Alginate Composition Research Articles

Enhanced Photodegradation of Imidacloprid Using ZnO@Ca‐Alginate Composites: Optimization of pH and pHzcp for Effective Water Treatment

AbstractThis research focused on the photodegradation of the insecticide imidacloprid (IM) via a ZnO@Ca‐Alginate composite catalyst to address water contamination issues, particularly in agricultural areas such as Palestine. The composite was synthesized and characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), energy dispersive X‐ray (EDX), thermogravimetric analysis (TGA), and Fourier transform infrared (FT‐IR) spectroscopy, confirming the presence of ZnO. Photocatalytic experiments under simulated solar light revealed significant IM degradation, with a 50 % reduction in 40 minutes, an 80 % reduction in 2 hours, and up to 94 % in 3 hours. The degradation efficiency was influenced by the point of zero charge (pHzcp) and solution pH, with optimal performance under neutral to slightly basic conditions. UV‐visible spectrophotometry, high‐performance liquid chromatography (HPLC), and total organic carbon (TOC) analyses verified complete IM mineralization, yielding CO₂, Cl−, and NO₃− after 3 hours. The ZnO@Ca‐Alginate composite demonstrated high reusability, highlighting its potential for treating pesticide‐contaminated water. This study emphasizes the need for efficient pollutant removal technologies in regions where agricultural pollutants are prevalent.

Poly(3-Hexylthiophene) Based Bioelectronic Interface Using Conducting Nanofibers (CNFs) for the Sensitive Determination of Folate Receptor Cancer Biomarkers in Human Plasma

Folate receptors (FRs) are important biomarkers that can indicate the presence of various cancers. Sensitive and accurate detection of FRs is crucial for early cancer diagnosis and treatment. The current methods of FRs detection have high cost, potential cytotoxicity, and complex production by relying on metallic nanomaterials, or have low electrical conductivity and sensitivity such as biopolymers. To address these challenges, a new approach using conducting nanofibers (CNFs) as bioelectronic surface was developed. A composite of sodium alginate (SA), a bio-friendly polymer, poly-ethylene oxide (PEO), an antifouling polymer, and poly(3-hexylthiophene) (P3HT), a semi-conducting organic polymer nanofiber was synthesized, with folic acid conjugated to the CNFs as a biorecognition element to target (FRs). The electrochemical and electrical properties were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy in a solution containing both a redox marker and free redox species. The CNFs exhibit electroactivity in buffer solution without a redox marker, owing to the electronic properties of the P3HT of EIS readout. The obtained biosensor significantly improved sensitivity, enabling the detection of FRs with a limit of detection (LOD) of 0.12 pM in human plasma, the high sensitivity compared to all previous approaches and a 25-fold improvement compared to the sensor described in our previous study, with improved selectivity. Additionally, the results showed a good biocompatibility toward MCF-7 breast cancer cells, which opens the way for their use as theragnostic nanoprobes for cancer cells diagnosis and therapy. This study provided a simple, low cost and sensitive analytical approach for folate receptor detection.

Blood Coagulation Activities and Influence on DNA Condition of Alginate-Calcium Composites Prepared by Freeze-Drying Technique.

The aim of this research was to synthesize and characterize alginate-calcium composites using a freeze-drying method, with a focus on their potential applications in biomedicine. This study specifically explored the biochemical properties of these composites, emphasizing their role in blood coagulation and their capacity to interact with DNA. Additionally, the research aimed to assess how the cross-linking process influences the structural and chemical characteristics of the composites. Detailed analyses, including microscopic examination, surface area assessment, and atomic absorption spectrometry, yielded significant results. The objective of this study was to examine the impact of calcium chloride concentration on the calcium content in alginate composites. Specifically, the study assessed how varying concentrations of the cross-linking solution (ranging from 0.5% to 2%) influence the calcium ion saturation within the composites. This investigation is essential for understanding the physicochemical properties of the materials, including calcium content, porosity, and specific surface area. The results are intended to identify the optimal cross-linking conditions that maximize calcium enrichment efficiency while preserving the material's structural integrity. The study found that higher calcium chloride concentrations in alginate cross-linking improve the formation of a porous structure, enhanced by two-stage freeze-drying. Increased calcium levels led to a larger surface area and pore volume, and significantly higher calcium content. Furthermore, assays of activated partial thromboplastin time (aPTT) showed a reduction in clotting time for alginate composites containing calcium ions, indicating their potential as hemostatic agents. The aPTT test showed shorter clotting times with higher calcium ion concentrations, without enhanced activation of the extrinsic clotting pathway. The developed alginate material with calcium effectively supports hemostasis and reduces the risk of infection. The study also explored the capacity of these composites to interact with and modify the structure of plasmid DNA, underscoring their potential for future biomedical applications.

Multifunctional conductive SA/ATO@TiO2 whisker aerogels for piezoresistive pressure sensor application

Ultralight and flexible aerogel sensors have garnered significant interest, yet challenges persist in developing their high elasticity and exceptional piezoresistive properties. In this work, laminated porous composite aerogels have been successfully prepared by a composite of sodium alginate (SA) and antimony-doped SnO2 coated titanium dioxide whiskers (ATO@TiO2) via directional freezing technique. The resulting SA and ATO@TiO2 (SAT) aerogels with laminated porous structure demonstrate lightweight with low-density (0.06 g·cm−3), good compressive properties, superplastic, and conductive properties. The incorporation of small amounts of rod-like ATO@TiO2 whiskers into SAT aerogels not only enhances its electrical conductivity and thermal insulation, but also imparts a light-colored appearance to the aerogel. The assembled SAT aerogel sensors exhibit high sensitivity within 1.0 kPa (225 kPa−1, 17.86 kPa−1) and maintains excellent fatigue resistance even over 1000 cycles. The temperature-responsive properties of SAT aerogel sensors presented superior thermal insulation properties, and it can operate properly even at a high temperature of 100 °C. More importantly, SAT piezoresistive sensors facilitated real-time monitoring and human-computer interactive activities related to human movement and health, showcasing significant potential in diverse fields.

Alginate edible films as delivery systems for green tea polyphenols

This study investigated the potential of alginate edible films to act as vehicles for the delivery of polyphenols to the intestinal tract. Sodium alginate (0.5–2% w/v) and green tea extract (GTE, 25–50% w/w) were combined to form films with different microstructural properties via the casting method, where their physical, mechanical and barrier properties were analysed. Release studies into a 50% ethanol (v/v) food simulant and under simulated in vitro digestion were also conducted, and the resulting kinetics of polyphenols release was investigated. Composite alginate films with 25% w/w GTE (E∼2500 MPa; EAB∼14%; k∼0.04) showed significantly enhanced mechanical properties and slower rates of polyphenol release than samples with 50% w/w GTE (E∼6000 MPa; EAB∼6%; k∼0.18). Polyphenols entrapped within the 2% alginate – GTE films were successfully released during digestion (∼54%), demonstrating their bioaccessibility and availability for absorption by the gastrointestinal tract. The bioaccessibility of green tea polyphenols was significantly enhanced by films with good sustained-release effect (2% alginate – GTE, C/C0 = 54.41 ± 0.75%) respect to the free GTE (C/C0 = 33.73 ± 6.57%). These findings highlight the versatility of bioactive alginate edible films and create a blueprint for the design of sustainable active packaging alternatives with dual functionality.

Alginate composite films incorporated with Zn-based inorganic antimicrobials for food packaging: Effects of morphology.

Biopolymers-based food packaging materials have drawn attention as potential candidates for substitution of petroleum-based materials. In this study, composite alginate films were developed by incorporating Zn-based antimicrobials to overcome the intrinsic disadvantages of alginates that hinder their wide applications. Antimicrobials with different morphologies (nanoplatelets, nanorods, and nanospheres) were employed to investigate the effects of antimicrobials' morphology on antibacterial, thermal, mechanical, and barrier performance of composite alginate films. Meanwhile, morphological and structural characterizations were carried out to explore the interactions between antimicrobials and alginate matrix. Results indicated that films with nanospheres exhibited superior antibacterial property, while those with one-dimensional nanorods possessed better mechanical and barrier performance. Besides, preliminary test on fresh-cut potatoes and chicken breasts indicated that the composite films showed potential in extending shelf life of foods. By incorporating antimicrobials with three different morphologies, this study provides particular insights into improving properties of composite packaging materials.

A strategy for the efficient removal of acidic and basic dyes in wastewater by organophilic magadiite@alginate beads: Box-Behnken Design optimization

In this study, four adsorbents were developed: layered silicate magadiite material (mag), Hexadecyltrimethylammonium intercalated magadiite (HDTMA@mag), a cross-linked composite of sodium alginate and magadiite (ALG@mag) and a cross-linked composite of sodium alginate and HDTMA@magadiite (ALG@HDTMA@mag). The adsorbents were evaluated for their effectiveness in removing of Methylene Blue (MB) and Eriochrome Black T (EBT) dyes. The prepared adsorbents were characterized using SEM, XRD, FTIR, and zeta potential measurements. Kinetic modeling results indicated that both film diffusion and intraparticle diffusion are useful as rate-determining processes in adsorption for all adsorbents. For both dyes, the Langmuir isotherm model provided a good correlation with the adsorption equilibrium data. ANOVA analysis for the best adsorbent (ALG@HDTMA@mag beads) revealed that MB removal was significantly influenced by the positive individual effects of contact time and ALG@HDTMA@mag dose. However, the individual effect of MB concentration exhibited an antagonistic effect throughout the adsorption process. The optimal parameters for achieving an adsorption capacity of 118.54 mg/g were a dye concentration of 60 ppm, a contact period of 1800 min, and an ALG@HDTMA@mag dose of 50 mg.

The Impact of Gelatin and Fish Collagen on Alginate Hydrogel Properties: A Comparative Study.

Hydrogel materials based on sodium alginate find versatile applications in regenerative medicine and tissue engineering due to their unique properties, such as biocompatibility and biodegradability, and the possibility of the customization of their mechanical properties, such as in terms of the individual requirements of separate clinical applications. These materials, however, have numerous limitations in the area of biological activity. In order to eliminate their limitations, sodium alginate is popularly applied in combination with added gelatin, which represents a product of collagen hydrolysis. Despite numerous beneficial biological properties, matrix materials based on gelatin have poor mechanical properties and are characterized by their ability for rapid degradation in an aqueous environment, particularly at the physiological temperature of the body, which significantly limits the independent application opportunities of this type of composition in the range of scaffolding production dedicated for tissue engineering. Collagen hydrogels, unlike gelatin, are characterized by higher bioactivity, dictated by a greater number of ligands that allow for cell adhesion, as well as better stability under physiological conditions. Fish-derived collagen provides a material that may be efficiently extracted without the risk of mammalian prion infection and can be used in all patients without religious restrictions. Considering the numerous advantages of collagen indicating its superiority over gelatin, within the framework of this study, the compositions of hydrogel materials based on sodium alginate and fish collagen in different concentrations were developed. Prepared hydrogel materials were compared with the properties of a typical composition of alginate with the addition of gelatin. The rheological, mechanical, and physicochemical properties of the developed polymer compositions were evaluated. The first trials of 3D printing by extrusion technique using the analyzed polymer solutions were also conducted. The results obtained indicate that replacing gelatin with fish collagen at an analogous concentration leads to obtaining materials with a lower swelling degree, better mechanical properties, higher stability, limited release kinetics of calcium ions cross-linking the alginate matrix, a slowed process of protein release under physiological conditions, and the possibility of extrusion 3D printing. The conducted analysis highlights that the optimization of the applied concentrations of fish collagen additives to composition based on sodium alginate creates the possibility of designing materials with appropriate mechanical and rheological properties and degradation kinetics adjusted to the requirements of specific applications, leading to the prospective opportunity to produce materials capable of mimicking the properties of relevant soft tissues. Thanks to its excellent bioactivity and lower-than-gelatin viscosity of the polymer solution, fish collagen also provides a prospective solution for applications in the field of 3D bioprinting.

Synergistic adsorption of methylene blue using ternary composite of phosphoric acid geopolymer, calcium alginate, and sodium lauryl sulfate.

The removal of dyes from the aquatic ecosystem is necessary being a major threat to life. For enhanced remediation of methylene blue (MB) dye, a new ternary biopolymer-geopolymer-surfactant composite adsorbent is synthesized by combining phosphoric acid geopolymer (PAGP), calcium alginate (Alg), and sodium lauryl sulfate (SLS). During the synthesis of the composites, PAGP and SLS were mixed with the alginate matrix, producing porous hybrid beads. The PAGP-SLS-alginate (PSA) beads prepared were characterized using different analytical tools, i.e., scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR), X-ray diffractometry (XRD), surface area and porosimetery (SAP), and thermogravimetric analysis (TGA). To ascertain the ideal conditions for the adsorption process, a batch reactor procedure was used to investigate the effects of several parameters on MB adsorption, including pH (2, 4, 6, 8, 10), PSA adsorbent dosage (0.06-0.12 g), MB concentration (50-500 mg/L), contact time (15 to 300 min), and temperature (25, 35, and 45 °C). The SEM investigation indicated that ~ 1860 μm-sized PSA beads with 6-8 μm voids are generated. Based on XRD, FTIR, and SAP examinations, the material is amorphous, having numerous functional groups and an average pore size of 6.42 nm. Variation of pH has a little effect on the adsorption process, and the pH of 7.44 was found to be the pHpzc of the PSA beads. According to the findings of the batch study, equilibrium adsorption was obtained in 270-300 min, showing that the adsorption process was moderately slow-moving and effective. The dye adsorption linearly increased with initial dye concentration over concentration range of 50-500 mg/L and reciprocally decreased with rise in temperature. 0.06 g adsorbent dose, 25 °C, pH10, and 270 min were found to be the better conditions for adsorption experiments. Langmuir isotherm fitted well compared to Freundlich, Temkin, and Dubinin-Radushkevich (DR) isotherm models on the experimental data, and the maximum adsorption capacity(qmax) calculated was 1666.6 mg. g-1. Pseudo-second-order (PSO) kinetics model and multi steps (two) intra particle diffusion (IPD) model fitted well on the adsorption kinetics data. The system's entropy, Gibbs free energy, and change in enthalpy were measured and found to be -109.171 J. mol-1. K-1, - 8.198 to - 6.014 kJ. mol-1, and - 40.747 kJ. mol-1. Thermodynamics study revealed that adsorption process is exothermic, energetically favorable and resulting in the decrease in randomness. Chemisorption is found to be the dominant mechanism as confirmed by pH effect, Langmuir isotherm, PSO kinetics, IPD model, and thermodynamics parameters. PSA beads were successfully regenerated using ethanol in a course of 120 min and re-used for five times. To sum up, the PSA adsorbent's impressive adsorption capability of 1666.66 mg/g highlights its potential as a successful solution for methylene blue removal. The results of this study add to the expanding corpus of information on sophisticated adsorption materials and demonstrate PSA's potential for real-world uses in wastewater treatment and environmental clean-up.

Integrating classical and fractional calculus rheological models in developing hydroxyapatite-enhanced hydrogels

This study presents a novel method for comprehending the rheological behavior of biomaterials utilized in bone regeneration. The focus is on gelatin, alginate, and hydroxyapatite nanoparticle composites to enhance their mechanical properties and osteoconductive potential. Traditional rheological models are insufficient for accurately characterizing the behavior of these composites due to their complexity and heterogeneity. To address this issue, we utilized fractional calculus rheological models, such as the Scott-Blair, Fractional Kelvin-Voigt, Fractional Maxwell, and Fractional Kelvin-Zener models, to accurately represent the viscoelastic properties of the hydrogels. Our findings demonstrate that the fractional calculus approach is superior to classical models in describing the intricate, time-dependent behaviors of the hydrogel-hydroxyapatite composites. Furthermore, the addition of hydroxyapatite not only improves the mechanical strength of hydrogels but also enhances their bioactivity. These findings demonstrate the potential of these composites in bone tissue engineering applications. The study highlights the usefulness of fractional calculus in biomaterials science, providing new insights into the design and optimization of hydrogel-based scaffolds for regenerative medicine.

Diverse Approaches in Wet-Spun Alginate Filament Production from the Textile Industry Perspective: From Process Optimization to Composite Filament Production.

Alginate, categorized as a natural-based biodegradable polymer, stands out for its inherently exclusive properties. Although this unique polymer is widely processed using film, coating, and membrane technologies for different usage areas, textile applications are still limited. This study aims to compile promising approaches that will pave the way for the use of wet-spun alginate filaments in textile applications. In this regard, this study provides information about the molecular structure of alginate, the gel formation mechanism, and cross-linking using different techniques. Our literature review categorizes parameters affecting the mechanical properties of wet-spun alginate filaments, such as the effect of ion source and spinning dope concentration, needle diameter, temperature, and coagulants. Following this, a detailed and comprehensive literature review of the various approaches, such as use of additives, preparation of blended filaments, and grafted nanocrystal addition, developed by researchers to produce composite alginate filaments is presented. Additionally, studies concerning the use of different cations in the coagulation phase are reported. Moreover, studies about the functionalism of wet-spun alginate filaments have been offered.

Zinc oxide nanoparticles encapsulated in alginate beads: a promising and recyclable adsorbent for simultaneous uptake of toxic metals

Heavy metal toxicity is a known problem and various methods are used for treatment. Adsorption has some advantages and it would be promising if environmentally friendly and cheap materials were utilized. Alginate and zinc oxide nanoparticles were selected and composite alginate beads were used for the removal of mixed metals from aqueous solutions. Batch and column experiments were conducted to determine some parameters’ effects and the adsorbent’s real application potential. According to the batch experiments, zinc oxide nanoparticles to alginate ratio of 0.5 g g−1, and pH levels nearby to the neutral range led to better metal removals. 0.5 ml min−1 of flow rate supplied better metal removal efficiencies in columns, with the highest treatment as 86% of Pb2+. Acid treatment can be successfully applied for the regeneration of the adsorbent, at least three times only with a 4% reduction in the adsorption efficiency. Heavy metal uptake was compatible with the pseudo 2nd order model indicating chemisorption as a dominant mechanism. Also, the intraparticle diffusion model illustrated adsorption might govern more than one step. The Langmuir model had the best fit and suggested monolayer covering for Pb2+, 76.3 mg g−1. Alginate-based nanocomposite beads were useful for mixed metal removal and could be used.

TiO2-Alginate-Chitosan-Based Composites for Skin Tissue Engineering Applications.

The UV-B component of sunlight damages the DNA in skin cells, which can lead to skin cancer and premature aging. Therefore, it is necessary to use creams that also contain UV-active substances. Many sunscreens contain titanium dioxide due to its capacity to absorb UV-B wavelengths. In the present study, titan dioxide was introduced in alginate and chitosan-alginate hydrogel composites that are often involved as scaffold compositions in tissue engineering applications. Alginate and chitosan were chosen due to their important role in skin regeneration and skin protection. The composites were cross-linked with calcium ions and investigated using FT-IR, Raman, and UV-Vis spectroscopy. The stability of the obtained samples under solar irradiation for skin protection and regeneration was analyzed. Then, the hydrogel composites were assayed in vitro by immersing them in simulated body fluid and exposing them to solar simulator radiation for 10 min. The samples were found to be stable under solar light, and a thin apatite layer covered the surface of the sample with the two biopolymers and titanium dioxide. The in vitro cell viability assay suggested that the anatase phase in alginate and chitosan-alginate hydrogel composites have a positive impact.

Ultralight molybdenite-doped and phosphate rich alginate composites exhibiting superb chelating ability for UO22+: Adsorption thermodynamics, kinetics and mechanistic evaluation

In the present research work, molybdenite-doped and phosphate-rich alginate composites (MDPA) were developed for uranium removal from aqueous medium and characterized through different analytical techniques such as XPS, FTIR, XRD, SEM-EDS, and elemental mapping. The mass ratio of molybdenite in different MDPA hydrogel beads was optimized, and it was concluded that MDPA-II material (having 22.5% w/w MoS2) has superb chelating ability for UO22+ ions from aqueous solution. The XPS data showed the involvement of S coordination with UO22+ species. It proves that the UO22+ ions bonded to MoS2 surfaces by forming a U-S bond. Moreover, phosphate (OPO3-) group of phytic acid and SMo=S linkages of molybdenite reinforced inner-spherical complexation with UO22+ ions. Kinetics followed pseudo-second-order rate model (R2≈0.99) and equilibrium sorption data found in close agreement with the Langmuir and Temkin models (R2≈0.99). The qm (mg/g) at 298 K was found to be 311.16±7.76 mg/g at optimized pH of 4.5. The study shows the improved sorption performance of MDPA-II hydrogel beads for the uranium competitive recovery.

Functionalized Chitosan and Alginate Composite Hydrogel-Immobilized Laccase with Sustainable Biocatalysts for the Effective Removal of Organic Pollutant Bisphenol A

The immobilization of enzymes is an important strategy to improve their stability and reusability. Enzyme immobilization technology has broad application prospects in biotechnology, biochemistry, environmental remediation, and other fields. In this study, composites of chitosan (CS) and sodium alginate (SA) with Cu2+ forming a double-network crosslinked structure of hydrogels were prepared and used for the immobilization of laccase. Fourier infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy tests revealed that laccase molecules were immobilized on the composite hydrogel surface by a covalent bonding method. Compared to free laccase, the pH, temperature, and storage stability of the immobilized laccase were markedly improved. In addition, the immobilized laccase could be easily separated from the reaction system and reused, and it maintained 81.6% of its initial viability after six cycles of use. Bisphenol A (BPA) in polluted water was efficiently degraded using immobilized laccase, and the factors affecting the degradation efficiency were analyzed. Under the optimal conditions, the BPA removal was greater than 82%, and the addition of a small amount of ABTS had a significant effect on BPA degradation, with a removal rate of up to 99.1%. Experimental results indicated that immobilized laccases had enormous potential in actual industrial applications.

On the performance of Sargassum-derived calcium alginate ion exchange resins for Pb2+ adsorption: batch and packed bed applications

Driven by climate change and human activity, Sargassum blooming rates have intensified, producing copious amount of the invasive, pelagic seaweed across the Caribbean and Latin America. Battery recycling and lead-smelter wastes have heavily polluted the environment and resulted in acute lead poisoning in children through widespread heavy metal contamination particular in East Trinidad. Our study details a comprehensive investigation into the use of Sargassum (S. natans), as a potential resource-circular feedstock for the synthesis of calcium alginate beads utilized in heavy metal adsorption, both in batch and column experiments. Here, ionic cross-linking of extracted sodium alginate with calcium chloride was utilized to create functional ion-exchange beads. Given the low quality of alginates extracted from Sargassum which produce poor morphological beads, composite beads in conjunction with graphene oxide and acrylamide were used to improve fabrication. Stand-alone calcium alginate beads exhibited superior Pb2+ adsorption, with a capacity of 213 mg g−1 at 20 °C and pH 3.5, surpassing composite and commercial resins. Additives like acrylamide and graphene oxide in composite alginate resins led to a 21–40% decrease in Pb2+ adsorption due to reduced active sites. Column operations confirmed Alginate systems’ practicality, with 20–24% longer operating times, 15 times lower adsorbent mass on scale-up and 206% smaller column diameters compared to commercial counterparts. Ultimately, this study advocates for Sargassum-based Alginate ion-exchange beads as a bio-based alternative in Trinidad and developing nations for dealing with heavy metal ion waste, offering superior heavy metal adsorption performance and supporting resource circularity.Graphical

Denitrification enhanced by composite carbon sources in AAO-biofilter: Efficiency and metagenomics research

Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor. An economical solid carbon source was developed by composition of polyvinyl alcohol, sodium alginate, and corncob, which was utilized as external carbon source in the anaerobic anoxic oxic (AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage, and the nitrogen removal was remarkably improved from 63.2% to 96.5%. Furthermore, the effluent chemical oxygen demand maintained at 35 mg/L or even lower, and the total nitrogen was reduced to less than 2 mg/L. Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides, respectively. The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO3−-N to NO2−-N conversion in both AAO and the biofilter reactors, thus enabled stable reaction. The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abundance of genes related to the tricarboxylic acid cycle, and then guaranteed efficient carbon metabolism. The results indicate that the composite carbon source is feasible for denitrification enhancement of AAO-biofilter, which contribute to the theoretical foundation for practical nitrogen removal application.

Alginate-Based Encapsulation Fabrication Technique for Drug Delivery: An Updated Review of Particle Type, Formulation Technique, Pharmaceutical Ingredient, and Targeted Delivery System.

Alginate is a natural biopolymer widely studied for pharmaceutical applications due to its biocompatibility, low toxicity, and mild gelation abilities. This review summarizes recent advances in alginate-based encapsulation systems for targeted drug delivery. Alginate formulations like microparticles, nanoparticles, microgels, and composites fabricated by methods including ionic gelation, emulsification, spray drying, and freeze drying enable tailored drug loading, enhanced stability, and sustained release kinetics. Alginate microspheres prepared by spray drying or ionic gelation provide gastric protection and colon-targeted release of orally delivered drugs. Alginate nanoparticles exhibit enhanced cellular uptake and tumor-targeting capabilities through the enhanced permeation and retention effect. Crosslinked alginate microgels allow high drug loading and controlled release profiles. Composite alginate gels with cellulose, chitosan, or inorganic nanomaterials display improved mechanical properties, mucoadhesion, and tunable release kinetics. Alginate-based wound dressings containing antimicrobial nanoparticles promote healing of burns and chronic wounds through sustained topical delivery. Although alginate is well-established as a pharmaceutical excipient, more extensive in vivo testing is needed to assess clinical safety and efficacy of emerging formulations prior to human trials. Future opportunities include engineered systems combining stimuli-responsiveness, active targeting, and diagnostic capabilities. In summary, this review discusses recent advances in alginate encapsulation techniques for oral, transdermal, and intravenous delivery, with an emphasis on approaches enabling targeted and sustained drug release for enhanced therapeutic outcomes.

Production of letrozole-loaded alginate oxide-gelatin microgels using microfluidic systems for drug delivery applications

Microfluidic systems are capable of producing microgels with a monodisperse size distribution and a spherical shape due to their laminar flow and superior flow. A significant challenge in producing these drug-carrying microgels is simultaneous drug loading into microgels. Various factors such as the type of polymer, the type of drug, the volume ratio of the drug to the polymer, and the geometry of the microfluidic system used to generate microgels can effectively address these challenges.The overall goal of this study was to produce mono-disperse drug-carrying microgels capable of controlled drug release. To achieve this goal, this study used a stream-focused microfluidic chip containing a coating current to prevent chip clogging. Alginate oxide was synthesized with a 30 % oxidation percentage. Alginate oxide, gelatin, and compositions of them with volume ratios of 50–50, 70–30, and 30–70, by determining their appropriate weight percentage, were used for the controlled release of letrozole. The properties of the produced microgels were measured through various tests such as drug release test, loading percentage, SEM, FTIR, swelling ratio, and dimensional stability.It was found that microgels made of a combination of alginate oxide-gelatin with volume ratios of 70–30 had a good swelling ratio and structural stability. The drug loading percentages for alginate, alginate oxide, and alginate oxide-gelatin with volume ratios of 50–50 and 30–70, respectively, were 56 %, 68 %, and 66 %, 61 % and the alginate oxide-gelatin with a volume ratio of 70–30 compared to other samples had over 70 % drug loading percentages. Furthermore, samples of alginate, alginate oxide, and alginate oxide-gelatin with volume ratios of 50–50 and 30–70 had 94 %, 63 %, 56 %, and 68 % drug release in 13 days, respectively. However, alginate oxide-gelatin with a volume ratio of 70–30 had a release rate of about 50 % in 13 days, which is a more controlled release for letrozole compared to the volume ratios of 50–50 and 30–70. Examining the drug release profile, it was concluded that drug release follows the Higuchi model and therefore follows Fick's first law of diffusion. It can be concluded that the combination of alginate oxide-gelatin produces more suitable microgels than alginate and alginate oxide for the controlled-release of letrozole. A comparison of microgels of alginate oxide and gelatin with volume ratios of 50–50 and 70–30 had better results for the cytotoxicity study compared to other samples.

New insight into the effect of layer-by-layer & in-situ growth of MOF on alginate vs preformed MOF mixed alginate composites on dye adsorption

Over the past years, the processing of metal–organic frameworks (MOFs) into body-shaped materials has received remarkable research interest to overcome the difficulties of using MOFs in powder form for advanced applications. In this work, shaped MOF-biopolymer composites are prepared from Iron (Fe), trimesic acid (BTC) for the MOF named Fe-BTC and sodium alginate as biopolymer using different strategies including the conventional mixed phases, the in-situ growth and layer-by-layer synthetic strategies to highlight the role of each method for the accessibility of active sites and determine which one is better for the adsorption capability. The obtained samples were characterized to reveal the interaction between the biopolymer and the MOF and subsequently tested for methylene blue dye adsorption to elucidate the effect of each strategy on the adsorption performance. The results indicated that the layer-by-layer synthetic strategy showed better accessibility for the active sites and thus an enhanced adsorption performance of the dye achieving 88.779 mg/g, surpassing the efficiency of the other strategies.