous cross-link for SA-SeNPs, and cubic rod-shaped morphology for PET-SeNPs. Raman's spectroscopy identified characteristic vibrations of monoclinic selenium in SeNPs, SA-SeNPs, and PET-SeNPs. DLS analysis indicated an average particle size distribution ranging from 140 to 192 nm, with a zeta potential value signifying the nanoparticles' excellent stability. The antioxidant properties of SeNPs, SA-SeNPs, and PET-SeNPs via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay indicated significantly higher scavenging activity for SA-SeNPs (72%) and PET-SeNPs (64%) compared to pure SeNPs (61%). Furthermore, cytotoxicity experiments on the C2C12 cell line showed reductions in cell death at 10 µg/mL concentrations of 16.3%, 11.8%, and 6.7% for SeNPs, SA-SeNPs, and PET-SeNPs, respectively. These results underscore the potential applications of PET-SeNPs and SA-SeNPs in diverse biomedical domains, including their use as antioxidant agents, drug delivery systems, and therapeutic agents for cardiovascular issues. [ABSTRACT FROM AUTHOR]

Hearing loss is a widespread condition, affecting people from a range of demographics. Gene therapy is an emerging method for the amelioration of this condition. Challenges associated with the delivery of genes to various sites within the ear remain a significant challenge. In the present work, a novel polymer nanoparticle delivery system was developed, incorporating a bile acid excipient. Bile acids have previously been shown to improve drug delivery through their permeation enhancing properties; however, few studies report their use in gene delivery systems. Nanoparticles were developed with sodium alginate and poly-L-lysine through an ionotropic gelation method. Various surfactants including Tween-80 and poly-ethylene glycol 6000 were incorporated to both improve the solubility of the bile acid, ursodiol, and to modify nanoparticle properties. The evaluation of the nanoparticle's safety profiles was the primary outcome of this study. The secondary aims were to perform genetic studies, such as transfection efficiency. The nanoparticles generated in this study demonstrated formulation-dependent variability in particle size ranging from 30 to 300 nm. Several of the developed formulations demonstrated suitable safety profiles; further, the introduction of bile acid helped to reduce toxicity. Transfection efficiency for all formulations remained low, potentially due to poor plasmid release inside the cell. Poor transfection efficiency is one of the key pitfalls associated with polymer nanoparticles Overall the present study developed nanoparticles with suitable safety profiles but limited efficacy. The use of modified polymers, additional excipients, and cell-targeting peptides are potential methods that may be explored in future studies to help further improve gene delivery. [ABSTRACT FROM AUTHOR]

One of the major challenges in harnessing the therapeutic benefits of curcumin (an active ingredient from turmeric) is its poor bioavailability due to its short biological half-life. In this regard, nanoformulations have shown tremendous hope for improving the pharmacokinetic and therapeutic behavior of curcumin by altering its biological stability and bioavailability. Biopolymers, especially alginate and chitosan, have received special attention as excipients to prepare nanoformulations of curcumin due to their abundant availability, biocompatibility, and amicability to form different types of self-assembled structures and ease of undergoing chemical modifications. However, there are certain challenges, such as poor water solubility under physiological conditions and heterogeneity with regard to molecular weight and large-scale production of well-preserved nanostructures. Substantial advancement has been achieved towards overcoming these challenges by developing newer derivatives through a chemical modifications approach, and this has ascertained the suitability of alginate and chitosan as excipients for drug delivery systems (DDS). The present minireview briefly discusses curcumin and its limitation as a drug molecule, carbohydrates as DDS, and the recent developments related to the alginate and chitosan-based nanoformulations of curcumin. Special emphasis has been given to highlighting the impact of alginate and chitosan-based nanoformulations in improving the therapeutic efficacy and bioavailability of curcumin. [ABSTRACT FROM AUTHOR]

The development of next‐generation materials for essential components in lithium‐ion batteries, such as collectors, is crucial owing to considerations of performance, cost, and environmental impact. From this perspective, new‐generation material studies are being carried out to increase the performance of current collectors and reduce environmental damage. In this study, a novel biodegradable Ag nanoparticle‐doped calcium alginate cryogel was produced and used as the current collector for Li‐ion batteries to improve performance, reduce environmental damage, and develop new‐generation batteries. The synthesis of Ag NPs was achieved using an inexpensive and environmentally friendly chemical reduction method, followed by their incorporation into the gels. Freeze‐drying was employed to obtain cryogels without the inclusions on the current collector. Structural analysis of both the particles and gels was performed via XRD, SEM, EDS, and FTIR, DSC respectively. The results showed that the synthesized Ag NPs were spherical with an average diameter of 10 nm. The cryogels exhibited desirable chemical structures, as indicated by FTIR analysis. The addition of Ag NPs led to changes in peak positions and intensities, indicating crosslinking homogenization and increased hydrophobicity. Galvanostatic Charge/Discharge Analysis was conducted to evaluate the electrochemical performance of the cryogels as current collectors. The cryogels demonstrated balanced lithiation/delithiation behavior but had a limited operational duration, likely due to structural instability. Postmortem analysis conducted by FTIR and DSC analysis for disassembled cryogels showed the presence of lithium salts from the electrolyte in the structure, and the usage of a solid electrolyte was recommended to improve the system's performance. [ABSTRACT FROM AUTHOR]

The availability of alginate, an abundant macroalgal polysaccharide, induces compositional and functional responses among marine microbes, but these dynamics have not been characterized across the Pacific Ocean. We investigated alginate‐induced compositional and functional shifts (e.g., heterotrophic production, glucose turnover, hydrolytic enzyme activities) of microbial communities in the South Subtropical, Equatorial, and Polar Frontal North Pacific in mesocosms. We observed that shifts in response to alginate were site‐specific. In the South Subtropical Pacific, prokaryotic cell counts, glucose turnover, and peptidase activities changed the most with alginate addition, along with the enrichment of the widest range of particle‐associated taxa (161 amplicon sequence variants; ASVs) belonging to Alteromonadaceae, Rhodobacteraceae, Phormidiaceae, and Pseudoalteromonadaceae. Some of these taxa were detected at other sites but only enriched in the South Pacific. In the Equatorial Pacific, glucose turnover and heterotrophic prokaryotic production increased most rapidly; a single Alteromonas taxon dominated (60% of the community) but remained low (<2%) elsewhere. In the North Pacific, the particle‐associated community response to alginate was gradual, with a more limited range of alginate‐enriched taxa (82 ASVs). Thus, alginate‐related ecological and biogeochemical shifts depend on a combination of factors that include the ability to utilize alginate, environmental conditions, and microbial interactions. [ABSTRACT FROM AUTHOR]

The administration of protein therapeutics through oral means is seen as a convenient and painless experience for patients, making it a significant consideration in the field of drug delivery. Nevertheless, the challenging conditions within the gastrointestinal tract, along with the obstacles to absorption, impede the efficient transportation of proteins. Here, we successfully implemented post-synthetic modifications to attach medium-chain lipids (C10) onto the surface of zeolitic imidazole framework-90 (ZIF-90), then encapsulated the nanoparticles with sodium alginate, resulting in a potential platform for the oral administration of proteins. By means of biomimetic mineralization, ZIF-90 achieves a simple and efficient encapsulation of proteins of varying sizes, while shielding them against degradation by digestive enzymes. Sodium alginate hydrogel protects proteins against gastric acid and helps the cargo to rapidly penetrate the mucus layer. Through a mixed mechanism dominated by micropinocytosis, the C10-conjugated ZIF-90 (ZIF-90-C10) can be uptake by Caco-2 cells with a 200–400% increase and transported through the Golgi apparatus after escaping from lysosomes, exhibiting enhanced uptake in the overall gastrointestinal tract. Furthermore, ZIF-90-C10 retains its adenosine triphosphate-responsive release, which drastically lowers the likelihood of accumulation in vivo and allows targeted delivery for disease cells. Our work highlights mid-chain lipid conjugation as a potent approach to enhancing nanoparticle delivery efficiency and a potential strategy for oral delivery of biomacromolecules when combined with pH-responsive gels. [Display omitted] • A Gel-Metal-Organic Framework oral delivery system with dual pH and ATP response. • Efficient encapsulation of proteins of different sizes by biomimetic mineralization. • Modification of ZIF-90 with mid-chain lipid increases cellular uptake by 200%–400%. • Effective delivery and protection of protein in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Black locust flower extract contains various polyphenols and their glucosides contribute to the potential health benefits. After intake of these bioactive compounds and passage through the gastrointestinal tract, their degradation can occur and lead to a loss of biological activity. To overcome this problem, the bioactive compounds should be protected from environmental conditions. This study aimed to encapsulate the black flower extract in the microparticles based on biodegradable polysaccharides, alginate, and chitosan. In the extract, the total antioxidant content was found to be 3.18 ± 0.01 g gallic acid equivalent per 100 g of dry weight. Also, the presence of lipids (16), phenolics (27), organic acids (4), L-aspartic acid derivative, questinol, gibberellic acid, sterol, and saponins (2) was confirmed using the UHPLC–ESI–MS analysis. In vitro assays showed that the extract has weak anti-α-glucosidase activity and moderate antioxidant and cytotoxic activity against the HeLa cell line. The extrusion method with secondary air flow enabled the preparation of microparticles (about 270 μm) encapsulated with extract. An encapsulation efficiency of over 92% was achieved in the alginate and alginate–chitosan microparticles. The swelling study confirmed a lower permeability of alginate–chitosan microparticles compared with alginate microparticles. For both types of microparticles, the release profile of antioxidants in the simulated gastrointestinal fluids at 37 °C followed the Korsmeyer–Peppas model. A lower diffusion coefficient than 0.5 indicated the simple Fick diffusion of antioxidants. The alginate–chitosan microparticles enabled a more sustained release of antioxidants from extract compared to the alginate microparticles. The obtained results indicated an improvement in the antioxidant activity of bioactive compounds from the extract and their protection from degradation in the simulated gastric conditions via encapsulation in the polymer matrixes. Alginate–chitosan showed slightly slower cumulative antioxidant release from microparticles and better antioxidant activity of the extract compared to the alginate system. According to these results, alginate–chitosan microparticles are more suitable for further application in the encapsulation of black locust flower extract. Also, the proposed polymer matrix as a drug delivery system is safe for human use due to its biodegradability and non-toxicity. [ABSTRACT FROM AUTHOR]

Rugulopteryx okamurae (RO) is an invasive brown seaweed that causes severe environmental problems in the Mediterranean Sea. This work proposed an extraction method that enables their use as a raw material for producing sodium alginate. Alginate was successfully extracted from this invasive seaweed, with its gelling performance in the presence of Ca2+ ions comparable to existing commercial alginates. The mannuronic acid (M)-to-guluronic (G) acid ratio in the 1H-NMR profile indicated a higher percentage of G in the RO-extracted alginate, which implies a greater formation of so-called egg box structures. These differences resulted in their different rheological behaviour, as sodium alginate aqueous solutions exhibited a greater viscosity ( η at 1 s−1 = 3.8 ± 0.052 Pa·s) than commercial alginate (2.8 ± 0.024 Pa·s), which is related to the egg box structure developed. When gelled in the presence of calcium, an increase in the value of the elastic modulus was observed. However, the value of the tan δ for the extracted alginate was lower than that of commercial alginate gels, confirming a structure more densely packed, which implies a different restructuring of the alginate chain when gelling. These results confirm the suitability of using invasive Rugulopteryx okamurae as a source of calcium alginate gels. In this way, sustainable bio-based materials may be produced from undesired biomass that currently poses a threat to the ecosystem. [ABSTRACT FROM AUTHOR]

Materials that speed up wound healing can be of great benefit to patients and healthcare providers. One-layer dressings, however, have unsatisfactory healing efficacy since it is impossible to use materials with different properties simultaneously, and drug delivery is limited by the depth of penetration. The present study utilized a multilayer wound dressing composed of bacterial cellulose (BC) hydrogel, gelatin/alginate (Gel/Alg) hydrogel, and polycaprolactone (PCL) nanofibers loaded with ciprofloxacin (CIP) to promote the healing process in vivo. The designed dressings showed significant water absorption and sufficient water vapor transmission rate (WVTR) after one week, confirming their ability to absorb wound exudate. Within the first four hours, significant amounts of CIP were released from the drug-containing dressing. Then, between hours 4 and 24, the rate decreased and plateaued on day 9. Both positive and negative bacterial strains were inhibited by the gradual release of CIP, while fibroblasts retained their normal morphology and metabolic activity. Lastly, in vivo tests demonstrated that CIP-loaded multilayer dressings could significantly speed up full-thickness wound healing during 14 days, by reducing inflammation, stimulating re-epithelialization, and enhancing skin regeneration. Our findings indicate that multilayering BC hydrogels with drug-loaded nanofibers provide a promising way to promote wound healing by utilizing all the distinctive properties of these layers. [Display omitted] [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI) leads to a cascade of primary and secondary neurodegenerative events, often causing lifelong disabilities. Brain-derived neurotrophic factor (BDNF) is a potential therapeutic for functional recovery of neurons. Unfortunately, BDNF is unstable and expensive, making direct infusion impractical. Therefore, we sought to develop a controlled release formulation to deliver BDNF. Our therapeutic construct encapsulates BDNF in poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs), and further encapsulates these NPs in an alginate hydrogel. Encapsulating BDNF within NPs protects and assists in drug delivery, while further encapsulating the BDNF-NPs in alginate enables localization and sustained release. The BDNF-NPs were synthesized and evaluated for size, stability and BDNF release profile. A MATLAB model was developed to determine the approximate quantity of BDNF-NPs needed to evaluate therapeutic efficacy in neurons injured with hydrogen peroxide. We then compared the therapeutic efficacy and BDNF release profile of these BDNF-NPs to our novel alginate/BDNF-NP formulation. We have successfully designed and fabricated a double encapsulation positionally controllable construct that preserves BDNF bioactivity and extends its release. We also demonstrated that very low dosages of BDNF may be equally effective in promoting neuroprotection, thereby potentially reducing therapeutic costs without compromising efficacy. Our novel formulation offers a promising avenue for treating severe TBI and other neurological disorders which would benefit from a long-lasting and positionally controllable neuroprotective treatment. This approach can easily accommodate additional biologics for localized drug delivery with minimal re-formulation. [ABSTRACT FROM AUTHOR]

Calcium alginate gel microspheres exhibiting pH response release characteristics were prepared, and utilizing Bovine serum albumin (BSA) to evaluate drug release performance. Hydrogels composed of gelatin (GL) and sodium alginate oxide (NALO), with varying ratios (7:3; 4:1; 3:2) were prepared by controlling their composition. Scanning electron microscopy (SEM) and a microplate reader (ELIASA) were used to characterize the microspheres' microstructure and in vitro BSA release behavior, respectively. The results demonstrated that, under acidic conditions, the BSA release was slower than in neutral conditions. The hydrogels' physical and chemical properties were analyzed using optical microscopy, Fourier transform infrared spectroscopy (FTIR), swelling experiments and mechanical testing of the hydrogels and microsphere loaded hydrogels. The results showed that a GL to NALO ratio of 7:3 increased the swelling degree, while a 4:1 ratio optimized the mechanical characteristics. The study concluded that the microsphere-loaded hydrogels exhibited significant potential for human drug delivery applications. [ABSTRACT FROM AUTHOR]

Purpose: Sodium alginate (Na-Alg) is a natural polysaccharide with a rich and renewable production that is widely used in the food, pharmaceutical and daily necessities industries, among other fields. The purpose of this study is to obtain a green and degradable shape memory material, calcium alginate (Ca-Alg) film was prepared and the mechanical properties, the shape memory effect of the film were investigated and confirmed. Design/methodology/approach: The Ca-Alg films were prepared by Na-Alg, calcium chloride (CaCl2) solution, and flow extension method. Dissolve sodium alginate powder, remove bubbles, pour into petri dish, dry at 60°C, add calcium chloride solution cross-linking and finally dry naturally. The effect of CaCl2 solution concentration on the mechanical properties of the films were investigated and discussed by universal tensile tester. The shape memory behavior and degradation performance of thin films were verified and studied by the fold-deploy shape memory test and soil embedding method, respectively. Findings: The Ca-Alg films exhibited good mechanical and shape memory properties, with a 72.2% shape memory fixity ratio and a 92.3% shape memory recovery ratio, respectively. For a period of 120 days, the film treated with a 6 wt% CaCl2 solution degraded at a rate of approximately 53%. Research limitations/implications: Shape memory polymers (SMPs) as intelligent materials are an important research direction for the development of modern high-tech materials. On the other hand, plastic pollution is a major problem today; as a result, preparing green degradable SMPs is essential. Originality/value: This study synthesized transparent and degradable shape memory Ca-Alg films using Na-Alg and CaCl2 solution and the flow extension method. [ABSTRACT FROM AUTHOR]

ObjectivesTo develop alginate nanoparticles functionalized with polysorbate 80 (P80) as miltefosine carriers for brain targeting in the oral treatment of cryptococcal meningitis.MethodsMiltefosine-loaded alginate nanoparticles functionalized or not with P80 were produced by an emulsification/external gelation method and the physicochemical characteristics were determined. The haemolytic activity and cytotoxic and antifungal effects of nanoparticles were assessed in an in vitro model of the blood-brain barrier (BBB). A murine model of disseminated cryptococcosis was used for testing the efficacy of oral treatment with the nanoparticles. In addition, serum biomarkers were measured for toxicity evaluation and the nanoparticle biodistribution was analysed.ResultsP80-functionalized nanoparticles had a mean size of ∼300 nm, a polydispersity index of ∼0.4 and zeta potential around -50 mV, and they promoted a sustained drug release. Both nanoparticles were effective in decreasing the infection process across the BBB model and reduced drug cytotoxicity and haemolysis. In in vivo cryptococcosis, the oral treatment with two doses of P80 nanoparticles reduced the fungal burden in the brain and lungs, while the non-functionalized nanoparticles reduced fungal amount only in the lungs, and the free miltefosine was not effective. In addition, the P80-functionalization improved the nanoparticle distribution in several organs, especially in the brain. Finally, treatment with nanoparticles did not cause any toxicity in animals.ConclusionsThese results support the potential use of P80-functionalized alginate nanoparticles as miltefosine carriers for non-toxic and effective alternative oral treatment, enabling BBB translocation and reduction of fungal infection in the brain.

Cardiac tissue engineering is an emerging approach for cardiac regeneration utilizing the inherent healing responses elicited by the surviving heart using biomaterial templates. In this study, we aimed to develop hydrogel scaffolds for cardiac tissue regeneration following myocardial infarction (MI). Two superabsorbent hydrogels, CAHA2A and CAHA2AP, were developed employing interpenetration chemistry. CAHA2A was constituted with alginate, carboxymethyl cellulose, (hydroxyethyl) methacrylate, and acrylic acid, where CAHA2AP was prepared by interpenetrated CAHA2A with polyvinyl alcohol. Both hydrogels displayed superior physiochemical characteristics, as determined by attenuated total reflection infrared spectroscopy spectral analysis, differential scanning calorimetry measurements, tensile testing, contact angle, water profiling, dye release, and conductivity. In vitro degradation of the hydrogels displayed acceptable weight composure and pH changes. Both hydrogels were hemocompatible, and biocompatible as evidenced by direct contact and MTT assays. The hydrogels promoted anterograde and retrograde migration as determined by the z-stack analysis using H9c2 cells grown with both gels. Additionally, the coculture of the hydrogels with swine epicardial adipose tissue cells and cardiac fibroblasts resulted in synchronous growth without any toxicity. Also, both hydrogels facilitated the production of extracellular matrix by the H9c2 cells. Overall, the findings support an appreciable in vitro performance of both hydrogels for cardiac tissue engineering applications.

Macrocystis pyrifera (giant kelp), is a brown macroalga of great ecological importance as a primary producer and structure-forming foundational species that provides habitat for hundreds of species. It has many commercial uses (e.g. source of alginate, fertilizer, cosmetics, feedstock). One of the limitations to exploiting giant kelp's economic potential and assisting in giant kelp conservation efforts is a lack of genomic tools like a high quality, contiguous reference genome with accurate gene annotations. Reference genomes attempt to capture the complete genomic sequence of an individual or species, and importantly provide a universal structure for comparison across a multitude of genetic experiments, both within and between species. We assembled the giant kelp genome of a haploid female gametophyte de novo using PacBio reads, then ordered contigs into chromosome level scaffolds using Hi-C. We found the giant kelp genome to be 537 MB, with a total of 35 scaffolds and 188 contigs. The assembly N50 is 13,669,674 with GC content of 50.37%. We assessed the genome completeness using BUSCO, and found giant kelp contained 94% of the BUSCO genes from the stramenopile clade. Annotation of the giant kelp genome revealed 25,919 genes. Additionally, we present genetic variation data based on 48 diploid giant kelp sporophytes from three different Southern California populations that confirms the population structure found in other studies of these populations. This work resulted in a high-quality giant kelp genome that greatly increases the genetic knowledge of this ecologically and economically vital species.

Endoscopic resection techniques require the use of submucosal injection. Normal saline and sodium hyaluronate solutions are mainly used for this purpose, but an ideal solution has not yet been developed. The aim of this study was to assess a new solution, MC-003—a novel submucosal injection solution developed with sodium alginate as the main ingredient. Normal saline, a commercial sodium hyaluronate solution (Endo-Ease), and MC-003 were examined. A total of 18 gastric submucosal cushions were created in the stomachs of six pigs. The height of mucosal elevation was measured sequentially using endoscopic sonography. After euthanizing the animals either 2 h or 5 days after the procedure, pathologic examination was performed for each injection site. Although not statistically significant over the entire study period, MC-003 showed a superior result to normal saline and an equivalent result to Endo-Ease in the submucosal cushion height and its rate of decrease. There were no adverse outcomes after injection of the three solutions and there was no pathologically identified detrimental change in the resected specimens. MC-003 creates a sufficient submucosal fluid cushion without apparent tissue damage. It can be considered as an effective submucosal injection material. [ABSTRACT FROM AUTHOR]

This research paper presents a technology for preparing hydrogels based exclusively on natural materials (alginate, carboxymethylcellulose and starch) as carriers of micronutrients (Cu, Mn and Zn). Experiments were performed to select the hydrogel matrix components, including a comparison of the viscosity and density of sodium alginates purchased from different manufacturers, as well as the effect of additives (carboxymethylcellulose and starch) on the swelling properties and strength of the structures. Finally, a solution containing 2 wt% alginate, 2 wt% carboxymethylcellulose and 10 wt% starch was used to prepare reproducible spherical hydrogels. The influence of hydrogel preparation methods on their sorption capacity and strength (either direct dropping into micronutrient solution or two-step, i.e., dropping into calcium chloride and later sorption in micronutrient solution) was also explored. The study revealed that the enrichment of hydrogels with micronutrients by the two-step method is slower, but the structures have better mechanical strength (Young's modulus more than 4 times higher) than those enriched by the one-step method. A series of analyses (FTIR, TGA, XRD and TEM) showed that obtained hydrogels have a semicrystalline structure, are thermally stable and mainly involve carboxylic acid groups in the enrichment process. The effectiveness of the designed hydrogel matrix for the slowed release of micronutrients has been preliminarily proven in winter wheat germination tests. The best results (12.2 cm stem length and 47.9 cm roots) were obtained for the group, where hydrogels were applied at a dose equivalent to 50% of the wheat's Cu, Mn and Zn requirements. [ABSTRACT FROM AUTHOR]

Traditional artificial skin gels often only focuses on a single perspective and overlooks the necessity of multidimensional synergistic design for sensitivity enhancement. To address these problems, the innovative introduction of dual solvents on the surface of polyacrylamide/sodium alginate gel induces to the transformation of supramolecular interactions including ion coordination, crystalline alcohol, and phase separation, synergistically achieving adjustable wrinkle wavelengths (304.2 ± 19.9 to 2393.5 ± 95.9 µm) and modulated chemical compositions with tunable moduli (87.5 ± 3.3 to 157.6 ± 3.7 kPa). This flexible strategy allows the construction of long‐range ordered wrinkled microstructures of three‐dimensional surfaces and complex morphologies. Meanwhile, the bridge effect induced by crystalline alcohols directs the insertion of ethanol molecules into the polymer chains, effectively reducing intramolecular friction. Benefiting from the small wavelength and low modulus dominated by crystalline alcohol, the wrinkled gel exhibits extremely high sensitivity of 164 kPa−1 (<0.5 kPa) and wide detection range (44.3 kPa). The wrinkled gel remains stable high sensitive to detect micro‐ and large stress, tactile perception, and human motion behaviors. This work proposes a new strategy for constructing highly sensitive bioinspired skin from multiple dimensions, showing broad application prospects in the fields of bioengineering and behavioral cognition. [ABSTRACT FROM AUTHOR]