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Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in therapy due to their anti-inflammatory and analgesic properties. However, their clinical use is often associated with gastrointestinal complications. Thus, this study aimed to investigate the protective effect of a sulfated iota-carrageenan isolated from the marine alga Solieria filiformis (IC-Sf) against naproxen-induced gastrointestinal injury. Methods: Parameters of gastrointestinal injury, secretory and motor functions, and toxicity were evaluated. Results: The results demonstrated that IC-Sf significantly reduced naproxen-induced gastrointestinal macroscopic injury, with a maximum effect observed at 30 mg/kg. IC-Sf also preserved gastrointestinal antioxidant defense and prevented lipid peroxidation, with a reduction in the non-protein sulfhydryl group (NP-SH) and malondialdehyde (MDA) concentrations induced by naproxen. Additionally, IC-Sf mitigated naproxen-induced gastrointestinal inflammation, as evidenced by reduced myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β). IC-Sf did not alter gastric secretion or gastrointestinal motility. In addition, the animals treated with IC-Sf did not present toxic effects. Conclusions: In conclusion, IC-Sf protected the gastrointestinal tract against the harmful effects of naproxen by inhibiting the inflammatory response and lipid peroxidation, suggesting its potential as a new therapeutic agent or food additive. [ABSTRACT FROM AUTHOR]

Red seaweed carrageenans are frequently used in industry for its texturizing properties and have demonstrated antiviral activities that can be used in human medicine. However, their high viscosity, high molecular weight, and low skin penetration limit their use. Low-weight carrageenans have a reduced viscosity and molecular weight, enhancing their biological properties. In this study, ι-carrageenan from Solieria chordalis, extracted using hot water and dialyzed, was depolymerized using hydrogen peroxide and ultrasound. Ultrasonic depolymerization yielded fractions of average molecular weight (50 kDa) that were rich in sulfate groups (16% and 33%) compared to those from the hydrogen peroxide treatment (7 kDa, 6% and 9%). The potential bioactivity of the polysaccharides and low-molecular-weight (LMW) fractions were assessed using WST-1 and LDH assays for human fibroblast viability, proliferation, and cytotoxicity. The depolymerized fractions did not affect cell proliferation and were not cytotoxic. This research highlights the diversity in the biochemical composition and lack of cytotoxicity of Solieria chordalis polysaccharides and LMW fractions produced by a green (ultrasound) depolymerization method. [ABSTRACT FROM AUTHOR]

The present investigation combines diverse experimental methodologies with meticulous examination of the alterations throughout the technique and sheds new light on the interaction between iota carrageenan and ethanol. The interaction of ethanol and iota-carrageenan gives an unstable conformer (eclipsed) with the help of interaction between the disulfate and hydroxy group, which gives the soluble solution phase instead of gel from. The results regarding the interaction between disulfate and ethanol confirm the essential role of disulfate, and the alteration in the physical characteristic of ethanol further substantiates the presence of hydrogen bonding, as evidenced by the widening of the infrared peak of C–O–S (710–720 cm−1), S–O (1100 cm−1); moreover, the broadening of the peak corresponds to the S=O strongly suggests the interaction with ethanol through hydrogen bonding. The interaction of the carrageenan and ethanol was also confirmed by the evaporation process, which suggests the 20% reduction in the volume of ethanol where iota carrageenan was added; however, in case of kappa, the volume reduction was 60%. In addition to that, the microscopic analysis of the carrageenan and ethanol also supports the possibility of interaction and role of disulfate in the interaction. The solution phase of carrageenan can be utilized further for the chemical reaction for the functionalization and grafting, while in most of the solvent it remains in insoluble form or in gel form, which does not provide a homogenous system to molecule colloids for the reaction. [ABSTRACT FROM AUTHOR]

Soft actuators belong to a type of actuators made of soft materials which are capable of converting applied energy to mechanical motion. They have been utilized in several fields due to their flexibility, low weight, inexpensiveness and simple fabrication. In this work, iota‐carrageenan (푖C) was chosen as the starting material for a hydrogel‐based actuator. The 푖C hydrogels were fabricated via a simple solvent‐casting technique at various concentrations: 2.4% (v/v), 2.8% (v/v) and 3.2% (v/v). All 푖C hydrogels were characterized for their chemical, thermal, rheological and morphological properties as well as the actuation performances under applied electric field. The 푖C hydrogels showed monotonic increases in the static bending distance and dielectrophoretic force with increasing electric field strength. Above the critical electrical field strengths, the ribbon‐like 푖C hydrogels oscillated back and forth due to the competition between the dielectrophoresis force, the resisting elastic force, the weight and the inertia force. Stability diagrams were constructed for the first time separating static bending from oscillation behavior under constant applied electric fields. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, novel smart graft hydrogels (SGHs) were prepared by simultaneous grafting/crosslinking of acrylamide and maleic acid onto iota-carrageenan (CR) in the presence of N,N′-methylenebisacrylamide or 1,4-butanediol diacrylate crosslinkers. The SGHs were characterized by FTIR, SEM, TG, DSC analysis and swelling studies. The sizes of the cavities in the SGHs were determined by digital image analysis using micrographs from the SEM. The average cavity diameters in SGHs are around 10 to 12 μm and have a heterogeneous distribution. The adsorption of uranyl ion on SGHs was investigated by spectroscopic, kinetic and equilibrium studies. The accuracy of the pseudo-first and pseudo-second-order kinetic models applied to the swelling and adsorption properties of the hydrogels were evaluated by correlation coefficient (R2), mean bias error (MBE), root mean square error (RMSE), reduced chi-square (χ2) and t-statistic model. The swelling and adsorption kinetics of the hydrogels were found to be consistent with the pseudo-second-order model. The adsorption isotherms of uranyl ion on SGHs were found to be L-type according to the Giles isotherm classification. Freundlich and Langmuir models were applied to these isotherms and adsorption parameters were calculated. From the Langmuir model, the monolayer adsorption capacities of SGH-N and SGH-B were calculated to be 162 and 167 mg g−1, and the maximum fractional occupancy values were calculated to be 99% and 97%, respectively. The pH-responsive swelling and adsorption behavior of the hydrogels was determined and the transition points were determined by applying Saraydın's model to the plotted curves. It was also observed that the amount of uranyl ions adsorbed increased with the increase of adsorbent mass. In conclusion, this study demonstrates that the synthesized SGHs can be used as an effective adsorbent for the removal of uranyl ions from an aqueous solution. [ABSTRACT FROM AUTHOR]

Nicole Unger-Manhart,1,* Martina Morokutti-Kurz,1,* Petra U Zieglmayer,2,3 Patrick Lemell,2 Markus Savli,4 René Zieglmayer,2 Eva Prieschl-Grassauer1 1Marinomed Biotech AG, Korneuburg, Austria; 2Vienna Challenge Chamber, Vienna, Austria; 3Competence Center for Allergology and Immunology, Karl Landsteiner University, Krems, Austria; 4Biostatistik & Consulting GmbH, Zurich, Switzerland*These authors contributed equally to this workCorrespondence: Eva Prieschl-Grassauer, Marinomed Biotech AG, Hovengasse 25, Korneuburg, 2100, Austria, Tel +43 226292300, Email office@marinomed.comPurpose: Nonpharmacological, barrier-forming nasal sprays are used to manage symptoms of allergic rhinitis. We aim to evaluate the safety and effectiveness of Callergin (investigational product, IP), a nasal spray containing barrier-forming iota-carrageenan, in the treatment of allergic rhinitis (AR).Methods: In this randomized, controlled, crossover trial, adults with grass pollen allergy underwent a treatment sequence with IP, VisAlpin (comparator product, CP), and no treatment in random order. Treatment blocks consisted in prophylactic administration of the assigned treatment or no treatment, followed by a 3-hr allergen exposure, and were separated by a washout period of 7 days. Primary endpoint was a mean change from baseline in “Total Nasal Symptom Score” (TNSS, sum of rhinorrhea, itching, sneezing, and congestion scores) over 3 hr, recorded every 15 min during the challenge period.Results: A total of 42 participants underwent randomization. Exposure to grass pollen for 3 hr induced a notable TNSS increase from baseline in all participants at all times. Mean TNSS change from baseline over 3 hr was lower when participants received IP compared to no treatment, although the difference did not reach statistical significance (untreated 6.96 ± 2.30; IP 6.59 ± 1.93; difference 0.37 points [95% CI (confidence interval) − 0.17 to 0.91]; p=0.170). In a post-hoc analysis, mean TNSS at 3 hr was significantly reduced after IP treatment compared to no treatment (untreated 8.29 ± 2.64; IP 7.70 ± 2.56; difference 0.60 points [95% CI − 0.10 to 1.29] p=0.028). While all individual nasal symptoms contributed to this effect, rhinorrhea (p=0.013) and congestion (p=0.076) contributed most. Consistently, nasal secretion weight was slightly reduced with IP treatment (p=0.119). IP was safe and well-tolerated, with similar incidence of adverse events across treatment groups.Conclusion: Prophylactic treatment with the iota-carrageenan nasal spray IP is safe, well-tolerated, and alleviates nasal allergy symptoms in adults with grass pollen-induced AR.Trial Registration: NCT04531358.Keywords: allergic rhinitis, nonpharmacological, drug-free, barrier, iota-carrageenan

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in therapy due to their anti-inflammatory and analgesic properties. However, their clinical use is often associated with gastrointestinal complications. Thus, this study aimed to investigate the protective effect of a sulfated iota-carrageenan isolated from the marine alga Solieria filiformis (IC-Sf) against naproxen-induced gastrointestinal injury. Methods: Parameters of gastrointestinal injury, secretory and motor functions, and toxicity were evaluated. Results: The results demonstrated that IC-Sf significantly reduced naproxen-induced gastrointestinal macroscopic injury, with a maximum effect observed at 30 mg/kg. IC-Sf also preserved gastrointestinal antioxidant defense and prevented lipid peroxidation, with a reduction in the non-protein sulfhydryl group (NP-SH) and malondialdehyde (MDA) concentrations induced by naproxen. Additionally, IC-Sf mitigated naproxen-induced gastrointestinal inflammation, as evidenced by reduced myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β). IC-Sf did not alter gastric secretion or gastrointestinal motility. In addition, the animals treated with IC-Sf did not present toxic effects. Conclusions: In conclusion, IC-Sf protected the gastrointestinal tract against the harmful effects of naproxen by inhibiting the inflammatory response and lipid peroxidation, suggesting its potential as a new therapeutic agent or food additive.

Red seaweed carrageenans are frequently used in industry for its texturizing properties and have demonstrated antiviral activities that can be used in human medicine. However, their high viscosity, high molecular weight, and low skin penetration limit their use. Low-weight carrageenans have a reduced viscosity and molecular weight, enhancing their biological properties. In this study, ι-carrageenan from Solieria chordalis, extracted using hot water and dialyzed, was depolymerized using hydrogen peroxide and ultrasound. Ultrasonic depolymerization yielded fractions of average molecular weight (50 kDa) that were rich in sulfate groups (16% and 33%) compared to those from the hydrogen peroxide treatment (7 kDa, 6% and 9%). The potential bioactivity of the polysaccharides and low-molecular-weight (LMW) fractions were assessed using WST-1 and LDH assays for human fibroblast viability, proliferation, and cytotoxicity. The depolymerized fractions did not affect cell proliferation and were not cytotoxic. This research highlights the diversity in the biochemical composition and lack of cytotoxicity of Solieria chordalis polysaccharides and LMW fractions produced by a green (ultrasound) depolymerization method.

Extrusion-based bioprinting has demonstrated significant potential for manufacturing constructs, particularly for 3D cell culture. However, there is a greatly limited number of bioink candidates exploited with extrusion-based bioprinting, as they meet the opposing requirements for printability with indispensable rheological features and for biochemical functionality with desirable microenvironment. In this study, a blend of silk fibroin (SF) and iota-carrageenan (CG) was chosen as a cell-friendly printable material. The SF/CG ink exhibited suitable viscosity and shear-thinning properties, coupled with the rapid sol-gel transition of CG. By employing photo-crosslinking of SF, the printability with Pr value close to 1 and structural integrity of the 3D constructs were significantly improved within a matter of seconds. The printed constructs demonstrated a Young's modulus of approximately 250 kPa, making them suitable for keratinocyte and myoblast cell culture. Furthermore, the high cell adhesiveness and viability (maximum >98%) of the loaded cells underscored the considerable potential of this 3D culture scaffold applied for skin and muscle tissues, which can be easily manipulated using an extrusion-based bioprinter.

The aim of this work was to evaluate the influence of high intensity ultrasound (HIUS) treatment on the molecular conformation of whey protein isolated (WPI) as a previous step for complex coacervation with iota carrageenan (IC) and its effect on the surface functional properties of complex coacervates (CC). Both biopolymers were hydrated (1% w/w) separately. A WPI suspension was treated with an ultrasonic bath (40 kHz, 600 W, 30 and 60 min, 100% amplitude). A non-sonicated protein was used as a control. Coacervation was achieved by mixing WPI and IC dispersions (10 min). FTIR-ATR analysis (400–4000 cm−1) detected changes after sonication on WPI secondary structure (1600–1700 cm−1), electrostatic interaction between WPI and IC by electronegative IC charged groups like sulfate (1200–1260 cm−1), anhydrous oxygen of the 3.6 anhydro-D-galactose (940–1066 cm−1) and the electropositive regions of WPI. Rheology results showed pseudoplastic behavior of both IC and WPI-IC with a significant change in viscosity level. Further, HIUS treatment had a positive effect on the emulsifying properties of the WPI-IC coacervates, increasing the time foaming (30 min) and emulsion stability (1 month) percentage. HIUS and complex coacervation proved to be an efficient tool to improve the surface functional properties of WPI. [ABSTRACT FROM AUTHOR]

Biodegradable polymer films composed of Iota-Carrageenan and Copper Sulphate Pentahydrate (CuSO4.5H2O) were prepared by using the Solution Casting process. To investigate the optical property, different wt.% of CuSO4.5H2O were added to I-carrageenan polymer films. X-Ray diffraction analysis was used to study the structural properties of prepared electrolytes. FTIR study revealed the complexation between the polymer and the salt. The increase in the amorphous nature of the film by the addition of the salt was confirmed using an X-Ray Diffraction (XRD) pattern. The functional group and interaction between the different components present in the polymer film are observed from Fourier Transform Infrared (FTIR) analysis, implying that the addition of (CuSO4.5H2O) salt causes microstructural differences in the polymer film. The UV-Visible Spectrometer was used to record the optical properties like the absorption coefficient, extinction coefficient, and optical bandgap energy of the polymer blend electrolytes. From this, it was observed that the absorption value was increased with the addition of salt. The optical band gap was also recorded and it was observed that 20 wt.% of CuSO4.5H2O added film was found to have a higher energy gap (4.3 eV) compared with the other. [ABSTRACT FROM AUTHOR]

Even with its endemic transition, the COVID-19 pandemic remains a public health threat, particularly in the light of emerging variants of concern (VoCs) and the need for pandemic preparedness in the future. In November 2021, the SARS-CoV-2 VoC Omicron emerged and its subvariants BA.1, BA.2 and BA.5 became predominant. Although the protease inhibitor Paxlovid® and the polymerase inhibitors Molnupiravir and Remdesivir were approved as specific antiviral treatment options for COVID-19 patients in the early stages after infection, effective prophylactically acting substances without adverse effects are not available yet. In a recent study, we demonstrated that iota-carrageenan, a sulfated polysaccharide extracted from red seaweed, efficiently inhibits the replication of the SARS-CoV-2 Wuhan Type and the VoCs Alpha, Beta, Gamma and Delta. Now, we extended this study by investigating the antiviral effects of iota-, lambda- and kappa-carrageenans on the VoC Omicron subvariants BA.1, BA.2 and BA.5. Using a VoC Omicron BA.1 spike pseudotyped murine leukemia virus (BA.1 MLVOMVLP) as well as patient-derived SARS-CoV-2 Omicron isolates BA.1, BA.2 and BA.5 (SARS-CoV-2OM BA.1, SARS-CoV-2OM BA.2 and SARS-CoV-2OM BA.5), we demonstrate that iota-carrageenan exhibits similar antiviral activity against all analyzed Omicron subvariants. As with other VoCs shown before, the biologically inert iota-carrageenan was more efficient than kappa- and lambda-carrageenan. Altogether, these results confirm that, independent of the current and potential future variants, the physical barrier provided by iota-carrageenan might be applicable for prophylaxis and early treatment of SARS-CoV-2 infections. [ABSTRACT FROM AUTHOR]

In this research, iota carrageenan (ιC) was cross-linked with N, N-methylene bisacrylamide (MBA) to form ιC-g-MBA, as a new green solid acid catalyst. The catalyst structure and morphplogy were explored using FT-IR, TGA, BET, FESEM, and XRD techniques. It was used in 5-hydroxymethylfurfural (5-HMF) production by fructose and glucose dehydration. Factors contributing to reaction optimization, such as the solvent, temperature, catalyst amount, and reaction duration, were explored. The optimal conditions of the reaction for fructose dehydration were 160 °C and 1 h as the reaction temperature and time, respectively. It was established that the conversion of fructose and HMF yield was 95.5% and 93.1%, respectively. Similarly, the optimal temperature and time for the reaction of glucose dehydration were 160 °C and 2 h, respectively. Moreover, the HMF yield and glucose conversions were 46% and 93%. Reusability of the catalyst was analyzed, whereupon the catalyst proved capable of being reemployed after four runs. [ABSTRACT FROM AUTHOR]

This study demonstrated a one-pot process for the preparation of seaweed-based antibacterial foot care gel for the removal of odor. Foot gel comprised 97.5% water, 1.2% seaweed polymer, 0.2% bioactive molecule, and 1.1% preservative. The antibacterial efficiency of foot gel was tested against 14 bacterial strains, isolated from foot swab samples from five different healthy volunteers having foul foot odor. The 16S rRNA partial gene sequencing identification revealed all 14 bacterial strains were different Bacillus species. Foot gel was characterized using FTIR, Rheology, TGA, and gelling properties. The volunteer's feet were treated with just two drops (around 200 L) of foot care gel before wearing socks, which showed restriction in the growth of bacterial strains causing a foul odor within a few hours, therefore resulting in restrained the foul foot odor. Furthermore, the volunteer's remarks about feeling freshness, coolness, dryness, and smooth feet after applying the foot gel were very encouraging. The shelf life of foot gel was monitored for up to six months and during that time, no significant change in rheological characteristics and antibacterial efficiency was observed. Foot gel was compared with commercially available foot care products and foul odor removal efficiency was found identical in both. Results of this study showed that the odor-removing efficacy of developed foot gel was found better than other commercial products. [ABSTRACT FROM AUTHOR]

During the past few years, the world community has faced a number of problems related to the delivery and storage of milk and milk products. In particular, the situation provoked by quarantine restrictions in various coun - tries of the world forces to look for solutions regarding the use of non-traditional raw materials for the production of classic or similar food products. As a result, it is quite promising to use dairy products with extended shelf life, in particular, dry milk concentrates as the main protein carriers for the production of stable protein-fat systems. The use of dry milk proteins makes it possible to manufacture restored structural products that can be used as an alternative to classic ones. Therefore, the object of research is food components of various origins, in particular food modified starches, food fibers and their modifications, hydrocolloids. Characteristic indicators of viscosity with increasing shear stress were determined for 5 % solutions of modified starches of various types after brewing at a temperature of 80 °C. It was found that when the shear stress increases to a value of 200 Pa, there is a significant decrease in viscosity, which generally characterizes them as structural systems. The functional and technological indicators of wheat (VF-200), bamboo (BAF-200) food fibers (fiber length 200 microns) and carboxyl methyl cellulose (CMC) were studied. Increased functional and technological capabilities of CMC compared to dietary fibers were revealed. The kinetics of swelling of dietary fibers and CMC were studied, while the period of maximum intensification of the process, which is between 5 and 15 minutes, was determined. The maximum value of the swelling coefficient is characteristic for CMC 4.4 ± 0.04, for wheat fiber 4.01 ± 0.06, for bamboo fiber 3.81 ± 0.05. Using the method of mathematical and statistical processing of experi - mental data, optimization of concentration and technological modes was carried out to achieve maximum hydration and strength of iota-carrageenan gel. It was determined that at a concentration of 1 % during brewing at 80 °C and a time of 5 min. high enough gel strength can be achieved for optimum consistency in the overall system. The result of the work is a comprehensive study of the functional technological characteristics of food additives that will form the consistency of a structural protein-fat product of the cheese type, which can be used in sausage products as a filler, with the aim of improving the organoleptic, structural-mechanical and nutritional values of the finished products. [ABSTRACT FROM AUTHOR]

Martina Morokutti-Kurz, 1 Nicole Unger-Manhart, 1 Philipp Graf, 1 Pia Rauch, 2 Julia Kodnar, 1 Maximilian Große, 2 Christian Setz, 2 Markus Savli, 3 Friedrich Ehrenreich, 4 Andreas Grassauer, 1 Eva Prieschl-Grassauer, 1 Ulrich Schubert 2 1Marinomed Biotech AG, Korneuburg, 2100, Austria; 2Institute of Virology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany; 3Biostatistik & Consulting Savli, Hartberg, 8230, Austria; 4Practice Dr. Friedrich Ehrenreich, Vienna, 1170, AustriaCorrespondence: Martina Morokutti-KurzMarinomed Biotech AG, Korneuburg, 2100, AustriaEmail martina.morokutti-kurz@marinomed.comUlrich SchubertInstitute of Virology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, GermanyEmail ulrich.schubert@fau.dePurpose: The aim of this study was to investigate whether sucking of an iota-carrageenan containing lozenge releases sufficient iota-carrageenan into the saliva of healthy subjects to neutralize representatives of the most common respiratory virus families causing common cold and SARS-CoV-2.Patients and Methods: In this monocentric, open label, prospective clinical trial, 31 healthy subjects were included to suck a commercially available iota-carrageenan containing lozenge. Saliva samples from 27 subjects were used for ex vivo efficacy analysis. The study’s primary objective was to assess if the mean iota-carrageenan concentration of the saliva samples exceeded 5 μg/mL, which is the concentration known to reduce replication of human rhinovirus (hRV) 1a and 8 by 90%. The iota-carrageenan concentration of the saliva samples was analyzed by UV-Vis spectroscopy. The antiviral effectiveness of the individual saliva samples was determined in vitro against a panel of respiratory viruses including hRV1a, hRV8, human coronavirus OC43, influenza virus A H1N1pdm09, coxsackievirus A10, parainfluenza virus 3 and SARS-CoV-2 using standard virological assays.Results: The mean iota-carrageenan concentration detected in the saliva exceeds the concentration needed to inhibit 90% of hRV1a and hRV8 replication by 134-fold (95% CI 116.3– 160.8-fold; p < 0.001). Thus, the study met the primary endpoint. Furthermore, the iota-carrageenan saliva concentration was 60 to 30,351-fold higher than needed to reduce viral replication/binding of all tested viruses by at least 90% (p < 0.001). The effect was most pronounced in hCoV OC43; in case of SARS-CoV-2, the IC 90 was exceeded by 121-fold (p < 0.001).Conclusion: Sucking an iota-carrageenan containing lozenge releases sufficient iota-carrageenan to neutralize and inactivate the most abundant respiratory viruses as well as pandemic SARS-CoV-2. The lozenges are therefore an appropriate measure to reduce the viral load at the site of infection, hereby presumably limiting transmission within a population as well as translocation to the lower respiratory tract.Trial Registration: NCT04533906.Keywords: iota-carrageenan, respiratory viruses, corona virus, lozenges, antiviral, clinical study, SARS-CoV-2

The gel properties of scallop (Patinopecten yessoensis) male gonad hydrolysates (SMGHs) combined with different concentrations of iota-carrageenan (ι-C) were studied. SMGHs at 5% (w/v) were dispersed in 0.26%, 0.56% and 1.25% ι-C solution, respectively. The storage modulus value of SMGHs/ι-C increased with the increasing of ι-C concentration and reached 1392.7 Pa for 1.25% ι-C at 0.1 Hz, which was almost 116-fold greater than that of SMGHs. SMGHs combined with different concentrations of ι-C exhibited thermoreversible gel properties with melting and gelling temperatures of 40.2–51.3 °C and 30.6–33.9 °C, respectively. Non-destructive testing of gel samples by low-field nuclear magnetic resonance showed that the degree of water trapping in SMGHs/ι-C was in a ι-C concentration-dependent manner. SMGHs/ι-C showed three-dimensional network structures with a tendency toward denser with increasing of ι-C concentration. The improved gelation by the combination of SMGHs and ι-C as well as controlling the concentration of ι-C can provide information for potential application in food formulation. [ABSTRACT FROM AUTHOR]

Experiments were conducted to study the rheological behavior of iota-carrageenan Gels to which potato starch and low-esterified amidated pectin were added. The rheological measurements of carrageenan jellies were performed by a texture analyzer at different concentrations of gelling agent (iota-carrageenan) and fixed concentrations of starch (1.3 %) and pectin (0.3%). Following the experiments, rheological patterns related to rupture force, rupture deformation and firmness of the gels were evaluated. Potato starch and low esterified amidated pectin at certain concentrations do not show synergistic effects with iota-carrageenan. The addition of low esterified amidated pectin or potato starch in iota-carrageenan gel results in a significant reduction in deformation and a minimal reduction in the rupture force.

Iota-carrageenan (IC) nasal spray, a medical device approved for treating respiratory viral infections, has previously been shown to inhibit the ability of a variety of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to enter and replicate in the cell by interfering with the virus binding to the cell surface. The aim of this study was to further investigate the efficacy and safety of IC in SARS-CoV-2 infection in advanced in vitro models of the human respiratory epithelium, the primary target and entry port for SARS-CoV-2. We extended the in vitro safety assessment of nebulized IC in a 3-dimensional model of reconstituted human bronchial epithelium, and we demonstrated the efficacy of IC in protecting reconstituted nasal epithelium against viral infection and replication of a patient-derived SARS-CoV-2 strain. The results obtained from these two advanced models of human respiratory tract epithelia confirm previous findings from in vitro SARS-CoV-2 infection assays and demonstrate that topically applied IC can effectively prevent SARS-CoV-2 infection and replication. Moreover, the absence of toxicity and functional and structural impairment of the mucociliary epithelium demonstrates that the nebulized IC is well tolerated.

Iota-carrageenan is a sulfated polysaccharide extracted from red seaweeds, which, formulated into a nasal spray, has already been proven safe and effective in viral upper respiratory infections. In Calu-3, a human respiratory epithelium cell line, we explored the activity of a formula of iota-carrageenan and sodium chloride against SARS-CoV-2. In this study, the assayed formula, already approved as a nasal spray for human use, effectively inhibited SARS-CoV-2 infection, providing a more substantial reference for clinical studies or developments.

Objective: There is no specific antiviral treatment available for coronavirus disease 2019 (COVID-19). Among the possible natural constituents is carrageenan, a polymer derived from marine algae that possesses a variety of antiviral properties. The purpose of this review was to summarize the evidence supporting carrageenan subtypes' antiviral activity against the emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19. Methods: PubMed/MEDLINE and Google Scholar searches were conducted for publications using the terms ‘carrageenan’, ‘iota carrageenan’, ‘kappa carrageenan’, lambda-carrageenan’, 'coronavirus', ‘common cold’, 'rhinovirus', and ‘SARS-CoV-2′ search was also done in grey literature to increase our understanding. A search for the word “carrageenan” was also carried out. Most of the publications were discussed in narrative. Results: Carrageenan has been shown to have potent antiviral activity against both coronaviruses (coronavirus NL63, SARS-CoV-2) and non-coronaviruses such as dengue virus, herpes simplex virus, cytomegalovirus, vaccinia virus, vesicular stomatitis virus, sindbis virus, human immunodeficiency virus, influenza virus, human papillomavirus, rabies virus, junin virus, tacaribe virus, African swine fever, bovine herpes virus, suid herpes virus, and rhinovirus. No in vivo study has been conducted using carrageenan as an anti-SARS-CoV-2 agent. The majority of the in vivo research was done on influenza, a respiratory virus that causes common cold together with coronavirus. Thus, various clinical trials were conducted to determine the transferability of these in vitro data to clinical effectiveness against SARS-CoV-2. When combined with oral ivermectin, nasally administered iota-carrageenan improved outcome in COVID-19 patients. It is still being tested in clinics for single-dose administration. Conclusion: Though the carrageenan exhibited potent antiviral activity against SARS-CoV-2 and was used to treat COVID-19 under emergency protocol in conjunction with oral medications such as ivermectin, there is no solid evidence from clinical trials to support its efficacy. Thus, clinical trials are required to assess its efficacy for COVID-19 treatment prior to broad application.

Abstract In this individual patient data meta‐analysis we examined datasets of two randomized placebo‐controlled trials which investigated the effect of nasal carrageenan separately on children and adults. In both trials, iota‐carrageenan was administered nasally three times per day for 7 days for patients with the common cold and follow‐up lasted for 21 days. We used Cox regression to estimate the effect of carrageenan on recovery rate. We also used quantile regression to calculate the effect of carrageenan on colds of differing lengths. Nasal carrageenan increased the recovery rate from all colds by 54% (95% CI 15%–105%; p = .003). The increase in recovery rate was 139% for coronavirus infections, 119% for influenza A infections, and 70% for rhinovirus infections. The mean duration of all colds in the placebo groups of the first four quintiles were 4.0, 6.8, 8.8, and 13.7 days, respectively. The fifth quintile contained patients with censored data. The 13.7‐day colds were shortened by 3.8 days (28% reduction), and 8.8‐day colds by 1.3 days (15% reduction). Carrageenan had no meaningful effect on shorter colds. In the placebo group, 21 patients had colds lasting over 20 days, compared with six patients in the carrageenan group, which corresponds to a 71% (p = .003) reduction in the risk of longer colds. Given that carrageenan has an effect on diverse virus groups, and effects at the clinical level on two old coronaviruses, it seems plausible that carrageenan may have an effect on COVID‐19. Further research on nasal iota‐carrageenan is warranted.

In this individual patient data meta-analysis we examined datasets of two randomized placebo-controlled trials which investigated the effect of nasal carrageenan separately on children and adults. In both trials, iota-carrageenan was administered nasally three times per day for 7 days for patients with the common cold and follow-up lasted for 21 days. We used Cox regression to estimate the effect of carrageenan on recovery rate. We also used quantile regression to calculate the effect of carrageenan on colds of differing lengths. Nasal carrageenan increased the recovery rate from all colds by 54% (95% CI 15%-105%; p = .003). The increase in recovery rate was 139% for coronavirus infections, 119% for influenza A infections, and 70% for rhinovirus infections. The mean duration of all colds in the placebo groups of the first four quintiles were 4.0, 6.8, 8.8, and 13.7 days, respectively. The fifth quintile contained patients with censored data. The 13.7-day colds were shortened by 3.8 days (28% reduction), and 8.8-day colds by 1.3 days (15% reduction). Carrageenan had no meaningful effect on shorter colds. In the placebo group, 21 patients had colds lasting over 20 days, compared with six patients in the carrageenan group, which corresponds to a 71% (p = .003) reduction in the risk of longer colds. Given that carrageenan has an effect on diverse virus groups, and effects at the clinical level on two old coronaviruses, it seems plausible that carrageenan may have an effect on COVID-19. Further research on nasal iota-carrageenan is warranted. [ABSTRACT FROM AUTHOR]

Healthy foods, known as functional and medicinal foods, are gaining popularity as they contain reasonable amounts of bioactive compounds (BCs) that can boost immunity. However, the intrinsic water insolubility and instability of BCs limit the design and development of healthy foods. To this end, carriers are effective in overcoming these setbacks. Among the several carrier choices, herein, human-compatible hydrocolloid iota-carrageenan (IC), a food hydrocolloid with the ability to form thermos-reversible gels, is chosen due to its intrinsic non-toxic and inexpensive traits. The ordered network structures of iota-carrageenan have been created by complexing with α-, β-, and γ-cyclodextrin (CD); later, curcumin has been encapsulated. Curcumin release has been tested in aqueous, simulated gastrointestinal, and simulated intestinal conditions. The maximum curcumin release was obtained in the aqueous conditions, and the IC fibers containing 50 mM NaCl displayed the highest curcumin release of 1.55 mg/g, followed by IC50-0.1β-CD of 1.37 mg/g. On the other hand, in IC fibers with 100 mM NaCl, the best release obtained was from IC100-0.1γ-CD and IC100 of 0.84 and 0.83 mg/g, respectively, and the minimum release of 0.39 mg/g was from the IC100-0.5γ-CD fibers. In simulated gastric fluid (SGF) media (pH 1.2), the highest release detected was 0.26 mg/g from the fibers with 50 mM NaCl. However, in simulated intestinal fluid (SIF) conditions (pH 6.8), the maximum achieved release of 1.00 mg/g was from the IC50 fibers, followed by 0.93 mg/g from the IC50-0.1β-CD fibers. Overall, the IC-CD network thermally protects curcumin, and the type of CD impacts its sustained release nature. The outcome is important in designing value-added delivery systems of bioactive compounds required to develop novel functional foods and improve human health. [Display omitted] • A novel hydrocolloid encapsulation carrier system was designed and tested for affinity to embed nutraceutical compounds. • Curcumin forms an ordered complex matrix with an iota-carrageenan: cyclodextrin network. • The IC:CD:Curcumin complexes display different release kinetics. [ABSTRACT FROM AUTHOR]

The research features the technological challenge of producing jelly desserts by replacing gelatin by non-starch polysaccharides of plant, bacterial, and algal origin (separately or in binary mixtures) in order to overcome religious and ethical constraints. The authors focused on the texture which is responsible for gel network formation of desserts. Hydrocolloids are widely used in many food formulations to improve quality attributes and shelf-life. The polysaccharides under analysis included alginate, pectin, iota-carrageenan, konjac glucomannan, xanthan, and guar gum, separately or in binary mixtures. The experiment made it possible to determine polysaccharides and their optimal concentrations (konjac glucomannan 0.4 % : xanthan gum 0.6 %; locust bean gum 0.2 % : xanthan gum 0.8 %; iota-carrageenan 0.4 %) as gelling agents for the production of desserts without gelatin. Formation of a gel network in desserts occurs as a result of a complex interaction of hydrocolloids, milk fat, and sugar. Structure formation of jelly desserts with polysaccharides occurs already at 18 ± 2°C in 20–40 minutes. In contrast, the structure formation of the control sample occurred at 4 ± 2°C in 2–3 hours. Sensory evaluation of the products was conducted by panellists according to the following criteria: taste, colour, consistency, aroma, and appearance. The paper also describes an analysis of texture indicators. The shelf-life was assessed according to moisture content and water activity as 24 hours at 4 ± 2°C. Several economically-viable new formulations were identified: they successfully reproduced the essential attributes of well-established and widely-consumed traditional gelatin desserts.

In this work free-standing gels formed from gellan gum (GG) by solvent evaporation are coated with polysaccharide-based polyelectrolyte multilayers, using the layer-by-layer approach. We show that PEMs composed of iota -carrageenan (CAR) and three different natural polycationic polymers have composition-dependent antimicrobial properties, and support mammalian cell growth. Cationic polymers (chitosan (CHT), N , N , N -trimethyl chitosan (TMC), and an amino-functionalized tannin derivative (TN)) are individually assembled with the anionic iota -carrageenan (CAR) at pH 5.0. PEMs (15-layers) are alternately deposited on the GG film. The GG film and coated GG films with PEMs are characterized by infrared spectroscopy with attenuated total reflectance (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle (WCA) measurements. The TN/CAR coating provides a hydrophobic (WCA = 127°) and rough surface (R q = 243 ± 48 nm), and the TMC/CAR coating provides a hydrophilic surface (WCA = 78°) with the lowest roughness (R q = 97 ± 12 nm). Polymer coatings promote stability and durability of the GG film, and introduce antimicrobial properties against Gram-negative (Salmonella enteritidis) and Gram-positive (Staphylococcus aureus) bacteria. The films are also cytocompatible. Therefore, they have properties that can be further developed as wound dressings and food packaging. • A commercial gellan gum is characterized, supporting stable films due to the metallic ions presence in its composition. • The solvent evaporation method provides a stiffer gellan gum film. • The film is coated with polyelectrolyte multilayers due to the carboxylate moieties on the gellan gum. • Chitosan/ iota -carrageenan and N , N , N -trimethyl chitosan/ iota -carrageenan coatings support antimicrobial activities. • The coated films can be applied in the food and biomedical fields. [ABSTRACT FROM AUTHOR]

Gel properties of hydrogel-forming by Ala-Lys dipeptide (AK) and iota-carrageenan (ι-C) were investigated by rheological behavior, fourier transform infrared analysis, cryo-scanning electron microscopy, low field-NMR relaxometry and magnetic resonance imaging. Iota-carrageenan was changed from a liquid to a gel with the addition of AK, and the existence of AK significantly increased the storage modulus (G') of ι-C from 590.4 to 1077.8 Pa. In the ι-C/AK gel, the blue-shift of O H stretching and water deformation were observed, meanwhile, the presence of amide I band at 1682 cm−1 was observed. The network of ι-C/AK gel showed a dense honeycomb structure with flocculating continuous phase and rough entanglement morphology. After adding AK, the water free in the pores of ι-C entered the ι-C/AK gel matrix, and the binding capacity of bound water was enhanced. These scenarios proved that the AK as the cationic dipeptide could control the conversion of negatively charged ι-C from an original random structure to a helical structure due to electrostatic interactions and hydrogen bonds. This study provides a new opportunity for the peptides into carbohydrate-based gel matrices, which could provide insights for the further application of ι-C/AK gels in the fields of food industry, tissue engineering and drug delivery. • AK dipeptide enhanced the gel properties of iota-carrageenan. • Electrostatic interactions was the main force in AK/ ι-C gel. • The hydrogen bond stabilized the AK/ι-C gel structure. • AK induced regular and homogenous network structure in the ι-C gel. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to provide a control drug delivery system through a newly approved work to enhance the absorption and bioavailability of enalapril maleate loaded floating microspheres by ionotropic gelation technique using a hydrophilic carrier. Materials and Methods: Eleven developed formulations of floating microspheres were prepared by ionotropic gelation using different concentrations of sodium alginate, iota-carrageenan, sodium bicarbonate, calcium chloride, and the drug. These microspheres were characterized using a diversity of parameters like micrometric properties, percentage yield, entrapment efficiency, in vitro buoyancy, in vitro drug release, and kinetics of drug release. The optimum formula was evaluated and identified for drug-excipients compatibility using fourier transform-infrared spectroscopy (FT-IR), surface morphology, powder X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Results: From the results, F4 was selected as the optimum formula since it provides a faster and premium release of drug from the matrix (91.4%). Kinetics of drug release was found to depend on both diffusion and erosion mechanisms, as the correlation coefficient (R2) was best fitted with Korsmeyer's model and the release exponent (n) was shown to be between 0.43 and 0.84. Scanning electron microscopy images demonstrated spherical, discrete, and freely flowing microspheres with a particle size of 199.4±0.04 µm. Optimum buoyancy properties, percentage yield, and drug entrapment efficiency were achieved. FT-IR showed no interaction between enalapril and the polymers. DSC and XRD showed the miscibility of the drug with the polymers while maintaining the stable crystalline properties of enalapril loaded in the prepared microspheres. Conclusion: The developed floating microspheres of enalapril maleate can be considered a promising controlled drug delivery system, thereby improving patient compliance. [ABSTRACT FROM AUTHOR]

A non-toxic and bio-active natural polymer electrolyte iota-carrageenan (i-carrageenan) with LiClO4 has been prepared by conventional solution casting technique. Succinonitrile (SN) plastic crystal has been used as an additive to optimize the conductivity of i-carrageenan biopolymer electrolytes. The obtained biopolymer electrolytes are characterized by X-ray diffraction, Fourier-transform infrared, differential scanning calorimetry and AC impedance studies. The highest ionic conductivity at room temperature is 3.57 × 10−4 S cm−1 for the film composition of 1.0 g i-carrageenan/0.5 wt% LiClO4. The inclusion of 0.3 wt% of SN into this polymeric system has improved the value of ionic conductivity to 3.33 × 10−3 S cm−1 at ambient temperature, and the activation energy is found to be very low for this concentration. Transference number analysis also reveals that the cause of conductivity is primarily due to ions with the highest ionic transference number of 0.92 (Wagner's method) and cationic transference number of 0.58 (Bruce and Vincent method) for the highest conducting plasticized sample. Transport parameters of diffusion coefficients and mobility of cations and anions are also in tune with the conductivity results. Linear sweep voltammetry shows that the highest conducting sample is electrochemically stable up to 2.36 V without SN, and it is 3.1 V with SN addition. These results recommend the suitability of the fabricated polymer electrolyte for lithium ion battery system. [ABSTRACT FROM AUTHOR]

Magnetic aerogels were prepared via physical cross-linking of Iota-carrageenan and polyamidoamine (PAMAM) dendrimer using different amounts of magnetic nanoparticles (1, 3 and 5%). A blank sample of chemically cross-linked Iota-carrageenan was prepared for comparison. The prepared magnetic nanoparticles and aerogels were fully characterized using particle size analyzer, X-ray diffraction (XRD), vibrating Sample Magnetometer (VSM), FT-IR, SEM and energy-dispersive X-ray (EDX). The surface area and porosity were calculated using Brunauer, Emmett, and Teller (BET), Barrett, Joyner and Halenda (BJH) equations. The nitrogen contents of the aerogels were determined using the Kjeldal method. These aerogels are environmentally safe, eco-friendly and cheap. The adsorption behavior of the aerogels was evaluated for Cr (VI), Co2+, Cu2+, Cd2+, Mn7+, and Alphanol fast blue dye. The synergetic effect for the presence of the chelating groups with different natures (i.e. sulfate and amine) was revealed via the high ability of the aerogels to remove the cations and oxyanions in a similar manner. The prepared aerogels had high removal efficiency with selectivity order Co2+ > Cu2+ > Mn7+ > Cd2+ > Cr (VI). The maximum adsorption efficiency of Co2+ was 99% achieved by using CAR M3. [ABSTRACT FROM AUTHOR]

Iota-Carrageenan (i-carrageenan) was cross-linked with Polyamidoamine hyperbranched polymer generation 1 (PAMAM). The resulted hydrogels were dried using freeze-drying technique to give new bio-based i-carrageenan aerogels. These aerogels were characterized using FT-IR and their nitrogen contents were determined using Kjeldahl method. The morphology and the surface areas of the aerogels were investigated using scanning electron microscope and Brunauer–Emmett–Teller method, respectively. The ability of the aerogels to remediate different metal ions e.g. Cr(VI), Mn(II), Co(II), Cu(II), or Cd(II) and alphanol fast blue dye (acid dye) from aqueous medium was carefully investigated. The removal investigation was conducted without pH adjustment in case of metal ions and at pH 2 for acid dye. The aerogel with the higher nitrogen content (CAR4) exhibited the highest remediation efficiency of both metal ions and acid dye. [ABSTRACT FROM AUTHOR]

Green solid polymer electrolytes have drawn attention as multifunctional electrolyte as compared to liquid electrolyte due to their flexibility membranes. In the present work, biodegradable iota-carrageenan polymer has been chosen as the host polymer with magnesium tri-fluromethanesulfonate (MgTf2) as the salt. The polymer film was incorporated with methyl-trioctylammonium bis(trifluoromethyl sulfonyl)imide (AmNTFSI) ionic liquid to amplify the ionic conductivity via adding mobile cations and tuning the crystallinity as well as the glass temperature of the polymer. Upon the incorporation of AmNTFSI, the ionic conductivity was remarkably augmented from (1.24 + 0.01) × 10−6 S cm−1 to the maximum value of (3.20 + 0.01) × 10−3 S cm−1 at room temperature. The thermal, structural, and temperature dependence conductivity measurements of polymer films (with and without AmNTFSI) have been analyzed, and the performance as the supercapacitor electrolytes has been evaluated. [ABSTRACT FROM AUTHOR]

A biopolymer electrolyte consisting of iota-carrageenan (I-Carrageenan) and LiCl is prepared using solution casting method. XRD analysis confirms the enhancement in amorphous nature of the prepared polymer electrolytes due to the incorporation of LiCl. Fourier transform infrared (FTIR) spectroscopy is used to analyze the complexation of electrolytes. Electrochemical impedance spectroscopy is utilized to find the ac electrical conductivity of the electrolytes. The combination of 1.0 g I-Carrageenan and 0.3 g LiCl displays highest ionic conductivity value of 5.33 × 10−3 S cm−1 at room temperature. Transference number measurements indicate that the conductivity process is predominantly by Li+ ions. Lithium ion conducting battery is constructed with the highest conducting polymer electrolyte, and its discharge performance is analyzed. [ABSTRACT FROM AUTHOR]

Gel polymer electrolytes (GPE) were prepared with iota-carrageenan, sodium iodide (NaI), and 1-butyl-3-methylimidazolium iodide (BMIMI). The enhancement of ionic conductivity has achieved from 1.34 × 10−2 S cm−1 to 2.11 × 10−2 S cm−1 after the addition of BMIMI. The dielectric studies show that the dielectric constant increases with increasing concentration and temperature. The modulus studies show that ionic conductivity is dominant in the GPE samples. The XRD analysis shows that 30 wt.% BMIMI (IL30) has the optimum amorphous nature, and the combination of crystalline salt and semi crystalline polymer with amorphous ionic liquid gives a better amorphous nature. The FTIR studies confirm that there is complexation occurs between the iota-carrageenan, NaI, and BMIMI. Dye-sensitized solar cells (DSSC) were fabricated using the prepared GPE samples and characterized using photovoltaic studies. DSSC with IL30 sample shows the highest photovoltaic efficiency of 0.72%. [ABSTRACT FROM AUTHOR]

Women are the most affected by genital herpes, which is one of the most common sexually transmitted infections, affecting more than 400 million people worldwide. The application of vaginal microbicides could provide a safe method of protection. Acyclovir is a safe and effective medication for vaginal administration, and numerous benefits have been observed in the treatment of primary or recurrent lesions due to genital herpes. Vaginal tablets based on a combination of the polymers iota-carrageenan and hydroxypropyl methylcellulose were developed for the controlled release of acyclovir. Swelling, mucoadhesion and drug release studies were carried out in simulated vaginal fluid. The tablets, containing a combination of iota-carrageenan and hydroxypropyl methylcellulose, have an adequate uptake of the medium that allows them to develop the precise consistency and volume of gel for the controlled release of acyclovir. Its high mucoadhesive capacity also allows the formulation to remain in the vaginal area long enough to ensure the complete release of acyclovir. These promising formulations for the prevention of genital herpes deserve further evaluation.

Extrusion-based bioprinting has demonstrated significant potential for manufacturing constructs, particularly for 3D cell culture. However, there is a greatly limited number of bioink candidates exploited with extrusion-based bioprinting, as they meet the opposing requirements for printability with indispensable rheological features and for biochemical functionality with desirable microenvironment. In this study, a blend of silk fibroin (SF) and iota-carrageenan (CG) was chosen as a cell-friendly printable material. The SF/CG ink exhibited suitable viscosity and shear-thinning properties, coupled with the rapid sol-gel transition of CG. By employing photo-crosslinking of SF, the printability with Pr value close to 1 and structural integrity of the 3D constructs were significantly improved within a matter of seconds. The printed constructs demonstrated a Young's modulus of approximately 250 kPa, making them suitable for keratinocyte and myoblast cell culture. Furthermore, the high cell adhesiveness and viability (maximum >98%) of the loaded cells underscored the considerable potential of this 3D culture scaffold applied for skin and muscle tissues, which can be easily manipulated using an extrusion-based bioprinter., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Yun Jung Yang reports financial support was provided by Ministry of Science and ICT, Korea. Yun Jung Yang reports financial support was provided by Korea Institute of Marine Science & Technology Promotion (10.13039/501100011705KIMST) funded by the 10.13039/501100003566Ministry of Oceans and Fisheries, Korea., (© 2024 The Authors.)

Abstract This study investigates the mineralisation calcium phosphate (CaP) and carbonate (CaCO 3) within chitosan/iota-carrageenan multilayer films using a simulated body fluid (SBF) and simulated sea-water (SSW), respectively. Small angle neutron scattering measurements were taken on a range of mineralisation conditions including exposure time (0.5, 3 and 18 h), Ca2+:carboxylic acid molecule molar ratio (1:1, 1000:1) and the type of acid molecule (l -glutamic acid, citric acid and poly(acrylic acid). The modelling of the SANS data was used to obtain two physical parameters indicative of the extent of mineralisation, SANS power law slope and the lamellar neutron scattering density within the multilayer biopolymer film. Mineralisation of CaCO 3 within these templates was enhanced with the addition of each of the acid molecules. However, no obvious trend could be found in relation to extent of exposure time or concentration. The enhanced CaCO 3 mineralisation was also observed using in-situ ellipsometry at the solid-liquid interface of a 2-bilayer chitosan/iota-carrageenan film. Thickness increase rates as high as 5.3 nm min−1 were observed for the acid molecule containing SSW compared to a rate of 2.3 nm min−1 in the SSW not containing acid molecules. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte based on iota-carrageenan (i-carrageeenan) with ammonium thiocyanate (NH4SCN) has been prepared by solution casting technique using distilled water as solvent. Increase of amorphous nature of the polymer/salt complex has been confirmed by XRD analysis. The complex formation between the polymer and salt has been confirmed by FTIR analysis. A shift in glass transition temperature (Tg) of the i-carrageeenan/ NH4SCN electrolytes has been observed from the DSC thermograms. From AC impedance spectroscopy, the maximum conductivity value has been found to be 3.56 × 10−3 S/cm for i-carrageeenan (1 g): NH4SCN (0.3 wt%) at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plots has been found to be low (0.21 eV) for i-carrageeenan (1 g): NH4SCN (0.3 wt%) polymer electrolyte. The ionic transference number has been measured using DC Wagner’s polarization method for highest conducting polymer membrane and the result indicates that the conductivity of the electrolyte is predominantly due to ions. The electrochemical stability of the electrolyte i-carrageeenan (1 g): NH4SCN (0.3 wt%) has been studied by linear sweep voltammetry. Using this maximum ionic conductivity polymer electrolyte, the proton battery and fuel cell have been constructed and the cell parameters have been reported.Possible interaction between i-carrageeenan and NH4SCN. [ABSTRACT FROM AUTHOR]

The seaweeds are bio-resource rich in sulfated and neutral polysaccharides. The tropical seaweed species used in this study (Solieria filiformis), after dried, shows 65.8% (w/w) carbohydrate, 9.6% (w/w) protein, 1.7% (w/w) lipid, 7.0% (w/w) moisture and 15.9% (w/w) ash. The dried seaweed was easily hydrolyzed under mild conditions (0.5 M sulfuric acid, 20 min.), generating fermentable monosaccharides with a maximum hydrolysis efficiency of 63.21%. Galactose and glucose present in the hydrolyzed were simultaneously fermented by Saccharomyces cerevisiae when the yeast was acclimated to galactose and cultivated in broth containing only galactose. The kinetic parameters of the fermentation of the seaweed hydrolyzed were Y(P⁄S) = 0.48 ± 0.02 g.g−1, PP = 0.27 ± 0.04 g.L−1.h−1, h = 94.1%, representing a 41% increase in bioethanol productivity. Therefore, S. filiformis was a promising renewable resource of polysaccharides easily hydrolyzed, generating a broth rich in fermentable monosaccharides for ethanol production.

The conservation of traditional chocolate fillings can present some hurdles due to the use of perishable raw matters, physical changes during processing and to the influence of external factors, which tends to shorten shelf-life of traditional filled pralinés to only 3-4 months. The aim of this study was to evaluate the influence of the concentration of iota-carrageenan on chemical, rheological, image analysis and microbial properties of reduced-fat white chocolate fillings during storage time. Two batches of reduced-fat filling were produced using white chocolate, commercial grade sugar, skimmed milk, inverted sugar and iota-carrageenan (at 0.5% w/w and 1.0% w/w concentration) and stored at 4 °C during 12 months. A control batch with no hydrocolloid was also produced. The results presented a decrease in pH, aw and moisture during storage time. The rheological characterization concluded that all formulations presented a shearthinning behaviour and both flow index (n) and consistency (K) were correlated with iota-carrageenan concentration and with storage time. The concentration of iota-carrageenan did not influence the digital image analysis of chocolate fillings, but a shift was observed during storage time, especially at the end. The microbial analysis showed a positive correlation to storage time in the formulation using 1.0% iota-carrageenan, nevertheless all results were quite acceptable and within the recommended safety values. [ABSTRACT FROM AUTHOR]

The essential part of electrochemical devices, such as fuel cells and batteries, is the polymer electrolyte with good mechanical, thermal, and chemical stability. The search for a new proton-conducting membrane with easy processability, non-toxic, and low-cost has been growing rapidly. The bio-based polymer electrolytes are now receiving much attention due to the green environment. Among the commercially available biopolymers, iota-Carrageenan (I-Carrageenan) is one of the biopolymer with good film-forming nature and with good mechanical stability. I-Carrageenan-based biopolymer membranes doped with ammonium bromide (NHBr) have been prepared using solution-casting technique, and distilled water is used as a solvent. The prepared I-Carrageenan-based biopolymer membranes have been characterized using FTIR, XRD, and AC impedance techniques. The complexation between the polymer and salt has been revealed by FTIR. The increase in the amorphous nature of the film due to the addition of salt has been confirmed by XRD. From AC impedance technique, the conductivity of pure I-Carrageenan has been found to be 1.46 × 10 S/cm. The addition of different wt% of NHBr increases the conductivity and reaches the highest value of 1.08 × 10 S/cm for 20% NHBr, and the conductivity decreases on further addition of NHBr due to the formation of ion aggregates. [ABSTRACT FROM AUTHOR]