Gels | September 2024 - Browse Articles

11 pages, 4027 KiB

Open AccessArticle

Acid Hydrolysis of Quinoa Starch to Stabilize High Internal Phase Emulsion Gels

by Songnan Li, Chaohui Sun, Ye Sun, Enpeng Li, Ping Li and Jun Wang

Gels 2024, 10(9), 559; https://doi.org/10.3390/gels10090559 (registering DOI) - 28 Aug 2024

Starch nanocrystals (SNCs) to stabilize high internal phase emulsions (HIPEs) always suffer low production efficiency from acid hydrolysis. Due to its small granule size, Quinoa starch (QS) was selected to produce SNCs as a function of acid hydrolysis time (0–4 days), and their [...] Read more.

Starch nanocrystals (SNCs) to stabilize high internal phase emulsions (HIPEs) always suffer low production efficiency from acid hydrolysis. Due to its small granule size, Quinoa starch (QS) was selected to produce SNCs as a function of acid hydrolysis time (0–4 days), and their structural changes and potential application as HIPEs’ stabilizers were further explored. With increasing the acid hydrolysis time from 1 day to 4 days, the yield of QS nanocrystals decreased from 30.4% to 10.8%, with the corresponding degree of hydrolysis increasing from 51.2% to 87.8%. The occurrence of QS nanocrystals was evidenced from the Tyndall effect and scanning electron microscopy with particle size distribution. The relative crystallinity of QS subjected to different hydrolysis times (0–4 days) increased from 22.27% to 26.18%. When the acid hydrolysis time of QS was 3 and 4 days, their HIPEs showed self-standing after inversion, known as high internal phase emulsion gels (HIPE gels), closely related to their densely packed interfacial architecture around oil droplets, seen on an optical microscope, and relatively high apparent viscosity. This study could provide a theoretical guidance for the efficient production and novel emulsification of SNCs from QS to HIPE gels. Full article

(This article belongs to the Special Issue Advancements in Food Gelation: Exploring Mechanisms and Applications)

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13 pages, 4626 KiB

Open AccessArticle

Developments in Nanostructured MoS₂-Decorated Reduced Graphene Oxide Composite Aerogel as an Electrocatalyst for the Hydrogen Evolution Reaction

by Sadhasivam Thangarasu, Mrunal Bhosale, Gowthami Palanisamy and Tae Hwan Oh

Gels 2024, 10(9), 558; https://doi.org/10.3390/gels10090558 - 28 Aug 2024

Abstract

Developing lightweight, highly active surfaces with a high level of performance and great stability is crucial for ensuring the dependability of energy harvesting and conversion devices. Aerogel-based electrocatalysts are an efficient option for electrocatalytic hydrogen production because of their numerous benefits, such as [...] Read more.

Developing lightweight, highly active surfaces with a high level of performance and great stability is crucial for ensuring the dependability of energy harvesting and conversion devices. Aerogel-based electrocatalysts are an efficient option for electrocatalytic hydrogen production because of their numerous benefits, such as their compatibility with interface engineering and their porous architecture. Herein, we report on the facile synthesis of a nanorod-like molybdenum sulfide–reduced graphene oxide (M-rG) aerogel as an electrocatalyst for the hydrogen evolution reaction (HER). The 3D architecture of the network-like structure of the M-rG hybrid aerogel was created via the hydrothermal technique, using a saturated NaCl solution-assisted process, where the MoS₂ was homogeneously incorporated within the interconnected rGO aerogel. The optimized M-rG-300 aerogel electrocatalyst had a significantly decreased overpotential of 112 mV at 10 mA/cm² for the HER in alkaline conditions. The M-rG-300 also showed a higher level of reliability. The remarkable efficiency of the HER involving the M-rG-300 is principally attributed to the excellent connectivity between the rGO and MoS₂ in the aerogel structure. The efficient interconnection influenced the achievement of a larger electrochemically active surface area, increased electrical conductivity, and the exposure of more active sites for the HER. Furthermore, the creation of a synergistic effect in the M-rG-300 aerogel is the most probable mechanism to boost the electrocatalytic activity. Full article

(This article belongs to the Special Issue Hydrogel-Based Flexible Electronics and Devices)

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16 pages, 8276 KiB

Open AccessArticle

Fish Gelatin-Based Flexible and Self-Healing Hydrogel Modified by Fe₂(SO₄)₃

by Lili Zhang, Haimei Liu and Qin Zhao

Gels 2024, 10(9), 557; https://doi.org/10.3390/gels10090557 - 28 Aug 2024

Abstract

The application of fish gelatin (FG) is limited due to its poor mechanical properties and thermal stability, both of which could be significantly improved by gellan gum (GG) found in previous research. However, the FG/GG composite hydrogel was brittle and easily damaged by [...] Read more.

The application of fish gelatin (FG) is limited due to its poor mechanical properties and thermal stability, both of which could be significantly improved by gellan gum (GG) found in previous research. However, the FG/GG composite hydrogel was brittle and easily damaged by external forces. It was found that the composite hydrogel with Fe₂(SO₄)₃ showed good flexibility and self-healing properties in the pre-experiment. Thus, the synergistic effect of FG, GG and Fe₂(SO₄)₃ on the mechanical properties of the composite hydrogel was investigated in this study. According to one-way experiments, response surface tests and Texture Profile Analysis, it was found that under the optimum condition of FG concentration 186.443 g/L, GG concentration 8.666 g/L and Fe₂(SO₄)₃ concentration 56.503 g/L, the springiness of the composite cylindrical hydrogel with the height of 25 mm formed in 25 mL beakers (bottom diameter 30 mm) was 7.602 mm. Determination of the rheological properties, compression performance, adhesive performance and self-healing properties showed that the composite hydrogel had good thermal stability, flexibility and self-healing properties with good adhesion, skin compliance and compressive strength, and it was easy to remove. The composite hydrogel showed strong antimicrobial activity against A. salmonicida and V. parahaemolyticus. All hydrogels showed a uniform and porous structure. The 3D structure of the composite hydrogel was much looser and more porous than the pure FG hydrogel. The flexible and self-healing composite hydrogel with some antimicrobial activity is suitable for the development of medical dressings, which broadens the applications of the composite hydrogel. Full article

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26 pages, 19363 KiB

Open AccessArticle

Temperature-Regulated Synthesis of Hyaluronic Acid-Interpenetrated Polyacrylamide/Poly(Acrylic Acid Sodium Salt) Semi-Interpenetrated Polymer Network Gel for the Removal of Methyl Violet

by Nida Özcan and Nermin Orakdogen

Gels 2024, 10(9), 556; https://doi.org/10.3390/gels10090556 - 28 Aug 2024

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Abstract

An alternative synthetic pathway was proposed for the optimization of synthesis to find a better correlation between the swelling and elasticity of hyaluronic acid-interpenetrated gels via temperature regulation. An experimental design methodology was presented for the synthesis of polyacrylamide/poly(acrylic acid sodium salt)/hyaluronic acid, [...] Read more.

An alternative synthetic pathway was proposed for the optimization of synthesis to find a better correlation between the swelling and elasticity of hyaluronic acid-interpenetrated gels via temperature regulation. An experimental design methodology was presented for the synthesis of polyacrylamide/poly(acrylic acid sodium salt)/hyaluronic acid, PAAm/PSA/HyA, gels by modifying the one-pot procedure using free radical crosslinking copolymerization of AAm with the addition of anionic linear PSA chains in the presence of various amount of HyA, ranging between 0.05% and 0.20% (w/v). Semi-interpenetrated polymer network (IPN)-structured gels were designed with tunable elasticity, in which the extent of covalent crosslinking interactions is controlled by polymerization temperature ranging between −18 and 45 °C. Depending on the HyA content added in the synthesis and the polymerization temperature, the swelling ratio could be controlled. The addition of 0.05% (w/v) HyA increased the swelling of semi-IPNs, while the elastic modulus increased with increasing HyA content and decreased with the polymerization temperature. PAAm/PSA/HyA semi-IPNs showed the typical pH-sensitive swelling of anionic gels, and the swelling reached a maximum at a pH of 11.2. PAAm/PSA/HyA gels were tested for the removal of methyl violet from wastewater. Adsorption kinetics were shown to be well-fitted with the pseudo-second-order model using linear and nonlinear regression analysis. With the clear relationship between increased modulus and composition, this study enabled the fine-tuning of semi-IPN interactions by varying the polymerization temperature. Full article

(This article belongs to the Special Issue Polysaccharide: Gelation Arts)

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18 pages, 27165 KiB

Open AccessArticle

High-Performance Flexible Sensor with Sensitive Strain/Magnetic Dual-Mode Sensing Characteristics Based on Sodium Alginate and Carboxymethyl Cellulose

by Chong Liu, Longwang Yue, Yu Fu, Zhenshuai Wan, Li Wang, Yangke Wei and Sha Li

Gels 2024, 10(9), 555; https://doi.org/10.3390/gels10090555 - 27 Aug 2024

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Abstract

Flexible sensors can measure various stimuli owing to their exceptional flexibility, stretchability, and electrical properties. However, the integration of multiple stimuli into a single sensor for measurement is challenging. To address this issue, the sensor developed in this study utilizes the natural biopolymers [...] Read more.

Flexible sensors can measure various stimuli owing to their exceptional flexibility, stretchability, and electrical properties. However, the integration of multiple stimuli into a single sensor for measurement is challenging. To address this issue, the sensor developed in this study utilizes the natural biopolymers sodium alginate and carboxymethyl cellulose to construct a dual interpenetrating network, This results in a flexible porous sponge that exhibits a dual-modal response to strain and magnetic stimulation. The dual-mode flexible sensor achieved a maximum tensile strength of 429 kPa and elongation at break of 24.7%. It also exhibited rapid response times and reliable stability under both strain and magnetic stimuli. The porous foam sensor is intended for use as a wearable electronic device for monitoring joint movements of the body. It provides a swift and stable sensing response to mechanical stimuli arising from joint activities, such as stretching, compression, and bending. Furthermore, the sensor generates opposing response signals to strain and magnetic stimulation, enabling real-time decoupling of different stimuli. This study employed a simple and environmentally friendly manufacturing method for the dual-modal flexible sensor. Because of its remarkable performance, it has significant potential for application in smart wearable electronics and artificial electroskins. Full article

(This article belongs to the Special Issue Application of Smart Gel Material in Flexible and Wearable Electronics)

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13 pages, 2102 KiB

Open AccessArticle

Machine Learning Techniques to Analyze the Influence of Silica on the Physio-Chemical Properties of Aerogels

by Hamdi Chaouk, Emil Obeid, Jalal Halwani, Jack Arayro, Rabih Mezher, Omar Mouhtady, Eddie Gazo-Hanna, Semaan Amine and Khaled Younes

Gels 2024, 10(9), 554; https://doi.org/10.3390/gels10090554 - 27 Aug 2024

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Abstract

This study explores the application of machine learning techniques, specifically principal component analysis (PCA), to analyze the influence of silica content on the physical and chemical properties of aerogels. Silica aerogels are renowned for their exceptional properties, including high porosity, large surface area, [...] Read more.

This study explores the application of machine learning techniques, specifically principal component analysis (PCA), to analyze the influence of silica content on the physical and chemical properties of aerogels. Silica aerogels are renowned for their exceptional properties, including high porosity, large surface area, and low thermal conductivity, but their mechanical brittleness poses significant challenges. The study initially utilized cross-correlation analysis to examine the relationships between key properties such as the Brunauer–Emmett–Teller (BET) surface area, pore volume, density, and thermal conductivity. However, weak correlations prompted the application of PCA to uncover deeper insights into the data. The PCA results demonstrated that silica content has a significant impact on aerogel properties, with the first principal component (PC1) showing a strong positive correlation (R² = 94%) with silica content. This suggests that higher silica levels correspond to lower thermal conductivity, porosity, and BET surface area, while increasing the density and elastic modulus. Additionally, the analysis identified the critical role of thermal conductivity in the second principal component (PC2), particularly in samples with moderate to high silica content. Overall, this study highlights the effectiveness of machine learning techniques like PCA in optimizing and understanding the complex inter-relationships among the physio-chemical properties of silica aerogels. Full article

(This article belongs to the Special Issue Aerogels—Preparation and Properties)

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30 pages, 5265 KiB

Open AccessFeature PaperReview

Conducting Polymer-Based Gel Materials: Synthesis, Morphology, Thermal Properties, and Applications in Supercapacitors

by Mohammad Mizanur Rahman Khan and Nilave Chakraborty

Gels 2024, 10(9), 553; https://doi.org/10.3390/gels10090553 - 26 Aug 2024

Viewed by 378

Abstract

Despite the numerous ongoing research studies in the area of conducting polymer-based electrode materials for supercapacitors, the implementation has been inadequate for commercialization. Further understanding is required for the design and synthesis of suitable materials like conducting polymer-based gels as electrode materials for [...] Read more.

Despite the numerous ongoing research studies in the area of conducting polymer-based electrode materials for supercapacitors, the implementation has been inadequate for commercialization. Further understanding is required for the design and synthesis of suitable materials like conducting polymer-based gels as electrode materials for supercapacitor applications. Among the polymers, conductive polymer gels (CPGs) have generated great curiosity for their use as supercapacitors, owing to their attractive qualities like integrated 3D porous nanostructures, softness features, very good conductivity, greater pseudo capacitance, and environmental friendliness. In this review, we describe the current progress on the synthesis of CPGs for supercapacitor applications along with their morphological behaviors and thermal properties. We clearly explain the synthesis approaches and related phenomena, including electrochemical approaches for supercapacitors, especially their potential applications as supercapacitors based on these materials. Focus is also given to the recent advances of CPG-based electrodes for supercapacitors, and the electrochemical performances of CP-based promising composites with CNT, graphene oxides, and metal oxides is discussed. This review may provide an extensive reference for forthcoming insights into CPG-based supercapacitors for large-scale applications. Full article

(This article belongs to the Special Issue Applications of Gels in Energy Materials and Devices)

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14 pages, 1941 KiB

Open AccessArticle

Co-Complexes-Based Self-Oscillating Gels Driven by the Belousov–Zhabotinsky Reaction

by Ilya L. Mallphanov, Michail Y. Eroshik, Dmitry A. Safonov and Anastasia I. Lavrova

Gels 2024, 10(9), 552; https://doi.org/10.3390/gels10090552 - 26 Aug 2024

Viewed by 243

Abstract

We report the synthesis of novel cobalt complexes-based catalysts designed for the oscillatory Belousov–Zhabotinsky (BZ) reaction. For the first time, we introduce cobalt complex-based self-oscillating gels that demonstrate autonomous color oscillations within a BZ reagent solution, functioning without the need for any external [...] Read more.

We report the synthesis of novel cobalt complexes-based catalysts designed for the oscillatory Belousov–Zhabotinsky (BZ) reaction. For the first time, we introduce cobalt complex-based self-oscillating gels that demonstrate autonomous color oscillations within a BZ reagent solution, functioning without the need for any external stimuli. We created acrylamide-based self-oscillating gels containing immobilized tris(2,2′-bipyridine)cobalt(II) or tris(1,10-phenanthroline)cobalt(II) complexes and gels containing covalently bound (5-acrylamido-1,10-phenanthroline)bis(2,2′-bipyridine)cobalt(II), (5-acrylamido-1,10-phenanthroline)bis(1,10-phenanthroline) cobalt(II), or tris(5-acrylamido-1,10-phenanthroline)cobalt(II) complexes. When the BZ reaction takes place within the gels, it results in the observation of moving chemical waves and reversible color changes. We believe that Co-complexes-based self-oscillating gels have potential applications in the design of soft actuators and chemical devices for signal processing. Full article

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12 pages, 885 KiB

Open AccessArticle

Comparison of Colorimetric Methods for Measuring the Solubility of Legume Proteins

by Terrence Dent, Allison LeMinh and Farnaz Maleky

Gels 2024, 10(9), 551; https://doi.org/10.3390/gels10090551 - 25 Aug 2024

Viewed by 264

Abstract

Increasing the use of plant proteins in foods requires improving their physical and chemical properties, such as emulsification, gelation capacity, and thermal stability. These properties determine the acceptability and functionality of food products. Higher protein solubility significantly impacts these properties by affecting denaturation [...] Read more.

Increasing the use of plant proteins in foods requires improving their physical and chemical properties, such as emulsification, gelation capacity, and thermal stability. These properties determine the acceptability and functionality of food products. Higher protein solubility significantly impacts these properties by affecting denaturation and the stability of emulsifiers or gels. Therefore, developing plant-based protein ingredients requires accurately and conveniently measuring their solubility. Colorimetric solubility methods overcome many issues of more robust combustion and titration methods, but complicated chemical mechanisms limit their applicability for certain proteins. This study aims to compare the effectiveness of four common colorimetric solubility measurement methods for pulse and non-pulse legume proteins and hydrolysates. Pea, chickpea, lentil, and soy protein isolates were made from defatted flour and their solubility at a range of pHs was measured using the Bradford, Lowry, bicinchoninic acid (BCA), and biuret methods. Solubility was also measured for chickpea and soy protein hydrolysates made using Alcalase and Flavourzyme. A comparison of the methods for solubility quantification revealed that the Bradford and Lowry methods most closely match the expected results for the unhydrolyzed protein, with the BCA and biuret methods underestimating solubility by 30%. The Lowry method was the preferred method for hydrolysate solubility measurement, with the Bradford method measuring 0% solubility at the isoelectric point due to an inability to interact with peptides that are soluble at this pH. This study identifies reliable methods for measuring plant protein solubility that establish uniform outcomes and enable a better comparison across studies, giving a consensus for key functional properties in food applications. Full article

(This article belongs to the Special Issue Recent Advances in Protein Gels)

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10 pages, 3051 KiB

Open AccessArticle

A Novel Biomineralized Collagen Liquid Crystal Hydrogel Possessing Bone-like Nanostructures by Complete In Vitro Fabrication

by Xiaoting Li, Qiaoying Wang and Qingrong Wei

Gels 2024, 10(9), 550; https://doi.org/10.3390/gels10090550 - 25 Aug 2024

Viewed by 405

Abstract

The microstructure of bone consists of nano-hydroxyapatite (nano-HA) crystals aligned within the interspaces of collagen fibrils. To emulate this unique microstructure of bone, this work applied two biomimetic techniques to obtain bone-like microstructures in vitro, that is, combining the construction of collagen liquid [...] Read more.

The microstructure of bone consists of nano-hydroxyapatite (nano-HA) crystals aligned within the interspaces of collagen fibrils. To emulate this unique microstructure of bone, this work applied two biomimetic techniques to obtain bone-like microstructures in vitro, that is, combining the construction of collagen liquid crystal hydrogel (CLCH) with the application of a polymer-induced liquid precursor (PILP) mineralization process. Upon the elevation of pH, the collagen macromolecules within the collagen liquid crystal (CLC) were activated to self-assemble into CLCH, whose fibrils packed into a long and dense fiber bundle in high orientation, emulating the dense-packed matrix of bone. We demonstrated that the fibrillar mineralization of CLCH, leading to a bone-like nanostructured inorganic material part, can be achieved using the PILP crystallization process to pre-mineralize the dense collagen substrates of CLCH with CaCO₃, immediately followed by the in situ mineral phase transformation of CaCO₃ into weak-crystalline nano-HA. The combination of CLCH with the biomineralization process of PILP, together with the mineral phase transformation, achieved the in vitro simulation of the nanostructures of both the organic extracellular matrix (ECM) and inorganic ECM of bone. This design would constitute a novel idea for the design of three-dimension biomimetic bone-like material blocks for clinical needs. Full article

(This article belongs to the Special Issue Novel Polymer Gels: Synthesis, Properties, and Applications)

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21 pages, 2947 KiB

Open AccessArticle

Impact of Antioxidant-Enriched Edible Gel Coatings and Bio-Based Packaging on Cherry Tomato Preservation

by Corinne Giacondino, Alessandra De Bruno, Davide Puntorieri, Martina Pizzimenti and Amalia Piscopo

Gels 2024, 10(9), 549; https://doi.org/10.3390/gels10090549 - 24 Aug 2024

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Abstract

This research investigates the effects of using edible gel coatings and bio-based packaging materials on extending the shelf life of cherry tomatoes. Two edible gel coatings (guar gum and guar gum +5% of a lemon (Citrus limon (L.) Osbeck pomace extract obtained [...] Read more.

This research investigates the effects of using edible gel coatings and bio-based packaging materials on extending the shelf life of cherry tomatoes. Two edible gel coatings (guar gum and guar gum +5% of a lemon (Citrus limon (L.) Osbeck pomace extract obtained in the research laboratory) were applied on cherry tomatoes, then they were packaged in bio-based materials (cellulose tray + PLA lid). Guar gum, glycerol, sorbitol, extra virgin olive oil, and tween 20 were used in coating formulation. Uncoated tomatoes packed in bio-based materials and conventional plastic (PET trays + lid) were tested as a control. Samples were stored for 45 days at 20 °C and their quality parameters were evaluated. Coated tomatoes maintained firmness and weight, and the enriched coated samples showed a significant increase in phenol content, derived from the antioxidant extract. Samples packed in PET showed a sensory unacceptability (<4.5) after 45 days correlated with a greater decline in firmness (from 10.51 to 5.96 N) and weight loss (from 7.06 to 11.02%). Therefore, edible gel coating and bio-based packaging proved to be effective in maintaining the overall quality of cherry tomatoes for 45 days, offering a promising approach to reduce plastic polymer use and food waste. Full article

(This article belongs to the Special Issue Edible Gel Coatings and Membranes)

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32 pages, 6972 KiB

Open AccessReview

Gels/Hydrogels in Different Devices/Instruments—A Review

by Md Murshed Bhuyan and Jae-Ho Jeong

Gels 2024, 10(9), 548; https://doi.org/10.3390/gels10090548 - 23 Aug 2024

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Abstract

Owing to their physical and chemical properties and stimuli-responsive nature, gels and hydrogels play vital roles in diverse application fields. The three-dimensional polymeric network structure of hydrogels is considered an alternative to many materials, such as conductors, ordinary films, constituent components of machines [...] Read more.

Owing to their physical and chemical properties and stimuli-responsive nature, gels and hydrogels play vital roles in diverse application fields. The three-dimensional polymeric network structure of hydrogels is considered an alternative to many materials, such as conductors, ordinary films, constituent components of machines and robots, etc. The most recent applications of gels are in different devices like sensors, actuators, flexible screens, touch panels, flexible storage, solar cells, batteries, and electronic skin. This review article addresses the devices where gels are used, the progress of research, the working mechanisms of hydrogels in those devices, and future prospects. Preparation methods are also important for obtaining a suitable hydrogel. This review discusses different methods of hydrogel preparation from the respective raw materials. Moreover, the mechanism by which gels act as a part of electronic devices is described. Full article

(This article belongs to the Special Issue Applications of Gels in Energy Materials and Devices)

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31 pages, 19426 KiB

Open AccessReview

Natural Regenerative Hydrogels for Wound Healing

by Mariana Chelu, Jose M. Calderon Moreno, Adina Magdalena Musuc and Monica Popa

Gels 2024, 10(9), 547; https://doi.org/10.3390/gels10090547 - 23 Aug 2024

Viewed by 456

Abstract

Regenerative hydrogels from natural polymers have come forth as auspicious materials for use in regenerative medicine, with interest attributed to their intrinsic biodegradability, biocompatibility, and ability to reassemble the extracellular matrix. This review covers the latest advances in regenerative hydrogels used for wound [...] Read more.

Regenerative hydrogels from natural polymers have come forth as auspicious materials for use in regenerative medicine, with interest attributed to their intrinsic biodegradability, biocompatibility, and ability to reassemble the extracellular matrix. This review covers the latest advances in regenerative hydrogels used for wound healing, focusing on their chemical composition, cross-linking mechanisms, and functional properties. Key carbohydrate polymers, including alginate, chitosan, hyaluronic acid, and polysaccharide gums, including agarose, carrageenan, and xanthan gum, are discussed in terms of their sources, chemical structures and specific properties suitable for regenerative applications. The review further explores the categorization of hydrogels based on ionic charge, response to physiological stimuli (i.e., pH, temperature) and particularized roles in wound tissue self-healing. Various methods of cross-linking used to enhance the mechanical and biological performance of these hydrogels are also examined. By highlighting recent innovations and ongoing challenges, this article intends to give a detailed understanding of natural hydrogels and their potential to revolutionize regenerative medicine and improve patient healing outcomes. Full article

(This article belongs to the Special Issue Advanced Hydrogels for Regenerative Medicine and Tissue Engineering (3rd Edition))

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23 pages, 4213 KiB

Open AccessArticle

Deep Cleaning of Crystal Violet and Methylene Blue Dyes from Aqueous Solution by Dextran-Based Cryogel Adsorbents

by Maria Marinela Lazar, Roxana P. Damaschin, Irina Volf and Maria Valentina Dinu

Gels 2024, 10(9), 546; https://doi.org/10.3390/gels10090546 - 23 Aug 2024

Viewed by 360

Abstract

Polysaccharides have recently attracted growing attention as adsorbents for various pollutants, since they can be extracted from a variety of renewable sources at low cost. An interesting hydrophilic and biodegradable polysaccharide is dextran (Dx), which is well-known for its applications in the food [...] Read more.

Polysaccharides have recently attracted growing attention as adsorbents for various pollutants, since they can be extracted from a variety of renewable sources at low cost. An interesting hydrophilic and biodegradable polysaccharide is dextran (Dx), which is well-known for its applications in the food industry and in medicine. To extend the application range of this biopolymer, in this study, we investigated the removal of crystal violet (CV) and methylene blue (MB) dyes from an aqueous solution by Dx-based cryogels using the batch technique. The cryogel adsorbents, consisting of cross-linked Dx embedding a polyphenolic (PF) extract of spruce bark, were prepared by the freeze-thawing approach. It was shown that the incorporation of PF into the Dx-based matrix induced a decrease in porosity, pore sizes and swelling ratio values. Moreover, the average pore sizes of the DxPF cryogels loaded with dyes further decreased from 42.30 ± 7.96 μm to 23.68 ± 2.69 μm, indicating a strong interaction between the functional groups of the cryogel matrix and those of the dye molecules. The sorption performances of the DxPF adsorbents were evaluated in comparison to those of the Dx cryogels and of the PF extract. The experimental sorption capacities of the DxPF cryogel adsorbents were higher in comparison to those of the Dx cryogels and the PF extract. The DxPF cryogels, particularly those with the highest PF contents (sample DxPF2), demonstrated sorption capacities of 1.2779 ± 0.0703 mmol·g⁻¹, for CV, and 0.3238 ± 0.0121 mmol·g⁻¹, for MB. The sorption mechanisms were analyzed using mathematical models, including Langmuir, Freundlich, Sips and Dubinin–Radushkevich isotherms, and kinetic models, like pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich and intra-particle diffusion (IPD). The sorption process was best described by the Sips isotherm and PSO kinetic models, indicating chemisorption as the dominant mechanism. This study outlines the importance of developing advanced renewable materials for environmental applications. Full article

(This article belongs to the Special Issue Properties of Hydrogels, Aerogels, and Cryogels Composites (2nd Edition))

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15 pages, 1289 KiB

Open AccessReview

Topical Probiotic Hydrogels for Burn Wound Healing

by Tavinda Arshad, Varsha Mundrathi, Victoria E. Perez, Jeilyn M. Nunez and Hyunah Cho

Gels 2024, 10(9), 545; https://doi.org/10.3390/gels10090545 - 23 Aug 2024

Viewed by 539

Abstract

Hydrogels have increasingly been used to enhance the effective healing of various wounds, including burn wounds. Similarly, the application of probiotics has recently been explored in wound healing and skin repairs. While probiotics have been consumed to provide therapeutic effects that aid with [...] Read more.

Hydrogels have increasingly been used to enhance the effective healing of various wounds, including burn wounds. Similarly, the application of probiotics has recently been explored in wound healing and skin repairs. While probiotics have been consumed to provide therapeutic effects that aid with improving gut health, topical applications have been found to accelerate wound healing both in vitro and in vivo. For wounds that have complex healing mechanisms, such as burn wounds which depend on factors such as the depth of the burn, size of the afflicted area, and cause of the injury, probiotics with or without conventional therapeutic agents topically delivered via hydrogel technology are proven to be effective in the recovery of the damaged skin. This article aims to investigate the microorganisms present in the human skin microbiome and observe the effects of probiotics delivered by hydrogels on burn wound healing. Full article

(This article belongs to the Special Issue Multifunctional Hydrogel for Wound Healing and Tissue Repair)

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