Gels | May 2025 - Browse Articles

20 pages, 6700 KiB

Open AccessArticle

The Hypoglycemic Activity of Gracilaria lemaneiformis Polysaccharide Gels Based on IR/IRS-2/PI3k/Akt/Glut4 and Glycometabolism Signaling Pathways in HepG2 Cells

by Xiaoshan Long, Shucheng Liu, Xianqing Yang, Yongqiang Zhao, Shaoling Yang, Ya Wei, Chuang Pan, Shengjun Chen, Peihong Jiang, Bo Qi and Xiao Hu

Gels 2025, 11(5), 366; https://doi.org/10.3390/gels11050366 - 15 May 2025

Abstract

The aim of this study was to investigate the hypoglycemic activity and mechanism of G. lemaneiformis polysaccharide gels (GLP and GLP-HV) based on IR/IRS-2/PI3k/Akt/Glut4 and glycometabolism signaling pathways in HepG2 cells. After H₂O₂-Vc degradation, the molecular weight of G. [...] Read more.

The aim of this study was to investigate the hypoglycemic activity and mechanism of G. lemaneiformis polysaccharide gels (GLP and GLP-HV) based on IR/IRS-2/PI3k/Akt/Glut4 and glycometabolism signaling pathways in HepG2 cells. After H₂O₂-Vc degradation, the molecular weight of G. lemaneiformis polysaccharide gel declined from 1478 kDa to 16 kDa. Molecular weight chromatogram and distribution indicated that GLP-HV had a high molecular weight homogeneity compared to GLP. G. lemaneiformis polysaccharide gels significantly decreased the TC, TG, LDL-C, MDA, and LDH contents and enhanced the activities of HDL-C, T-AOC, CAT, GSH-PX, SOD, insulin, and glycogen in HepG2 cells. Fluorescent staining results showed that G. lemaneiformis polysaccharide gels reduced ROS and calcium ions levels in HepG2 cells. GLP and GLP-HV displayed excellent hypoglycemic activity, with GLP-HV performing better. Furthermore, qPCR and Western blot analysis revealed that G. lemaneiformis polysaccharide gels remarkably strengthened the levels of IR, IRS-2, PI3K, Akt, Glut4, HK, G6PD, PFK, PEPCK, GK, PK genes, and proteins. Spearman’s correlation analysis revealed that the IR/IRS-2/PI3k/Akt/Glut4 signaling pathway played a dominant role in regulating activity. These results show that G. lemaneiformis polysaccharide gels present a prominent hypoglycemic effect mediated by the IR/IRS-2/PI3k/Akt/Glut4 and glycometabolism signaling pathways, with the former playing a dominant role. Full article

(This article belongs to the Special Issue Food Gels: Gelling Process and New Applications)

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22 pages, 5233 KiB

Open AccessArticle

A Novel Green In Situ Amine-Functionalized Aerogel UiO-66-NH₂/TOCNF for the Removal of Azo Anionic Dyes

by Rabia Amen, Islam Elsayed, Yunsang Kim, Gregory T. Schueneman, Emad M. El-Giar and El Barbary Hassan

Gels 2025, 11(5), 365; https://doi.org/10.3390/gels11050365 - 15 May 2025

Abstract

UiO-66-NH₂ is a metal–organic framework (MOF) with open metal sites, making it a promising candidate for adsorption and catalysis. However, the powdery texture of MOFs and the use of toxic solvents during synthesis limit their application. A novel solution to this issue [...] Read more.

UiO-66-NH₂ is a metal–organic framework (MOF) with open metal sites, making it a promising candidate for adsorption and catalysis. However, the powdery texture of MOFs and the use of toxic solvents during synthesis limit their application. A novel solution to this issue is to create a layered porous composite by encasing the MOF within a flexible and structurally robust aerogel substrate using safe, eco-friendly, and green solvents such as ethanol. The fibrous MOF aerogels, characterized by a desirable macroscopic shape of cylindrical block and hierarchical porosity, were synthesized by two approaches: in situ growth of amine-functionalized UiO-66-NH₂ crystals on a TEMPO-oxidized cellulose nanofiber (TOCNF) and ex situ crosslinking of UiO-66-NH₂ crystals onto a TOCNF network to form UiO-66-NH₂/TOCNF. The incorporation of MOF into the cellulose nanofibrils via the in situ method reduces their aggregation potential, alters the nucleation/growth balance to produce smaller MOF crystals, and enhances mechanical flexibility, as evidenced by SEM images. The three adsorbents, including UiO-66-NH₂, ex situ UiO-66-NH₂/TOCNF, and in situ UiO-66-NH₂/TOCNF, were synthesized and used in this study. The effects of pH, time, temperature, and initial concentration were studied. A maximum adsorption capacity (Qmax) of 549.45 mg/g for Congo Red (CR) and 171.23 mg/g for Orange II (ORII) was observed at pH 6, using 10 mg of in situ UiO-66-NH₂/TOCNF at 40 °C with a contact time of 75 min for CR and 2 h for ORII. The adsorption of both dyes primarily occurs through monolayer chemisorption on the in situ UiO-66-NH₂/TOCNF. The main removal mechanisms were hydrogen bonding and surface complexation. The noteworthy adsorption capacity of in situ UiO-66-NH₂/TOCNF coupled with environment-friendly fabrication techniques indicates its potential applications on a large scale in real wastewater systems. Full article

(This article belongs to the Special Issue Cellulose-Based Gels: Synthesis, Properties, and Applications)

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25 pages, 3964 KiB

Open AccessArticle

Development of Liposome-Based Hydrogel Patches Incorporating Essential Oils of African Plants and Deep Eutectic Solvents

by Wanhang Jiang, Sara Toufouki, Subhan Mahmood, Ali Ahmad, Alula Yohannes, Yang Xiang and Shun Yao

Gels 2025, 11(5), 364; https://doi.org/10.3390/gels11050364 - 15 May 2025

Abstract

A nanoliposome-integrated polymeric hydrogel was developed for the controlled release of essential oils (Argania spinosa, Passiflora edulis). A deep eutectic solvent (DES) composed of betaine and phytic acid enhanced the solubility and stability of essential oils, facilitating uniform encapsulation within nanoliposomes. The hydrogel [...] Read more.

A nanoliposome-integrated polymeric hydrogel was developed for the controlled release of essential oils (Argania spinosa, Passiflora edulis). A deep eutectic solvent (DES) composed of betaine and phytic acid enhanced the solubility and stability of essential oils, facilitating uniform encapsulation within nanoliposomes. The hydrogel exhibited a swelling capacity of 100% and retained 51.7% of water after 7 h, ensuring prolonged hydration. Structural analysis confirmed a homogeneous dispersion of nanoliposomes, contributing to the gradual release of bioactive components. Additionally, the hydrogel demonstrated high mechanical strength (7.5 MPa), ensuring flexibility and durability. The polymeric network, formed by acrylamide, sodium alginate, and bentonite, provided a stable and elastic matrix, optimizing water retention and mechanical performance. The controlled diffusion mechanism of the nanoliposomes was validated through in vitro release studies, indicating Fickian-controlled release behavior. These findings highlight the potential of this polymeric hydrogel system as a functional material for skincare formulations, offering enhanced hydration and sustained bioactive delivery. Full article

(This article belongs to the Special Issue Oleogels, Bigels, and Emulgels: Fabrication, Application and Research Trends)

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22 pages, 15068 KiB

Open AccessArticle

Utilization of Cassava Starch–Glycerol Gel as a Sustainable Material to Decrease Metal Ion Surface Contamination

by Rezky Anggakusuma, Gemilang Lara Utama, Dadan Sumiarsa, Permata Apriliani Dewi Muslimah and Ali Asgar

Gels 2025, 11(5), 363; https://doi.org/10.3390/gels11050363 - 14 May 2025

Abstract

Many studies have examined the ability of polymer-based gels or hydrogels to serve various purposes, particularly as absorbents. Several studies have reported that polyvinyl alcohol (PVA), with specific compositions and additives, is an absorbent and a decontamination material usable for heavy metals and [...] Read more.

Many studies have examined the ability of polymer-based gels or hydrogels to serve various purposes, particularly as absorbents. Several studies have reported that polyvinyl alcohol (PVA), with specific compositions and additives, is an absorbent and a decontamination material usable for heavy metals and radioactive substances. PVA has a high cost and is slowly degradable under anaerobic conditions. This study investigated the potential of natural materials, namely cassava starch, which is an environmentally friendly, non-toxic, and readily available gel-forming polymer that, notably, is inexpensive in Indonesia. The FTIR analysis showed a bond and polymer formation between cassava starch and glycerol. The cassava starch–glycerol–water mixture was applied to media such as glass, aluminum plates, and ceramics contaminated with heavy-metal stable ions which correspond to a radionuclide. The media, stored at room temperature for 24 h, becomes a film. According to the SEM and XRF results, the gel becomes a film that binds and absorbs metals when dried. The SEM results showed the presence of metals corresponding with the sources of contamination, and the XRF results showed that the quantity of metals absorbed was large. The cassava starch gel absorption results indicated the formation of an amorphous compound, as indicated by the XRF results. Based on all the analyses, the cassava starch–glycerol gel has enormous potential. It is almost equivalent to a PVA gel as an absorbent material and heavy-metal decontamination material, when used for radioactive decontamination on the material’s surface. Full article

(This article belongs to the Special Issue Gel-Related Papers from the 9th Asian Conference on Colloid and Interface Science 2023 (ACCIS 2023))

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33 pages, 10150 KiB

Open AccessReview

Mechanical Properties of Cement-Based Gel Composites Reinforced by Plant Fiber: A Review

by Peng Zhang, Xiao Zhang, Jinjun Guo, Yuanxun Zheng and Zhen Gao

Gels 2025, 11(5), 362; https://doi.org/10.3390/gels11050362 - 14 May 2025

Abstract

Plant fibers (PFs) have been increasingly employed in cement-based gel composites (CCs) on account of their excellent mechanical properties, toughness and sustainability. Researchers have engaged in a lot of studies on plant fiber-reinforced cement-based gel composites (PFRCCs). Based on these studies, the chemical [...] Read more.

Plant fibers (PFs) have been increasingly employed in cement-based gel composites (CCs) on account of their excellent mechanical properties, toughness and sustainability. Researchers have engaged in a lot of studies on plant fiber-reinforced cement-based gel composites (PFRCCs). Based on these studies, the chemical components and mechanical characteristics of PFs are summed up in this review. In addition, the modification methods for matrices and PFs are also discussed. The mechanical properties of PFRCCs, including static and dynamic properties, are reviewed. Predictive equations for the mechanical properties of PFRCCs are summarized in this paper. In the end, the characteristics of the interface transition zones between PFs and CCs are analyzed. According to the results of previous studies, the addition of PFs can enhance the flexural strength and tensile strength of CCs, but it can have an uncertain effect on compressive strength. The elastic modulus and fracture behavior of PFRCCs increases with the addition of PFs. At the same time, modification methods have been proved to be useful in reducing the degradation of PFs in CCs. Generally speaking, PFRCCs are new building materials which have extensive application prospects. The aim of this review is to help researchers understand the mechanical properties of PFRCCs and to promote the application of PFRCCs in future projects. Full article

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

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24 pages, 6987 KiB

Open AccessReview

Advances in Carbon-Based Aerogels for CO₂ Capture: Fundamental Design Strategies and Technological Progress

by Shakila Parveen Asrafali, Thirukumaran Periyasamy and Gazi A. K. M. Rafiqul Bari

Gels 2025, 11(5), 361; https://doi.org/10.3390/gels11050361 - 14 May 2025

Abstract

Carbon-based aerogels have garnered significant attention for CO₂ capture owing to their low-cost precursors, tunable structures, and high porosity. Their performance in CO₂ adsorption is intricately linked to their microstructural and textural features, including pore size distribution, surface area, and surface [...] Read more.

Carbon-based aerogels have garnered significant attention for CO₂ capture owing to their low-cost precursors, tunable structures, and high porosity. Their performance in CO₂ adsorption is intricately linked to their microstructural and textural features, including pore size distribution, surface area, and surface chemistry. Micropores (<2 nm) are particularly effective due to their size compatibility with CO₂ molecules, while surface functional groups enhance adsorption through hydrogen bonding and electrostatic interactions. Strategic design approaches have focused on tailoring these properties to optimize CO₂ uptake under realistic conditions. This review provides a comprehensive overview of recent advancements in the structural engineering of carbon aerogels, emphasizing the role of hierarchical porosity and heteroatom doping (nitrogen, oxygen, sulfur, etc.) in enhancing adsorption capacity and selectivity. Experimental and theoretical studies have highlighted how the synergistic control of microstructure and surface chemistry leads to superior adsorption performance. Furthermore, this review identifies current challenges, such as limited structural stability and insufficient mechanistic understanding, which hinder further progress. Future research directions are proposed, including advanced pore architecture control, functional group engineering, and the integration of in situ characterization techniques. Overall, this review serves as a guide for the rational design of next-generation carbon-based aerogels tailored for efficient and scalable CO₂ capture technologies. Full article

(This article belongs to the Special Issue Aerogels: Recent Progress in Novel Applications)

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1 pages, 219 KiB

Open AccessCorrection

Correction: Ramírez-Chavarría et al. Study of Polyvinyl Alcohol Hydrogels Applying Physical-Mechanical Methods and Dynamic Models of Photoacoustic Signals. Gels 2023, 9, 727

by Roberto G. Ramírez-Chavarría, Argelia Pérez-Pacheco, Emiliano Terán and Rosa M. Quispe-Siccha

Gels 2025, 11(5), 360; https://doi.org/10.3390/gels11050360 - 14 May 2025

Abstract

In the original publication [...] Full article

19 pages, 1355 KiB

Open AccessReview

Recent Advances in the Utilization of Cellulose from Food Processing Byproducts for the Generation of Aerogels

by Jaspreet Kaur and Ali Ubeyitogullari

Gels 2025, 11(5), 359; https://doi.org/10.3390/gels11050359 - 14 May 2025

Viewed by 34

Abstract

Aerogels have garnered significant attention from the scientific community due to their extraordinary properties, including low density, high porosity, low thermal conductivity, and large surface area. These properties make them interesting candidates for diverse applications such as thermal insulation, drug delivery, catalysis, fillers, [...] Read more.

Aerogels have garnered significant attention from the scientific community due to their extraordinary properties, including low density, high porosity, low thermal conductivity, and large surface area. These properties make them interesting candidates for diverse applications such as thermal insulation, drug delivery, catalysis, fillers, tissue engineering, and biosensors. However, the production of conventional aerogels is often constrained by environmental issues, the high cost of raw materials, and energy-intensive fabrication methods. In contrast, cellulose aerogels have emerged as promising sustainable materials with the potential to transform various low-cost waste products into high-value biomaterials. Food-processing byproducts provide numerous untapped opportunities for the generation of aerogels. This review highlights the recent advancements in the development of cellulose aerogels derived from food processing byproducts, emphasizing their role in contributing to the circular bioeconomy. Specifically, this study focuses on the fabrication processes of cellulose aerogels from food processing byproducts, which would otherwise go to waste. The review discusses the extraction, gel formation, drying, and functionalization processes for cellulose aerogel formation, along with the environmental and economic benefits of utilizing these waste streams. Full article

(This article belongs to the Special Issue Aerogels: Promising Materials for Environmental Applications)

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26 pages, 2841 KiB

Open AccessReview

Modified Phospholipid Vesicular Gel for Transdermal Drug Delivery: The Influence of Glycerin and/or Ethanol on Their Lipid Bilayer Fluidity and Penetration Characteristics

by Marwa H. Abdallah, Mona M. Shahien, Hemat El-Sayed El-Horany and Enas Haridy Ahmed

Gels 2025, 11(5), 358; https://doi.org/10.3390/gels11050358 - 13 May 2025

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Abstract

This review explores the enhanced transdermal therapy of several skin disorders with the application of carriers comprising phospholipid vesicular gel systems. Topical drug delivery has several advantages compared to other administration methods, including enhanced patient compliance, the avoidance of the first-pass impact associated [...] Read more.

This review explores the enhanced transdermal therapy of several skin disorders with the application of carriers comprising phospholipid vesicular gel systems. Topical drug delivery has several advantages compared to other administration methods, including enhanced patient compliance, the avoidance of the first-pass impact associated with oral administration, and the elimination of the need for repeated doses. Nonetheless, the skin barrier obstructs the penetration of drugs, hence affecting its therapeutic efficacy. Carriers with phospholipid soft vesicles comprise a novel strategy used to augment drug delivery into the skin and boost therapeutic efficacy. These vesicles encompass chemicals that possess the ability to fluidize phospholipid bilayers, producing a pliable vesicle that facilitates penetration into the deeper layers of the skin. Phospholipid-based vesicular carriers have been extensively studied for improved drug delivery through dermal and transdermal pathways. Traditional liposomes are limited to the stratum corneum of the skin and do not penetrate the deeper layers. Ethosomes, glycerosomes, and glycethosomes are nanovesicular systems composed of ethanol, glycerol, or a combination of ethanol and glycerol, respectively. Their composition produce pliable vesicles by fluidizing the phospholipid bilayers, facilitating deeper penetration into the skin. This article examines the impact of ethanol and glycerol on phospholipid vesicles, and outlines their respective manufacturing techniques. Thus far, these discrepancies have not been analyzed comparatively. The review details several active compounds integrated into these nanovesicular gel systems and examined through in vitro, in vivo, or clinical human trials involving compositions with various active molecules for the treatment of various dermatological conditions. Full article

(This article belongs to the Special Issue Recent Advances in Gels Engineering for Drug Delivery (2nd Edition))

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24 pages, 5625 KiB

Open AccessReview

A Review of High-Temperature Resistant Silica Aerogels: Structural Evolution and Thermal Stability Optimization

by Zhenyu Zhu, Wanlin Zhang, Hongyan Huang, Wenjing Li, Hao Ling and Hao Zhang

Gels 2025, 11(5), 357; https://doi.org/10.3390/gels11050357 - 13 May 2025

Viewed by 169

Abstract

Silica aerogels exhibit exceptionally low thermal conductivity and a low apparent density, as they are unique porous nanomaterials. They are extensively used in thermal insulation in terms of aerospace and building construction, adsorption processes for environmental applications, concentrating solar power systems, and so [...] Read more.

Silica aerogels exhibit exceptionally low thermal conductivity and a low apparent density, as they are unique porous nanomaterials. They are extensively used in thermal insulation in terms of aerospace and building construction, adsorption processes for environmental applications, concentrating solar power systems, and so on. However, the degradation of the silica aerogel’s nanoporous structure at high temperatures seriously restricts their practical applications. Through a comprehensive review of the high-temperature structural evolution and sintering mechanisms of silica aerogels, this paper introduces two strategies to enhance their thermal stability, including heteroatom doping and surface heterogeneous structure construction. In particular, atomic layer deposition (ALD) of ultra-thin coatings on silica aerogel holds significant potential for enhancing thermal stability, while preserving its ultra-low thermal conductivity. Full article

(This article belongs to the Special Issue Advanced Aerogels: From Design to Application)

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19 pages, 5545 KiB

Open AccessArticle

Core-Shell Hydrogels with Tunable Stiffness for Breast Cancer Tissue Modelling in an Organ-on-Chip System

by Ilaria Parodi, Maria Elisabetta Federica Palamà, Donatella Di Lisa, Laura Pastorino, Alberto Lagazzo, Fabio Falleroni, Maurizio Aiello, Marco Massimo Fato and Silvia Scaglione

Gels 2025, 11(5), 356; https://doi.org/10.3390/gels11050356 - 13 May 2025

Viewed by 161

Abstract

Breast cancer remains the most common malignancy in women, yet, many patients fail to achieve full remission despite significant advancements. This is largely due to tumour heterogeneity and the limitations of current experimental models in accurately replicating the complexity of in vivo tumour [...] Read more.

Breast cancer remains the most common malignancy in women, yet, many patients fail to achieve full remission despite significant advancements. This is largely due to tumour heterogeneity and the limitations of current experimental models in accurately replicating the complexity of in vivo tumour environment. In this study, we present a compartmentalised alginate hydrogel platform as an innovative in vitro tool for three-dimensional breast cancer cell culture. To mimic the heterogeneity of tumour tissues, we developed a core–shell structure (3.5% alginate core and 2% alginate shell) that mimic the stiffer, denser internal tumour matrix. The human triple-negative breast cancer cell line (MDA-MB-231) was embedded in core–shell alginate gels to assess viability, proliferation and hypoxic activity. Over one week, good cells proliferation and viability was observed, especially in the softer shell. Interestingly, cells within the stiffer core were more positive to hypoxic marker expression (HIF-1α) than those embedded in the shell, confirming the presence of a hypoxic niche, as observed in vivo. When cultured in the MIVO^® milli fluidic organ-on-chip resembling the physiological fluid flow conditions, cancer cells viability became comparable between core and shell hydrogel area, emphasising the importance of the fluid flow in nutrients diffusion within three-dimensional matrixes. Cisplatin chemotherapy treatment further highlighted these differences: under static conditions, cancer cell death was prominent in the softer shell, whereas cells in the stiffer core remained resistant to cisplatin. Conversely, drug diffusion was more homogeneous in the core–shell structured treated in the organ-on-chip, leading to a uniform reduction in cell viability. These findings suggest that integrating a compartmentalised core–shell cell laden alginate model with the millifluidic organ on chip offers a more physiologically relevant experimental approach to deepening cancer cell behaviour and drug response. Full article

(This article belongs to the Special Issue Properties and Applications of Biomaterials Related to Gels (3rd Edition))

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21 pages, 9758 KiB

Open AccessArticle

Bionanocomposite Four-Channel Biosensor for Rapid and Convenient Monitoring of Glucose, Lactate, Ethanol and Starch

by Anna Kharkova, Lyubov Kuznetsova, Roman Perchikov, Maria Gertsen, Pavel Melnikov, Nikolay Zaitsev, Jun Zhang and Vyacheslav Arlyapov

Gels 2025, 11(5), 355; https://doi.org/10.3390/gels11050355 - 12 May 2025

Viewed by 197

Abstract

A biosensor for the determination of glucose, lactate, ethanol and starch in beverages has been developed using enzymes immobilized by a redox-active gel on a screen-printed electrode. A significant improvement proposed for multichannel biosensors, overcoming stability and sensitivity issues by covalently binding phenazine [...] Read more.

A biosensor for the determination of glucose, lactate, ethanol and starch in beverages has been developed using enzymes immobilized by a redox-active gel on a screen-printed electrode. A significant improvement proposed for multichannel biosensors, overcoming stability and sensitivity issues by covalently binding phenazine mediators to a biocompatible protein hydrogel, enhancing the packaging of the enzyme. Glucose oxidase (GOx), alcohol oxidase (AOx) and lactate oxidase (LOx) were used as biological materials, as well as a mixture of GOx with γ-amylase (Am). Redox gels were synthesized from bovine serum albumin (BSA) and phenazine derivatives. It was shown that a neutral red-based redox gel combined with single-walled carbon nanotubes is more promising than other substrates for enzyme immobilization. The lower limit of quantification for glucose, ethanol, lactate and starch using these systems is 0.035 mM, 2.3 mM, 15 mM and 2 mg/L, respectively. Biosensors were used to analyze the content of these substances in alcoholic, kvass and fermentation mass. Statistical analysis of the results showed that the values of glucose, ethanol, lactic acid and starch determined using biosensors and obtained by reference methods differ insignificantly. A set of biosensors developed on the basis of specifically selected enzymes is effective for controlling biotechnological processes and can be used as an alternative to classical analytical methods. Full article

(This article belongs to the Special Issue Recent Progress of Hydrogel Sensors and Biosensors)

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22 pages, 10357 KiB

Open AccessArticle

Development of an Asymmetric Alginate Hydrogel Loaded with S-Nitrosoglutathione and Its Application in Chronic Wound Healing

by Jiafeng Tan, Minna Wen, Yifan Zhang, Shuyun Zhang, Min Fang, Junxiao Xiang, Xinshuo Liu, Jinhuan Tian, Lu Lu, Binghong Luo, Changren Zhou and Lihua Li

Gels 2025, 11(5), 354; https://doi.org/10.3390/gels11050354 - 12 May 2025

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Abstract

Nitric oxide (NO) is an endogenous signaling molecule that plays a critical role in wound healing. However, the gaseous nature, short half-life, and low stability of NO present challenges for its clinical application. To address these issues, this study introduces an innovative S-nitrosoglutathione [...] Read more.

Nitric oxide (NO) is an endogenous signaling molecule that plays a critical role in wound healing. However, the gaseous nature, short half-life, and low stability of NO present challenges for its clinical application. To address these issues, this study introduces an innovative S-nitrosoglutathione (GSNO)-loaded asymmetric alginate (SA) hydrogel (GSNO-SA) as a novel solution for treating infected chronic wounds. The hydrogel is designed with a layer-by-layer melting-permeation crosslinking approach, forming a dense upper layer and a sparse lower layer structure, effectively promoting exudate management while delaying NO release. The results demonstrate that the GSNO-SA hydrogel extends NO release for up to 48 h, exhibits rapid exudate absorption (72.3 ± 1.5% equilibrium swelling after 5 min), significant antibacterial activity (over 90% antibacterial rate against E. coli and S. aureus), and anti-inflammatory effects (marked reduction in TNF-α expression), and promotes angiogenesis (90.00 ± 5.92% migration rate at 48 h). Additionally, animal studies show that the GSNO-SA hydrogel accelerates wound healing, achieving a 99.2 ± 0.1% closure rate at 14 days. Histological and immunohistochemical evaluations further confirm its ability to regulate inflammation (13.34-fold upregulation of CD163) and promote angiogenesis (3.02-fold upregulation of α-SMA). Theoretically, this asymmetric design provides a novel strategy for developing exudate-managing dressings by integrating controlled NO release with hierarchical pore structures. Full article

(This article belongs to the Special Issue Biopolymer Gel-Assisted Synthesis of Particles for Biomedical Applications (2nd Edition))

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19 pages, 1485 KiB

Open AccessArticle

Polydextrose Reduces the Hardness of Cooked Chinese Sea Rice Through Intermolecular Interactions

by Chang Liu, Bing Dai, Xiaohong Luo, Hongdong Song and Xingjun Li

Gels 2025, 11(5), 353; https://doi.org/10.3390/gels11050353 - 11 May 2025

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Abstract

Supposing that polydextrose molecules could improve the hard texture of cooked rice based on intermolecular interactions and forming a hydrogel-like network structure, this study added polydextrose (moisture content 1%) at 0%, 3%, 5%, 7%, and 10% concentrations to rice (cv. Super Qianhao, SQ) [...] Read more.

Supposing that polydextrose molecules could improve the hard texture of cooked rice based on intermolecular interactions and forming a hydrogel-like network structure, this study added polydextrose (moisture content 1%) at 0%, 3%, 5%, 7%, and 10% concentrations to rice (cv. Super Qianhao, SQ) milled from a 3-year-stored paddy and compared their cooking properties, their cooked rice texture, the pasting and thermal properties of their flours, the thermo-mechanical characteristics of their flour dough, and the microstructure of their cooked rice grains with a newly harvested japonica rice cv. Nanjing 5 (NJ5). With an increase in polydextrose addition, a General Linear Model (GLM) analysis showed that the cooking times of two japonica rice varieties was significantly (p < 0.05) reduced, and their gruel solid loss increased. Adding polydextrose significantly reduced the hardness, springiness, gumminess, and chewiness of cooked rice and increased the cohesiveness and resilience. By increasing polydextrose addition in rice flours, the peak, breakdown, and setback viscosities of pasting were significantly decreased, but the pasting temperature and peak time increased. Adding polydextrose reduced the gelatinization enthalpy and increased gelatinization peak temperature of the rice flour and significantly decreased the ageing of the retrograded rice flour paste stored at 4 °C when measured at 21 days. A Mixolab test showed that the stability time of the rice flour dough increased, and the protein weakening, gelatinization peak torque, and starch breakdown, as well as the starch setback and the speeds of heating, gelatinization, and enzymatic degradation all decreased. The addition of 5–10% polydextrose significantly reduced the amorphous and crystalline regions of starch and relative percent of β-sheet in cooked rice grains, with an increase in the relative percent of α-helix, random coil, and β-turn. Observing the microstructure, we confirmed that polydextrose addition facilitated the formation of a soft and evenly swollen honeycomb structure of the cooked rice. These results suggest that polydextrose might decrease the cooked rice hardness and improve the eating quality of sea rice through intermolecular interactions. Full article

(This article belongs to the Special Issue Recent Advances in Food Gels (2nd Edition))

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20 pages, 22930 KiB

Open AccessArticle

Poly(vinyl alcohol)/Gentamicin and Poly(vinyl alcohol)/Chitosan/Gentamicin: Promising Materials for Rapid Burn Wound Healing

by Anja Nikolić, Ivan Milošević, Ana Janković, Bogomir Bolka Prokić, Emilija Nićković, Danica Marković, Milena Stevanović, Maja Vukašinović-Sekulić, Vesna Mišković-Stanković and Tijana Lužajić Božinovski

Gels 2025, 11(5), 352; https://doi.org/10.3390/gels11050352 - 10 May 2025

Viewed by 128

Abstract

Scar formation and delayed wound healing pose significant challenges in treating skin injuries, especially in severe cases like burns and diabetic wounds. This study investigates the effectiveness of novel Poly(vinyl alcohol) (PVA)/Gentamicin (Gent) and PVA/Chitosan (CHI)/Gent hydrogels in promoting healing of second-degree burn [...] Read more.

Scar formation and delayed wound healing pose significant challenges in treating skin injuries, especially in severe cases like burns and diabetic wounds. This study investigates the effectiveness of novel Poly(vinyl alcohol) (PVA)/Gentamicin (Gent) and PVA/Chitosan (CHI)/Gent hydrogels in promoting healing of second-degree burn wounds in a rat model. Following in vitro testing, these hydrogels were deemed non-toxic and suitable for in vivo analysis. Clinical evaluations were conducted on the 3rd, 7th, 14th, and 21st post-injury days, assessing parameters such as blistering, edema, redness, crust, bleeding, secretion, scar tissue formation, and wound contraction percentage. Histological analyses focused on re-epithelization and dermal evaluation at specific time points. Results showed that both hydrogels significantly reduced inflammation, particularly redness, by the 14th day and improved re-epithelization, with the PVA/CHI/Gent group outperforming on the 14th day and the PVA/Gent group excelling on the 21st day. Histological findings indicated increased fibroblast proliferation and collagen deposition in treated groups, suggesting enhanced dermal healing. The PVA/CHI/Gent hydrogel demonstrated notable antibacterial properties, likely due to the synergistic effects of CHI and Gent, leading to reduced inflammation and edema. Overall, both hydrogels show promise as effective wound dressings, facilitating faster healing and improved tissue recovery in burn injuries. This study supports the use of biomimetic scaffolds for enhanced wound management in clinical practices. Full article

(This article belongs to the Special Issue Characterization Techniques for Hydrogels and Their Applications)

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9 pages, 270 KiB

Open AccessEditorial

Gels: Synthesis, Characterization and Applications in High Performance Chemistry (2nd Edition)

by Viorel-Puiu Paun and Maria-Alexandra Paun

Gels 2025, 11(5), 351; https://doi.org/10.3390/gels11050351 - 10 May 2025

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Abstract

This Editorial of the Special Issue proposed and managed by Prof [...] Full article

(This article belongs to the Section Gel Applications)

32 pages, 14332 KiB

Open AccessArticle

Research and Development of a High-Temperature-Resistant, Gel-Breaking Chemical Gel Plugging Agent and Evaluation of Its Physicochemical Properties

by Junwei Fang, Jinsheng Sun, Xingen Feng, Lijuan Pan, Yingrui Bai and Jingbin Yang

Gels 2025, 11(5), 350; https://doi.org/10.3390/gels11050350 - 8 May 2025

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Abstract

Gas channeling phenomena in carbonate fracture-vuggy reservoirs frequently occur, primarily in the form of negative pressure gas channeling and displacement gas channeling, with the possibility of mutual conversion between the two. This is accompanied by the risk of hydrogen sulfide (H₂S) [...] Read more.

Gas channeling phenomena in carbonate fracture-vuggy reservoirs frequently occur, primarily in the form of negative pressure gas channeling and displacement gas channeling, with the possibility of mutual conversion between the two. This is accompanied by the risk of hydrogen sulfide (H₂S) release from the reservoir, which poses significant challenges to controlling safety. Currently, liquid bridging and gel plugging technologies are effective methods for mitigating complex issues such as downhole overflow, fluid loss, and heavy oil backflow. This paper focuses on the development and optimization of key treatment agents, including high-temperature-resistant polymers and crosslinking agents, to formulate a high-temperature chemical gel plugging agent. A gel-breaking, high-strength colloidal chemical gel plugging agent system capable of withstanding temperatures up to 150 °C was developed, and it has an apparent viscosity of about 7500 mPa·s, an energy storage modulus and a loss modulus of 51 Pa and 6 Pa, respectively, after gel formation at elevated temperatures, and an apparent viscosity retention rate of the gel of greater than 82% after aging for 9 d at a temperature of 150 °C. This system forms a stable gas isolation barrier in the wellbore, with performance remaining stable after 7 to 12 days of aging, and the degradation rate reaches 99.8% after 24 h at 150 °C. This technology is of significant importance in solving complex issues such as overflow, fluid loss, and heavy oil backflow in gas injection and recovery wells in high-temperature, high-pressure reservoir conditions. Full article

(This article belongs to the Special Issue Chemical and Gels for Oil Drilling and Enhanced Recovery)

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23 pages, 16269 KiB

Open AccessArticle

Development of Eco-Friendly Date Palm Biomass-Based Hydrogels for Enhanced Water Retention in Soil

by Faisal S. Alsubaie, Mouyed Srdar, Osama Fayraa, Faris M. Alsulami, Feras Omran and Khalid A. Alamry

Gels 2025, 11(5), 349; https://doi.org/10.3390/gels11050349 - 8 May 2025

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Abstract

The growth of plants highly depends on the soil’s water availability and properties. Hydrogels (HGs) have been used for decades to enhance soil water retention, whereas developing eco-friendly and sustainable HGs for agricultural applications is still necessary to ensure water and food security. [...] Read more.

The growth of plants highly depends on the soil’s water availability and properties. Hydrogels (HGs) have been used for decades to enhance soil water retention, whereas developing eco-friendly and sustainable HGs for agricultural applications is still necessary to ensure water and food security. In this study, renewable and cost-effective HGs were prepared from all-lignocellulose fibers of date palm biomass after carboxymethylation followed by citric acid (CA) crosslinking. HGs showed high equilibrium swelling capacity (EWC%), even in salty media, whereas purified HGs showed about 700–400 EWC% in deionized water. Further, HGs’ effect on germination was studied on Chico III tomato, mint, Basilico red, and chia seeds. The results revealed that HGs enhanced the soil properties, with taller and healthier plants observed in HG-amended soil. FTIR, thermal analysis, and microscope imaging were utilized to evaluate HGs’ and raw materials’ characteristics. The findings in this study support the idea that all-lignocellulose could be used for HG production without separation. Full article

(This article belongs to the Special Issue Designing Hydrogels and Hydrogel-Derived Materials for Agriculture and Water Sustainability)

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13 pages, 3042 KiB

Open AccessArticle

A Mathematical Model of Myosin Heavy Chain Dynamics in the Disintegration of Golden Threadfin Bream Nemipterus virgatus Surimi Gel

by Ryoko Nakamizo, Tatsuya Hayashi, Yuri Kominami and Hideki Ushio

Gels 2025, 11(5), 348; https://doi.org/10.3390/gels11050348 - 8 May 2025

Viewed by 169

Abstract

Surimi gel, a type of hydrocolloidal food, is formed through the gelation of fish meat proteins. Myosin heavy chain (MHC), a key myofibrillar protein, plays a crucial role in the formation of the gel network via both transglutaminase (TGase)-catalyzed and non-enzymatic polymerization. Gel [...] Read more.

Surimi gel, a type of hydrocolloidal food, is formed through the gelation of fish meat proteins. Myosin heavy chain (MHC), a key myofibrillar protein, plays a crucial role in the formation of the gel network via both transglutaminase (TGase)-catalyzed and non-enzymatic polymerization. Gel disintegration in surimi is primarily attributed to the proteolytic degradation of MHC. This study focused on golden threadfin bream Nemipterus virgatus, a species characterized by low TGase activity and high protease activity at elevated temperatures. We investigated the competition between non-enzymatic polymerization and proteolytic degradation of MHC and their effects on gel mechanical properties using a mathematical model. A mathematical model based on kinetic reactions accurately reflected the changes in MHC observed through SDS-PAGE analysis during N. virgatus gel disintegration. Our results indicate that not only unpolymerized but also polymerized MHC was significantly degraded, which substantially contributed to the reduction in the mechanical properties of the N. virgatus surimi. Mathematically understanding the dynamics of MHC in surimi during heating helps promote the utilization of noncommercial fish species for surimi processing by enabling better control over surimi gel properties. Full article

(This article belongs to the Special Issue Food Gels: Fabrication, Characterization, and Application)

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14 pages, 4242 KiB

Open AccessArticle

Study on Filter Cake Removal Fluid of EZFLOW Weak Gel Drilling Fluid

by Haohan Hu, Youlin Hu and Xuejing Weng

Gels 2025, 11(5), 347; https://doi.org/10.3390/gels11050347 - 8 May 2025

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Abstract

EZFLOW weak gel drilling fluid, a drilling fluid system with distinctive internal architecture, has been extensively implemented in horizontal well drilling operations at the Western South China Sea oilfields. Its unique internal structure causes specific functional mechanisms. The rheological mechanism was investigated through [...] Read more.

EZFLOW weak gel drilling fluid, a drilling fluid system with distinctive internal architecture, has been extensively implemented in horizontal well drilling operations at the Western South China Sea oilfields. Its unique internal structure causes specific functional mechanisms. The rheological mechanism was investigated through microstructural characterization, revealing that the microstructure comprises a reversible network structure with sol particles either encapsulated within the network or embedded at nodal points. This distinctive spatial network configuration endows the system with exceptional rheological properties. The plugging mechanism was elucidated via pre- and post-PPA test characterization of sand disc surface morphology. Experimental results demonstrate that the rheology modifier EZVIS forms deformable aggregates and films through intermolecular or intramolecular association in aqueous solutions, effectively plugging micro-nano pores/throats and microfractures to inhibit drilling fluid filtrate invasion. Concurrently, the rigid plugging material EZCARB establishes physical barriers at micro-nano pores/throats through bridging mechanisms. Notably, the dense filter cake formed by EZFLOW weak gel drilling fluid exhibits poor flowback characteristics, potentially inducing reservoir damage. Based on mechanistic analyses of rheological behavior, plugging performance, and filter cake composition, a filter cake removal fluid formulation was developed through: (1) creation of retarded acid HWCP to degrade polymer EZVIS and dissolve temporary plugging agent EZCARB; (2) development of corrosion inhibitor HWCI to mitigate corrosion rates. Laboratory evaluations demonstrated effective filter cake elimination and reservoir protection capabilities. Post-treatment analysis of EZFLOW-contaminated reservoir cores showed complete filter cake removal at core end faces with permeability recovery values exceeding 95%, indicating superior filter cake dissolution capacity and reservoir protection performance that significantly reduces formation damage. Full article

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

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30 pages, 12571 KiB

Open AccessArticle

Injectable and Conductive Polyurethane Gel with Load-Responsive Antibiosis for Sustained Root Canal Disinfection

by Bo Mu, Xiaoyu Lei, Yinglong Zhang, Jingzheng Zhang, Qingda Du, Yuping Li, Dongyu Huang, Li Wang, Jidong Li, Yubao Li and Yi Zuo

Gels 2025, 11(5), 346; https://doi.org/10.3390/gels11050346 - 7 May 2025

Viewed by 144

Abstract

To address the limitations of conventional antibacterial therapies, we developed an injectable, conductive polyurethane-based composite gel system for sustained root canal disinfection. This gel incorporates piezoelectric nanoparticles (n-BaTiO₃) and conductive segments (aniline trimer, AT) within a polyurethane matrix, which synergistically interact [...] Read more.

To address the limitations of conventional antibacterial therapies, we developed an injectable, conductive polyurethane-based composite gel system for sustained root canal disinfection. This gel incorporates piezoelectric nanoparticles (n-BaTiO₃) and conductive segments (aniline trimer, AT) within a polyurethane matrix, which synergistically interact with a static antimicrobial agent (n-ZnO) to achieve dynamic, mechano-responsive antibacterial activity. Under cyclic compression (simulating mastication), the piezoelectric gels exhibited enhanced electroactivity via the mechano-electric coupling effect, generating 2-fold higher voltage and a 1.8–1.9× increase in current compared to non-piezoelectric controls. The dynamic electroactivity of the gels enabled superior long-term performance, achieving 92–97% biofilm eradication, significantly higher than the static n-ZnO-only gel (88%). XPS and UV-vis spectroscopy analyses confirmed mechano-electrochemically amplified reactive oxygen species (ROS) generation, which contributed to improved biofilm disruption. The ISO-compliant gel provides durable, load-responsive disinfection while maintaining good biocompatibility, offering a promising solution to prevent post-treatment reinfection. Full article

(This article belongs to the Special Issue Oleogels, Bigels, and Emulgels: Fabrication, Application and Research Trends)

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34 pages, 7587 KiB

Open AccessReview

Multifunctional Carbon-Based Nanocomposite Hydrogels for Wound Healing and Health Management

by Tianyi Lu, Yaqian Chen, Meng Sun, Yuxian Chen, Weilong Tu, Yuxuan Zhou, Xiao Li and Tao Hu

Gels 2025, 11(5), 345; https://doi.org/10.3390/gels11050345 - 6 May 2025

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Abstract

Compared with acute wounds, typical chronic wounds (infection, burn, and diabetic wounds) are susceptible to bacterial infection and hard to heal. As for the complexity of chronic wounds, biocompatible hydrogel dressings can be employed to regulate the microenvironment and accelerate wound healing with [...] Read more.

Compared with acute wounds, typical chronic wounds (infection, burn, and diabetic wounds) are susceptible to bacterial infection and hard to heal. As for the complexity of chronic wounds, biocompatible hydrogel dressings can be employed to regulate the microenvironment and accelerate wound healing with their controllable physical and chemical properties. Recently, various nanomaterials have been introduced into hydrogel networks to prepare functional nanocomposite hydrogels. Among them, carbon-based nanomaterials (CBNs) have attracted wide attention in the biomedical field due to their outstanding physicochemical properties. However, comprehensive reviews on the use of CBNs for multifunctional hydrogel wound dressings in the past 10 years are very scarce. This review focuses on the research progress on hydrogel dressings made with typical CBNs. Specifically, a series of CBNs (carbon dots, graphene quantum dots, fullerenes, nanodiamonds, carbon nanotubes, graphene, graphene oxide and reduced graphene oxide) employed in the preparation of hydrogels are described as well as carbon-based nanocomposite hydrogels (CBNHs) with versatility (conductivity, antibacterial, injectable and self-healing, anti-inflammatory and antioxidant properties, substance delivery, stimulus response and real-time monitoring). Moreover, applications of CBNHs in treating different chronic wounds are concretely discussed. This review may provide some new inspirations for the future development of CBNHs in wound care and tissue engineering. Full article

(This article belongs to the Special Issue Gel-Based Materials for Sensing and Monitoring)

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27 pages, 7362 KiB

Open AccessArticle

Preparation and Properties of a Novel Multi-Functional Viscous Friction Reducer Suspension for Fracturing in Unconventional Reservoirs

by Shenglong Shi, Jinsheng Sun, Shanbo Mu, Kaihe Lv, Yingrui Bai and Jian Li

Gels 2025, 11(5), 344; https://doi.org/10.3390/gels11050344 - 6 May 2025

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Abstract

Aiming at the problem that conventional friction reducers used in fracturing cannot simultaneously possess properties such as temperature resistance, salt resistance, shear resistance, rapid dissolution, and low damage. Under the design concept of “medium-low molecular weight, salt-resistant functional monomer, supramolecular physical crosslinking aggregation, [...] Read more.

Aiming at the problem that conventional friction reducers used in fracturing cannot simultaneously possess properties such as temperature resistance, salt resistance, shear resistance, rapid dissolution, and low damage. Under the design concept of “medium-low molecular weight, salt-resistant functional monomer, supramolecular physical crosslinking aggregation, and enhanced chain mechanical strength”, acrylamide, sulfonic acid salt-resistant monomer 2-acrylamide-2-methylpropanesulfonic acid, hydrophobic association monomer, and rigid skeleton functional monomer acryloyl morpholine were introduced into the friction reducer molecular chain by free radical polymerization, and combined with the compound suspension technology to develop a new type of multi-functional viscous friction reducer suspension (SAMD), the comprehensive performance of SAMD was investigated. The results indicated that the critical micelle concentration of SAMD was 0.33 wt%, SAMD could be dissolved in 80,000 mg/L brine within 3.0 min, and the viscosity loss of 0.5 wt% SAMD solution was 24.1% after 10 min of dissolution in 80,000 mg/L brine compared with that in deionized water, the drag reduction rate of 0.1 wt% SAMD solution could exceed 70% at 120 °C and still maintained good drag reduction performance in brine with a salinity of 100,000 mg/L. After three cycles of 170 s⁻¹ and 1022 s⁻¹ variable shear, the SAMD solution restored viscosity quickly and exhibited good shear resistance. The Tan δ (a parameter characterizing the viscoelasticity of the system) of 1.0 wt% SAMD solution was 0.52, which showed a good sand-carrying capacity, and the proppant settling velocity in it could be as low as 0.147 mm/s at 120 °C, achieving the function of high drag reduction at low concentrations and strong sand transportation at high concentrations. The viscosity of 1.4 wt% SAMD was 95.5 mPa s after shearing for 120 min at 140 °C and at 170 s⁻¹. After breaking a gel, the SAMD solution system had a core permeability harm rate of less than 15%, while the SAMD solution also possessed the performance of enhancing oil recovery. Compared with common friction reducers, SAMD simultaneously possessed the properties of temperature resistance, salt resistance, shear resistance, rapid dissolution, low damage, and enhanced oil recovery. Therefore, the use of this multi-effect friction reducer is suitable for the development of unconventional oil reservoirs with a temperature lower than 140 °C and a salinity of less than 100,000 mg/L. Full article

(This article belongs to the Special Issue Chemical and Gels for Oil Drilling and Enhanced Recovery)

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27 pages, 6626 KiB

Open AccessReview

Multifunctional Janus Hydrogels: Surface Design Strategies for Next-Generation Clinical Solutions

by Taoxu Yan, Junyao Cheng, Haoming Liu, Yifan Wang, Chuyue Zhang, Da Huang, Jianheng Liu and Zheng Wang

Gels 2025, 11(5), 343; https://doi.org/10.3390/gels11050343 - 6 May 2025

Viewed by 253

Abstract

Janus hydrogels, distinguished by their dual-sided structure with distinct physical and chemical properties, have garnered significant attention in the medical field, particularly for applications in drug delivery, tissue engineering, and wound healing. Their ability to simultaneously perform multiple functions, such as targeted drug [...] Read more.

Janus hydrogels, distinguished by their dual-sided structure with distinct physical and chemical properties, have garnered significant attention in the medical field, particularly for applications in drug delivery, tissue engineering, and wound healing. Their ability to simultaneously perform multiple functions, such as targeted drug release and biomimetic tissue interaction, positions them as a promising platform for advanced therapeutic strategies. The growing interest in these hydrogels is primarily driven by their multifunctionality and capacity to address complex biological needs. This review delves into the design, fabrication methods, and applications of Janus hydrogels in medicine, focusing on their potential to overcome the limitations of conventional therapies and providing a comprehensive overview of their role in contemporary biomedical applications. Full article

(This article belongs to the Special Issue Innovative Applications of Gelated Matrices in Biomedical and Environmental Engineering)

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20 pages, 1353 KiB

Open AccessReview

Hydrogels in Simulated Microgravity: Thermodynamics at Play

by Azadeh Sepahvandi, Joseph Johnson, Ava Arasan, Ryan Cataldo and Seyed Majid Ghoreishian

Gels 2025, 11(5), 342; https://doi.org/10.3390/gels11050342 - 3 May 2025

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Abstract

Hydrogels have become indispensable in biomedical research and regenerative therapies due to their high water content, tissue-like mechanics, and tunable biochemical properties. However, their behavior under altered gravitational conditions—particularly simulated microgravity (SMG)—presents a frontier of challenges and opportunities that remain underexplored. This comprehensive [...] Read more.

Hydrogels have become indispensable in biomedical research and regenerative therapies due to their high water content, tissue-like mechanics, and tunable biochemical properties. However, their behavior under altered gravitational conditions—particularly simulated microgravity (SMG)—presents a frontier of challenges and opportunities that remain underexplored. This comprehensive review provides a detailed comparative analysis of hydrogel performance in normal gravity versus SMG environments, focusing on the structural, physicochemical, and thermodynamic parameters that govern their functionality. We critically examine how microgravity influences polymer network formation, fluid dynamics, swelling behavior, mechanical stability, and degradation kinetics. SMG disrupts convection, sedimentation, and phase separation, often leading to inhomogeneous crosslinking and altered diffusion profiles. These changes can compromise hydrogel uniformity, anisotropy, and responsiveness, which are essential for biomedical applications such as drug delivery, tissue regeneration, and biosensing. To address these limitations, we propose a thermodynamic framework that integrates osmotic pressure regulation, entropy-driven swelling, and pressure–temperature control to enhance hydrogel stability and functionality in low-gravity environments. The integration of predictive modeling approaches—including finite element simulations, phase-field models, and swelling kinetics—provides a robust pathway to design space-adapted hydrogel systems. The review also outlines future directions for optimizing hydrogel platforms in extraterrestrial settings, advocating for synergistic advances in material science, biophysics, and space health. These insights offer a strategic foundation for the rational development of next-generation hydrogel technologies tailored for long-duration space missions and planetary biomedical infrastructure. Full article

(This article belongs to the Special Issue Structure and Properties of Functional Hydrogels (2nd Edition))

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19 pages, 5379 KiB

Open AccessArticle

Development of Edible Carbohydrate–Protein Sports Gels to Optimize the Muscle Glycogen Re-Synthesis

by Vishal Verma, Vishal Gill, Avinash Kumar and Shailendra Pratap Singh

Gels 2025, 11(5), 341; https://doi.org/10.3390/gels11050341 - 2 May 2025

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Abstract

This study was aimed at providing athletes a solution to replenish the muscle glycogen re-synthesis at an optimal rate with hemp seeds as a natural protein source and Bengal gram dal and its use for the preparation of gel. The gel contains the [...] Read more.

This study was aimed at providing athletes a solution to replenish the muscle glycogen re-synthesis at an optimal rate with hemp seeds as a natural protein source and Bengal gram dal and its use for the preparation of gel. The gel contains the richest source of energy, and it is an effective way to provide energy and nutrients to athletes. The gel was prepared in three variations with different hemp seed concentrations. We then analyzed the gel for pH and macronutrient composition. The sensory characteristics were analyzed for seven parameters, including appearance, taste, color, texture, aroma, consistency, and acceptability, using a hedonic scale on 25 panelists. A sensory analysis showed that sample A received an overall acceptability score of 7.16 ± 0.99 from the sensory panel. The shelf life was observed at the recommended temperature of 4 degrees Celsius, which was 12 days. The best formulation was sample B with 38 g of hemp seeds, which showed better taste, color, aroma, and acceptability and a lower average pH value (6.68 ± 1.44, 6.56 ± 1.29, 7.6 ± 1.16, 7 ± 1.26, and 5.822 ± 0.0183, respectively). Sample B contained 30.8 g of protein, 16.09 g of carbohydrates, 8.4 g of fat, and 263.16 kcal of energy per 100 g. The resulting ratio of carbohydrates to protein is optimal for use as a high-protein post-workout meal. Hence, it can be considered a post-workout supplement. Full article

(This article belongs to the Special Issue Edible Coatings and Film: Gel-Based Innovations)

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12 pages, 6442 KiB

Open AccessArticle

Tandem Visual Recognition of Cu²⁺ and Chiral Tartaric Acid by Sequence Gel Formation and Collapse

by Jian Zeng, Yixuan Jiang, Xiao-Qi Yu and Shanshan Yu

Gels 2025, 11(5), 340; https://doi.org/10.3390/gels11050340 - 1 May 2025

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Abstract

A chiral gelator (R)-H₆L with multiple carboxyl groups based on a 1,1′-bi-2,2′-naphthol (BINOL) skeleton was prepared, and it could form a supramolecular gel under the induction of water in DMSO/H₂O and DMF/H₂O (1/1, v/ [...] Read more.

A chiral gelator (R)-H₆L with multiple carboxyl groups based on a 1,1′-bi-2,2′-naphthol (BINOL) skeleton was prepared, and it could form a supramolecular gel under the induction of water in DMSO/H₂O and DMF/H₂O (1/1, v/v). In the EtOH/H₂O system, the original partial gel transformed into a stable metal–organic gel (MOG), specifically with Cu²⁺ among 20 metal ions. It is proposed that Cu²⁺ coordinates with the carboxyl groups of (R)-H₆L to form a three-dimensional network structure. With the addition of a variety of α-hydroxy acids and amino acids, the Cu²⁺-MOG collapsed with merely 0.06 equivalents of L-tartaric acid (L-TA), while other acids required much larger amounts to achieve the same effect, realizing the visual chemoselective and enantioselective recognition of tartaric acid. Therefore, the chiral gelator (R)-H₆L achieved the tandem visual recognition of Cu²⁺ and chiral tartaric acid by sequence gel formation and collapse, offering valuable insights for visual sensing applications and serving as a promising model for future chiral sensor design. Full article

(This article belongs to the Special Issue Design of Supramolecular Hydrogels)

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22 pages, 4241 KiB

Open AccessArticle

Impact of Alkali-Activated Tannery Sludge-Derived Geopolymer Gel on Cement Properties: Workability, Hydration Process, and Compressive Strength

by Shoukai Chen, Beiying Liu, Phu Minh Vuong Nguyen, Jinping Liu, Jialin Chen and Fei Zhou

Gels 2025, 11(5), 339; https://doi.org/10.3390/gels11050339 - 1 May 2025

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Abstract

The utilization of tannery sludge (TS) in construction materials not only effectively reduces pollution and resource consumption associated with waste disposal, but also promotes low carbon transformation in the building materials sector, further advancing sustainable development of green construction. This study aims to [...] Read more.

The utilization of tannery sludge (TS) in construction materials not only effectively reduces pollution and resource consumption associated with waste disposal, but also promotes low carbon transformation in the building materials sector, further advancing sustainable development of green construction. This study aims to investigate the impact of sludge-based geopolymer gel on cementitious material performance, revealing the evolution mechanisms of material fluidity, setting time, hydration process, and compressive strength under the coupled effects of tannery sludge and alkali activation, thereby providing a reusable technical pathway to address the resource utilization challenges of similar special solid wastes. A series of alkali-activated composite cementitious materials (AACC) were prepared in the study by partially substituting cement with alkaline activators, TS, and fly ash (FA), through adjustments in TS–FA ratios and alkali equivalent (AE) variations. The workability, hydration process, and compressive strength evolution of AACC were systematically investigated. The experimental results indicated that as the TS content increased from 0% to 100%, the fluidity of fresh AACC decreased from 147 mm to 87 mm, while the initial and final setting times exhibited an exponential upward trend. The incorporation of TS was found to inhibit cement hydration, though this adverse effect could be mitigated by alkaline activation. Notably, 20–40% sludge dosages (SD) enhanced early-age compressive strength. Specifically, the compressive strength of the 0% TS group at 3 d age was 24.3 MPa, that of the 20% TS group was 25.9 MPa (an increase rate of 6.58%), and that of the 40% TS group was 24.5 MPa (an increase rate of 0.82%), whereas excessive additions resulted in the reduction of hydration products content and diminished later stage strength development. Furthermore, the investigation into AE effects revealed that maximum compressive strength (37.4 MPa) was achieved at 9% AE. These findings provide critical data support for realizing effective utilization of industrial solid wastes. Full article

(This article belongs to the Section Gel Processing and Engineering)

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23 pages, 427 KiB

Open AccessArticle

Effects of Gelatin/Chitosan and Chitosan Active Films with Rice Bran Extract for the Preservation of Fresh Pork Meat

by María Cabeza de Vaca, Rosario Ramírez, Javier Rocha-Pimienta, David Tejerina and Jonathan Delgado-Adámez

Gels 2025, 11(5), 338; https://doi.org/10.3390/gels11050338 - 30 Apr 2025

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Abstract

Films formulated with gelatin and chitosan (GL/CH) or chitosan (CH), without or with 0.3% and 0.5% concentrations of rice bran extract (RBE), have been developed. The migrations of rice bran extract and the antioxidant and antimicrobial properties in vitro have been assessed. The [...] Read more.

Films formulated with gelatin and chitosan (GL/CH) or chitosan (CH), without or with 0.3% and 0.5% concentrations of rice bran extract (RBE), have been developed. The migrations of rice bran extract and the antioxidant and antimicrobial properties in vitro have been assessed. The effects of the film formulations in maintaining color stability, oxidative status and microbial loads on fresh pork meat during 9 days of refrigerated storage were studied. For the films, releases of γ-oryzanol only were observed in low polarity simulant. The highest migrations and antioxidant activity were related to gelatine films, enhanced with the addition of rice bran extract. Only chitosan films showed antimicrobial activity in vitro against Escherichia coli and Listeria innocua, reaching decreases of 7.68 and 8.06 Log CFU at 72 h, respectively. Both gelatin/chitosan and chitosan films prevented the color changes in meat during storage, preventing the paleness, and chitosan films also provoked an increment of redness until 2.88 units of CIE b* at day 9. The films did not prevent either lipid or protein oxidation in meat, despite the rice bran extract inclusion, even increasing the lipid oxidations with chitosan films. However, all films helped to control the microbial counts in meat throughout all the storage, with chitosan being the most effective films, especially with the addition of RBE. Overall, gelatin/chitosan and chitosan films offer a sustainable alternative for fresh pork meat packaging. Full article

(This article belongs to the Special Issue Nature Polymer Gels for Food Packaging)

20 pages, 9466 KiB

Open AccessArticle

Oil Recovery Mechanism of Polymer Gel Injection Between Injection Wells and Production Wells to Block the Dominant Channel of Water Flow

by Dong Zhang, Yan Wang, Peng Ye, Shutong Li, Jianguang Wei, Lianbin Zhong and Runnan Zhou

Gels 2025, 11(5), 337; https://doi.org/10.3390/gels11050337 - 30 Apr 2025

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Abstract

Gel system profile control and flooding is a novel profile control technology designed to address the issue of inefficient and ineffective water circulation in high water cut reservoirs during their later stages, demonstrating significant development potential. This system expands on the swept volume [...] Read more.

Gel system profile control and flooding is a novel profile control technology designed to address the issue of inefficient and ineffective water circulation in high water cut reservoirs during their later stages, demonstrating significant development potential. This system expands on the swept volume and enhances oil displacement efficiency, ultimately improving oil recovery. In this study, a new “injection well + intermediate well” configuration was employed to conduct physical simulation experiments on core modules using the gel system (Partially Hydrolyzed Polyacrylamide + Cr³⁺ cross-linker + Stabilizer). By adjusting the gel system dosage and the location of the intermediate well (0.123 PV + midway between the injection and production wells), changes in the recovery rate, water cut, seepage field, pressure field, oil saturation field, and swept volume were observed. The experimental results indicate that under these conditions, the model achieved the highest total recovery rate, with optimal displacement of remaining oil. Additionally, the gel system exhibited strong stability after formation and was resistant to breakthrough. Compared to single-injection well profile control and flooding, the configuration increased the recovery rate by 16.7%, demonstrating promising development prospects and application potential. Full article

(This article belongs to the Special Issue Advanced Gels for Oil Recovery (2nd Edition))

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