Gels, Volume 10, Issue 12 (December 2024) – 94 articles

Altrenogest is a key regulatory hormone for intensive and batch management of reserve sows in breeding farms. As a synthetic hormone, altrenogest could make ovaries stay at the initial stage of follicles and inhibit estrus and ovulation in animals. However, the currently used oral altrenogest solution needs to be administered continuously every day for more than two weeks in clinical practice. In this study we developed a phospholipid-based injectable gel carrying altrenogest to decrease the number of administrations, sustain release of the drug, and enhance therapeutic efficacy for clinical use. The altrenogest gel had a viscosity of 100 cP before phase transition and over 1,000,000 cP after phase transition. In vitro, altrenogest can be continuously released from gel for over two weeks. The pharmacokinetic results showed that the AUC _(0–∞) of the altrenogest gel was almost double that of the altrenogest solution. The MRT _(0–∞) was 40.92 ± 7.21 h and the t_1/2 of the altrenogest gel was 80.03 ± 20.79 h. The altrenogest gel demonstrated excellent fluidity, ease of injectability, high drug-loading capacity, and appropriate sustained-release characteristics both in vitro and in vivo, making it a potential drug delivery system for swine production. Full article

The application of nanocomposites based on polyacrylamide hydrogels as well as silica nanoparticles in various tasks related to the petroleum industry has been rapidly developing in the last 10–15 years. Analysis of the literature has shown that the introduction of nanoparticles into hydrogels significantly increases their structural and mechanical characteristics and improves their thermal stability. Nanocomposites based on hydrogels are used in different technological processes of oil production: for conformance control, water shutoff in production wells, and well killing with loss circulation control. In all these processes, hydrogels crosslinked with different crosslinkers are used, with the addition of different amounts of nanoparticles. The highest nanoparticle content, from 5 to 9 wt%, was observed in hydrogels for well killing. This is explained by the fact that the volumes of injection of block packs are counted only in tens of cubic meters, and for the sake of trouble-free workover, it is very important to preserve the structural and mechanical properties of block packs during the entire repair of the well. For water shutoff, the volumes of nanocomposite injection, depending on the well design, are from 50 to 150 m³. For conformance control, it is required to inject from one to several thousand cubic meters of hydrogel with nanoparticles. Naturally, for such operations, service companies try to select compositions with the minimum required nanoparticle content, which would ensure injection efficiency but at the same time would not lose economic attractiveness. The aim of the present work is to develop formulations of nanocomposites with increased structural and mechanical characteristics based on hydrogels made of partially hydrolyzed polyacrylamide crosslinked with resorcinol and paraform, with the addition of commercially available nanosilica, as well as to study their thermal degradation, which is necessary to predict the lifetime of gel shields in reservoir conditions. Hydrogels with additives of pyrogenic (HCSIL200, HCSIL300, RX380) and hydrated (white carbon black grades: ‘BS-50’, ‘BS-120 NU’, ‘BS-120 U’) nanosilica have been studied. The best samples in terms of their structural and mechanical properties have been established: nanocomposites with HCSIL200, HCSIL300, and BS-120 NU. The addition of hydrophilic nanosilica HCSIL200 in the amount of 0.4 wt% to a hydrogel consisting of partially hydrolyzed polyacrylamide (1%), resorcinol (0.04%), and paraform (0.09%) increased its elastic modulus by almost two times and its USS by almost three times. The thermal degradation of hydrogels was studied at 140 °C, and the experimental time was converted to the exposure time at 80 °C using Van’t Hoff’s rule. It was found that the nanocomposite with HCSIL200 retains its properties at a satisfactory level for 19 months. Filtration studies on water-saturated fractured reservoir models showed that the residual resistance factor and selectivity of the effect of nanocomposites with HCSIL200 on fractures are very high (226.4 and 91.6 for fracture with an opening of 0.05 cm and 11.0 for porous medium with a permeability of 332.3 mD). The selectivity of the isolating action on fractured intervals of the porous formation was noted. Full article

Currently, materials with specific, strictly defined functional properties are becoming increasingly important. A promising strategy for achieving these properties involves developing methods that facilitate the formation of hierarchical porous materials that combine micro-, meso-, and macropores in their structure. Macropores facilitate effective mass transfer of substances to the meso- and micropores, where further adsorption or reaction processes can occur. Aerogels represent a promising class of materials for implementing this approach. The formation of hierarchical porous structures in aerogels can be achieved using soft and hard templating methods or by foaming techniques. This paper presents a comprehensive study of three methods for forming hierarchical porous structures in alginate aerogels: (1) employing surfactants (Pluronic F-68), (2) using zein as a pore-forming component, and (3) foaming in a carbon dioxide medium. The results of micro-CT showed that each of the methods contributes to the formation of macropores within the structure of the resulting aerogels. Size distribution curves of the detected macropores were obtained, showing the presence of macropores ranging from 16 to 323 μm in size for samples obtained using surfactants, from 5 to 195 μm for samples obtained using zein, and from 20 μm to 3 mm for samples obtained by foaming in a carbon dioxide medium. The SEM images demonstrated the macro- and mesoporous fibrous structure of the obtained materials. The nitrogen porosimetry results indicated that samples obtained using surfactants and zein are characterized by a high specific surface area (592–673 m²/g), comparable to the specific surface area for an alginate-based aerogel obtained without the use of pore-forming components. However, the use of the developed methods for the formation of a hierarchical porous structure contributes to an increase in the specific mesopores volume (up to 17.7 cm³/g). The materials obtained by foaming in a carbon dioxide medium are characterized by lower specific surface areas (112–239 m²/g) and specific mesopores volumes (0.6–2.1 cm³/g). Thus, this paper presents a set of methods for forming hierarchical porous structures that can obtain delivery systems for active substances with a controlled release profile and highly efficient platforms for cell culturing. Full article

This research enhances the thermal safety of hydrophobic silica aerogel (HSA) by integrating layered double oxides (LDOs). XRD and FTIR confirm that the introduction of LDOs does not affect the formation of SA. The LDO/SA composites demonstrate a low density (0.14–0.16 g/cm³), low thermal conductivity (23.28–28.72 mW/(m·K)), high porosity (93.4–96.1%), and a high surface area (899.2–1006.4 m²/g). The TG-DSC results reveal that LDO/SA shows enhanced thermal stability, with increases of 49 °C in the decomposition onset temperature and 47.4 °C in the peak decomposition temperature. The gross calorific value of LDO/SA-15% (with 15 wt% LDO) exhibits a 23.9% reduction in comparison to that of pure SA. The decrease in gross calorific value, along with improved thermal stability, indicates a boost in the thermal safety characteristics of the LDO/SA composites. This study demonstrates that incorporating LDOs enhances the thermal safety of HSA, while preserving its superior performance, thus broadening its potential applications in thermal insulation. Full article

Chronic wounds represent a persistent clinical challenge due to prolonged inflammation and impaired tissue repair mechanisms. Cannabidiol (CBD), recognized for its anti-inflammatory and pro-healing properties, shows therapeutic promise in wound care. However, its delivery via lipid nanoparticles (LNPs) remains challenging due to CBD’s inherent instability and low bioavailability. This study developed and characterized a novel hydrogel scaffold composed of CBD-loaded LNPs (CBD/LNPs) integrated into a polyvinyl alcohol (PVA) and sodium alginate (SA) matrix, designed to enhance wound repair and mitigate inflammation. The characteristics of the hydrogel scaffold were observed including the degree of swelling and LNPs’ release profiles. Furthermore, in the results, CBD/LNPs displayed enhanced stability and reduced cytotoxicity compared to unencapsulated CBD. In vitro assays demonstrated that CBD/LNPs significantly promoted fibroblast migration in gap-closure wound models and reduced intracellular reactive oxygen species, supporting their potential as a biocompatible and efficacious agent for cellular repair and oxidative stress attenuation. In vivo experiments using adult male Wistar rats with aseptic cutaneous wounds revealed that treatment with CBD/LNP-PVA/SA hydrogel scaffold significantly accelerated wound closure relative to blank hydrogel controls, demonstrating a substantial reduction in the wound area over time. Histological analysis confirms notable improvements in skin morphology in wounds treated with CBD/LNP-PVA/SA hydrogel scaffold with evidence of accelerated epithelialization, enhanced collagen deposition, and increased dermal thickness and vascularization. Additionally, skin histology showed a more organized epidermal layer and reduced inflammatory cell infiltration in CBD/LNP-PVA/SA hydrogel scaffold-treated wounds, corresponding to a 35% increase in the wound closure rate by day 28 post-treatment. These findings suggest that CBD/LNP-PVA/SA hydrogel scaffolds facilitate inflammation resolution and structural wound healing through localized, sustained CBD delivery. The dual anti-inflammatory and wound-healing effects position CBD/LNP-PVA/SA hydrogel scaffold as a promising approach for chronic wound management. Future investigations are warranted to elucidate the mechanistic pathways by which CBD modulates the skin architecture and to explore its translational applications in clinical wound care. Full article

This paper provides a solid foundation for understanding the synthesis, properties, and applications of cellulose-based gels. It effectively showcases the potential of these gels in diverse applications, particularly in biomedicine, and highlights key synthesis methods and properties. However, to push the field forward, future research should address the gaps in understanding the environmental impact, mechanical stability, and scalability of cellulose-based gels, while also considering how to overcome barriers to their industrial use. This will ultimately allow for the realization of cellulose-based gels in large-scale, sustainable applications. Full article

The local application of broad-spectrum antibiotics via polymeric drug delivery systems is a promising alternative to their systemic administration in wound healing, prevention and treatment of infections associated with surgical implants. However, low and poorly controlled loading efficiency and 100% burst release are common problems for the materials with weak physical interaction between antibiotics and polymeric matrices. Here, we report a new multifunctional carboxymethyl chitosan (CMC) cryogel, which efficiently prevents bacterial adhesion to the surface, kills bacteria in the solution via controlled release of ciprofloxacin (CIP), and promotes fibroblast proliferation. The suggested approach is based on CIP loading to Zn²⁺-chelated CMC cryogel via the ligand exchange reaction. We have shown that, due to the strong binding of Zn²⁺ to CMC, the antibacterial effect and toxicity to fibroblasts of CMC-Zn-CIP cryogels were mainly determined by the content of loaded CIP, which can be precisely controlled via Zn²⁺ content in cryogel. CMC cryogels containing 20 mgZn/g can be loaded with CIP amounts sufficient to completely suppress the growth of hospital strain Klebsiella oxytoca with MIC of 0.125 µg/mL, while maintaining a fibroblast viability at the level of 85–90%. Full article

The study aimed to prepare complex gels of sonicated quinoa protein (QP) and polysaccharides, comparing the effects of different protein components and pH on gel properties. FTIR analysis demonstrated that the β-structure in protein at pH 7.0 was enhanced by ultrasonic treatment, which could promote the formation of a gel network. Moreover, XG-AG (gel prepared by xanthan gum and albumin) and XG-GG (gel prepared by xanthan gum and globulin) exhibited higher levels of disulfide bonds and free sulfhydryl groups in the gel, requiring more energy to break the intermolecular sulfide bonds during heating. Under the same heating conditions, the rheological properties and gel strength of XG-UQPG (gel prepared by xanthan gum and ultrasonically treated QP) were superior to those of XG-UGG (gel prepared by xanthan gum and ultrasonically treated globulin) and XG-UAG (gel prepared by xanthan gum and ultrasonically treated albumin). Additionally, XG-UGG (pH 7.0) demonstrated the highest water holding capacity (WHC) and oil holding capacity (OHC). This was attributed to the disulfide bonds created in the proteins by the ultrasound treatment, encouraging them to interact to form more uniform holes in gel that can hold more water/oil molecules. Conversely, at pH 4.5, the WHCs of the gels were reduced due to the presence of rougher protein structures. These findings shed light on the impact of protein composition on gel properties and offer insights into enhancing the quality of quinoa protein gel. Full article

This work presents a novel hydrothermally aided sol-gel method for preparation of mesoporous silica nanoparticles (MSNs) with a narrow particle size distribution and varied pore sizes. The method was carried out in alkaline media in presence of polyethylene glycol (PEG) and cetyltrimethylammonium chloride (CTAC) as dual templates and permitted the synthesis of spherical mesoporous silica with a high surface area (1011.42 m²/g). The MSN materials were characterized by FTIR, Thermogravimetric (TG), Nitrogen adsorption and desorption and Field emission scanning electron microscopic analysis (FESEM). The materials feasibility as solid phase adsorbent has been demonstrated using cationic dyes; Rhodamine B (RB) and methylene blue (MB) as models. Due to the large surface area and variable pore width, the adsorption behaviors toward cationic dyes showed outstanding removal efficiency and a rapid sorption rate. The adsorption isotherms of RB and MB were well-fitted to the Langmuir and Freundlich models, while the kinetic behaviours adhered closely to the pseudo-second-order pattern. The maximum adsorption capacities were determined to be 256 mg/g for MB and 110.3 mg/g for RB. The findings suggest that MSNs hold significant potential as solid-phase nanosorbents for the extraction and purification of dye pollutants, particularly in the analysis and treatment of effluents containing cationic dyes. Full article

Tumor whole-cell vaccines are designed to introduce a wide range of tumor-associated antigens into the body to counteract the immunosuppression caused by tumors. In cases of lymphoma of which the specific antigen is not yet determined, the tumor whole-cell vaccine offers distinct advantages. However, there is still a lack of research on an effective preparation method for the lymphoma whole-cell vaccine. To solve this challenge, we prepared a whole-cell vaccine derived from non-Hodgkin B-cell lymphoma (A20) via the photothermal effect mediated by Prussian blue nanoparticles (PBNPs). The immune activation effect of this vaccine against lymphoma was verified at the cellular level. The PBNPs-treated A20 cells underwent immunogenic cell death (ICD), causing the loss of their ability to form tumors while retaining their ability to trigger an immune response. A20 cells that experienced ICD were further ultrasonically crushed to prepare the A20 whole-cell vaccine with exposed antigens and enhanced immunogenicity. The A20 whole-cell vaccine was able to activate the dendritic cells (DCs) to present antigens to T cells and trigger specific immune responses against lymphoma. Whole-cell vaccines are primarily administered through direct injection, a method that often results in low delivery efficiency and poor patient compliance. Comparatively, the microneedle patch system provides intradermal delivery, offering enhanced lymphatic absorption and improved patient adherence due to its minimally invasive approach. Thus, we developed a porous microneedle patch system for whole-cell vaccine delivery using Gelatin Methacryloyl (GelMA) hydrogel and n-arm-poly(lactic-co-glycolic acid) (n-arm-PLGA). This whole-cell vaccine combined with porous gel microneedle patch delivery system has the potential to become a simple immunotherapy method with controllable production and represents a promising new direction for the treatment of lymphoma. Full article

The objective of this work was to develop a supersaturated gel formulation (SGF) loaded with the maximum atorvastatin calcium trihydrate (ATR) dose. The maximum dose strength of ATR needs to be reduced through improving solubility and dissolution rate to mitigate side effects due to the necessity of taking high doses. ATR has highly pH-dependent solubility at 37 °C, leading to poor solubility (<10 μg/mL) in stomach acid (pH 1.2). Among the various molecular weights of polyethylene glycols (PEGs) and surfactants, PEG 200 and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were selected as the solubilizer and precipitation inhibitor for ATR, respectively. PEG 200 demonstrated very high solubility for ATR (>60%, w/w), and the combined use of TPGS and PEG 200 formed an organogel state and suppressed ATR precipitation, showing 15-fold higher dispersion solubility in buffer solution at pH 1.2 compared to the formulation with PEG 200 alone. The optimal SGF composition (ATR/PEG 200/TPGS = 10/60/30, w/w) exhibited an over 95% dissolution rate within 2 h at pH 1.2, compared to less than 50% for the original commercial product. In a transmission electron microscope analysis, the SGF suppressed ATR precipitation and revealed smaller precipitated particles (<300 nm) compared to the control samples. In the XRD analysis, the SGF was physically stable for 100 days at room temperature without the recrystallization of ATR. In conclusion, the SGF suggested in this work would be an alternative formulation for the treatment of dyslipidemia with enhanced solubility, dissolution, and physical stability. Full article

Buccal drug delivery offers a promising alternative for avoiding gastrointestinal degradation and first-pass metabolism. However, enhancing the buccal epithelial barrier’s permeability remains challenging. This study explores the effects of ethanolic extracts from Citrus medica var. Balady (CM), Citrus medica var. Calabria (CMC), and Origanum dayi (ORD) on buccal epithelium permeability in vitro using a TR146 cell-based model. The cell viability assay revealed that the extracts were non-toxic at the concentration range tested (<0.5% w/v). Surprisingly, none of the tested extracts significantly enhanced the buccal permeability of 40 kDa Fluorescein Isothiocyanate Dextran (FD40). However, the CMC and ORD extracts significantly reduced the epithelial permeability of FD40, mirroring the effects of hyaluronic acid (HA), a known barrier integrity enhancer. The total phenolic content (TPC) analysis suggested a potential link between the phenolic concentration and epithelial barrier reinforcement. The rapid colorimetric response method was applied to assess the interaction of these extracts with biological membranes. The results indicated that HA interacts with cellular membranes via lipid bilayer penetration, whereas the extracts likely influence the barrier integrity through alternative mechanisms, such as ligand–receptor interactions or extracellular matrix modulation. These findings highlight the potential of CMC and ORD extracts as natural agents to enhance buccal epithelial integrity. In conclusion, incorporating these extracts into formulations, such as hydrogels, could offer a cost-effective and biocompatible alternative to HA for improving buccal cavity health. Full article

Bacterial-infected skin wounds caused by trauma remain a significant challenge in modern medicine. Clinically, there is a growing demand for wound dressings with exceptional antibacterial activity and robust regenerative properties. To address the need, this study proposes a novel multifunctional dressing designed to combine efficient gas exchange, effective microbial barriers, and precise drug delivery capabilities, thereby promoting cell proliferation and accelerating wound healing. This work reports the development of a 3D-printed hydrogel scaffold incorporating flavanone (FLA)-loaded ZIF-8 nanoparticles (FLA@ZIF-8 NPs) within a composite matrix of κ-carrageenan (KC) and konjac glucomannan (KGM). The scaffold forms a stable dual-network structure through the chelation of KC with potassium ions and intermolecular hydrogen bonding between KC and KGM. This dual-network structure not only enhances the mechanical stability of the scaffold but also improves its adaptability to complex wound environments. In mildly acidic wound conditions, FLA@ZIF-8 NPs release Zn²⁺ and flavanone in a controlled manner, providing sustained antibacterial effects and promoting wound healing. In vivo studies using a rat full-thickness infected wound model demonstrated that the FLA@ZIF-8/KC@KGM hydrogel scaffold significantly accelerated wound healing, showcasing its superior performance in the treatment of infected wounds. Full article

An imbalance in the body’s pH or temperature may modify the immune response and result in ailments such as autoimmune disorders, infectious diseases, cancer, or diabetes. Dual pH- and thermo-responsive carriers are being evaluated as advanced drug delivery microdevices designed to release pharmaceuticals in response to external or internal stimuli. A novel drug delivery system formulated as hydrogel was developed by combining a pH-sensitive polymer (the “biosensor”) with a thermosensitive polymer (the delivery component). Thus, the hydrogel was created by cross-linking, using a solvent-free thermal approach, of poly(N-isopropylacrylamide-co-N-hydroyethyl acrylamide), P(NIPAAm-co-HEAAm), and poly(methylvinylether-alt-maleic acid), P(MVE/MA). The chemical structure of the polymers and hydrogels was analyzed using Fourier-transform infrared (FTIR) and proton nuclear magnetic resonance (¹H NMR) spectroscopies. The pH/thermosensitive hydrogel loses its thermosensitivity under physiological conditions but, remarkably, can recover the thermosensitive capabilities when certain physiologically active biomolecules, acting as triggering agents, electrostatically interact with pH-sensitive units. Our research aimed to develop a drug delivery system that could identify the disturbance of normal physiological parameters and instantaneously send a signal to thermosensitive units, which would collapse and modulate the release profiles of the drug. Full article

Under the increasing severity of drought issues and the urgent need for the resourceful utilization of agricultural waste, this study aimed to compare the soil water retention properties of hydrogels prepared from Chinese cabbage waste (CW) and banana peel (BP) using grafting techniques with acrylic acid (AA) and acrylamide (AAm). Free radical polymerization was initiated with ammonium persulfate (APS), and N, N′-methylene bisacrylamide (MBA) served as the crosslinking agent to fabricate the grafted polymer hydrogels. The hydrogels were subjected to detailed evaluations of their water absorption, reusability, and water retention capabilities through indoor experiments. The optimal hydrogel was identified and its applicability in wheat seedling growth was assessed. The findings revealed that the CW-gel, with an equilibrium swelling ratio of 551.8 g/g in ultrapure water, demonstrated remarkable performance and sustained a high water retention of 57.6% even after drying, which was markedly superior to that of the BP-gel. The CW-gel with the best comprehensive properties significantly improved water retention in sandy soil by 78.2% and prolonged the retention time by five days, indicating its potential for long-term irrigation management. In contrast, the BP-gel showed better performance in clay soil, with an increased water-holding capacity of 43.3%. The application of a 1.5% CW-gel concentration under drought stress significantly improved wheat seedling growth, highlighting the role of hydrogels in agriculture and providing a new path for sustainable water resource management in dryland farming. Full article

This paper investigates the flow performance and mechanical properties of underground gelled filling materials made from potash mine tailings, using lime as a gel. It demonstrates the feasibility of using lime as a gel, potash mine tailings as aggregate, and replacing water with potash mine tailings to create filling materials that meet design requirements for flow and compressive strength. The role of lime in the hardening process is explored through X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and infrared analysis. Results show that hydration products vary with lime dosage. With 9% lime (L9), the products are primarily ghiaraite (CaCl₂·4H₂O) and carnallite (KMgCl₃·6H₂O); with 5% lime (L5), tachyhydrite (CaMg₂Cl₆·12H₂O) predominates, along with minor amounts of antarcticite (CaCl₂·6H₂O) and korshunovskite (Mg₂Cl(OH)₃·4H₂O); and with 2.6% lime (L2.6), the products include tachyhydrite, ghiaraite, bischofite (MgCl₂·6H₂O), and korshunovskite. These hydration products form a dense, interwoven structure, enhancing the strength of the filling material. This study offers a theoretical foundation for using lime gel as a filling material in potash mining, with significant implications for sustainable mining practices. Full article

Three-dimensional (3D) models with improved biomimicry are essential to reduce animal experimentation and drive innovation in tissue engineering. In this study, we investigate the use of alginate-based materials as polymeric inks for 3D bioprinting of osteogenic models using human bone marrow stem/stromal cells (hBMSCs). A composite bioink incorporating alginate, nano-hydroxyapatite (nHA), type I collagen (Col) and hBMSCs was developed and for extrusion-based printing. Rheological tests performed on crosslinked hydrogels confirm the formation of solid-like structures, consistently indicating a superior storage modulus in relation to the loss modulus. The swelling behavior analysis showed that the addition of Col and nHA into an alginate matrix can enhance the swelling rate of the resulting composite hydrogels, which maximizes cell proliferation within the structure. The LIVE/DEAD assay outcomes demonstrate that the inclusion of nHA and Col did not detrimentally affect the viability of hBMSCs over seven days post-printing. PrestoBlue^TM revealed a higher hBMSCs viability in the alginate-nHA-Col hydrogel compared to the remaining groups. Gene expression analysis revealed that alginate-nHA-col bioink favored a higher expression of osteogenic markers, including secreted phosphoprotein-1 (SPP1) and collagen type 1 alpha 2 chain (COL1A2) in hBMSCs after 14 days, indicating the pro-osteogenic differentiation potential of the hydrogel. This study demonstrates that the incorporation of nHA and Col into alginate enhances osteogenic potential and therefore provides a bioprinted model to systematically study osteogenesis and the early stages of tissue maturation in vitro. Full article

This study investigates 3D extrusion bioinks for cartilage tissue engineering by characterizing the physical properties of 3D-printed scaffolds containing varying alginate and polyvinyl alcohol (PVA) concentrations. We systematically investigated the effects of increasing PVA and alginate concentrations on swelling, degradation, and the elastic modulus of printed hydrogels. Swelling decreased significantly with increased PVA concentrations, while degradation rates rose with higher PVA concentrations, underscoring the role of PVA in modulating hydrogel matrix stability. The highest elastic modulus value was achieved with a composite of 5% PVA and 20% alginate, reaching 0.22 MPa, which approaches that of native cartilage. These findings demonstrate that adjusting PVA and alginate concentrations enables the development of bioinks with tailored physical and mechanical properties, supporting their potential use in cartilage tissue engineering and other biomedical applications. Full article

This study aimed to prepare ultrasonically modified peanut protein–guar gum composite emulsion gels for 3D printing. The composition of the composite emulsion gels was determined in single-factor and orthogonal experiments. The results revealed that the optimal composite emulsion gels consisted of 6% peanut protein, 50% oil and 0.2% guar gum. After crushing pretreatment for 45 s, the printing deviation of the composite emulsion gels was reduced to 8.58 ± 0.20%. Moreover, after ultrasonic treatment (200 W for 20 min) of peanut proteins, the obtained composite emulsion gels presented the highest yield stress, hardness and G’ values, as well as a denser and more homogeneous microstructure. After protein ultrasonic modification (200 W or 600 W for 20 min), the printing accuracy and self-supporting properties of the composite emulsion gels for printing complex shapes significantly improved, which was attributed to their stronger textural and rheological properties; however, ultrasonically modified peanut protein–guar gum composite emulsion gels were not suitable for printing products with smooth surfaces. Full article

This study explores the innovative potential of native lignin as a sustainable biopolyol for synthesizing polyurethane aerogels with variable microstructures, significant specific surface areas, and high mechanical stability. Three types of lignin—Organosolv, Aquasolv, and Soda lignin—were evaluated based on structural characteristics, Klason lignin content, and particle size, with Organosolv lignin being identified as the optimal candidate. The microstructure of lignin polyurethane samples was adjustable by solvent choice: Gelation in DMSO and pyridine, with high affinity to lignin, resulted in dense materials with low specific surface areas, while the use of the low-affinity solvent e.g acetone led to aggregated, macroporous materials due to microphase separation. Microstructural control was achieved by use of DMSO/acetone and pyridine/acetone solvent mixtures, which balanced gelation and phase separation to produce fine, homogeneous, mesoporous materials. Specifically, a 75% DMSO/acetone mixture yielded mechanically stable lignin polyurethane aerogels with a low envelope density of 0.49 g cm⁻³ and a specific surface area of ~300 m² g⁻¹. This study demonstrates a versatile approach to tailoring lignin polyurethane aerogels with adjustable textural and mechanical properties by simple adjustment of the solvent composition, highlighting the critical role of solvent–lignin interactions during gelation and offering a pathway to sustainable, high-performance materials. Full article

In the oil dispersion of chitosan, the formation of a capillary bridge was triggered by adding a small amount of water to obtain an oleogel. With this method, the types of liquid oil and the ratio of oil/chitosan/water were explored to achieve an optimal oleogel. MCT performed best, followed by soybean oil, which was chosen for its edibility and cost. Increasing chitosan from 15% to 45% reduced oil loss from 46% to 13%, and raising the water/chitosan ratio from 0 to 0.8 lowered oil loss from 37% to 13%. After normalization, the optimal soybean oil, chitosan, and water ratio was 1:0.45:0.36, yielding a solid-like appearance, minimal oil loss of 13%, and maximum gel strength and viscosity. To assess the potential application of the optimized oleogel, it was incorporated into pork meatballs as a replacement for pork fat. Textural and cooking experiments revealed that as the oleogel content increased, the hardness of the pork meatballs increased, while the cooking loss decreased. It suggested that the chitosan oleogel could enhance the quality of pork meatballs while also contributing to a healthier product by reducing saturated fat content. Full article

Natural deep eutectic solvents (NaDES) were employed for the extraction of bilberry and green tea leaves. This study explored the incorporation of these NaDES extracts into various carrier systems: hydrogels, emulsions, and emulgels stabilized with hydroxyethyl cellulose or xanthan gum. The results demonstrated that, when combined with synthetic UV filters, the NaDES extracts significantly enhanced the SPF and improved the antioxidant properties of the formulation. Although NaDES extracts cannot fully replace synthetic UV filters (homosalate, ethylhexyl methoxycinnamate, and benzophenone-4), they can serve as effective UV boosters, significantly enhancing the SPFs of formulations containing UV filters. Hence, the SPF of the formulation could be improved without increasing the concentrations of synthetic filters. Moreover, NaDES extracts, unlike UV filters, significantly increased the antioxidant potential of the formulations. Among the carriers, hydrogels with xanthan gum and emulgels with hydroxyethyl cellulose achieved the highest SPFs when containing both NaDES extracts and synthetic filters. A texture analysis further revealed that the NaDES extracts positively impacted the mechanical properties of the formulations by increasing their cohesiveness, thus enhancing their physical stability under mechanical pressure. These findings pave the way for further research into NaDES-based formulations, including in vivo testing, to optimize and confirm their efficacy on human skin and validate NaDES extracts as eco-friendly ingredients in cosmetics, with antioxidant and UV boosting potential. Full article

This study examines the hemocompatibility of gellan-gum-based hybrid hydrogels, with varying gellan-gum concentrations and constant sodium alginate and silk fibroin concentrations, respectively, in accordance with ISO 10993-4 standards. While previous studies have focused on cytocompatibility, the hemocompatibility of these hydrogels remains underexplored. Hydrogels were formulated with 0.3%, 0.5%, 0.75%, and 1% gellan gum combined with 3% silk fibroin and 4.2% sodium alginate separately, using physical and ionic cross-linking. Swelling behavior was analyzed in phosphate (pH 7.4) and acetic (pH 1.2) buffers and surface morphology was examined by scanning electron microscopy (SEM). Hemocompatibility tests included complete blood count (CBC), coagulation assays, hemolysis index, erythrocyte morphology, and platelet adhesion analysis. Results showed that gellan gum–sodium alginate hydrogels exhibited faster swelling than gellan gum–silk fibroin formulations. SEM indicated smoother surfaces with sodium alginate, while silk fibroin increased roughness, further amplified by higher gellan-gum concentrations. Hemocompatibility assays confirmed normal profiles in formulations with 0.3%, 0.5%, and 0.75% gellan gum, while 1% gellan gum caused significant hemolytic and thrombogenic activity. These findings highlight the excellent hemocompatibility of gellan-gum-based hydrogels, especially the sodium alginate variants, supporting their potential in bioengineering, tissue engineering, and blood-contacting biomedical applications. Full article

Genitourinary syndrome of menopause (GSM) affects a significant percentage of postmenopausal women and manifests as vaginal dryness, irritation, and urinary discomfort, typically treated with vaginal estrogens. Hydrogels are preferred over creams due to their superior comfort and mucoadhesive properties. This study introduces a novel vaginal gel formulation containing hydroxyethyl cellulose (HEC) and estriol-hydroxypropyl-β-cyclodextrin complex (E3-HPBCD) for the treatment of GSM. The estriol (E3) release profile of the gel was evaluated using a Franz diffusion cell system, and its permeability was tested on reconstructed human vaginal epithelium. Biocompatibility was assessed using (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) (MTT), lactate dehydrogenase (LDH) assays, and real-time cell analysis (RTCA) on human skin keratinocyte (HaCaT) cells, which showed increased cell viability and no obvious cytotoxicity. The results indicated that efficient E3 release and satisfactory epithelial permeability with HPBCD provide the bioavailability of E3. These results suggest the potential of the gel as a biocompatible and effective alternative for the treatment of GSM. Further studies are required to assess the long-term safety and clinical efficacy. Full article

Hydrogels are widely used in the field of adhesive materials. However, hydrogel adhesion has previously required the covalent graft of supramolecular groups on polymeric chains. In contrast to that, here, a hydrogel adhesion induced by covalent polymer entanglement between two hydrogel networks was reported. Hydrogels G1 and G2 contain the monomers M1, with diazonium groups, and M2, with sulfonate groups, respectively. When the two hydrogels come into contact, the monomers diffuse into each other’s networks and assemble into supramolecular polymers (SPs) based on electrostatic interactions, threading the two hydrogel networks. Subsequently, SPs convert into covalent polymers (CPs) under UV light stimulation due to the reaction between the diazonium groups and sulfonate groups, leading to the entanglement of the two hydrogel networks and the production of an adhesive effect. This finding provides a novel strategy for hydrogel adhesion. Full article

Chinese herbal medicine has offered an enormous source for developing novel bio-soft materials. In this research, the natural polysaccharide isolated from the Chinese herbal medicine Dendrobium was employed as the secondary building block to fabricate a “hybrid” hydrogel with synthetic poly (vinyl alcohol) (PVA) polymers. Thanks to the presence of mannose units that contain cis-diol motifs on the chain of the Dendrobium polysaccharides, efficient crosslinking with the borax is allowed and reversible covalent borate ester bonds are formed. Eventually, highly dynamic and double-networked hydrogels were successfully prepared by the integration of Dendrobium polysaccharides and PVA. Interestingly, the introduction of polysaccharides has given rise to more robust and dynamic hydrogel networks, leading to enhanced thermal stability, mechanical strength, and tensile capacity (>1000%) as well as the rapid self-healing ability (<5 s) of the “hybrid” hydrogels compared with the PVA/borax single networked hydrogel. Moreover, the polysaccharides/PVA double network hydrogel showed selective antibacterial activity towards S. aureus. The reported polysaccharides/PVA double networked hydrogel would provide a scaffold to hybridize bioactive natural polysaccharides and synthetic polymers for developing robust but dynamic multiple networked hydrogels that are tailorable for biomedical applications. Full article

Angiogenesis, the formation of new blood vessels, is a fundamental process in both physiological repair mechanisms and pathological conditions, including cancer and chronic inflammation. Hydrogels are commonly used as in vitro models to mimic the extracellular matrix (ECM) and support endothelial cell behavior during angiogenesis. Mesenchymal stem cells further augment cell and tissue growth and are therefore widely used in regenerative medicine. Here we examined the combination of distinct hydrogel types—fibrin, collagen, and human platelet lysate (HPL)—on the formation of capillaries in a co-culture system containing human umbilical vein endothelial cells (HUVECs) and bone marrow-derived mesenchymal stem cells (BM-MSCs). The mechanical properties and structural changes of the hydrogels were characterized through scanning electron microscopy (SEM) and nanoindentation over 10 days. Fibrin and HPL gels sustained complex network formations, with HPL gels promoting even vascular tube formation of up to 10-fold capillary caliber. Collagen gels supported negligible angiogenesis. Our results suggest that HPL gels in combination with MSC-EC co-culture may be employed to obtain robust vascularization in tissue engineering. This study provides a comparative analysis of fibrin, collagen, and HPL hydrogels, focusing on their ability to support angiogenesis under identical conditions. Our findings demonstrate the superior performance of HPL gels in promoting robust vascular structures, highlighting their potential as a versatile tool for in vitro angiogenesis modeling. Full article

Oleogels developed through the direct-dispersion method offer an innovative, scalable, and efficient alternative to traditional fats in sausage production, providing a solution to health concerns associated with the high saturated fat content of conventional formulations. By closely mimicking the texture, stability, and mouthfeel of animal fats, these oleogels provide a novel approach to improving the nutritional profile of sausages while maintaining desirable sensory characteristics. This review critically evaluates cutting-edge research on oleogels, emphasizing innovations in their ability to enhance emulsion stability, increase cooking yield, reduce processing weight loss, and optimize fatty acid composition by reducing overall fat and saturated fat levels. Despite their potential, sausage formulations with oleogel still face challenges in achieving consistent sensory properties, texture, and oxidative stability, often failing to fully replicate the sensory qualities and shelf-life of animal fats. To push the boundaries of oleogel technology and meet the increasing demand for healthier, high-quality sausage products, we propose focused innovations in refining oil-to-gelator ratios, exploring a wider range of novel gelators, optimizing production methods, and developing cost-effective, scalable strategies. These advancements hold significant potential for revolutionizing the sausage industry by improving both the technological and nutritional qualities of oleogels. Full article

Clostridioides difficile is a common etiological factor of hospital infections, which, in extreme cases, can lead to the death of patients. Most strains belonging to this bacterium species synthesize very dangerous toxins: toxin A (TcdA) and B (TcdB) and binary toxin (CDT). The aim of this study was to assess the suitability of agarose gel electrophoresis separation of multiplex PCR amplicons to investigate the toxinogenic potential of C. difficile strains. Additionally, the frequency of C. difficile toxin genes and the genotypes of toxin-producing strains were determined. Ninety-nine C. difficile strains were used in the detection of the presence of genes encoding all of these toxins using the multiplex PCR method. In 85 (85.9%) strains, the presence of tcdA genes encoding enterotoxin A was detected. In turn, in 66 (66.7%) isolates, the gene encoding toxin B (tcdB) was present. The lowest number of strains tested was positive for genes encoding a binary toxin. Only 31 (31.3%) strains possessed the cdtB gene and 22 (22.2%) contained both genes for the binary toxin subunits (the cdtB and cdtA genes). A relatively large number of the strains tested had genes encoding toxins, whose presence may result in a severe course of disease. Therefore, the accurate diagnosis of patients, including the detection of all known C. difficile toxin genes, is very important. The multiplex PCR method allows for the quick and accurate determination of whether the tested strains of this bacterium contain toxin genes. Agarose gel electrophoresis is a useful tool for visualizing amplification products, allowing one to confirm the presence of specific C. difficile toxin genes as well as investigate their dissemination for epidemiological purposes. Full article