Gels最新文献

To address the problem of serious gas channeling during CO₂ flooding in low-permeability reservoirs, which leads to poor oil recovery, this study developed a CO₂-resistant gel using a novel CO₂-responsive polymer (ADA) for gas channel control. The ADA polymer was synthesized via free-radical copolymerization of acrylamide (AM), dimethylaminopropyl methacrylamide (DMAPMA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), which introduced protonatable tertiary-amine groups and sulfonate moieties into the polymer backbone. Comprehensive characterizations confirmed the designed structure and adequate thermal stability of the ADA polymer. Rheological tests demonstrated that the ADA polymer solution exhibits significant CO₂-triggered viscosity enhancement and excellent shear resistance. When crosslinked with phenolic resin, the resulting ADA gel showed outstanding CO₂ tolerance under simulated reservoir conditions (110 °C, 10 MPa). After 600 s of CO₂ exposure, the ADA gel retained over 99% of its initial viscosity, whereas a conventional HPAM-based industrial gel degraded to 61% of its original viscosity. The CO₂-resistance mechanism involves protonation of tertiary amines to form quaternary ammonium salts, which electrostatically interact with sulfonate groups, creating a reinforced dual-crosslinked network that effectively protects the gel from H⁺ ion attack. Core flooding experiments confirmed its ability to enhance oil recovery by plugging high-permeability channels and diverting flow, achieving a final recovery of up to 48.5% in heterogeneous cores. This work provides a novel gel system for improving sweep efficiency and storage security during CO₂ flooding in low-permeability reservoirs.

The development of sustainable catalysts is the main objective in green chemistry approaches. In this study, a catalytically active polymer based on a tertiary amine was synthesized, functionalized with a photo-crosslinker, and structured into nanofibers via electrospinning technique with polycaprolactone (PCL) as a stabilizing additive. Subsequent photo-crosslinking yielded hierarchically porous polymers with high swelling properties and increased surface areas, thereby improving the accessibility of the immobilized catalytically active sites. The nanofiber mats were incorporated into a microfluidic reactor (MFR) setup and utilized as heterogeneous catalysts for the Knoevenagel reaction of malononitrile with different aldehydes. It was observed that the system demonstrated a substantial improvement in NMR yields (40-60%) and turnover frequencies (50-80 h^-1) in comparison to catalytical systems that had been previously published. Reusability studies showed reproducibility of NMR yields over up to three cycles. The obtained results demonstrate the potential of electrospun, photo-crosslinked nanofibers as efficient heterogeneous catalysts in microfluidic synthesis, thus contributing to more sustainable production of valuable malononitrile derivatives.

Bone regeneration remains a clinical challenge, particularly in critical-size defects, motivating the investigation of biomaterials and adjuvant therapies that may support tissue repair. This experimental study evaluated bone healing in critical-size calvarial defects created in rats, using different combinations of regenerative strategies, including heterologous fibrin biopolymer gel, bovine cortical bone biological membrane, and photobiomodulation. Standardized 5.0 mm calvarial defects were surgically created in sixty Wistar rats, which were randomly allocated into six experimental groups according to the filling material and the application or absence of photobiomodulation. The treatments included clot alone, fibrin biopolymer gel, biological membrane, photobiomodulation, or their respective combinations. Animals were euthanized at 14 or 42 days, and bone repair was evaluated by histomorphometric analysis. At 14 days, differences in the extent of newly formed bone were observed among the experimental groups, with higher bone formation values detected in groups receiving combined treatments and lower values in groups treated with fewer regenerative components. At 42 days, all groups showed progression of bone repair, with greater bone formation observed in groups in which a biological membrane was used, regardless of photobiomodulation. Overall, the findings indicate that the association of different regenerative approaches was related to variations in bone repair patterns over time, suggesting that photobiomodulation, when applied in combination with biomaterials, may be associated with differences in early bone healing, without implying a direct causal effect.

With the continuous increase in energy density of lithium-ion batteries, thermal safety has become a critical constraint on their further development. To address the limitations of mechanical brittleness and high-temperature infrared transparency in SiO₂ aerogels for thermal safety applications in lithium-ion batteries, this study developed a novel nanofiber aerogel composite by incorporating chitosan and MXene into a SiO₂ aerogel matrix. This material retains the characteristics of being ultra-lightweight and highly elastic while significantly enhancing mechanical strength and high-temperature insulation performance. It exhibits a thermal conductivity of 0.034 W/m K at room temperature and 0.053 W/m K at 400 °C, alongside a compressive strength of 1.172 MPa. In battery thermal runaway propagation tests, the aerogel successfully prevented propagation in serially connected and electrically isolated systems, and delayed thermal runaway propagation by 35 s in a parallel system, demonstrating excellent thermal runaway suppression capability. This work provides an effective material solution for the practical application of high-performance thermal insulation aerogels in battery safety protection and offers inspiration for developing new insulating ceramic aerogels.

Valorization of black carrot pomace (BCP), an industrial by-product rich in bioactive compounds, was performed using sustainable extraction and formulation approaches. Bioactive compounds were extracted, using water as a solvent, via ultrasonic processing. The resulting liquid extract (BCP-E) was then freeze-dried with a gum Arabic gel system to obtain a powder formulation (FD-BCP). The technological, physicochemical, and bioactive characteristics of both formulations are described. Total monomeric anthocyanin and antioxidant activities (DPPH and ABTS) did not differ substantially (p > 0.05), but the liquid extract's total phenolic content was significantly higher (4.95 mg GAE/g db) than the powder formulation's (4.46 mg GAE/g db). While FD-BCP had three main hydrophilic phenolic compounds, suggesting partial encapsulation, high-resolution LC-MS analysis identified 21 phenolic compounds in BCP-E, dominated by chlorogenic, quinic, and protocatechuic acids. The development of a stable gum Arabic matrix that maintains the phenolics' structural integrity was confirmed by SEM and FTIR observations. According to cytotoxicity tests conducted on L929 fibroblast cells, both formulations were biocompatible (>70% viability) and even stimulated cell growth at moderate dosages. Dose- and time-dependent viability patterns were successfully described by Principal Component Analysis and Artificial Neural Network models, highlighting the fact that formulation type is the main factor influencing biological response. Overall, ultrasonic extraction and freeze-drying offer efficient and sustainable strategies for producing stable and bioactive-rich components from black carrot pomace that may be used in functional foods and biomedical products.

Plant-derived proteins have been growing in interest for the design of innovative foods and ingredients following the trend of animal protein substitution. These proteins display interesting functional properties, including emulsifying, foaming, and gelling capacity. Unfortunately, commercially available plant protein ingredients often present limited functionality due to the modifications induced during production. In this study, ohmic heating (OH) was evaluated as a physical modification strategy to enhance the functionality of commercial pea protein (PP). PP dispersions were subjected to OH at 100 °C, 130 °C, and 150 °C, and their physicochemical, foaming, emulsifying, and gelling properties were assessed. OH processing significantly reduced mean particle size, with the surface-area weighted diameter (D(3,2)) decreasing from approximately 76.1 µm in untreated PP to 56.5, 31.1, and 10.6 µm after OH at 100, 130, and 150 °C, respectively. These structural changes resulted in a clear improvement in foaming performance, with foaming capacity increasing by approximately 40% compared to the control, while all foams remained stable for at least 60 min. In contrast, emulsifying activity showed no substantial enhancement. Cold-set gels prepared from OH-treated PP exhibited significantly altered rheological behavior, characterized by lower complex modulus values (G* ≈ 0.8-5.4 kPa at 1 Hz) compared to the untreated PP gel (≈25.2 kPa), indicating the formation of softer yet more homogeneous gel networks. Overall, the results demonstrate that OH is an effective tool to tailor the functional properties of commercial pea protein, particularly by enhancing foaming performance and modulating gel structure, supporting its potential application in the development of novel plant-based food products.

Ultra-short peptides (USPs; ≤7-8 amino acids) emerge as minimal self-assembling building blocks for hydrogel-based biomaterials. Their intrinsic biocompatibility, straightforward synthesis, and ease of tunability make them particularly attractive candidates for potential use in bioprinting. This review provides an overview of the properties of USPs along with their applications in three-dimensional (3D) bioprinting. We first discuss how peptide sequence, terminal and side-chain modifications, and environmental triggers govern USPs' self-assembly into nanofibers and 3D networks and how these supramolecular features translate into key rheological properties such as shear-thinning, rapid gelation, and mechanical tunability. We then survey reported applications in tissue engineering, wound healing, and organotypic models, as well as emerging ultra-short peptide-based systems for drug delivery, biosensing, and imaging, highlighting examples where printed constructs support cell viability, differentiation, and matrix deposition. Attention is given to hybrid and multi-material formulations in which USPs provide bioactivity while complementary components contribute structural robustness or additional functionality. Finally, this review outlines the main challenges that currently limit widespread adoption, including achieving high print fidelity with cytocompatible crosslinking, controlling batch-to-batch variability, and addressing the scalability, cost, and sustainability of peptide manufacturing. We conclude by discussing future opportunities such as AI-assisted peptide design, adaptive and multi-material bioprinting workflows, and greener synthetic routes, which together may accelerate the translation of ultra-short peptide-based bioinks from proof-of-concept studies to clinically and industrially relevant platforms.

Agomelatine (AG) is a novel antidepressant characterized by distinct mechanism of action and minimal side effects. However, extensive first-pass hepatic metabolism limits its clinical efficacy after oral administration, leading to low bioavailability (<5%). To get around these restrictions, the current study set out to create and assess a rectal thermosensitive in situ gel using biosynthesized AG-silver nanoparticles (AG-AgNPs). AG-AgNPs were successfully synthesized with gum acacia as a stabilizing agent, using silver nitrate as a precursor, and ascorbic acid as a reducing agent. The in situ gel formulation was optimized using a 3² factorial design, and then physicochemical, in vitro, and in vivo assessments were conducted. Nanoparticle formation was also evidenced by the appearance of a visible color change, UV-VIS, TEM, and XRD analysis techniques, which depicted spherical-shaped nanoparticles and a crystalline nature. The formulated optimized thermosensitive in situ gel showed good properties, which included drug content of 91.64%, gelation temperature of 26.63 °C, pH of 7.2, gel strength of 36.98 s, and sustained drug release of 80.24% in 6 h. The relative bioavailability in animal studies showed a remarkable increase in systemic availability with 277.5% relative bioavailability in comparison to an oral tablet formulation. In summary, results show that the AG-AgNP-loaded thermosensitive in situ gel could have potential use as a rectal delivery drug for bypassing first-pass effects and improving bioavailability for the drug Agomelatine.

Inflammation is the body's natural immune response to invasion by foreign pathogens and is closely linked to many diseases. Chronic inflammation, if not properly controlled, can pose serious health risks and even threaten life. Currently, the main anti-inflammatory drugs are classified into steroidal and non-steroidal anti-inflammatory drugs, but both have significant side effects that limit their clinical applications. α-Hederin, a pentacyclic triterpenoid saponin, is derived from various plants, including Pulsatilla chinensis, Hedera helix, and Nigella sativa. It has been reported that α-hederin can be used to treat both acute and chronic inflammatory diseases. However, it has poor water solubility and low bioavailability. This study shows that α-hederin can directly self-assemble into a hydrogel through hydrogen bonds and van der Waals forces, called He-Gel. The mechanical properties of He-Gel were further characterized using rheological and microrheological methods. Its self-assembly mechanism was comprehensively elucidated through a combination of spectroscopic analyses and computational chemistry. Furthermore, in vitro experiments showed that He-Gel exhibits lower cytotoxicity and more excellent anti-inflammatory activity compared to free α-hederin. In conclusion, this research provides a solution for the further development of α-hederin. Unlike conventional approaches that rely on polymers as drug carriers, this preparation method is both green and economical. More importantly, it highlights that direct self-assembly of natural small molecules represents a promising strategy for anti-inflammatory therapy.

In this study, we present the synthesis and characterization of graphene oxide (GO)-based hydrogels reinforced with hydroxyapatite (HA), titanium dioxide (TiO₂), zinc oxide (ZnO), silicon oxide (SiO₂), silver (Ag), and graphitic carbon nitride (g-C₃N₄). The aim is to develop multifunctional hydrogels with enhanced structural and biological performance and photocatalytic activity, opening the way for applications in regenerative medicine. The structure and composition of the hydrogels were investigated using FTIR and UV-Vis spectroscopy, which highlighted the chemical interactions between GO and the incorporated nanoparticles. The morphology was analyzed through scanning electron microscopy (SEM) and metallographic optical microscopy (MOM), confirming a uniform distribution of the inorganic phases and an internal architecture optimized for stability and bioactivity. Antibacterial activity was evaluated against Gram-positive and Gram-negative strains, both in the absence and presence of photodynamic therapy. The latter was activated by a Woodpecker laser at a 420 nm wavelength. The results showed significant bacterial inhibition, further enhanced by laser exposure, suggesting a synergistic effect between photocatalytic activation and the hydrogel components. Overall, the obtained hydrogels demonstrate robust mechano-structural properties and promising biological activity, supporting their potential for innovative biomedical applications in the tissue regeneration field and for the emerging biofunctional technologies.