Статті в журналах: "Chitosan beads"

1

Worthen, Andrew, Kelly Irving, and Yakov Lapitsky. "Supramolecular Strategy Effects on Chitosan Bead Stability in Acidic Media: A Comparative Study." Gels 5, no. 1 (February 25, 2019): 11. http://dx.doi.org/10.3390/gels5010011.

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Chitosan beads attract interest in diverse applications, including drug delivery, biocatalysis and water treatment. They can be formed through several supramolecular pathways, ranging from phase inversion in alkaline solutions, to the ionic crosslinking of chitosan with multivalent anions, to polyelectrolyte or surfactant/polyelectrolyte complexation. Many chitosan bead uses require control over their stability to dissolution. To help elucidate how this stability depends on the choice of supramolecular gelation chemistry, we present a comparative study of chitosan bead stability in acidic aqueous media using three common classes of supramolecular chitosan beads: (1) alkaline solution-derived beads, prepared through simple precipitation in NaOH solution; (2) ionically-crosslinked beads, prepared using tripolyphosphate (TPP); and (3) surfactant-crosslinked beads prepared via surfactant/polyelectrolyte complexation using sodium salts of dodecyl sulfate (SDS), caprate (NaC10) and laurate (NaC12). Highly variable bead stabilities with dissimilar sensitivities to pH were achieved using these methods. At low pH levels (e.g., pH 1.2), chitosan/SDS beads were the most stable, requiring roughly 2 days to dissolve. In weakly acidic media (at pH 3.0–5.0), however, chitosan/TPP beads exhibited the highest stability, remaining intact throughout the entire experiment. Beads prepared using only NaOH solution (i.e., without ionic crosslinking or surfactant complexation) were the least stable, except at pH 5.0, where the NaC10 and NaC12-derived beads dissolved slightly faster. Collectively, these findings provide further guidelines for tailoring supramolecular chitosan bead stability in acidic media.

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2

Jobin, Guy, Gilles Grondin, Geneviève Couture, and Carole Beaulieu. "Microscopic Examination of Chitosan–Polyphosphate Beads with Entrapped Spores of the Biocontrol Agent,Streptomyces melanosporofaciensEF-76." Microscopy and Microanalysis 11, no. 2 (March 8, 2005): 154–65. http://dx.doi.org/10.1017/s1431927605050142.

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Spores of the biocontrol agent,Streptomyces melanosporofaciensEF-76, were entrapped by complex coacervation in beads composed of a macromolecular complex (MC) of chitosan and polyphosphate. A proportion of spores entrapped in beads survived the entrapment procedure as shown by treating spores from chitosan beads with a dye allowing the differentiation of live and dead cells. The spore-loaded chitosan beads could be digested by a chitosanase, suggesting that, once introduced in soil, the beads would be degraded to release the biocontrol agent. Spore-loaded beads were examined by optical and scanning electron microscopy because the release of the biological agent depends on the spore distribution in the chitosan beads. The microscopic examination revealed that the beads had a porous surface and contained a network of inner microfibrils. Spores were entrapped in both the chitosan microfibrils and the bead lacuna.

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3

Steiger, Bernd G. K., and Lee D. Wilson. "Modular Chitosan-Based Adsorbents for Tunable Uptake of Sulfate from Water." International Journal of Molecular Sciences 21, no. 19 (September 27, 2020): 7130. http://dx.doi.org/10.3390/ijms21197130.

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The context of this study responds to the need for sorbent technology development to address the controlled removal of inorganic sulfate (SO42−) from saline water and the promising potential of chitosan as a carrier system for organosulfates in pharmaceutical and nutraceutical applications. This study aims to address the controlled removal of sulfate using chitosan as a sustainable biopolymer platform, where a modular synthetic approach was used for chitosan bead preparation that displays tunable sulfate uptake. The beads were prepared via phase-inversion synthesis, followed by cross-linking with glutaraldehyde, and impregnation of Ca2+ ions. The sulfate adsorption properties of the beads were studied at pH 5 and variable sulfate levels (50–1000 ppm), where beads with low cross-linking showed moderate sulfate uptake (35 mg/g), while cross-linked beads imbibed with Ca2+ had greater sulfate adsorption (140 mg/g). Bead stability, adsorption properties, and the point-of-zero charge (PZC) from 6.5 to 6.8 were found to depend on the cross-linking ratio and the presence of Ca2+. The beads were regenerated over multiple adsorption-desorption cycles to demonstrate the favorable uptake properties and bead stability. This study contributes to the development of chitosan-based adsorbent technology via a modular materials design strategy for the controlled removal of sulfate. The results of this study are relevant to diverse pharmaceutical and nutraceutical applications that range from the controlled removal of dextran sulfate from water to the controlled release of chondroitin sulfate.

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4

Mahasawat, Pawika, Ketsarin Hlongkeaw, and Sutthida Charoenrit. "Effect of Chitosan and Alginate Concentration on Size and Bactericidal Activity against Escherichia coli of Chitosan/Alginate/Silver Nanoparticle Beads." Applied Mechanics and Materials 855 (October 2016): 54–59. http://dx.doi.org/10.4028/www.scientific.net/amm.855.54.

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Silver nanoparticles have been used in combination with biological polymer for antibacterial application. This study prepared chitosan/alginate/AgNP beads with varying chitosan and alginate concentration to use as an antibacterial material. The sizes of neat beads were larger (1286 ± 172, 1344 ± 142 and 1529 ± 73 μm for C1, C2 and C3, respectively) with increasing concentration of chitosan and alginate. Moreover, smaller beads were observed for the chitosan/alginate/AgNP beads, in which their sizes were 1151 ± 201, 1261 ± 204 and 1324 ± 198 µm for S1, S2 and S3, respectively, when compared to the chitosan/alginate beads. Furthermore, the minimum bactericidal concentration (MBC) of chitosan/alginate/AgNP beads against E. coli was 10, 10 and 3 µg/ml for S1, S2 and S3, respectively. This study suggested that the beads with the higher concentration of chitosan and alginate resulted in the greater bactericidal activity. Therefore, the chitosan/alginate/AgNP beads prepared in this study showed the bactericidal activity which can be used for antibacterial application.

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5

Wang, Taoran, and Yangchao Luo. "Chitosan Hydrogel Beads Functionalized with Thymol-Loaded Solid Lipid–Polymer Hybrid Nanoparticles." International Journal of Molecular Sciences 19, no. 10 (October 11, 2018): 3112. http://dx.doi.org/10.3390/ijms19103112.

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In this study, the innovative and multifunctional nanoparticles–hydrogel nanocomposites made with chitosan hydrogel beads and solid lipid–polymer hybrid nanoparticles (SLPN) were prepared through conjugation between SLPN and chitosan beads. The SLPNs were first fabricated via coating the bovine serum albumin (BSA)-emulsified solid lipid nanoparticles with oxidized dextran. The aldehyde groups of the oxidized dextran on the surface of the SLPN enabled an in situ conjugation with the chitosan beads through the Schiff base linkage. The obtained nano-on-beads composite exhibited a spherical shape with a homogeneous size distribution. The successful conjugation of SLPN on the chitosan beads was confirmed by a Fourier transform infrared spectroscopy and a scanning electron microscope. The effects of the beads dosage (50, 100, 200, and 300 beads) and the incubation duration (30, 60, 90, 120, and 150 min) on the conjugation efficiency of SLPN onto the beads were comprehensively optimized. The optimal formulations were found to be a 200 bead dosage, with 30–90 min incubation duration groups. The optimal formulations were then used to encapsulate thymol, an antibacterial agent, which was studied as a model compound. After encapsulation, the thymol exhibited sustained release profiles in the phosphate buffer saline. The as-prepared nanoparticles–hydrogel nanocomposites reported in this proof-of-concept study hold promising features as a controlled-release antibacterial approach for improving food safety.

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6

Sabarudin, Akhmad, and Armeida D. R. Madjid. "Preparation and Kinetic Studies of Cross-Linked Chitosan Beads Using Dual Crosslinkers of Tripolyphosphate and Epichlorohydrin for Adsorption of Methyl Orange." Scientific World Journal 2021 (February 17, 2021): 1–11. http://dx.doi.org/10.1155/2021/6648457.

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Preparation of cross-linked chitosan beads using dual crosslinkers of tripolyphosphate (TPP) and epichlorohydrin (ECH) for the adsorption and kinetic studies of methyl orange (MO) had been carried out. FTIR spectra showed that TPP could act as the protecting agent of the NH2 group of chitosan and ECH reacted with the primary hydroxyl group of chitosan. Various concentrations of TPP, ECH, and immersing time in the TPP solution for bead formation were studied. The effect of pH and kinetics of adsorption were investigated to define the mechanism of adsorption and rate-limiting step. As a result, pH 3, 10% (w/v) TPP, 5% (v/v) ECH, and 12 h immersing time in TPP were selected as the optimum conditions for preparing the beads as indicated by the highest adsorption amount of MO. The cross-linked chitosan beads’ adsorption capacity for MO under optimum condition was found to be 79.55 mg/g with the adsorption rate constant (k) of 1.29 × 10−3/min. Furthermore, it was found that a low concentration of ECH could maintain the stability of chitosan in acidic conditions, whereas the concentration of TPP and immersing time controlled pore size and morphology of chitosan beads. The mechanism of adsorption of MO was controlled by the pore and rigidity of cross-linked chitosan beads. Bulk diffusion acted as a rate-limiting step, and a high concentration of MO inhibited diffusion and adsorption itself.

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7

Li, N., and R. Bai. "Development of chitosan-based granular adsorbents for enhanced and selective adsorption performance in heavy metal removal." Water Science and Technology 54, no. 10 (November 1, 2006): 103–13. http://dx.doi.org/10.2166/wst.2006.736.

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Novel chitosan-based granular adsorbents were developed for enhanced and selective separation of heavy metal ions. The research included the synthesis of chitosan hydrogel beads, the cross-linking of the hydrogel beads with ethylene glycol diglycidyl ether (EGDE) in a conventional and a novel amine-shielded method, the functionalization of the chitosan beads through surface grafting of polyacrylamide via a surface-initiated atom transfer radical polymerization (ATRP) method, and the examination of the adsorption performance of the various types of chitosan beads in the removal of heavy metal ions. It was found that chitosan beads were effective in heavy metal adsorption, the conventional cross-linking method improved the acidic stability of the beads but reduced their adsorption capacity, the novel amine-shielded cross-linking method retained the good adsorption capacity while it improved the acidic stability of the beads, and the grafting of polyacrylamide on chitosan beads not only enhanced the adsorption capacity but also provided the beads with excellent selectivity for mercury over lead ions. XPS analyses indicated that the adsorption of metal ions on chitosan beads was mainly attributed to the amine groups of chitosan, the novel amine-shielded cross-linking method preserved most of the amine groups from being consumed by the cross-linking process and hence improved the adsorption capacity of the cross-linked chitosan beads, and the many amide groups from the polyacrylamide grafted on the chitosan beads increased the adsorption capacity and also made possible selective adsorption of mercury ions because the amide groups can form covalent bonds with mercury ions.

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8

Li, Hao, Jin Wang, Yu Luo, Bo Bai, and Fangli Cao. "pH-Responsive Eco-Friendly Chitosan–Chlorella Hydrogel Beads for Water Retention and Controlled Release of Humic Acid." Water 14, no. 8 (April 8, 2022): 1190. http://dx.doi.org/10.3390/w14081190.

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For improving the mechanical strength of controlled release fertilizer (CRF) hydrogels, a novel material of Chlorella was employed as a bio-based filler to prepare chitosan–chlorella hydrogel beads with physical crosslink method. Here, the synthesis mechanism was investigated, and the chitosan–chlorella hydrogel beads exhibited enhanced mechanical stability under centrifugation and sonication than pure chitosan hydrogel beads. Chlorella brought more abundant functional groups to original chitosan hydrogel, hence, chitosan–chlorella hydrogel beads represented greater sensitivity and controllable response to external factors including pH, salt solution, temperature. In distilled water, the hydrogel beads with 40 wt% Chlorella reached the largest water absorption ratio of 42.92 g/g. Moreover, the mechanism and kinetics process of swelling behavior of the chitosan–chlorella hydrogel beads were evaluated, and the loading and releasing of humic acid by the hydrogel beads as a carrier material were pH-dependent and adjustable, which exhibit the potential of chitosan–chlorella hydrogel beads in the field of controlled release carrier biomaterials.

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9

Wulan, Putri, Yuni Kusumastuti, and Agus Prasetya. "Removal of Fe (II) from Aqueous Solution by Chitosan Activated Carbon Composite Beads." Applied Mechanics and Materials 898 (May 2020): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amm.898.3.

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The high levels of Fe2+ metal ion in water can be reduced by adsorption process. The adsorbent used is a composite of chitosan activated carbon. The composites were prepared by adding 1.5 g of activated carbon into chitosan solution 1.5% (w/v). The gels of chitosan activated carbon were then dropped into a 2.8% NaOH solution mixture to produce composite beads. The beads were neutralized using aquadest and dried in an oven at 50oC for 2 hours. The dried bead was used as adsorbent. The adsorption process was carried out with erlenmeyer in shaker bath with 0.5 g, 1 g, and 1.5 g at 25oC, 35oC and 45oC in 50 mL solution of Fe2+ metal ion having concentration of 10 ppm. Sample were taken in 5, 10, 20, 40 60, 80 and 120 min. Adsorbent were characterized by SEM and EDX. The composite beads adsorbent was analyzed by SEM and EDX. SEM results show that chitosan was successfully coated on activated carbon with a porous surface structure. The EDX results show that chitosan activated carbon composite beads can absorb Fe2+ metal ions, with an adsorption capacity of 88.3% at 60 min in 1.5 g adsorbent dose.

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10

Piluarto, Bambang, Yusril Ihza Mahendra, and Novita Andarini. "HYBRID KITOSAN/BENTONIT SEBAGAI MATRIKS UNTUK PELEPASAN ION AMONIUM DALAM AIR." Jurnal Kimia Riset 1, no. 1 (June 1, 2016): 42. http://dx.doi.org/10.20473/jkr.v1i1.2441.

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AbstrakHybrid kitosan/bentonit dalam bentuk bead telah berhasil dibuat dengan berbagai rasio komposisi kitosan dan bentonit. Dalam penelitian ini, bead dari hybrid ini digunakan sebagai matriks untuk ion amonium. Bead dibuat dengan pengendapan suspensi kitosan dan bentonit menggunakan koagulan NaOH. Bead hybrid yang diperoleh dikarakterisasi daya serap air (DSA) dan pelepasan ion amonium dalam air. Hasil yang diperoleh menunjukkan bahwa bentuk bead dipengaruhi oleh kandungan bentonit dalam hybrid. Peningkatan kandungan bentonit dalam hybrid menurunkan nilai DSA, namun meningkatkan pelepasan ion amonium dalam air. Sisa basa pada permukaan bead hybrid mempengaruhi deteksi pelepasan ion amonium dalam air. Kata kunci: hybrid, bead, suspensi, daya serap air, pelepasan ion AbstractChitosan/bentonite hybrid in the form of beads was successfully prepared in various of chitosan and bentonite composition ratio. In this study, beads of hybrid play role as matrix for ammonium ions. Beads prepared by precipitation of chitosan and bentonite suspension using NaOH as coagulant. Characterization beads obtained were carried out on water uptake and release of ammonia ions in the water. The results showed that forms of bead were affected by bentonite content in the hybrid. Increasing of bentonite content decreased water uptake of hybrid, however the release of ammonia ions in the water increased. Remaining base in the beads surface affected detection of release of ammonia ions in the water. Keywords: hybrid, beads, suspension, water uptake, release of ions

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11

Kim, Sok. "Blending of waste biomass for cost-effective chitosan-based biosorbents for removal of reactive dye from aqueous solution." Environmental Engineering Research 27, no. 6 (December 19, 2021): 210457–0. http://dx.doi.org/10.4491/eer.2021.457.

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Chitosan (CS) is an attractive natural and biodegradable cationic adsorbent material for treatment of anionic pollutants. For chitosan-based sorbents to be practicable, their price should be low. This study aims at cost reduction of chitosan-based sorbent through making of composite chitosan beads with industrial fermentation waste biomass of Escherichia coli. The maximum biomass content for maintaining stable composite bead structure was approximately 70.4% (w/w). The adsorption properties of the bacterial biomass-chitosan composite beads (BCCB) were evaluated using an anionic dye material, Reactive Yellow 2 (RY 2). At pH 4, the maximum uptake of BCCB was 679.13±23.76 mg/g, whereas those of pristine CS bead (CSB) and raw E. coli biomass were 934.71±50.97 mg/g and 200.77±4.51 mg/g, respectively. However, considering bound amount of RY2 to CS molecules in the CS-based beads, the BCCB showed the 2.1 times higher dye sorption capacity of CS than that of the CS in the CSB. In addition, the cost of RY2 treatment process using BCCB is expected to be shortened by 58% compared to CSB. Therefore, this study suggests that compositing CS with biomass waste can be a practical way to design cost-effective adsorbents.

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12

Madjid, Armeida Dwi Ridhowati, Merpiseldin Nitsae, and Akhmad Sabarudin. "Perbandingan Butiran Kitosan dengan Pengikat Silang Epiklorohidrin (ECH) dan Glutaraldehid (GLA): Karakterisasi dan Kemampuan Adsorpsi Timbal (Pb)." ALCHEMY 6, no. 1 (March 30, 2018): 29. http://dx.doi.org/10.18860/al.v6i1.6790.

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<table width="661" border="1" cellspacing="0" cellpadding="0"><tbody><tr><td valign="top" width="408"><p class="BodyAbstract">Chitosan was an abundantly available source but it has a drawback which unstable in acid or base. So, it must be added with a crosslinker. In this article, we would compare the using of 2 crosslinkers, glutaraldehyde (GLA) and epichlorohydrin (ECH). Chitosan was formed as bead using tripolyphosphate (TPP). Chitosan beads crosslinked with GLA became browny beads and chitosan beads crosslinked with ECH became pearly white. IR characterization showed peaks in 1640 and 1540 cm<sup>-1</sup> represent phosphate contained TPP. There is no significant or unique peak differ GLA chitosan bead from ECH chitosan bead. Adsorption capacity of lead (Pb) in ECH chitosan bead was higher than in GLA chitosan bead. Morphology in SEM characterization exhibited a crinkle GLA chitosan bead then ECH chitosan bead.</p><p class="BodyAbstract"> </p><p class="BodyAbstract">Kitosan merupakan polimer alam dengan ketersediaan yang meruah tetapi memiliki kelemahan yaitu kurang stabil dalam asam maupun basa sehingga diperlukan pengikat silang. Dalam artikel ini akan dibandingkan dengan penggunaan 2 agen pengikatsilang yang dapat mengatasi permasalahan tersebut yaitu epiklorohidrin (ECH) dan glutaraldehid (GLA). Untuk pembuatan butiran kitosan digunakan tripolyphosphate (TPP). Setelah menjadi butiran kitosan diikatsilangkan dengan GLA menjadi butiran kitosan yang berwarna kecoklatan dan diikatsilangkan dengan ECH menjadi butiran kitosan bening. Karakterisasi spektrofotometri Infra Merah menunjukkan puncak pada daerah 1640 dan 1540 cm<sup>-1</sup> yang merupakan serapan khas dari tripolyphospate sedangkan tidak nampak perbedaan puncak spektra yang signifikan dari butiran kitosan GLA maupun ECH. Kemampuan adsorpsi butiran logam timbal (Pb) butiran kitosan ECH lebih tinggi jika dibandingkan dengan butiran kitosan GLA. Morfologi butiran kitosan dianalisis menggunakan Scanning Electron Morphology (SEM) dan menunjukkan bahwa morfologi untuk butiran GLA memiliki morfologi yang lebih berkerut jika dibandingkan dengan butiran ECH.</p></td></tr></tbody></table>

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13

Ngah, W. S. Wan, and S. Fatinathan. "Adsorption of Cu(II) ions in aqueous solution using chitosan beads, chitosan–GLA beads and chitosan–alginate beads." Chemical Engineering Journal 143, no. 1-3 (September 2008): 62–72. http://dx.doi.org/10.1016/j.cej.2007.12.006.

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14

Segale, Lorena, Lorella Giovannelli, Paolo Mannina, and Franco Pattarino. "Calcium Alginate and Calcium Alginate-Chitosan Beads Containing Celecoxib Solubilized in a Self-Emulsifying Phase." Scientifica 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/5062706.

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In this work alginate and alginate-chitosan beads containing celecoxib solubilized into a self-emulsifying phase were developed in order to obtain a drug delivery system for oral administration, able to delay the drug release in acidic environment and to promote it in the intestinal compartment. The rationale of this work was linked to the desire to improve celecoxib therapeutic effectiveness reducing its gastric adverse effects and to favor its use in the prophylaxis of colon cancer and as adjuvant in the therapy of familial polyposis. The systems were prepared by ionotropic gelation using needles with different diameters (400 and 600 μm). Morphology, particle size, swelling behavior, andin vitrodrug release performance of the beads in aqueous media with different pH were investigated. The experimental results demonstrated that the presence of chitosan in the formulation caused an increase of the mechanical resistance of the bead structure and, as a consequence, a limitation of the bead swelling ability and a decrease of the drug release rate at neutral pH. Alginate-chitosan beads could be a good tool to guarantee a celecoxib colon delivery.

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15

Minh Ngoc, Ta Thi. "MICROENCAPSULATION OF GAC OIL IN CHITOSAN BEAD." Vietnam Journal of Science and Technology 54, no. 2C (March 19, 2018): 451. http://dx.doi.org/10.15625/2525-2518/54/2c/11891.

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Gac oil is a Vietnamese traditional product that contains a high concentration of interestingcarotenoids (beta-carotene and lycopene), which are very useful in cancer treatment and antiagedprotection due to their strong antioxidant activity. However, its hydrophobicity restrains itsuses in food applications which are normally aqueous systems. This problem is possiblyovercome with the help of microencapsulation technology. In this paper, Gac oil wasencapsulated in chitosan beads using dripping method. Gac oil emulsified in chitosan 2 % wasdropped into alkaline solution. The bead’s formation was evaluated through the decrease of beadweight and pH of alkaline solution. Chitosan beads expressed a good protection to Gac oil with acalculated haft-time life of beta-carotene up to 2 years. Encapsulation yield and encapsulationefficiency were also determined.

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16

Wu, Bi, Yang Li, Yuan Y. Li, Zhi H. Shi, Xiao H. Bian, and Qiang Xia. "Nanostructured-lipid carriers-Chitosan hydrogel beads carrier system for loading of resveratrol: A new method of topical application." Journal of Biomaterials Applications 36, no. 8 (January 7, 2022): 1444–57. http://dx.doi.org/10.1177/08853282211053923.

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The aim of this study was to develop nanostructured-lipid carriers (NLC) encapsulated by Chitosan hydrogel beads for the efficient topical carrier. Dynamic light scattering (DLS), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) were conducted to study the influence of the encapsulation on the characteristic of resveratrol-loaded NLC, and the results showed that there was no impact on resveratrol-loaded NLC. Chitosan hydrogel beads could significantly improve the physical stability of resveratrol-loaded NLC. In vitro release study revealed that resveratrol-loaded NLC-Chitosan hydrogel beads had a more significant sustained-release effect on resveratrol. In vitro transdermal studies suggested that the skin permeation of resveratrol was promoted by the effect of Chitosan hydrogel beads and increased resveratrol distribution in the skin. In vitro cytotoxicity showed that resveratrol-loaded NLC-Chitosan hydrogel beads did not exert a hazardous effect on L929 cells. Hence, NLC-Chitosan hydrogel beads might be a promising method for topical applications of resveratrol.

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Park, Kyung Hee, Yeon Woo Choi, Heejoo Ryu, Hyoung Jae Lee, Jae-Hak Moon, Ho-Jun Song, and Yeong-Joon Park. "Controlled Drug Release Using Chitosan-Alginate-Gentamicin Multi-Component Beads." Materials 15, no. 21 (November 1, 2022): 7682. http://dx.doi.org/10.3390/ma15217682.

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This study aimed to develop improved multi-component beads with controlled, sustained delivery of antibiotics, such as gentamicin (GM). Antibiotic-loaded beads with rapid-release and the sustained-release system can be used for bone restoration. Single and multi-component beads were prepared by gelation using various combinations of chitosan and calcium chloride as cationic components and alginate and citric acid as anions. GM release was also controlled by crosslinking using citric acid. The optimum beads were obtained using 5% or 2% sodium alginate, 3% chitosan, and 0.1 mol/L citric acid. The beads were characterized by FTIR, TG-DTG, swelling behavior, and SEM. All GM-loaded beads revealed good antimicrobial activity. The rate and kinetics of release in the phosphate buffer solution were controlled by changing the amount of chitosan in the calcium chloride solution and using citric acid as the crosslinking agent. Crosslinked beads were prepared for the release of about 80% of the loaded drug within 24 h. The study concluded that the chitosan-alginate beads provided faster GM release but crosslinking with citric acid was efficient for sustained-release beads containing gentamicin.

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18

Ariyani, Dahlena, Dwi Rasy Mujiyanti, Uripto Trisno Santoso, Riana Maulana, Retno Elya Rohmah, and Utami Irawati. "Effect of Chitosan Concentration on Macroporous Chitosan-TPP Beads toward Turbidity, Dye Content, and COD of Sasirangan Wastewater." JKPK (Jurnal Kimia dan Pendidikan Kimia) 6, no. 3 (December 25, 2021): 264. http://dx.doi.org/10.20961/jkpk.v6i3.54259.

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<p>This research was carried out to determine the effect of chitosan concentration in synthesising crosslinked tripolyphosphate (TPP) macropore beads on turbidity, dye content, and Chemical of Demand (COD) Sasirangan wastewater. Macroporous chitosan-TPP beads were synthesised from chitosan solution with various concentrations of 2%, 3%, 4%, and 5% and added NaHCO<sub>3</sub> as a porogen, then dripped into 0.75% tripolyphosphate solution. It was further interacted with Sasirangan wastewater by adsorption method with its effect analysed by using the turbidity value, dye content, and COD. The results showed that beads with a 3% chitosan concentration were the most effective in reducing the turbidity, dye content, and COD value. Furthermore, using a more than 3% chitosan concentration indicates reduced effectiveness. Macroporous Chitosan-TPP beads were able to produce a decrease in turbidity, dye content and COD by 81.21%, 55.44%, and 59.37%. </p>

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19

Muhammad Firdaus Kumar, Nurhidayah Kumar, Chew Chee Meng, Nor Hasmaliana Abdul Manas, Rabiatul Adawiyah Ahmad, Siti Fatimah Zaharah Mohd Fuzi, Roshanida A. Rahman, and Rosli Md Illias. "Immobilization of maltogenic amylase in alginate-chitosan beads for improved enzyme retention and stability." Malaysian Journal of Fundamental and Applied Sciences 18, no. 1 (February 28, 2022): 43–51. http://dx.doi.org/10.11113/mjfas.v18n1.2381.

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Maltogenic amylase (Mag1) is a potent enzyme that hydrolyzes the glycosidic bond of polysaccharides to produce malto-oligosaccharides (MOS). However, the Mag1 enzyme has poor stability and reusability, leading to inefficient MOS production. Enzyme immobilization is a promising method to solve the enzyme stability problem. Entrapment and encapsulation technique was used in this study to immobilize Mag1 because of high biocompatibility and prevention of enzyme degradation, hence lesser loss of enzymatic activity. Chitosan was used as a coating membrane on the alginate matrix, preventing enzyme leaching from the beads. Mag1 entrapped in alginate-chitosan beads showed better performance compared to alginate beads in terms of thermostability, reusability and enzyme retention. Alginate-chitosan beads showed improvement of temperature stability of approximately 35%, 30% and 20% at a respective temperature of 30 °C, 40 °C and 50 °C. Reusability analysis showed immobilized Mag1 can be used up to at least eight cycles with retained activity of 80% and 70% from its initial activity for alginate-chitosan and alginate beads respectively. Enzyme leakage percentage in alginate-chitosan was 7-21%, while that in alginate was 12-35%. The overall findings envisage the promising application of alginate-chitosan beads immobilized Mag1 as a biocatalyst for MOS synthesis.

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Sánchez-Duarte, Reyna G., Dalia I. Sánchez-Machado, Jaime López-Cervantes, and Ma A. Correa-Murrieta. "Adsorption of allura red dye by cross-linked chitosan from shrimp waste." Water Science and Technology 65, no. 4 (February 1, 2012): 618–23. http://dx.doi.org/10.2166/wst.2012.900.

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The present study was designed to evaluate the chitosan, which has been obtained by deacetylation of chitin, as a biosorbent. The chitin was isolated from fermented shrimp waste by an important local industrial food biopolymer. The aim of this work was the characterization of chitosan and preparation of cross-linked chitosan- tripolyphosphate (chitosan-TPP) beads for the removal of allura red food dye from aqueous solutions. Conditions of batch adsorption such as pH, time and adsorbent dose were examined. The effectiveness of cross-linked chitosan beads for dye removal was found to be higher for pH 2 (98%, percentage of dye removal) and tends to decrease at pHs of 3 to 11 (up to 49%). The values of percentage removal show that the adsorption capacity increases with time of contact and dosage of chitosan-TPP, but red dye adsorption is mainly influenced by pH level. The cross-linked chitosan-TPP beads can significantly adsorb allura red monoazo dye from aqueous solutions even at acidic pHs unlike raw chitosan beads that tend to dissolve in acidic solutions. Consequently, this modified chitosan has characteristics that allow minimization of environmental pollution and widening the valorization of shrimp waste.

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Nurmasari, Radna, Uripto Trisno Santoso, Dewi Umaningrum, and Taufiqur Rohman. "IMMOBILIZATION OF HUMIC ACID ON CHITOSAN BEADS BY PROTECTED CROSS-LINKING METHOD AND ITS APPLICATION AS SORBENT FOR Pb(II)." Indonesian Journal of Chemistry 10, no. 1 (June 21, 2010): 88–95. http://dx.doi.org/10.22146/ijc.21485.

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Анотація:

Immobilization of humic acid (HA) on chitosan beads has been done using a protected cross-linking reaction method and the product was then utilized as sorbent for Pb(II). Protection of the active sites of HA was carried out by interacting HA with Pb(II) before performing the cross-linking reaction in order to maintain its adsorption capacity. Protected-HA was cross-linked with chitosan beads using glutaraldehyde in order to obtain sorbent insoluble both in aqueous acidic and basic solution. The result showed that the amount of immobilized HA on beads chitosan was 88.60% by weight. The adsorption capacity of the protected-sorbent beads for Pb(II) was 784 mg/g. As a comparison, the adsorption capacity of the non-protected sorbent beads for Pb(II) was only 142 mg/g. Keywords: immobilization, adsorption, crosslinking, humic acid, chitosan

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Gao, Yu Nan, Rong Xin Zhang, Xiang Yu Tang, Xin Fu, and Peng Cong. "Biosorption of Mn(II) by Immobilizing Dominant Bacteria on the Surface of Chitosan Cross-Linked GAC Beads." Applied Mechanics and Materials 361-363 (August 2013): 793–96. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.793.

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Анотація:

A static test was applied to study the biosorption of Mn (II) by immobilized dominant bacteria on the surface of chitosan cross-linked GAC(CCG) beads. The Citrobacter sp. was selected from the source water of the Shenyang first water treatment plant. Citrobacter sp. was immobilized on the surface of chitosan cross-linked GAC beads successfully. Langmuir models were applied to describe the isotherms. The Mn (II) removal rate was evaluated by the different dose rate and different contact time of the CCG beads. Results showed the dominant bacteria immobilized on chitosan cross-linked GAC beads were favourable adsorbers.

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Abdul, Bazigha K., and Sahar A. Fahmy. "Development of coated beads for oral controlled delivery of cefaclor: In vitro evaluation." Acta Pharmaceutica 63, no. 1 (March 1, 2013): 31–44. http://dx.doi.org/10.2478/acph-2013-0003.

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Анотація:

The aim of the present study was to develop and characterize coated chitosan-alginate beads containing cefaclor as a controlled release delivery system. Coated cefaclor beads were prepared by solvent evaporation techniques. Beads were found to be intact and spherical in shape. Their size range was 1.05 to 2.06. The loading efficiency showed maximum value when the concentration of cefaclor, chitosan and PEG 400 was 10 % (m/V), 0.5 % (m/V) and 2 % (V/V), respectively. Best retardation of cefaclor release from chitosan-alginate beads was achieved by coating with 15 % of shellac in formula F19. A significant antimicrobial activity (p < 0.05) against Staphylococcus aureus and Klebsiella pneumoniae was observed for formula F19 compared to the standard antibiotic disc. Furthermore, the simulated plasma profile showed the superiority of F19 in sustaining drug release for more than 12 h. Therefore, shellac coated chitosan-alginate beads could be considered a successful controlled release oral cefaclor dosage form.

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Lau, Kam Sheng, Nur Alia Sahira Azmi, Siew Xian Chin, Sarani Zakaria, and Chin Hua Chia. "Chitosan-Bead-Encapsulated Polystyrene Sulfonate for Adsorption of Methylene Blue and Regeneration Studies: Batch and Continuous Approaches." Polymers 15, no. 5 (March 2, 2023): 1269. http://dx.doi.org/10.3390/polym15051269.

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Textile industrialization causes water pollution due to the discharge of industrial effluents into the environment. To reduce the impact of industrial effluent, it must be treated in wastewater treatment plants before discharge into rivers. Among all wastewater treatment approaches, the adsorption process is one method to remove pollutants from wastewater, but it has some limitations in term of reusability and ionic selective adsorption properties. In this study, we prepared cationic poly (styrene sulfonate) (PSS)-incorporated anionic chitosan beads synthesized using the oil–water emulsion coagulation method. The produced beads were characterized using FESEM and FTIR analysis. In batch adsorption studies, the PSS-incorporated chitosan beads exhibited monolayer adsorption processes, that is, exothermic processes that occur spontaneously at low temperatures, which were analyzed based on the adsorption isotherms, adsorption kinetics, and thermodynamics model fittings. The presence of PSS enables cationic methylene blue dye to adsorb to the anionic chitosan structure via electrostatic interaction between the sulfonic group and the dye molecule. The maximum adsorption capacity of PSS-incorporated chitosan beads achieved 42.21 mg/g, as calculated from the Langmuir adsorption isotherm. Finally, the PSS-incorporated chitosan beads demonstrated good regeneration with different types of reagents, especially using sodium hydroxide as a regeneration reagent. With the use of sodium hydroxide regeneration of this adsorbent material, a continuous adsorption setup also demonstrated that PSS-incorporated chitosan beads can be reused for methylene blue adsorption for up to three cycle processes.

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Kotadiya, Rajendra M. "EFFECT OF SURFACTANT AND METHODS OF DRYING ON METHOTREXATE HYDROCHLORIDE LOADED CHITOSAN BEADS." Indian Drugs 60, no. 01 (January 27, 2023): 91–93. http://dx.doi.org/10.53879/id.60.01.12631.

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Анотація:

To get chitosan beads, an ionotropic gelation technique was used in which drug containing chitosan solution added into tripolyphosphate solution. Obtained beads were evaluated to study the effect of Span 80 and methods of drying on their properties. Air drying method resulted in shrunken beads, the oven drying method resulted in dark, brittle and cracked beads, and freeze-drying method showed adverse effect on sphericity and surface topography of the beads. Higher proportion of Span 80 in the beads showed faster release. Oven-dried beads gave delayed release compared to air- and freezedried beads. In vitro drug release data depicted t70% at 365 min with 88.17 % drug release for 12 h. Thus, formation of controlled release beads can be inferred.

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Hasan, Shameem, A. Iasir, Tushar Ghosh, Bhaskar Sen Gupta, and Mark Prelas. "Characterization and Adsorption Behavior of Strontium from Aqueous Solutions onto Chitosan-Fuller’s Earth Beads." Healthcare 7, no. 1 (March 26, 2019): 52. http://dx.doi.org/10.3390/healthcare7010052.

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Анотація:

Fuller’s earth spherical beads using chitosan as a binder were prepared for the removal of strontium ions from aqueous solution. The adsorbents were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which revealed the porous nature of the beads. The Brunauer–Emmett–Teller (BET) surface area of the beads was found to be 48.5 m2/g. The adsorption capacities of the beads were evaluated under both batch and dynamic conditions. The adsorption capacity was found to be ~29 mg/g of adsorbent at 298 K when the equilibrium concentration of strontium in the solution was 925 mg/L at pH 6.5. The X-ray photoelectron spectroscopy (XPS) data suggest that strontium uptake by the beads occurs mainly through an ion-exchange process. Kinetic data indicate that the sorption of strontium onto the beads follows anomalous diffusion. Thermodynamic data suggest that the ion-exchange of Sr2+ on the bead surface was feasible, spontaneous and endothermic in nature.

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Taha, Ali A., Nahida J. Hameed, and Farah H. Rashid. "Decolorization of Phenol Red Dye by Immobilized Laccase in Chitosan Beads Using Laccase - Mediator - System Model." Baghdad Science Journal 17, no. 3 (September 1, 2020): 0720. http://dx.doi.org/10.21123/bsj.2020.17.3.0720.

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This work describes the enhancement of phenol red decolorization through immobilizing of laccase in chitosan and enzyme recycling. Commercial laccase from white rot fungus, Trametesversicolor (Tvlac), was immobilizedin to freshly prepared chitosan beads by using glutaraldehyde as a cross linker. Characterization of prepared chitosan was confirmed by FTIR and scanning electron microscope (SEM). Tvlac (46.2 U/mL) immobilized into chitosan beads at 0.8 % glutaraldehyde (v/v) within 24 hrs. Synthetic (HBT) and natural (vanillin) mediators were used to enhance dye decolorizoation. It was found that 89 % of phenol red was decolorized by chitosan beads within 180 min. in the absence of enzyme and mediator, while decolorization percentage of the dye was completed (100%) at 120 min. when chitosan immobilizedlaccase was applied. Moreover, the decolorization was completed within 25 and 50 min. in the presence of chitosan immobilized laccase and of HBT or vanillin respectively. On the other hand, the recycling of chitosan immobilized laccase was still decolorize phenol red and continued up to ninth cycle to reach 70% of dye decolorization .

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Nguyen Thuy, Nga, Hoan Lai Thi, Anh Nguyen Duc, and Hien Ho Phuong. "Synthesis and study of adsorption for ion Cu(II) from aqueous solution by chitosan beads." Vietnam Journal of Catalysis and Adsorption 11, no. 3 (October 12, 2022): 48–53. http://dx.doi.org/10.51316/jca.2022.049.

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Анотація:

Chitosan beads were synthesized by sodium lauryl ether sulfate (SLES) gelation process and alkaline treatment. The characterization and morphology of chitosan beads were investigated by Fourier-transform infrared spectroscopy technique (FT-IR), optical microscope and scanning electron microscope technique (SEM). The influence of NaOH concentration, pH, reaction time and adsorption isotherm was studied. Langmuir and Freundlich adsorption models were applied to describe isothermal lines. The alkalization process enhanced significantly Cu(II) adsorption capacity of CS/SLES/NaOH to 4489,6 mg/g. The results showed that chitosan beads would be a promising material to remove heavy metals in wastewater.

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Brandi, Jamile, Júlio César Ximenes, Mariselma Ferreira, and Rafael Salomão. "Gelcasting of alumina–chitosan beads." Ceramics International 37, no. 4 (May 2011): 1231–35. http://dx.doi.org/10.1016/j.ceramint.2010.11.042.

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Loghin, Diana Felicia, Melinda Maria Bazarghideanu, Silvia Vasiliu, Stefania Racovita, Marius-Mihai Zaharia, Tudor Vasiliu, and Marcela Mihai. "Hydrogel Beads of Amidoximated Starch and Chitosan as Efficient Sorbents for Inorganic and Organic Compounds." Gels 8, no. 9 (August 30, 2022): 549. http://dx.doi.org/10.3390/gels8090549.

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Анотація:

The synthesis of hydrogel beads involving natural polymers is, nowadays, a leading research area. Among natural polymers, starch and chitosan represent two biomolecules with proof of efficiency and low economic impact in various utilization fields. Therefore, herein, the features of hydrogel beads obtained from chitosan and three sorts of starch (potato, wheat and rise starches), grafted with acrylonitrile and then amidoximated, were deeply investigated for their use as sorbents for heavy metal ions and dyes. The hydrogel beads were prepared by ionotropic gelation/covalent cross-linking of chitosan and functionalized starches. The chemical structure of the hydrogel beads was analyzed by FT-IR spectroscopy; their morphology was revealed by optical and scanning electron microscopies, while the influence of the starch functionalization strategies on the crystallinity changes was evaluated by X-ray diffraction. Molecular dynamics simulations were used to reveal the influence of the grafting reactions and grafted structure on the starch conformation in solution and their interactions with chitosan. The sorption capacity of the hydrogel beads was tested in batch experiments, as a function of the beads’ features (synthesis protocol, starch sort) and simulated polluted water, which included heavy metal ions (Cu2+, Co2+, Ni2+ and Zn2+) and small organic molecules (Direct Blue 15 and Congo red).

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Itoyama, Koki, and Siichi Tokura. "Studies on Functionalized Chitosan Beads II. Adsorption Behavior of Lysozyme onto Carboxylated Chitosan Beads." Sen'i Gakkaishi 50, no. 3 (1994): 118–23. http://dx.doi.org/10.2115/fiber.50.3_118.

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Han, Xiaobing, Rong Li, Pengpai Miao, Jie Gao, Guowen Hu, Yuan Zhao, and Tao Chen. "Design, Synthesis and Adsorption Evaluation of Bio-Based Lignin/Chitosan Beads for Congo Red Removal." Materials 15, no. 6 (March 21, 2022): 2310. http://dx.doi.org/10.3390/ma15062310.

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The morphology and intermolecular interaction are two of the most important factors in the design of highly efficient dye adsorbent in the industry. Millimeter-sized, bead-type, bio-based lignin/chitosan (Lig/CS) adsorbent was designed for the removal of Congo red (CR), based on the electrostatic attraction, π-π stacking, and hydrogen bonding, which were synthesized through the emulsification of the chitosan/lignin mixture followed by chemical cross-linking. The effects of the lignin/chitosan mass ratio, initial pH, temperature, concentration, and contact time on the adsorption were thoroughly investigated. The highest adsorption capacity (173 mg/g) was obtained for the 20 wt% Lig/CS beads, with a removal rate of 86.5%. To investigate the adsorption mechanism and recyclability, an evaluation of the kinetic model and an adsorption/desorption experiment were conducted. The adsorption of CR on Lig/CS beads followed the type 1 pseudo-second-order model, and the removal rate for CR was still above 90% at five cycles.

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Zhang, Haini, Hiroyuki Tachikawa, Xiao-Dong Gao, and Hideki Nakanishi. "Applied Usage of Yeast Spores as Chitosan Beads." Applied and Environmental Microbiology 80, no. 16 (June 6, 2014): 5098–105. http://dx.doi.org/10.1128/aem.00677-14.

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ABSTRACTIn this study, we present a nonhazardous biological method of producing chitosan beads using the budding yeastSaccharomyces cerevisiae. Yeast cells cultured under conditions of nutritional starvation cease vegetative growth and instead form spores. The spore wall has a multilaminar structure with the chitosan layer as the second outermost layer. Thus, removal of the outermost dityrosine layer by disruption of theDIT1gene, which is required for dityrosine synthesis, leads to exposure of the chitosan layer at the spore surface. In this way, spores can be made to resemble chitosan beads. Chitosan has adsorptive features and can be used to remove heavy metals and negatively charged molecules from solution. Consistent with this practical application, we find that spores are capable of adsorbing heavy metals such as Cu2+, Cr3+, and Cd2+, and removal of the dityrosine layer further improves the adsorption. Removal of the chitosan layer decreases the adsorption, indicating that chitosan works as an adsorbent in the spores. Besides heavy metals, spores can also adsorb a negatively charged cholesterol derivative, taurocholic acid. Furthermore, chitosan is amenable to chemical modifications, and, consistent with this property,dit1Δspores can serve as a carrier for immobilization of enzymes. Given that yeast spores are a natural product, our results demonstrate that they, and especiallydit1Δmutants, can be used as chitosan beads and used for multiple purposes.

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Verma, Navneet, Sunil Kumar Tiwari, Vijay Sharma, and Arvind Raghav. "A REVIEW ON CONTROLLED RELEASE BEADS OF ANTI-MICROBIAL DRUG." YMER Digital 21, no. 07 (July 18, 2022): 660–67. http://dx.doi.org/10.37896/ymer21.07/52.

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Alginate and chitosan polymers are widely used in the preparation of drug release. These two polymers can be used together or separately to form modified drug-loaded release beads. A method of ionotropic gelation and subtle modification in various ways is used to fix these beads of different characteristics. Bead characteristics such as morphology, buoyancy, inflammatory environment, drug efficacy, marketing, and liberal behavior are important and the therapeutic use of various bead modifications can be great for underwater soluble drugs, half-life biological Health, requires direct organ guidance, and has natural protein. The need for longer and better control over drug administration has increased the need for stitched polymers. Hydrocolloids such as alginate can play an important role in the production of a controlled by-product. At low pH the flow of, alginic acid leads to the formation of a high-viscosity ‘‘acid gel.’’ Alginate is also easily applied to the gel in the presence of a divalent cation like calcium ion. This review discusses the current use the future opportunities for alginate as a tool in drug development. Keywords: Alginate, chitosan, Controlled Release, Drug Delivery, ionotropic gelation, beads

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Verma, Shalu. "A REVIEW ON TRANSDERMAL DRUG DEIVERY SYSTEM." YMER Digital 21, no. 07 (July 18, 2022): 668–75. http://dx.doi.org/10.37896/ymer21.07/53.

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Анотація:

Alginate and chitosan polymers are widely used in the preparation of drug release. These two polymers can be used together or separately to form modified drug-loaded release beads. A method of ionotropic gelation and subtle modification in various ways is used to fix these beads of different characteristics. Bead characteristics such as morphology, buoyancy, inflammatory environment, drug efficacy, marketing, and liberal behavior are important and the therapeutic use of various bead modifications can be great for underwater soluble drugs, half-life biological Health, requires direct organ guidance, and has natural protein. The need for longer and better control over drug administration has increased the need for stitched polymers. Hydrocolloids such as alginate can play an important role in the production of a controlled by-product. At low pH the flow of, alginic acid leads to the formation of a high-viscosity ‘‘acid gel.’’ Alginate is also easily applied to the gel in the presence of a divalent cation like calcium ion. This review discusses the current use the future opportunities for alginate as a tool in drug development. Keywords: Alginate, chitosan, Controlled Release, Drug Delivery, ionotropic gelation, beads.

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Yoon, D. S., K. Won, Y. H. Kim, B. K. Song, S. J. Kim, S. J. Moon, and B. S. Kim. "Continuous removal of hydrogen peroxide with immobilised catalase for wastewater reuse." Water Science and Technology 55, no. 1-2 (January 1, 2007): 27–33. http://dx.doi.org/10.2166/wst.2007.016.

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Hydrogen peroxide was continuously removed for wastewater reuse using an immobilised biocatalyst. A commercial catalase, which is an enzyme to decompose hydrogen peroxide to water and oxygen, was entrapped in chitosan beads. Hydrogen peroxide in aqueous solutions of varying pH, temperature and concentration was continuously removed through a reactor containing the catalase-entrapped chitosan beads at high efficiency for 24 h. Additional silicate coating of the chitosan beads resulted in significant improvements in the catalase performance under harsh conditions, which are often found in peroxide-based industrial processes. We expect that immobilisation of catalases can enhance their applicability for continuous degradation of hydrogen peroxide for wastewater reuse.

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Ispirli Doğaç, Yasemin, İlyas Deveci, Mustafa Teke, and Bedrettin Mercimek. "TiO2 beads and TiO2-chitosan beads for urease immobilization." Materials Science and Engineering: C 42 (September 2014): 429–35. http://dx.doi.org/10.1016/j.msec.2014.05.058.

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Primadevi, Susan, and Dian Kresnadipayana. "Pengaruh Konsentrasi Glutaraldehida Terhadap Aktivitas Transesterase Enzim Lipase Terimobilisasi pada Proses Pembuatan Biodiesel dari Minyak Goreng Bekas." Biomedika 10, no. 1 (March 31, 2017): 61–66. http://dx.doi.org/10.31001/biomedika.v10i1.228.

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Анотація:

Penggunaan lipase sebagai biokatalis mempunyai beberapa kelemahan yaitu lipase tidak dapat digunakan kembali karena terlarut dalam media reaksi, struktur lipase sangat tidak stabil terhadap adanya perubahan lingkungan (suhu, pH, kekuatan ionik), sehingga menyebabkan enzim terdenaturasi. Solusi untuk mengatasi kelemahan penggunaan enzim tersebut adalah dengan imobilisasi enzim pada chitosan beads dengan metode crosslinking. Tujuan penelitian ini adalah mengetahui pengaruh variasi konsentrasi glutaraldehida terhadap aktivitas transesterase enzim lipase terimobilisasi pada proses pembuatan biodiesel . Penelitian diawali dengan pembuatan kitosan dari limbah cangkang rajungan. Kitosan serbuk kemudian dimodifikasi bentuknya melalui proses swelling menjadi chitosan beads. Tahap kedua adalah pemurnian minyak goreng bekas melalui tahap despicing, netralisasi dan bleaching. Tahap ketiga yaitu imobilisasi enzim lipase pada chitosan beads dengan metode crosslinking dengan menggunakan variasi konsentrasi glutaraldehida. Tahap terakhir adalah pembuatan biodiesel dari minyak goreng bekas. Hasil penelitian menunjukkan bahwa kitosan yang dihasilkan memiliki rendemen sebesar 39,43%, derajat deasetilasi 83,83%, kadar abu 0,73%, kadar air 4,74% dan kadar nitrogen 7,18%. Chitosan beads yang dihasilkan memiliki diameter sebesar 3,55±0,38 mm. Konsentrasi metil ester tertinggi dihasilkan pada saat konsentrasi glutaraldehida 2%.

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Rajinikanth, Parauvathanahalli, and Brahmeshwar mishra. "Preparation and in vitro characterization of gellan based floating beads of acetohydroxamic acid for eradication of H. pylori." Acta Pharmaceutica 57, no. 4 (December 1, 2007): 413–27. http://dx.doi.org/10.2478/v10007-007-0033-5.

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Анотація:

Preparation andin vitrocharacterization of gellan based floating beads of acetohydroxamic acid for eradication ofH. pyloriGellan based floating beads of acetohydroxamic acid (AHA) were prepared by the ionotropic gellation method to achieve controlled and sustained drug release for treatment ofHelicobacter pyloriinfection. The prepared beads were evaluated for diameter, surface morphology and encapsulation efficiency. Formulation parameters like concentrations of gellan, chitosan, calcium carbonate and the drug influenced thein vitrodrug release characteristics of beads. Drug and polymer interaction studies were carried out using differential scanning calorimetry. Chitosan coating increased encapsulation efficiency of the beads and reduced the initial burst release of the drug from the beads. Kinetic treatment of the drug release data revealed a matrix diffusion mechanism. Prepared floating beads showed good antimicrobial activity (in vitro H. pyloriculture) as potent urease inhibitors. In conclusion, an oral dosage form of floating gellan beads containing AHA may form a useful stomach site specific drug delivery system for the treatment ofH. pyloriinfection.

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Prasetyaningrum, Aji, Sadam Arrois, Fitri Lafifa, Aat Zaki Mubarok, Fadlillah Fani, Noer Abyor Handayani, Ratnawati Ratnawati, and Bakti Jos. "Encapsulation of Lemongrass Extract (Cymbopogon citratus) Coated Alginate/Chitosan Using Gelation Method." Reaktor 21, no. 3 (December 3, 2021): 124–32. http://dx.doi.org/10.14710/reaktor.21.3.124-132.

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Анотація:

Lemongrass (Cymbopogon citratus) is a medicinal plant with various biological activities such as antibacterial, antifungal, antiprotozoal, anti-inflammatory, and antioxidant. This study aimed to encapsulate lemongrass bioactive in alginate/chitosan complex by enhancing the properties of CaCl2 crosslinked incorporated with tween 80 by ionic gelation method. The hydrogel was prepared by mixing alginate solution (2% w/v) and chitosan solution (1% w/v) with a ratio (1:1 v/v). Tween 80 (2% v/v) was added as a dissolution enhancer and CaCl2 as a crosslinker agent. The formulation varying by concentration of CaCl2 (0.1M to 0.3M) and lemongrass extract (2% to 12%). Encapsulation lemongrass with alginate-chitosan beads is characterized to determine encapsulation efficiency, swelling study, morphology, functional groups, and release study. The results showed that encapsulation efficiency ranged from 74.81% to 83.07%. Encapsulation efficiency increased with the addition of CaCl2 and lemongrass extract concentration. The swelling ratio ranged from 27.29 to 37.81, it will decrease with the addition of CaCl2 and lemongrass extract concentration. The Scanning Electron Microscopy (SEM) analysis of hydrogel beads shows a polyhedral shape, porous, and rough surface which indicates bioactive of lemongrass trapped on the beads. The Fourier Transform Infrared Spectroscopy (FTIR) results show new peaks at 1734 cm-1 as carbonyl stretch vibrations in ketones, aldehydes, and carboxylic acids, indicating the addition of lemongrass extract. Bioactive of lemongrass extract loaded alginate-chitosan beads was successfully released as much as 87.12% at pH 6.8. This study suggested the strong potential alginate-chitosan beads as an encapsulating agent for lemongrass extract using the ionic gelation method, and it has potential as a drug delivery system.Keywords: encapsulation; lemongrass; alginate; chitosan; CaCl2

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KAWAMURA, Yoshihide. "Fabrication of Highly Porous Chitosan Beads and Adsorption of Mercury(II) on Polyaminated Chitosan Beads." Journal of Ion Exchange 9, no. 4 (1998): 183–91. http://dx.doi.org/10.5182/jaie.9.183.

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Nitayaphat, Walaikorn, and Thanut Jintakosol. "Removal of Silver (I) from Aqueous Solutions by Chitosan/Carbon Nanotube Nanocomposite Beads." Advanced Materials Research 893 (February 2014): 166–69. http://dx.doi.org/10.4028/www.scientific.net/amr.893.166.

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Chitosan/CNT nanocomposites were prepared by blending chitosan with carbon nanotubes (CNTs) and forming composite beads. The composites were used as Ag+adsorbents. Adsorption equilibrium experiments were carried out as a function of contact time, CNTs concentration, pH value, and adsorbent dosage level. The equilibrium time of Ag+adsorption was found to be 160 min. Composite adsorbent had the highest adsorption efficiency when the weight of CNTs was 0.01 wt%. The maximum Ag+removal took place at the initial pH value of 3. The optimum adsorbent dosage for Ag+removal was 5 g. Under above optimal conditions the maximum Ag+removal was 99.7%. The adsorption isotherm of chitosan/CNT nanocomposite bead agreed well with the Langmuir model. The maximum adsorption capacity was 0.393 mg/g.

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Du, Xiaoyu, Chihiro Kishima, Haixin Zhang, Naoto Miyamoto, and Naoki Kano. "Removal of Chromium(VI) by Chitosan Beads Modified with Sodium Dodecyl Sulfate (SDS)." Applied Sciences 10, no. 14 (July 9, 2020): 4745. http://dx.doi.org/10.3390/app10144745.

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Анотація:

In this study, chitosan beads modified with sodium dodecyl sulfate (SDS) were successfully synthesized and employed for the removal of chromium(VI) (Cr(VI)). The adsorption performance of the adsorbent (SDS-chitosan beads) was examined by batch experiments. The partition coefficient (PC) as well as the adsorption capacity were evaluated to assess the true performance of the adsorbent in this work. The adsorbent (SDS-chitosan beads) showed a maximum Cr(VI) adsorption capacity of 3.23 mg·g−1 and PC of 9.5 mg·g−1·mM−1 for Cr(VI). The prepared adsorbent was characterized by different techniques such as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR). We used inductively coupled plasma mass spectrometry (ICP-MS) for the determination of Cr(VI) in solution. The experimental data could be well-fitted by pseudo-second-order kinetic and Langmuir isotherm models. The thermodynamic studies indicated that the adsorption process was favorable under the higher temperature condition. The SDS-modified chitosan beads synthesized in this work represent a promising adsorbent for removing Cr(VI).

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Reshetova, V. Yu, A. F. Krivoshchepov, I. A. Butorova, N. B. Feldman, S. V. Lutsenko, and A. N. Kuskov. "Antibacterial Activity of Biodegradable Particles based on Chitosan Containing Colloidal Silver." Biotekhnologiya 36, no. 4 (2020): 87–93. http://dx.doi.org/10.21519/0234-2758-2020-36-4-87-93.

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Chitosan beads with colloidal silver nanoparticles inclued in the polymer matrix have been obtained by the introduction of chitosan into an acidified nanosilver sol. Dual interconnection of drops of the resulting solution was then carried out by ionotropic gelation at the first stage and covalent crosslinking of the polymer matrix with adipic acid at the second stage. The surface morphology of the obtained beads was studied by scanning electron microscopy. Data of Fourier transform IR spectroscopy confirmed the formation of covalent bonds between chitosan and adipic acid. The antibacterial activity of obtained beads against S. aureus and E. coli was evaluated using agar diffusion test. It was shown that the сhitosan beads modified with nanostructured silver exhibited an antibacterial effect against the tested strains, and they can be used as a basis for creating biodegradable wound healing dressings with a prolonged antibacterial effect. chitosan, silver nanoparticles, antibacterial activity, wound dressings This work was supported by the "Russian Academic Excellence Project 5-100". The study was carried out with the financial support of the Russian Foundation for Basic Research in the framework of the Scientific Project no. 18-29-18039.

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45

Nikiforova, T. E., V. A. Kozlov, and M. K. Islyaikin. "Regularities and mechanism of heavy metal cations sorption and (or) proton desorption by chitosan from aqueous solutions." Canadian Journal of Chemistry 97, no. 8 (August 2019): 621–28. http://dx.doi.org/10.1139/cjc-2018-0384.

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The sorption process of heavy metal ions from aqueous solutions using chitosan flakes and chitosan beads was studied. Chitosan gel beads were prepared using covalent crosslinking of chitosan chains by epichlorohydrin with ionic gelation by sodium tripolyphosphate. The capability of chitosan beads to absorb the heavy metal ions from aqueous solutions was studied, and the physicochemical characteristics of the sorbent were evaluated using SEM and FTIR on the model solution treatment. It was found that competitive proton sorption takes place in acidic media, which results in a transformation of amino groups into inactive ammonium-salt form and decreases in heavy metal sorption onto chitosan from aqueous acidic media. Batch adsorption experiments were performed to examine the influence of various factors such as the initial concentration of metal salts, pH, and agitation duration on the process. It was established that metal ion sorption is pH dependent and has an optimum effect at a pH of 6.0. Following the Langmuir equation, the maximum sorption of Cu2+ions is estimated to be 1,6 mol/kg of modified chitosan. The kinetic study revealed that the adsorption kinetics are well-fitted to the kinetic equation of pseudo second order. Thus, sorption of heavy metal ions by chitosan is considered to be a competitive process that occurs on amino groups of the sorbent with equivalent coordinated participation of metal cations, protons, and anions.

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Krunic, Tanja, Natasa Obradovic, Maja Bulatovic, Maja Vukasinovic-Sekulic, Kata Trifkovic, and Marica Rakin. "Impact of carrier material on fermentative activity of encapsulated yoghurt culture in whey based substrate." Chemical Industry 71, no. 1 (2017): 41–48. http://dx.doi.org/10.2298/hemind150717016k.

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The main objectives of this paper were to study the influence of the carrier material used for encapsulation and of bead size to fermentative activity and viability of the dairy starter culture ?Lactoferm ABY 6?. Encapsulation of yoghurt culture in beads with diameter of 1mm provides better results than encapsulation in beads with larger diameter. Alginate beads and chitosan coated beads have proved to be a strong barrier for nutrients from substrate, so samples with those beads have lower viable cell count, lower titratable acidity and higher pH value after 5h of fermentation at 42?C, than samples with WPC-alginate beads. Also those beads have significantly (P < 0.05) lower cell leaking, than WPC-alginate beads and lower antioxidant capacity. Encapsulation of yoghurt culture in WPC-alginate carrier with diameter of approximately 1mm provided the best characteristics for fermented product. Samples with these beads have significantly (P < 0.05) higher increase of viable cell number after fermentation, despite of major cell leaking (19.7 %). Moreover, sample with these beads have the highest titratable acidity, the lowest pH value after fermentation (the best fermentative activity) and the best antioxidant characteristics.

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Pestov, Aleksandr, Aleksandr Mekhaev, Yuliya Privar, Natalya Prokuda, Evgeniy Modin, and Svetlana Bratskaya. "SCREENING OF THE CATALYTIC ACTIVITY OF Pd0 AND Pd2+- SUPPORTED ON CHITOSAN BEADS AND CRYOGELS." Progress on Chemistry and Application of Chitin and its Derivatives XXIII (September 10, 2018): 149–58. http://dx.doi.org/10.15259/pcacd.23.015.

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Here, we report the results of screening of the catalytic activity of Pd-containing chitosan beads and cryogels in the cross-coupling reaction, hydrogenation of alkenes, nitro-, and carbonyl compounds and the hydrodechlorination of chlorophenols. Pd0-containing chitosan beads and cryogels show moderate catalytic activity in the reduction of alkenes and nitroaromatics. The conversion of nitroaromatics decreases for substrates with electron-withdrawing substituents, while the conversion of alkenes increases with the activation of carbon-carbon double bonds. For several substrates, a significant difference in kinetics and conversion degrees was observed for Pd nanoparticles supported on chitosan beads and cryogels. It was found that conversion in the hydrodechlorination reaction depends on substrate structure, being higher for substrates containing substituents with a positive mesomeric effect. Pd2+-chitosan catalysts showed high catalytic activity in cross-coupling (Heck reaction) offering the following advantages over known catalytic systems: lower reaction temperature, the selective functionalisation of C-I bonds, and the possibility to perform reactions with iodobenzene without base addition.

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Paraskevopoulou, Patrina, Irina Smirnova, Tamara Athamneh, Maria Papastergiou, Despoina Chriti, Gregor Mali, Tomaž Čendak, Grigorios Raptopoulos, and Pavel Gurikov. "Polyurea-crosslinked biopolymer aerogel beads." RSC Advances 10, no. 67 (2020): 40843–52. http://dx.doi.org/10.1039/d0ra07337g.

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Ouyang, An, and Ji Liang. "Tailoring the adsorption rate of porous chitosan and chitosan–carbon nanotube core–shell beads." RSC Adv. 4, no. 49 (2014): 25835–42. http://dx.doi.org/10.1039/c4ra04131c.

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de J. Martins, Douglas, Hanif-Ur-Rehman Hanif-Ur-Rehman, Samara R. Alves Rico, Iguatinã de M. Costa, Andrea C. Pio Santos, Rachel G. Szszudlowski, and Denise de Oliveira Silva. "Interaction of chitosan beads with a copper–naproxen metallodrug." RSC Advances 5, no. 109 (2015): 90184–92. http://dx.doi.org/10.1039/c5ra16878c.

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A new hybrid material resulting from the interaction of chitosan beads with a copper–naproxen metallodrug was prepared and characterized. The Acrycoat-coated beads were investigated for release behavior in gastric/intestinal pH simulated solutions.

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