Papers by Keyword: Alginate

Abstract: This article describes the development and characterization of a curcumin-loaded alginate-xanthan gum hydrogel, designed to provide both antibacterial activity and controlled drug release.The hydrogel formulation consisted of 4% (w/v) alginate, 4% (w/v) xanthan gum, and 500 μg/mL of curcumin. Sterilization was achieved through ethanol immersion, UV irradiation, and autoclaving, with the latter two methods proving to be the most effective in maintaining long-term sterility. Antibacterial efficacy was tested against Staphylococcus aureus, demonstrating a significant inhibition zone around the hydrogel. The curcumin release profile indicated a sustained release over 72 hours, suggesting its suitability for prolonged antibacterial applications.

Abstract: Hydrogels, a type of polymer, can be synthesized from both natural and synthetic sources, including some biopolymers like alginate and chitosan, making them particularly interesting for biomedical applications. The popularity of hydrogels in the medical field is due to their high-water content, flexibility, and biocompatibility. Hydrogels, which can swell in a hydrated state, are capable of controlling the release of active substances in pharmaceutical and biomedical applications. Alginate and chitosan exhibit polyanionic and polycationic properties when dissolved under appropriate conditions, allowing them to interact with each other. This interaction occurs through the carbonyl groups of alginates and the amino groups of chitosan. Alginate also has the advantages of being non-toxic, biodegradable, biocompatible, and non-allergenic. Therefore, these two materials readily form polyelectrolyte complexes. The use of calcium chloride in producing hydrogels is due to its ability to perform ionic cross-linking on polymers such as alginate. Calcium chloride reacts with the carboxylate groups in alginate, forming stable cross-links between polymer chains. This cross-linking process results in a three-dimensional network that provides structure and stability to the hydrogel. The benefits of adding CaCl₂, in addition to facilitating cross-linking, include increasing the viscosity of the alginate solution, which enhances the formation of the alginate matrix. This study demonstrates that the ratio of chitosan to alginate significantly influences the properties of the resulting hydrogel, impacting its swelling ratio, stability, and ultimately, its potential for biomedical applications. Specifically, the optimal ratio of 5A:1C exhibited superior swelling and gel fraction characteristics, suggesting its potential suitability for controlled drug delivery systems. The successful cross-linking confirmed by FTIR analysis further strengthens the viability of this specific composition for biomedical applications.

Abstract: Flexible and wearable electronics are increasingly popular and utilized in various forms. Batteries have become essential as an energy source for wearable electronics. To meet demands of such electronics, these batteries must remain flexible, lightweight, possess good electrochemical performance, customizable shape, and ensure safety. Zinc-ion batteries (ZIBs) have emerged as a promising energy source for these applications. However, ZIBs encounter challenges due to the lack of flexible electrolytes. Polyacrylamide (PAM) is a polymer widely used as gel polymer electrolytes (GPEs) owing to its versatile electrical conductivity and excellent flexibility. However, PAM alone lacks the mechanical strength required to support flexible and wearable electronics adequately. To address this limitation, alginate (Alg), a polysaccharide with good compatibility with PAM, is incorporated in varying concentrations (0-3 %wt.) to form interpenetrating networks (IPN) hydrogels, with a chemical network of PAM and a physical network of alginate to enhance the overall mechanical properties. Following this, the 3D-printed PAM/Alg hydrogels are immerged in a 2M ZnSO₄ electrolyte to create PAM/Alg gel polymer electrolytes (PAM/Alg-GPEs). This process significantly improves the mechanical properties of PAM/Alg-GPEs. Subsequently, the ionic conductivity of these 3D-printed PAM/Alg-GPEs is evaluated using electrochemical impedance spectroscopy (EIS). The results demonstrate that PAM/Alg-GPEs exhibit the desired flexibility along with sufficient electrochemical performance, making them promising candidates for use as wearable electrolytes in zinc-ion batteries.

Abstract: The main objective of this study was to characterize and investigate the performance of sodium alginate (SA)-based composite beads as adsorbents for manganese removal from the aqueous solution. In this study, 2% (w/v) of sodium alginate solution was prepared. The SA beads, SA-PCC (SA-P) beads, SA-BMnO (SA-B) beads, and SA-PCC-BMnO (SA-PB) beads were formed by mixing with ionic gelation in a crosslink solution of calcium chloride (CaCl₂). The composite beads were characterized using FESEM and thermogravitmetry analysis (TGA). According to FESEM micrographs, all the adsorbents were spherical in shape, with an average diameter of 1.40 mm to 1.50 mm. The results of TGA demonstrated that SA-PB beads had improved thermal stability and exhibited the highest manganese removal efficiency, with a percentage of removal of 96.14%.

Abstract: Synthesis of colloidal silver nanoparticles has been successfully conducted through the chemical reduction technique. The synthesis used AgNO₃, NaOH, and alginate as the precursor, accelerator reagent, and reducing agent and stabilizer, respectively. The effects of heating temperature, reaction time, accelerator concentration, and precursor concentration were investigated according to the localized surface plasmon resonance (LSPR) phenomenon using a UV-Vis spectrophotometer. The nanoparticle size distribution was observed via a Particle Size Analyzer (PSA). The stability of silver nanoparticles was studied for 8 weeks based on the LSPR phenomenon. Then, their antibacterial performance toward S. Aureus ATCC 25923 and E. Coli ATCC 25922 was examined. The results showed the absorbance intensities representing the number of silver nanoparticles formed were influenced by temperature, reaction time, NaOH concentration, and AgNO₃ concentration. At 50°C heating, the optimum synthesis of silver nanoparticles was achieved at 50 min with a NaOH concentration of 0.013M. The higher AgNO₃ concentration resulted in a greater concentration of silver nanoparticles produced. From the PSA characterization, the average particle sizes for the samples were 1.82 nm and 1.30 nm for AgNO₃ concentrations (% w/w; AgNO₃/Alginate) of 1.6% and 2.4%, respectively. Based on the LSPR phenomenon, colloidal silver nanoparticles were stable in storage for 8 weeks at room temperature. The increase in the concentration of silver nanoparticles within colloidal could enhance antibacterial performance against S. Aureus and E. Coli. Accordingly, silver nanoparticles synthesized with alginate as a stabilizer have the potential as an antibacterial compound for medical applications.

Abstract: In this work, the Cu-alginate/graphene aerogels were prepared by using alginate, graphene and copper chloride as precursors by a freeze-drying process. Finally, N-doped carbon aerogels supported by Cu nanoparticles (NPs) (Cu/N-CAs) were obtained through annealing in the NH₃ atmosphere. The morphology, microstructures, specific surface area, and pore size distribution were studied by SEM, XRD, and BET analysis. The results showed that a significant amount of Cu NPs were uniformly disseminated on the aerogels’ surface, and the catalysts’ specific surface area reached 141 m²/g. Electrochemical tests revealed good catalytic capabilities for the oxygen reduction reaction (ORR) of the as-obtained Cu/N-CAs. Compared to the commercial 20%Pt/C, the Cu/N-CAs exhibited comparable catalytic performance, superior catalytic stability and methanol resistance. The transfer of 3.94 electrons indicated that the Cu/N-CAs were undergoing a four-electron (4e^-) ORR process.

Abstract: Cherry tomatoes have many health benefits and have high economic value. However, cherry tomatoes are perishable and short lived. To protect and maintain the quality of cherry tomatoes, you can apply an edible coating. The materials used in this study were jackfruit seed starch, alginate, and ZnO nanoparticles. This study aims to determine the effect of edible coating on jackfruit seed starch and alginate incorporating ZnO nanoparticles applied to cherry tomatoes in terms of antibacterial activity and shelf life. Variations in the treatment in this study were edible coating materials for jackfruit seed starch and alginate, and the concentration of ZnO nanoparticles (0%; 5%; 10%; 15%). Antibacterial activity was analyzed against E. coli and S. aureus bacteria. The results showed that the edible coating of jackfruit seed starch with 10% and 15% ZnO nanoparticles incorporation was able to form an inhibition zone against E. coli bacteria, while the 5%, 10%, and 15% ZnO nanoparticle variations were able to form an inhibition zone against S bacteria. aureus. In edible coating alginate with 15% ZnO nanoparticles incorporation was able to form an inhibition zone against E. coli bacteria, whereas in all variations of ZnO nanoparticles it was able to form an inhibition zone against S. aureus bacteria. The addition of ZnO nanoparticles proved the formation of a larger bacterial inhibition zone compared to edible coatings without ZnO nanoparticles. The results also showed that cherry tomatoes coated with an edible coating of jackfruit seed starch and alginate with a variation of ZnO nanoparticles had a longer shelf life compared to cherry tomatoes that were not coated with an edible coating.

Abstract: Alginate impression material is a material that is commonly used to print dentures. This material is made from alginate. The properties of this material are rubbery, elastic, and not easily deformed so it can be applied as a bolus. This study aims to determine the tissue equivalence of this material by looking at aspects of the effective atomic number and radiation mass attenuation coefficient. To determine the effective atomic number, we used the EDX results from the SEM machine and input the concentration data of each element from alginate gel with 20% water content into the Autozeff software. The radiation mass attenuation coefficient is simulated by calculations involving each element’s concentration, then confirmed by CT-Number obtained from CT-Scan images. We obtained an effective atomic number and mass attenuation coefficient from the calculation results, which are described as a function of photon energy. Based on the results obtained, it can be concluded that the bolus made from alginate impression material is equivalent to soft tissue and breast tissue.

Abstract: Chitosan/Alginate Nanoparticles (CANPs) were produced via microemulsion method. SEM images captured that CANPs has rough, irregular, and porous surfaces. The particle sizes were in the range of 1-15 nm with an average diameter of 8.31 nm. CANPs were applied for trace metals removal. Optimum adsorption capacity of Zn(II) and Cu(II) were 8.144 and 5.582 mg g^-1, respectively. Kinetic studies show that the adsorption of Zn(II) and Cu(II) onto CANPs fitted pseudo second order model. Isotherm studies determined that the sorption followed Dubinin-radushkevich model. Zn(II) adsorbed CANPs (Zn/CANPs) and Cu(II) adsorbed CANPs (Cu/CANPs) were investigate their antibacterial activity againts E. coli and S. aureus. Zone of Inhibition (ZOI) of Zn/CANPs were 19.3 mm (E. coli) and 17.5 mm (S. aureus). ZOI of Cu/CANPs were 14.17 mm (E. coli) and 10.75 mm (S. aureus). The results revealed that CANPs were a promising bifunctional material for metals removal and has good antibacterial activity.

Abstract: Alginate is natural biodegradable polymers often used for wound treatments and drug delivery purposes. Due to thestructural characteristics, alginate polymers are able to form hydrogel. Alginate nanoparticles are obtained by diverse methodologies and the physical and chemical properties can be affected by production techniques and the molecules incorporated. Alginate possesses unique bioactivities such as biocompatibility, biodegradability, hydrophilicity and non-toxicity, so it has great potential for biomedical applications. Alginate based hydrogels and nanoparticles carrying active compounds are able to supply the optimal environments for wound healing and controlled drug administration including targeted or localized drug-delivery systems. In this review, the recent researches about the alginate and alginate-complex nanoparticles as potential tools for wound dressing membrane and drug delivery carriers are studied.