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Core-shell alginate-ghatti gum modified montmorillonite composite matrices for stomach-specific flurbiprofen delivery

Bera H, Ippagunta SR, Kumar S, Vangala P

Mater Sci Eng C Mater Biol Appl, 2017 Jul 01;76:715-726.
PMID: 28482582 DOI: 10.1016/j.msec.2017.03.074

Novel alginate-arabic gum (AG) gel membrane coated alginate-ghatti gum (GG) modified montmorillonite (MMT) composite matrices were developed for intragastric flurbiprofen (FLU) delivery by combining floating and mucoadhesion mechanisms. The clay-biopolymer composite matrices containing FLU as core were accomplished by ionic-gelation technique. Effects of polymer-blend (alginate:GG) ratios and crosslinker (CaCl2) concentrations on drug entrapment efficiency (DEE, %) and cumulative drug release after 8h (Q8h, %) were studied to optimize the core matrices by a 32factorial design. The optimized matrices (F-O) demonstrated DEE of 91.69±1.43% and Q8hof 74.96±1.56% with minimum errors in prediction. The alginate-AG gel membrane enveloped optimized matrices (F-O, coated) exhibited superior buoyancy, better ex vivo mucoadhesion and slower drug release rate. The drug release profile of FLU-loaded uncoated and coated optimized matrices was best fitted in Korsmeyer-Peppas model with anomalous diffusion and case-II transport driven mechanism, respectively. The uncoated and coated matrices containing FLU were also characterized for drug-excipients compatibility, drug crystallinity, thermal behaviour and surface morphology. Thus, the newly developed alginate-AG gel membrane coated alginate-GG modified MMT composite matrices are appropriate for intragastric delivery of FLU over an extended period of time with improved therapeutic benefits.

Matched MeSH terms: Alginates
Advanced Dome cellulose/alginate/chitosan composite matrix design with gastric and intestinal co-targeting capacities

Razali S, Bose A, Benetti C, Chong PW, Miller M, Colombo P, et al.

Int J Pharm, 2022 Nov 25;628:122226.
PMID: 36191818 DOI: 10.1016/j.ijpharm.2022.122226

Dome matrix was designed with gastric and intestinal targeting capacities using melatonin and caffeine as model drugs, and alginate, chitosan and cellulose as composite materials. The melatonin, caffeine and intermediate hydroxypropylmethylcelluose-based dispersible modules were prepared through compaction. Caffeine piled module was capped at both ends with melatonin void modules via intermediate dispersible modules into Dome matrix. Dispersion of intermediate module detached melatonin module from Dome matrix and had it floated in stomach providing a more complete melatonin release due to favorable pH-pKa relationship of dissolution medium and drug. With reference to the caffeine module, the detachment of melatonin module facilitated its gastrointestinal transit as a reduced size matrix, with majority of caffeine delivered in colon. The dual site-targeted and -release Dome matrix is applicable as reference oral carrier for pharmaceutical, nutraceutical, functional food and veterinary medicine where a complex formulation and performancein vivoare required.

Matched MeSH terms: Alginates
Entrapment of porous cross-linked enzyme aggregates of maltogenic amylase from Bacillus lehensis G1 into calcium alginate for maltooligosaccharides synthesis

Nawawi NN, Hashim Z, Rahman RA, Murad AMA, Bakar FDA, Illias RM

Int J Biol Macromol, 2020 May 01;150:80-89.
PMID: 32035147 DOI: 10.1016/j.ijbiomac.2020.02.032

Maltooligosaccharides (MOSs) are emerging oligosaccharides in food-based applications and can be synthesized through the enzymatic synthesis of maltogenic amylase from Bacillus lehensis G1 (Mag1). However, the lack of enzyme stability makes this approach unrealistic for industrial applications. The formation of cross-linked enzyme aggregates (CLEAs) is a promising tool for improving enzyme stability, and the substrate accessibility problem of CLEA formation was overcome by the addition of porous agents to generate porous CLEAs (p-CLEAs). However, p-CLEAs exhibited high enzyme leaching and low solvent tolerance. To address these problems, p-CLEAs of Mag1 (Mag1-p-CLEAs) were entrapped in calcium alginate beads (CA). Mag1-p-CLEAs-CA prepared with 2.5% (w/v) sodium alginate and 0.6% (w/v) calcium chloride yielded 53.16% (17.0 U/mg) activity and showed a lower deactivation rate and longer half-life than those of entrapped free Mag1 (Mag1-CA) and entrapped non-porous Mag1-CLEAs (Mag1-CLEAs-CA). Moreover, Mag1-p-CLEAs-CA exhibited low enzyme leaching and high tolerance in various solvents compared to Mag1-p-CLEAs. A kinetic study revealed that Mag1-p-CLEAs-CA exhibited relatively high affinity towards beta-cyclodextrin (β-CD) (Km = 0.62 mM). MOSs (300 mg/g) were synthesized by Mag1-p-CLEAs-CA at 50 °C. Finally, the reusability of Mag1-p-CLEAs-CA makes them as a potential biocatalyst for the continuous synthesis of MOSs.

Matched MeSH terms: Alginates/metabolism*; Alginates/chemistry
Fulltext Marine algae as a potential source for anti-obesity agents

Chu WL, Phang SM

Mar Drugs, 2016 Dec 07;14(12).
PMID: 27941599 DOI: 10.3390/md14120222

Obesity is a major epidemic that poses a worldwide threat to human health, as it is also associated with metabolic syndrome, type 2 diabetes and cardiovascular disease. Therapeutic intervention through weight loss drugs, accompanied by diet and exercise, is one of the options for the treatment and management of obesity. However, the only approved anti-obesity drug currently available in the market is orlistat, a synthetic inhibitor of pancreatic lipase. Other anti-obesity drugs are still being evaluated at different stages of clinical trials, while some have been withdrawn due to their severe adverse effects. Thus, there is a need to look for new anti-obesity agents, especially from biological sources. Marine algae, especially seaweeds are a promising source of anti-obesity agents. Four major bioactive compounds from seaweeds which have the potential as anti-obesity agents are fucoxanthin, alginates, fucoidans and phlorotannins. The anti-obesity effects of such compounds are due to several mechanisms, which include the inhibition of lipid absorption and metabolism (e.g., fucoxanthin and fucoidans), effect on satiety feeling (e.g., alginates), and inhibition of adipocyte differentiation (e.g., fucoxanthin). Further studies, especially testing bioactive compounds in long-term human trials are required before any new anti-obesity drugs based on algal products can be developed.

Matched MeSH terms: Alginates/pharmacology; Alginates/chemistry
Aging and microwave effects on alginate/chitosan matrices

Wong TW, Chan LW, Kho SB, Heng PW

J Control Release, 2005 Jun 2;104(3):461-75.
PMID: 15911046

The influence of microwave irradiation on the drug release properties of freshly prepared and aged alginate, alginate-chitosan and chitosan beads was investigated. The beads were prepared by extrusion method with sulphathiazole as a model drug. The dried beads were subjected to microwave irradiation at 80 W for 10 min, 20 min or three consecutive cycles of 10 and 20 min, respectively. The profiles of drug dissolution, drug content, drug stability, drug polymorphism, drug-polymer interaction, polymer crosslinkage and complexation were determined by dissolution testing, drug content assay, differential scanning calorimetry and Fourier transform infra-red spectroscopy. The chemical stability of drug embedded in beads was unaffected by microwave conditions and length of storage time. The release property of drug was mainly governed by the extent of polymer interaction in beads. The aged alginate beads required intermittent cycles of microwave irradiation to induce drug release retarding effect in contrast to their freshly prepared samples. Unlike the alginate beads, the level of polymer interaction was higher in aged alginate-chitosan beads than the corresponding fresh beads. The drug release retarding property of aged alginate-chitosan beads could be significantly enhanced through subjecting the beads to microwave irradiation for 10 min. No further change in drug release from these beads was observed beyond 30 min of microwave irradiation. Unlike beads containing alginate, the rate and extent of drug released from the aged chitosan beads were higher upon treatment by microwave in spite of the higher degree of polymer interaction shown by the latter on prolonged storage. The observation suggested that the response of polymer matrix to microwave irradiation in induction of drug release retarding property was largely affected by the molecular arrangement of the polymer chains.

Matched MeSH terms: Alginates/radiation effects*; Alginates/chemistry
Recent Advances in Polymer-based Wound Dressings for the Treatment of Diabetic Foot Ulcer: An Overview of State-of-the-art

Hussain Z, Thu HE, Shuid AN, Katas H, Hussain F

Curr Drug Targets, 2018;19(5):527-550.
PMID: 28676002 DOI: 10.2174/1389450118666170704132523

BACKGROUND: Diabetic foot ulcers (DFUs) are the chronic, non-healing complications of diabetic mellitus which compels a significant burden to the patients and the healthcare system. Peripheral vascular disease, diabetic neuropathy, and abnormal cellular and cytokine/chemokine activity are among the prime players which exacerbate the severity and prevent wound repair. Unlike acute wounds, DFUs impose a substantial challenge to the conventional wound dressings and demand the development of novel and advanced wound healing modalities. In general, an ideal wound dressing should provide a moist wound environment, offer protection from secondary infections, eliminate wound exudate and stimulate tissue regeneration.
OBJECTIVE: To date, numerous conventional wound dressings are employed for the management of DFUs but there is a lack of absolute and versatile choice. The current review was therefore aimed to summarize and critically discuss the available evidences related to pharmaceutical and therapeutic viability of polymer-based dressings for the treatment of DFUs.
RESULTS: A versatile range of naturally-originated polymers including chitosan (CS), hyaluronic acid (HA), cellulose, alginate, dextran, collagen, gelatin, elastin, fibrin and silk fibroin have been utilized for the treatment of DFUs. These polymers have been used in the form of hydrogels, films, hydrocolloids, foams, membranes, scaffolds, microparticles, and nanoparticles. Moreover, the wound healing viability and clinical applicability of various mutually modified, semi-synthetic or synthetic polymers have also been critically discussed.
CONCLUSION: In summary, this review enlightens the most recent developments in polymer-based wound dressings with special emphasis on advanced polymeric biomaterials, innovative therapeutic strategies and delivery approaches for the treatment of DFUs.

Matched MeSH terms: Alginates/pharmacology; Alginates/therapeutic use
Functional polysaccharides of fucoidan, laminaran and alginate from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana)

Mohd Fauziee NA, Chang LS, Wan Mustapha WA, Md Nor AR, Lim SJ

Int J Biol Macromol, 2021 Jan 15;167:1135-1145.
PMID: 33188815 DOI: 10.1016/j.ijbiomac.2020.11.067

Brown seaweeds are rich source of functional polysaccharides that exhibit various bioactivities. However, Malaysian seaweeds are under-utilised, leading to low revenue throughout the supply chain of the seaweed industry. The aims of this study were to extract the functional polysaccharides, namely fucoidan (F), laminaran (L) and alginate (A) from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana) and subsequently evaluate the properties of the extracted polysaccharides. P. boryana recorded the significantly (p ≤ 0.05) highest carbohydrate content (74.78 ± 1.63%) with highest fucoidan yield (Fpad = 1.59 ± 0.16%) while T. ornata contained significantly (p ≤ 0.05) highest alginate yield (Atur = 105.19 ± 3.45%). Water activities of these extracted polysaccharides varied from 0.63-0.71 with average score of browning indexes (~40). Fourier transform infrared (FTIR) spectroscopy analysis demonstrated that the extracted polysaccharides exhibited similar spectral pattern of spectra with the respective standards. Meanwhile, laminaran extracts showed the significantly highest (p ≤ 0.05) total phenolic contents (Lsar = 43.29 ± 0.43 mgGAE/g) and superoxide anion scavenging activity (Lsig = 21.7 ± 3.6%). On the other hand, the significantly highest (p ≤ 0.05) DPPH scavenging activity was recorded in alginate with Asar at 85.3 ± 0.8%. These findings reported the properties and bioactivities of natural polysaccharides from Malaysian brown seaweeds that revealed the potential to develop high-value functional ingredients from Malaysian brown seaweeds.

Matched MeSH terms: Alginates/isolation & purification; Alginates/chemistry*
Agarose- and alginate-based biopolymers for sample preparation: Excellent green extraction tools for this century

Sanagi MM, Loh SH, Wan Ibrahim WN, Pourmand N, Salisu A, Wan Ibrahim WA, et al.

J Sep Sci, 2016 Mar;39(6):1152-9.
PMID: 27027592 DOI: 10.1002/jssc.201501207

Recently, there has been considerable interest in the use of miniaturized sample preparation techniques before the chromatographic monitoring of the analytes in unknown complex compositions. The use of biopolymer-based sorbents in solid-phase microextraction techniques has achieved a good reputation. A great variety of polysaccharides can be extracted from marine plants or microorganisms. Seaweeds are the major sources of polysaccharides such as alginate, agar, agarose, as well as carrageenans. Agarose and alginate (green biopolymers) have been manipulated for different microextraction approaches. The present review is focused on the classification of biopolymer and their applications in multidisciplinary research. Besides, efforts have been made to discuss the state-of-the-art of the new microextraction techniques that utilize commercial biopolymer interfaces such as agarose in liquid-phase microextraction and solid-phase microextraction.

Matched MeSH terms: Alginates
Fulltext Effects of different drying methods and hydrocolloids on quality properties of semi-dried catfish jerky

Ishamri Ismail, Nur Husna Mohd Fauzi, Mastura Zahidi Baki, Ho, Lee Hoon

Malaysian Journal of Applied Sciences, 2018;2(1):11-18.
MyJurnal

This study was carried out to evaluate the effects of different drying methods (sun drying, cabinet
drying and convection oven) and hydrocolloids (carrageenan and alginate) on physicochemical
properties of semi-dried catfish jerky. The concentration of hydrocolloids used was 1% and 2%.
Samples without the addition of hydrocolloid served as the control group. The water activity of semidried catfish jerky decreased with the addition of hydrocolloids. For colour properties, lightness (L*)
value of semi-dried catfish jerky increased with the increased concentration of hydrocolloids. The
addition of 2% alginate (2%A) and 2% carrageenan (2%C) showed higher lightness (L*) than the
controlled group for all drying methods, except for sun drying with carrageenan. Both carrageenan and
alginate added into semi-dried catfish jerky increased the processing yields. The addition of 2%
carrageenan (2%C) and 1% alginate (1%A) improved the product yields for all drying methods. This
paper argues that the application of cabinet dryer gives better shelf stability due to the lower range of
water activity than other drying methods while preserving colour quality and product yields.

Matched MeSH terms: Alginates
Efficiency of pollutants removal in treated palm oil mill effluent (TPOME) using different concentrations of sodium alginate-immobilized Nannochloropsis sp. cells

Emparan Q, Harun R, Sing Jye Y

Int J Phytoremediation, 2021;23(5):454-461.
PMID: 32976718 DOI: 10.1080/15226514.2020.1825327

Palm oil mill effluent (POME) has high chemical oxygen demand (COD), thus requires effective treatments to environmentally benign levels before discharge. In this study, immobilized microalgae cells are used for removing pollutants in treated palm oil mill effluent (TPOME). Different ratios of microalgae beads to TPOME concentration were examined at 1:2.5, 1:5, and 1:10. The biomass concentration and COD removal were measured through a standard method. The color of the cultivated microalgae beads changed from light green to darker green after the POME treatment for 9 days, hence demonstrating that microalgae cells were successfully grown inside the beads with pH up to 9.84. The immobilized cells cultivated in the POME at 1:10 achieved a higher biomass concentration of 1.268 g/L and a COD removal percentage of 72% than other treatment ratios. The increment of the ratio of microalgae cells beads to POME concentration did not cause any improvement in COD removal efficiency. This was due to the inhibitory effect of self-shading resulting in the slow growth rate of microalgae cells which responsible for low COD removal. Therefore, this system could be a viable technology for simultaneous biomass production and POME treatment. This will contribute to research efforts toward the development of new and improved technologies in treating POME.

Matched MeSH terms: Alginates
Production of magnetic sodium alginate polyelectrolyte nanospheres for lead ions removal from wastewater

Wang J, Guo M, Luo Y, Shao D, Ge S, Cai L, et al.

J Environ Manage, 2021 Jul 01;289:112506.
PMID: 33831760 DOI: 10.1016/j.jenvman.2021.112506

Polyelectrolyte composite nanospheres are relatively new adsorbents which have attracted much attention for their efficient pollutant removal and reuse performance. A novel polyelectrolyte nanosphere with magnetic function (SA@AM) was synthesized via the electrostatic reaction between the polyanionic sodium alginate (SA) and the surface of a prepared terminal amino-based magnetic nanoparticles (AMs). SA@AM showed a size of 15-22 nm with 6.85 emu·g-1 of magnetization value, exhibiting a high adsorption capacity on Pb(II) ions representing a common heavy metal pollutant, with a maximum adsorption capacity of 105.8 mg g-1. The Langmuir isotherm adsorption fits the adsorption curve, indicating uniform adsorption of Pb(II) on the SA@AM surfaces. Repeated adsorption desorption experiments showed that the removal ratio of Pb(II) by SA@AM was more than 76%, illustrating improved regeneration performance. These results provide useful information for the production of bio-based green magnetic nano scale adsorption materials for environmental remediation applications.

Matched MeSH terms: Alginates
Fulltext Design of polysaccharidic nano-in-micro soft agglomerates as primary oral drug delivery vehicle for colon-specific targeting

Musa N, Wong TW

Carbohydr Polym, 2020 Nov 01;247:116673.
PMID: 32829801 DOI: 10.1016/j.carbpol.2020.116673

Microencapsulation of polysaccharidic nanoparticles is met with nanoscale and biological performance changes. This study designs soft agglomerates as nanoparticle vehicle without nanoparticles undergoing physical processes that alter their geometry. The nanoparticles were made of high molecular weight chitosan/pectin with covalent 5-fluorouracil/folate. Nanoparticle aggregation vehicle was prepared from low molecular weight chitosan. The nanoparticles and aggregation vehicle were blended in specific weight ratios to produce soft agglomerates. Nanoparticles alone are unable to agglomerate. Adding aggregation vehicle (< 2 μm) promoted soft agglomeration with nanoparticles deposited onto its surfaces with minimal binary coalescence. The large and rough-surfaced aggregation vehicle promoted nanoparticles deposition and agglomeration. A rounder vehicle allowed assembly of nanoparticles-on-aggregation vehicle into agglomerates through interspersing smaller between larger populations. Soft agglomeration reduced early drug release, and was responsive to intracapsular sodium alginate coat to further sustain drug release. The soft agglomerates can serve as a primary oral colon-specific vehicle.

Matched MeSH terms: Alginates
Fulltext Biological Self-Healing of Cement Paste and Mortar by Non-Ureolytic Bacteria Encapsulated in Alginate Hydrogel Capsules

Fahimizadeh M, Diane Abeyratne A, Mae LS, Singh RKR, Pasbakhsh P

Materials (Basel), 2020 Aug 22;13(17).
PMID: 32842561 DOI: 10.3390/ma13173711

Crack formation in concrete is one of the main reasons for concrete degradation. Calcium alginate capsules containing biological self-healing agents for cementitious materials were studied for the self-healing of cement paste and mortars through in vitro characterizations such as healing agent survivability and retention, material stability, and biomineralization, followed by in situ self-healing observation in pre-cracked cement paste and mortar specimens. Our results showed that bacterial spores fully survived the encapsulation process and would not leach out during cement mixing. Encapsulated bacteria precipitated CaCO3 when exposed to water, oxygen, and calcium under alkaline conditions by releasing CO32- ions into the cement environment. Capsule rupture is not required for the initiation of the healing process, but exposure to the right conditions are. After 56 days of wet-dry cycles, the capsules resulted in flexural strength regain as high as 39.6% for the cement mortar and 32.5% for the cement paste specimens. Full crack closure was observed at 28 days for cement mortars with the healing agents. The self-healing system acted as a biological CO32- pump that can keep the bio-agents retained, protected, and active for up to 56 days of wet-dry incubation. This promising self-healing strategy requires further research and optimization.

Matched MeSH terms: Alginates
Fulltext Field demonstration of irradiated sodium alginate as tea production booster

Hossain MA, Islam JMM, Hoque MM, Nahar S, Khan MA

Heliyon, 2021 Jan;7(1):e05881.
PMID: 33458447 DOI: 10.1016/j.heliyon.2020.e05881

Sodium alginate oligomers were tested for tea plant growth promoter and anti-fungal agent in this experiment. Sodium alginate solutions were irradiated by Co-60 gamma radiation with different radiation doses to produce the oligomers. Irradiated solutions were then diluted into 150, 300 and 500 ppm prior to foliar application. Solutions were applied through foliar spraying at 7 days interval and the best response of tea plants in terms of various attributes were recorded. Tea buds were collected in 10 days of interval and the growth attributes like- total number of buds, fresh weight of buds, average leaf area and weight per bud, weight of made tea etc. were calculated. The experiment was continued up to 12 weeks and the attributes were averaged to get results per plucking. 12 kGy radiation doses along with 300ppm solution showed the best results and about 36% increase in productivity was found based on the fresh weight of buds. Total fungal count in tea leaves was also found to be reduced greatly. Based on the present study, irradiated sodium alginate could be used as safe and environmentally friendly agent to increase tea production.

Matched MeSH terms: Alginates
Taguchi design-assisted immobilization of Candida rugosa lipase onto a ternary alginate/nanocellulose/montmorillonite composite: Physicochemical characterization, thermal stability and reusability studies

Mohd Hussin FNN, Attan N, Wahab RA

Enzyme Microb Technol, 2020 May;136:109506.
PMID: 32331714 DOI: 10.1016/j.enzmictec.2019.109506

Biomass from oil palm frond leaves (OPFL) is an excellent reservoir of lignocellulosic material which full potential remains untapped. This study aimed to statistically optimize the covalent immobilization of Candida rugosa lipase (CRL) onto a ternary support comprised of OPFL derived nanocellulose (NC) and montmorillonite (MMT) in alginate (ALG) (CRL-ALG/NC/MMT). The coarser topology and the presence of characteristic spherical globules in the field emission scanning electron micrographs and atomic force micrographs, respectively, supported the existence of CRL on ALG/NC/MMT. In addition, amide peaks at 3478 and 1640 cm-1 in the fourier transform infrared spectra affirmed that CRL was covalently bonded to ALG/NC/MMT. The optimized Taguchi Design-assisted immobilization of CRL onto ALG/NC/MMT (7 h of immobilization, 35℃, pH 5, 7 mg/mL protein loading) gave a production yield of 92.89 % of ethyl levulinate (EL), as proven by gas chromatography-mass spectrometric ([M] +m/z 144, C7H12O3), FTIR and nuclear magnetic resonance (CAS-539-88-8) data. A higher optimal reaction temperature (50℃) and the reusability of CRL-ALG/NC/MMT for up to 9 esterification cycles substantiated the appreciable structural rigidification of the biocatalyst by ALG/NC/MMT, which improved the catalytic activity and thermal stability of the lipase.

Matched MeSH terms: Alginates
Fulltext Development of seed treatments biofertilizer and nutrient uptake study using tracer technique for okra plants

Hoe, Phua Choo Kwai, Khairuddin Abdul Rahim, Ahmad Nazrul Abd Wahid

Jurnal Sains Nuklear Malaysia, 2013;25(1):16-23.
MyJurnal

Development of biofertilizer seed treatments for okra seeds were carried out by mixing phosphate
solubilising bacteria (AP 3) and plant growth promoter (AP 2) with adhesives. The seeds were
coated with inoculums and four types of adhesives namely, Gum Arabic; Polyethylene Glycol
(PEG); Sodium Alginate and Methycellulose respectively. From eight seed treatments, all seed
treatments significantly increased seed germinations except treatment T4 (Gum Arabic and AP3).
In general, maximum germination rates and log of viable cells were observed when treated with
polyethylene glycol 4000 (PEG) mixed with AP2 (T7) and AP3 (T8). These results show that using
PEG as adhesive enhanced the germination rates and log of viable cells of AP2 and AP3. Thus,
PEG could be a good adhesive for seed treatment. In greenhouse experiment, okra seeds treatment
with AP2 and PEG (T1) showed the highest dry weight compared to other treatments. Seeds
treatment with AP3 and PEG (T2) showed higher contribution of N compare to seeds treatment
(T1). There were no significant different within seed treatments and urea treatment in okra yield.
All treatments significantly increased yields compared with control

Matched MeSH terms: Alginates
Anti-thrombogenicity and permeability of polyethersulfone hollow fiber membrane with sulfonated alginate toward blood purification

Salimi E, Ghaee A, Ismail AF, Karimi M

Int J Biol Macromol, 2018 Sep;116:364-377.
PMID: 29709537 DOI: 10.1016/j.ijbiomac.2018.04.137

The main aim of this study was to evaluate the suitability of sulfonated alginate as a modifying agent to enhance the hemocompatibility of self-fabricated polyethersulfone (PES) hollow fiber membrane for blood detoxification. Sodium alginate was sulfonated with a degree of 0.6 and immobilized on the membrane via surface amination and using glutaraldehyde as cross-linking agent. Coating layer not only improved the membrane surface hydrophilicity, but also induced -39.2 mV negative charges on the surface. Water permeability of the modified membrane was enhanced from 67 to 95 L/m2·h·bar and flux recovery ratio increased more than 2-fold. Furthermore, the modified membrane presented higher platelet adhesion resistance (reduced by more than 90%) and prolonged coagulation time (35 s for APTT and 14 s for PT) in comparison with the pristine PES hollow fiber membrane, which verified the improved anti-thrombogenicity of the modified membrane. On the other hand, obtained membrane after 3 h coating could remove up-to 60% of the uremic toxins. According to the obtained data, sulfonated alginate can be a promising modifying agent for the future blood-contacting membrane and specially blood purification issues.

Matched MeSH terms: Alginates
The preparation of graphene ink from the exfoliation of graphite in pullulan, chitosan and alginate for strain-sensitive paper

Kasim NFA, W Idris WF, Abdullah AH, Yusoh K, Ismail Z

Int J Biol Macromol, 2020 Jun 15;153:1211-1219.
PMID: 31756469 DOI: 10.1016/j.ijbiomac.2019.10.251

A sonication of graphite in polysaccharide (pullulan, chitosan and alginate) is one of the viable methods for the preparation of few-layer graphene. However, the effect of these adsorbed polysaccharides on the electrical performance of the produced graphene so far is not yet clear. In order to investigate the present effect of pullulan, chitosan and alginate on the electrical characteristic of resulted graphene, we have produced few-layer graphene using bath sonication of graphite in pullulan, chitosan and alginate medium for the application as electrical conductive ink in strain-sensitive. Data from the TEM reveals the appearance of folded few-layer graphene flakes after sonication for 150 min while the XPS data shows that the chitosan-based graphene possesses the highest carbon-oxygen ratio of 7.2 as compared to that of the pullulan and alginate-based graphene. By subjecting the produced graphene as the ink for paper-based strain sensor, we have discovered that the chitosan-graphene has the best resistivity value (1.66 × 10-3 Ω⋅cm) and demonstrate the highest sensitivity towards strain (GF: 18.6). This result interestingly implies the potential of the reported chitosan-based conductive ink as a strain-sensitive material for future food packaging.

Matched MeSH terms: Alginates
Fabrication of alginate microspheres for drug delivery: A review

Uyen NTT, Hamid ZAA, Tram NXT, Ahmad N

Int J Biol Macromol, 2020 Jun 15;153:1035-1046.
PMID: 31794824 DOI: 10.1016/j.ijbiomac.2019.10.233

Alginate microspheres (AMs) have received much attention as a novel drug delivery system owing to various advantages of alginate such as inexpensiveness, nontoxicity, biocompatibility and biodegradability. The well-designed fabrication method is essential to achieve desired AMs suitable for specific drug delivery system. Reports on AMs preparation techniques have increased rapidly in the last decade. A number of synthesis parameters have been investigated for the improvement of physical, chemical and biological properties of AMs. Hence, this review summarizes the work to date on the fabrication techniques of AMs for drug delivery system, including spray-drying, extrusion and emulsification/gelation technique. Besides, the influence of various factors such as alginate concentration, oil phase, surfactant, cross-linker concentrations, cross-linking time, stirring speed, model drug and drug content on the morphologies, properties and encapsulation efficiency (EE) of AMs via extrusion and emulsification/gelation technique are summarized. Before embarking on the development of any drug delivery system, a thorough understanding of drug release mechanism and factors that impact the drug release profile are essential, which are also covered in this review.

Matched MeSH terms: Alginates
Progress and perspective on algal plastics - A critical review

Zhang C, Show PL, Ho SH

Bioresour Technol, 2019 Oct;289:121700.
PMID: 31262543 DOI: 10.1016/j.biortech.2019.121700

There is a growing interest in developing bio-based biodegradable plastics to reduce the dependence on depleting fossil fuels and provide a sustainable alternative. Bio-based plastics can usually be produced from lipids, proteins or carbohydrates, which are major components of microalgae. Despite its potential for algal plastics, little information is available on strain selection, culture optimization and bioplastics fabrication mechanism. In this review, we summarized the recent developments in understanding the utilization of seaweed polysaccharides, such as alginate and carrageenan for bio-based plastics. In addition, a conceptual biorefinery framework for algal plastics through promising components (e.g., lipids, carbohydrates and proteins) from microalgae is comprehensively presented. Moreover, the reasons for variations in bioplastics performance and underlying mechanism of various algal biocomposites have been critically discussed. We believe this review can provide valuable information to accelerate the development of innovative green technologies for improving the commercial viability of algal plastics.

Matched MeSH terms: Alginates

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