Extraction and In Vitro Skincare Effect Assessment of Polysaccharides Extract from the Roots of Abelmoschus manihot (L.).

Obtaining high-added value compounds from agricultural waste receives increasing attention, as it can both improve resource utilization efficiency and reduce waste generation. In this study, polysaccharides are extracted from the discarded roots of Abelmoschus manihot (L.) by the high-efficiency ultrasound-assisted extraction (UAE). The optimized condition was determined as solid-liquid ratio SL ratio = 1:20, temperature T = 30 °C and time T = 40 min, achieving an extraction yield of 13.41%. Composition analysis revealed that glucose (Glc, 44.65%), rhamnose (Rha, 26.30%), galacturonic acid (GalA, 12.50%) and galactose (Gal, 9.86%) are the major monosaccharides of the extract. The extract showed a low degree of esterification (DE) value of 40.95%, and its Fourier-transform infrared (FT-IR) spectrum exhibited several characteristic peaks of polysaccharides. Inspired by the wide cosmetic applications of polysaccharides, the skincare effect of the extract was evaluated via the moisture retention, total phenolic content (TPC) quantification, 2,2-Diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging activity, anti-hyaluronidase and anti-elastase activity experiments. The extract solutions demonstrated a 48 h moisture retention rate of 10.75%, which is superior to that of commercially available moisturizer hyaluronic acid (HA). Moreover, both the TPC value of 16.16 mg GAE/g (dw) and DPPH-free radical scavenging activity of 89.20% at the concentration of 2 mg/mL indicated the strong anti-oxidant properties of the extract. Furthermore, the anti-hyaluronidase activity and moderate anti-elastase activity were determined as 72.16% and 42.02%, respectively. In general, in vitro skincare effect experiments suggest moisturizing, anti-oxidant, anti-radical and anti-aging activities of the A. manihot root extract, indicating its potential applications in the cosmetic industry.

Physicochemical properties and fractal characterizations of the functionalized porous clinoptilolites for controlling alginate delivery in growing cauliflower and leaf mustard.

Using natural clinoptilolite (NCP) as a carrier and alginate (Alg)-calcium as an active species, the porous silicon calcium alginate nanocomposite (Alg-Ca-NCP) was successfully fabricated via adsorption-covalence-hydrogen bond. Its structural features and physicochemical properties were detailed investigated by various characterizations. The results indicated that Alg-Ca-NCP presented the disordered lamellar structures with approximately uniform particles in size of 300-500 nm. Specially, their surface fractal evolutions between the irregular roughness and dense structures were demonstrated via the SAXS patterns. The results elucidated that the abundant micropores of NCP were beneficial for unrestricted diffusing of Alg-Ca, which was conducive to facilitate a higher loading and sustainable releasing. The Ca content of leaf mustard treated with Alg-Ca-NCP-0.5 was 484.5 mg/100g on the 21st day, higher than that by water (CK) and CaCl2 solution treatments, respectively. Meanwhile, the prepared Alg-Ca-NCPs presented the obvious anti-aging effects on peroxidase drought stress of mustard leaves. These demonstrations provided a simple and effective method to synthesize Alg-Ca-NCPs as delivery nanocomposites, which is useful to improve the weak absorption and low utilization of calcium alginate by plants.

Evaluation of alginate-coated ß-tricalcium phosphate fiber scaffold for cell culture.

Ex vivo tissue engineering is an effective therapeutic approach for the treatment of severe cartilage diseases that require tissue replenishment or replacement. This strategy demands scaffolds that are durable enough for long-term cell culture to form artificial tissue. Additionally, such scaffolds must be biocompatible to prevent the transplanted matrix from taking a toll on the patient's body. From the viewpoint of structure and bio-absorbability, a ß-tricalcium phosphate (ß-TCP) fiber scaffold (ßTFS) is expected to serve as a good scaffold for tissue engineering. However, the fragility and high solubility of ß-TCP fibers make this matrix unsuitable for long-term cell culture. To solve this problem, we developed an alginate-coated ß-TCP fiber scaffold (ßTFS-Alg). To assess cell proliferation and differentiation in the presence of ßTFS-Alg, we characterized ATDC5 cells, a chondrocyte-like cell line, when grown in this matrix. We found that alginate coated the surface of ßTFS fiber and suppressed the elution of Ca2+ from ß-TCP fibers. Due to the decreased solubility of ßTFS-Alg compared with ß-TCP, the former provided an improved scaffold for long-term cell culture. Additionally, we observed superior cell proliferation and upregulation of chondrogenesis marker genes in ATDC5 cells cultured in ßTFS-Alg. These results suggest that ßTFS-Alg is suitable for application in tissue culture.

Role of galacturonic acid in acrylamide formation: Insights from structural analysis.

Acrylamide (AA) is a neoformed compound in heated foods, mainly produced between asparagine (Asn) and glucose (Glc) during the Maillard reaction. Galacturonic acid (GalA), the major component of pectin, exhibits high activity in AA formation. This study investigated the pathway for AA formation between GalA and Asn. Three possible pathways were proposed: 1) The carbonyl group of GalA directly interacts with Asn to produce AA; 2) GalA undergoes an oxidative cleavage reaction to release α-dicarbonyl compounds, which subsequently leads to AA production; 3) 5-formyl-2-furancarboxylic acid, the thermal degradation product of GalA, reacts with Asn to generate AA. Structural analysis revealed that the COOH group in GalA accelerated intramolecular protonation and electron transfer processes, thereby increasing the formation of AA precursors such as decarboxylated Schiff base and α-dicarbonyl compounds, promoting AA formation. This study provides a theoretical basis and new insights into the formation and control of AA.

Microwave-assisted synthesis of highly sulfated mannuronate glycans as potential inhibitors against SARS-CoV-2.

Algae-based marine carbohydrate drugs are typically decorated with negative ion groups such as carboxylate and sulfate groups. However, the precise synthesis of highly sulfated alginates is challenging, thus impeding their structure-activity relationship studies. Herein we achieve a microwave-assisted synthesis of a range of highly sulfated mannuronate glycans with up to 17 sulfation sites by overcoming the incomplete sulfation due to the electrostatic repulsion of crowded polyanionic groups. Although the partially sulfated tetrasaccharide had the highest affinity for the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant, the fully sulfated octasaccharide showed the most potent interference with the binding of the RBD to angiotensin-converting enzyme 2 (ACE2) and Vero E6 cells, indicating that the sulfated oligosaccharides might inhibit the RBD binding to ACE2 in a length-dependent manner.

Electrospray Nano-Micro Composite Sodium Alginate Microspheres with Shape-Adaptive, Antibacterial, and Angiogenic Abilities for Infected Wound Healing.

Nonhealing infectious wounds, characterized by bacterial colonization, wound microenvironment destruction, and shape complexity, present an intractable problem in clinical practice. Inspired by LEGOs, building-block toys that can be assembled into desired shapes, we proposed the use of electrospray nano-micro composite sodium alginate (SA) microspheres with antibacterial and angiogenic properties to fill irregularly shaped wounds instantly. Specifically, porous poly(lactic-co-glycolic acid) (PLGA) microspheres (MSs) encapsulating basic fibroblast growth factor (bFGF) were produced by a water-in-oil-in-water double-emulsion method. Then, bFGF@MSs were blended with the SA solution containing ZIF-8 nanoparticles. The resultant solution was electrosprayed to obtain nano-micro composite microspheres (bFGF@MS/ZIF-8@SAMSs). The composite MSs' size could be regulated by PLGA MS mass proportion and electrospray voltage. Moreover, bFGF, a potent angiogenic agent, and ZIF-8, bactericidal nanoparticles, were found to release from bFGF@MS/ZIF-8@SAMSs in a controlled and sustainable manner, which promoted cell proliferation, migration, and tube formation and killed bacteria. Through experimentation on rat models, bFGF@MS/ZIF-8@SAMSs were revealed to adapt to wound shapes and accelerate infected wound healing because of the synergistic effects of antibacterial and angiogenic abilities. In summation, this study developed a feasible approach to prepare bioactive nano-micro MSs as building blocks that can fill irregularly shaped infected wounds and improve healing.

Varying ratios of M/G in alginate to modulate macrophages polarization and its application for wound healing in diabetic.

Alginate (SA) comprises repeating unis of ß-1, 4 linked ß-D-mannuronic acid (M) and α-L-guloronic acid (G) in varying proportions. The M/G ratio greatly impacts its anti-inflammatory properties in tissue healing wound, as less knowledge reported. This study examined the performances of both SA and SA hydrogel crosslinked with copper ions (SA-Cu) with different M/G ratios are studied. SA with higher M/G ratios stimulated macrophage migration and shifted from M0 to the pro-inflammatory Ml phenotype, while lower M/G ratios shifted from M1 to the pro-repair M2 phenotype. Furthermore, SA-Cu hydrogels with lower M/G ratios exhibited enhanced cross-linking degree, mechanical and rheological properties, as well Cu releasing rate. The reason may be attributed to a relative easy binding between Cu ions and G unit among Cu ions, M unit and G unit. In vitro cell evaluation showed that SA-Cu hydrogel with M/G ratio of 1:1 activated M2 macrophages and up-regulated anti-inflammatory cytokines expression more effectively than those of SA-Cu ratios (2:1) and (1:2). In vivo, SA-Cu hydrogel with M/G ratio of 1:1 expedited diabetic wound healing, accelerating infiltration and phenotype shift of M2 macrophages, and enhancing anti-inflammatory factors, epithelialization and collagen deposition in healing phases. This research highlights the significant role of M/G ratios in SA materials in influencing macrophage behavior and inflammatory responses, which would benefit its application field.

All-aqueous droplets-templated tailorable core-shell alginate microspheres for constructing vascularized intestinal mucosain vitromodels.

Recently,in vitromodels of intestinal mucosa have become important tools for drug screening and studying the physiology and pathology of the intestine. These models enable the examination of cellular behavior in diseased states or in reaction to alterations in the microenvironment, potentially serving as alternatives to animal models. One of the major challenges in constructing physiologically relevantin vitromodels of intestinal mucosa is the creation of three-dimensional microstructures that accurately mimic the integration of intestinal epithelium and vascularized stroma. Here, core-shell alginate (Alg) microspheres were generated to create the compartmentalized extracellular matrix microenvironment needed to simulate the epithelial and vascularized stromal compartments of the intestinal mucosa. We demonstrated that NIH-3T3 and human umbilical vein endothelial cells embedded in the core of the microspheres can proliferate and develop a vascular network, while human colorectal adenocarcinoma cells (Caco-2) can form an epithelial monolayer in the shell. Compared to Caco-2 monolayer encapsulated within the shell, the presence of the vascularized stroma enhances their proliferation and functionality. As such, our core-shell Alg microspheres provide a valuable method for generatingin vitromodels of vascularized intestinal mucosa with epithelial and vascularized stroma arranged in a spatially relevant manner and demonstrating near-physiological functionality.

Technique for Rapidly Forming Networks of Microvessel-Like Structures.

Modeling organ-blood barriers through the inclusion of microvessel networks within in vitro tissue models could lead to more physiologically accurate results, especially since organ-blood barriers are crucial to the normal function, drug transport, and disease states of vascularized organs. Microvessel networks are difficult to form, since they push the practical limits of most fabrication methods, and it is difficult to coax vascular cells to self-assemble into structures larger than capillaries. Here, we present a method for rapidly forming networks of microvessel-like structures using sacrificial alginate structures. Specifically, we encapsulated endothelial cells within short alginate threads, and then embedded them in collagen gel. Following enzymatic degradation of the alginate, the collagen gel contained a network of hollow channels seeded with cells, all surrounding a perfusable central channel. This method uses a 3D-printed coaxial extruder and syringe pumps to generate short threads in a way that is repeatable and easily transferrable to other labs. The cell-laden, sacrificial alginate threads can be frozen after fabrication and thawed before embedding without significant loss of cell viability. The ability to freeze the threads enables future scale-up and ease of use. Within millifluidic devices that restrict access to media, the threads enhance cell survival under static conditions. These results indicate the potential for use of this method in a range of tissue engineering applications.

Bioremediation of 2,4,6-trichlorophenol by extracellular enzymes of white rot fungi immobilized with sodium alginate/hydroxyapatite/chitosan microspheres.

Hydroxyapatite, a calcium phosphate biomass material known for its excellent biocompatibility, holds promising applications in water, soil, and air treatment. Sodium alginate/hydroxyapatite/chitosan (SA-HA-CS) microspheres were synthesized by cross-linking sodium alginate with calcium chloride. These microspheres were carriers for immobilizing extracellular crude enzymes from white rot fungi through adsorption, facilitating the degradation of 2,4,6-trichlorophenol (2,4,6-TCP) in water and soil. At 50 °C, the immobilized enzyme retained 87.2% of its maximum activity, while the free enzyme activity dropped to 68.86%. Furthermore, the immobilized enzyme maintained 68.09% of its maximum activity at pH 7, surpassing the 51.16% observed for the free enzyme. Under optimal conditions (pH 5, 24 h), the immobilized enzymes demonstrated a remarkable 94.7% removal rate for 160 mg/L 2,4,6-TCP, outperforming the 62.1% achieved by free crude enzymes. The degradation of 2,4,6-TCP by immobilized and free enzymes adhered to quasi-first-order degradation kinetics. Based on LC-MS, the plausible biodegradation mechanism and reaction pathway of 2,4,6-TCP were proposed, with the primary degradation product identified as 1,2,4-trihydroxybenzene. The immobilized enzyme effectively removed 72.9% of 2,4,6-TCP from the soil within 24 h. The degradation efficiency of the immobilized enzyme varied among different soil types, exhibiting a negative correlation with soil organic matter content. These findings offer valuable insights for advancing the application of immobilized extracellular crude enzymes in 2,4,6-TCP remediation.

Interpenetrating gelatin/alginate mixed hydrogel: The simplest method to prepare an autoclavable scaffold.

The choice of sterilization method for hydrogels used for cell culture influences the ease of preparing the gel. We prepared interpenetrating gelatin/calcium alginate hydrogels containing 1% (w/v) alginate and 1-16% (w/v) gelatin by molding with the mixture of gelatin/sodium alginate solution, followed by the addition of calcium ions by incubation in calcium chloride solution. It is the simplest method to prepare autoclavable gelatin/sodium hydrogel. We measured various properties of the hydrogels including volume, Young's modulus in the compression test, storage modulus, and loss modulus in the dynamic viscoelasticity measurement. The gelatin/alginate hydrogel can be easily fabricated into any shape by this method. After autoclave treatment, the hydrogel was shrunk to smaller than the original shape in similar figures. The shape of the gelatin/alginate hydrogel can be designed into any shape with the reduction ratio of the volume. Human osteosarcoma (HOS) cells adhered to the gelatin/alginate hydrogel and then proliferated. Gelatin/calcium alginate hydrogels with a high concentration are considered to be autoclavable culture substrates because of their low deformation and gelatin elution rate after autoclaving and the high amount of cells attached to the hydrogels.

Analysis of unsaturated alginate oligosaccharides using high-performance anion exchange chromatography coupled with mass spectrometry.

Alginate is a commercially important polysaccharide composed of mannuronic acid and its C5 differential isomer guluronic acid. Comprehensive research on alginate and alginate lyases requires efficient and precise analytical methods for alginate oligosaccharides. In this research, high-performance anion exchange chromatography (HPAEC) in parallel with pulsed amperometric detection (PAD) and mass spectrometry (MS) was applied to the analysis of oligosaccharides obtained by alginate lyase. By optimizing the chromatographic conditions including mobile phase concentration, flow rate, and elution gradient, the analysis of a single sample could be completed in 30 min. Seven unsaturated alginate oligosaccharides were separated and identified through their analysis time observed with PAD, including all structurally different unsaturated disaccharides and trisaccharides. The quantitative analysis of seven oligosaccharides was performed based on the quantitative capability of PAD. The method exhibited adequate linearity and precision parameters. All the calibration curves showed good linearity at least in the concentration range of 0.002 to 0.1 mg/mL. The HPAEC-PAD/MS method provides a general and efficient online method to analyze alginate oligosaccharides.

A novel, microfluidic high-throughput single-cell encapsulation of human bone marrow mesenchymal stromal cells.

The efficacy of stem-cell therapy depends on the ability of the transplanted cells to escape early immunological reactions and to be retained at the site of transplantation. The use of tissue engineering scaffolds or injectable biomaterials as carriers has been proposed, but they still present limitations linked to a reliable manufacturing process, surgical practice and clinical outcomes. Alginate microbeads are potential candidates for the encapsulation of mesenchymal stromal cells with the aim of providing a delivery carrier suitable for minimally-invasive and scaffold-free transplantation, tissue-adhesive properties and protection from the immune response. However, the formation of stable microbeads relies on the cross-linking of alginate with divalent calcium ions at concentrations that are toxic for the cells, making control over the beads' size and a single-cell encapsulation unreliable. The present work demonstrates the efficiency of an innovative, high throughput, and reproducible microfluidic system to produce single-cell, calcium-free alginate coatings of human mesenchymal stromal cells. Among the various conditions tested, visible light and confocal microscopy following staining of the cell nuclei by DAPI showed that the microfluidic system yielded an optimal single-cell encapsulation of 2000 cells/min in 2% w/v alginate microcapsules of reproducible morphology and an average size of 28.2 ± 3.7 µm. The adhesive properties of the alginate microcapsules, the viability of the encapsulated cells and their ability to escape the alginate microcapsule were demonstrated by the relatively rapid adherence of the beads onto tissue culture plastic and the cells' ability to gradually disrupt the microcapsule shell after 24 h and proliferate. To mimic the early inflammatory response upon transplantation, the encapsulated cells were exposed to proliferating macrophages at different cell seeding densities for up to 2 days and the protection effect of the microcapsule on the cells assessed by time-lapse microscopy showing a shielding effect for up to 48 h. This work underscores the potential of microfluidic systems to precisely encapsulate cells by good manufacturing practice standards while favouring cell retention on substrates, viability and proliferation upon transplantation.

Simultaneous adsorption of chromate and arsenate onto ferrihydrite/alginate composite beads: Competition and mechanism.

Ferrihydrite is an effective adsorbent of chromate and arsenate. In order to gain insight into the application of ferrihydrite in water treatment, macroporous alginate/ferrihydrite beads, synthesized using two different methods (internal and encapsulation processes), were used in this work. The properties of the ferrihydrite were assessed using various techniques, including X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) theory, and zetametry. The results showed that the specific surface area of the ferrihydrite was 242 m2/g, and the PZC was pH8. The kinetic and isotherm adsorption properties of the ferrihydrite were evaluated in this study. The results indicate that the pseudo second-order and Freundlich models accurately describe the kinetic and isotherm adsorption properties of chromates and arsenates. For chromate removal, ferrihydrite exhibited a relatively high adsorption capacity (40.7 mgCr/g) compared to other adsorbents. However, the arsenate adsorption capacity of MFHB-SI (140.8 mgAs/g) was shown to be the most optimal. The internal synthesis process was suitable for arsenate retention due to the resulting arsenate precipitation. The competitive adsorption analyses indicated that the presence of chromate does not limit the adsorption of arsenate. However, the presence of arsenate almost completely inhibits the adsorption of chromate when the arsenate concentration is above 50 mg/L, due to the precipitation reaction of arsenate.

Adeno-Associated Virus-Encapsulated Alginate Microspheres Loaded in Collagen Gel Carriers for Localized Gene Transfer.

This work reports localized in vivo gene transfer by biodegradation of the adeno-associated virus-encapsulating alginate microspheres (AAV-AMs) loaded in collagen gel carriers. AAV-AMs are centrifugally synthesized by ejecting a mixed pre-gel solution of alginate and AAV to CaCl2 solution to form an ionically cross-linked hydrogel microsphere immediately. The AAV-AMs are able to preserve the AAV without diffusing out even after spreading them on the cells, and the AAV is released and transfected by the degradation of the alginate microsphere. In addition, AAV-AMs can be stored by cryopreservation until use. By implanting this highly convenient AAV-encapsulated hydrogel, AAV-AMs can be loaded into collagen gel carriers to fix the position of the implanted AAV-AMs and achieve localized gene transfer in vivo. In vivo experiments show that the AAV-AMs loaded in collagen gel carriers are demonstrated to release the encapsulated AAV for gene transfer in the buttocks muscles of mice. While conventional injections caused gene transfer to the entire surrounding tissue, the biodegradation of AAV-AMs shows that gene transfer is achieved locally to the muscles. This means that the proposed AAV-loaded system is shown to be a superior method for selective gene transfer.

Multichannel Multijunction Droplet Microfluidic Device to Synthesize Hydrogel Microcapsules with Different Core-Shell Structures and Adjustable Core Positions.

Core-shell hydrogel microcapsules have sparked great interest due to their unique characteristics and prospective applications in the medical, pharmaceutical, and cosmetic fields. However, complex synthetic procedures and expensive costs have limited their practical application. Herein, we designed and prepared several multichannel and multijunctional droplet microfluidic devices based on soft lithography for the effective synthesis of core-shell hydrogel microcapsules for different purposes. Additionally, two different cross-linking processes (ultraviolet (UV) exposure and interfacial polymerization) were used to synthesize different types of core-shell structured hydrogel microcapsules. Hydrogel microcapsules with gelatin methacryloyl (GelMA) as the core and polyacrylamide (PAM) as the thin shell were synthesized using UV cross-linking. Using an interfacial polymerization process, another core-shell structured microcapsule with GelMA as the core and Ca2+ cross-linked alginate with polyethylenimine (PEI) as the shell was constructed, and the core diameter and total droplet diameter were flexibly controlled by carving. Noteworthy, these hydrogel microcapsules exhibit stimuli-responsiveness and controlled release ability. Overall, a novel technique was developed to successfully synthesize various hydrogel microcapsules with core-shell microstructures. The hydrogel microcapsules possess a multilayered structure that facilitates the coassembly of cells and drugs, as well as the layered assembly of multiple drugs, to develop synergistic therapeutic regimens. These adaptable and controllable hydrogel microdroplets shall held great promise for multicell or multidrug administration as well as for high-throughput drug screening.

Assessment of calcium alginate gels as wall materials for encapsulation systems.

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 ( F G = 0.356) of sodium alginate were determined by capillary viscometry and 1 H-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 M g = 2.02 × 105 Da. An effective diffusion coefficient of water ( D eff , 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 ( k m = 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.

Development of alginate beads for precise environmental release applications: A design of experiment based approach and analysis.

Controlled release of active ingredients are important for drug delivery and more recently environmental applications including modulated dosing of chemical and biological controls. This study demonstrates the importance of investigating various material science factors that can influence the diffusion rates of alginate beads to improve and tune their performance for marine environmental applications. This investigation aimed to design a rational workflow to aid in leveraging alginate bead use as a carrier matrix for releasing a specific active agent into water. Experiments were conducted to focus on the narrow a large list of relevant material formulation parameters, which included chitosan molecular weight, chitosan concentration, calcium concentration, drop height, and bead size. Once the most relevant material preparation methods were screened, a more robust statistic Design of Experiments approach was performed and results determined the important (and unimportant) factors for increasing dye release kinetics in marine water. The process was further streamlined by narrowing the critical experimental factors to a three-level based on the prior analysis: chitosan MW, chitosan concentration, and bead size. Analysis of the collected data indicated that while chitosan MW had a negligible impact (Fstatistic = 0.22), bead size (Fstatistic = 60.33) significantly influenced the diffusion rates based on surface area. However, chitosan MW had minor effects where lower chitosan MW enabled higher product release rates. This case investigation was a novel application of the design of experiment approach towards environmental applications to understand differences in release rates to marine waters for the first time and the workflow provided also serve as the basis for researchers to optimize other environmental applications requiring optimization when it is unknown how a large number of formulation variables will impact performance in different environmental scenarios.

Ions-Induced Alginate Gelation According to Elemental Analysis and a Combinatorial Approach.

This study considers the potential of elemental analysis of polysaccharide ionotropic gels in elucidating the junction zones for different divalent cations. The developed algorithm ensures the correct separation of contributions from physically adsorbed and structure-forming ionic compounds, with the obtained results scaled to alginate C12 block. Possible versions of chain association into dimers and their subsequent integration into flat junction zones were analyzed within the framework of the "egg-box" model. The application of combinatorial analysis made it possible to derive theoretical relations to find the probability of various types of egg-box cell occurrences for alginate chains with arbitrary monomeric units ratio µ = M/G, which makes it possible to compare experimental data for alginates of different origins. Based on literature data and obtained chemical formulas, the possible correspondence of concrete biopolymer cells to those most preferable for filling by alkaline earth cations was established. The identified features of elemental composition suggest the formation of composite hydrated complexes with the participation of transition metal cations. The possibility of quantitatively assessing ordered secondary structures formed due to the physical sorption of ions and molecules from environment, correlating with the sorption capabilities of Me2+ alginate, was established.

Development and characterization of letrozole-encapsulated polymeric beads for sustained release.

The study aimed to prepare and characterize biodegradable sustained-release beads of letrozole (LTZ) for treating cancerous disease. The ionotropic gelation method was used for the preparation and calcium chloride (CaCl2) was used as a gelating agent, while chitosan (CTS) and sodium alginate (NaAlg) as biodegradable polymeric matrices in the blend hydrogel beads. The beads were characterized for their size, surface morphology, drug entrapment efficiency, drug-polymer interaction and crystallinity using different analytic techniques, including optical microscopy, Scanning Electron Microscopy (SEM), UV-spectroscopy, Fourier-transform Infrared Spectroscopy (FTIR), Thermo gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction Analysis (XRD) respectively. In vitro swelling studies were also applied to observe the response of these polymeric networks against different pH (at 1.2, 6.8 and 7.4 pH). The results from TGA and DSC exhibited that the components in the formulation possess better thermal stability. The XRD of polymeric networks displays a minor crystalline and significant amorphous nature. The SEM micrographs revealed that polymeric networks have uneven surfaces and grooves. Better swelling and in vitro outcomes were achieved at a high pH (6.8,7.4), which endorsed the pH-responsive characteristics of the prepared beads. Hence, beads based on chitosan and sodium alginate were successfully synthesized and can be used for the controlled release of letrozole.