Gels最新文献

Starches play a crucial role in determining the expansion, texture, and structural development of extruded meat analogs through their gelatinization behavior and interactions with proteins. In this study, corn, pea, tapioca, sweet potato, and potato starches were incorporated into soy protein-based formulations and processed under low-moisture and high-moisture extrusion conditions to investigate starch-dependent physicochemical properties. Amylose/amylopectin composition and starch pasting properties were evaluated, and the resulting extrudates were characterized in terms of expansion behavior, water-related properties, textural attributes, and internal structure. Distinct differences in pasting behavior were observed among starches, with potato starch exhibiting high peak viscosity and pea starch showing strong viscosity development during cooling. These differences were closely associated with extrusion outcomes, influencing expansion ratio and texture formation. In low-moisture extrusion, starches susceptible to thermal and shear degradation showed increased solubilization, whereas in high-moisture extrusion, enhanced starch gelatinization promoted starch-protein interactions and contributed to improved textural integrity and structural alignment. Overall, the results demonstrate that starch type is a key determinant of expansion behavior, texture, and structural organization in extruded meat analogs, highlighting the importance of starch selection and processing conditions for tailoring product quality.

Cleaning historical silk textiles is a particularly sensitive operation that requires precise control to prevent mechanical or chemical damage. In this study, we investigate using flexible PVA-borax-based gels to remove soot from silk, i.e., polyvinyl alcohol-borax (PVA-B) gels and polyvinyl alcohol-borax-agarose double network gels (PVA-B/AG DN) loaded with different cleaning agents-namely, 30% ethanol and 1% Ecosurf EH-6-in addition to plain gels loaded with water. These gel formulations were tested on simplified model systems (SMS) and were applied using two methods: placing and tamping. The cleaning results were compared with a traditional contact-cleaning approach; micro-vacuuming followed by sponging. Visual inspection, 3D opto-digital microscopy, colorimetry, and machine-learning-assisted (ML) soot counting were exploited for the assessment of cleaning efficacy. Rheological characterization provided information about the flexibility and handling properties of the different gel formulations. Among the tested systems, the DN gel containing only water, applied by tamping, was easy to handle and demonstrated the highest soot-removal effectiveness without leaving residues, as confirmed by micro-Fourier Transform Infrared (micro-FTIR) analysis. Scanning electron microscope (SEM) micrographs proved the structural integrity of the treated silk fibers. Overall, this work allows us to conclude that PVA-borax-based gels offer an effective, adaptable, and low-risk cleaning strategy for historical silk fabrics.

Needle-free injection (NFI) technology is a promising alternative to conventional syringe injection, as it mitigates needle-related complications and enhances patient compliance. However, achieving the controlled and efficient dispersion of larger-volume formulations (>1 mL) within tissues remains a significant challenge. This study presents a novel pneumatic NFI system that uses a two-phase driving mode to regulate driving pressure and duration with an ejection volume of 1.0-2.0 mL. The integrated pressure stabilization unit significantly reduces pressure fluctuations during the initial injection phase, generating a more stable and uniform spray distribution. It is designed to produce an ideal elliptical dispersion effect while eliminating splatter, enabling controlled large-volume delivery. Jet impact experiments were conducted to investigate the dynamic characteristics of microjets generated by conventional single-phase and novel two-phase driving modes. Furthermore, the influence of the driving mode on the dispersion behaviors of microjets in agarose gels was explored through high-speed imaging of gel injections. The results demonstrate that the two-phase driving mode produces a distinct two-phase jet pressure profile. Compared to the single-phase mode, the two-phase mode produced a significantly larger dispersion width at equivalent initial driving pressures. This promotes more uniform lateral drug distribution and achieves a higher percentage of liquid drug delivery in gels. Furthermore, favorable driving pressure combinations were identified for different volumes: (1.25-0.25) MPa for 1.0 mL, (1.25-0.50) MPa for 1.5 mL, and (1.50-0.50) MPa for 2.0 mL. This provides a practical basis for optimizing clinical parameters and advancing the development of controllable NFI systems.

Multifunctional wound dressings integrating moisture retention, antibacterial activity, and bioactive delivery are in demand, yet balancing structural stability and functional synergy in polysaccharide hydrogels remains a challenge. This study focused on developing such advanced dressings. Poria cocos glucan (PCG) hydrogels were fabricated via annealing, with PCG-4 (4 wt.%) identified as the optimal matrix. PCG-tannic acid (TA) composite hydrogels were subsequently prepared via TA loading, followed by systematic property characterization and in vivo wound healing evaluation in a rat full-thickness wound model. The composite hydrogel exhibited balanced porosity (56.7 ± 3.4%) and swelling (705.5 ± 11.3%), along with enhanced mechanical rigidity. It enabled temperature-responsive TA release, coupled with high antioxidant activity and antibacterial efficacy. Additionally, it showed excellent biocompatibility (hemolysis rate <2%; NIH-3T3 cell viability >98%) and accelerated rat wound closure with enhanced collagen deposition, suggesting a beneficial combined effect of the composite's components. PCG-TA holds promise as an advanced wound dressing, and the scalable annealing fabrication strategy supports its translational application potential.

A biomimetic cartilage scaffold featuring a continuous hydroxyapatite (HA) concentration gradient and a spatially curved architecture was developed using a dual-channel mixing extrusion-based 3D printing approach. By dynamically regulating the feeding rates of two bioinks during printing, a continuous HA gradient decreasing from the bottom to the top of the scaffold was precisely achieved, mimicking the compositional transition from the calcified to the non-calcified cartilage region in native articular cartilage. The integration of gradient material deposition with synchronized multi-axis motion enabled accurate fabrication of curved geometries with high structural fidelity. The printed scaffolds exhibited stable swelling and degradation behavior and showed improved compressive performance compared with step-gradient counterparts. Rheological analysis confirmed that the bioinks possessed suitable shear-thinning and recovery properties, ensuring printability and shape stability during extrusion. In vitro evaluations demonstrated good cytocompatibility, supporting bone marrow mesenchymal stem cell (BMSC) adhesion and proliferation. Chondrogenic assessment based on scaffold extracts indicated that the incorporation of HA and its gradient distribution did not inhibit cartilage-related extracellular matrix synthesis, confirming the biosafety of the composite hydrogel system. Overall, this study presents a controllable and versatile fabrication strategy for constructing curved, compositionally graded cartilage scaffolds, providing a promising platform for the development of biomimetic cartilage tissue engineering constructs.

Substrate stiffness critically regulates osteogenic differentiation, yet systematic identification of optimal mechanical conditions in three-dimensional culture remains limited. This study investigated how hydroxyapatite (HAp)-mediated mechanical modulation of gelatin methacryloyl (GelMA) hydrogels influences osteogenic differentiation of encapsulated SAOS-2 spheroids. GelMA hydrogels with HAp at 5, 10, and 15 μg/mL were characterized for mechanical properties and used to encapsulate pre-formed spheroids under osteogenic conditions. GelMA+HAp5 achieved the highest compressive modulus, while higher HAp concentrations reduced crosslinking efficiency. All formulations maintained comparable viability and metabolic activity. Notably, GelMA+HAp10 produced the highest alkaline phosphatase activity at Days 7 and 14, despite lower stiffness than GelMA+HAp5, demonstrating a non-linear relationship between substrate mechanics and osteogenic response. These results establish that optimizing rather than maximizing mechanical properties represents a more effective scaffold design strategy for bone tissue engineering.

Mechanical loading is a central cue in periodontal tissues, where compression of the periodontal ligament guides remodeling and orthodontic tooth movement (OTM). However, most mechanobiology studies have used two-dimensional cultures with poorly defined loading, and the role of autophagy under realistic three-dimensional compression remains unclear. In this study, we constructed a three-dimensional static compression model by encapsulating human periodontal ligament cells in collagen-alginate-CaSO₄ hydrogels, whose swelling, degradation, and viscoelasticity approximate those of native matrix. When exposed to a controlled static compressive stress, the cells exhibited an early autophagic response with increased ATG7, Beclin1, and LC3-II/LC3-I; accumulation of LC3-positive puncta; and reduced p62 expression between 4 and 8 h. Pharmacological modulation showed that activation of AKT-mTOR signaling suppressed this response, whereas its inhibition further augmented autophagy, identifying AKT-mTOR as a negative regulator of compression-induced autophagy. Together, these findings demonstrate that moderate static compression drives AKT-mTOR-dependent autophagy in periodontal ligament cells and establish a simple hydrogel platform for quantitative studies of periodontal remodeling.

The heating of plant proteins at high temperatures is often associated with phase separation due to the aggregation of protein fractions, resulting in weak or discontinuous gels in liquid processing systems. This study examined the high-temperature gelation behaviour of commercial yellow pea, faba bean, and mungbean protein isolates and evaluated how different levels of dry-fractionated starch substitution tailor viscosity development and final gel strength. To characterise structural changes during heating, pasting behaviour was evaluated at 95 °C and 120 °C using a high-temperature Rapid Visco Analyser, while gel strength, temperature-ramp rheology, and thermal transitions were measured using a texture analyser, rheometer, and Differential Scanning Calorimetry. At 95 °C, all systems showed controlled pasting behaviour, with yellow pea exhibiting moderate viscosity development and clear recovery during cooling, mungbean generating the highest peak viscosity, and faba bean forming the strongest elastic network and gel structure. At 120 °C, yellow pea showed reduced stability, whereas faba bean and mungbean retained higher viscosity during heating. Starch addition improved the viscosity stability and gel strength across all proteins by limiting excessive aggregation and supporting network formation. These findings clarify how protein type and starch substitution affect high-temperature gelation, supporting the development of a heat-stable, clean-label plant-based gel system.

Controlling CO₂ channeling in heterogeneous reservoirs remains a major challenge for both enhanced oil recovery (EOR) and secure geological storage. AMPS-HPAM copolymers exhibit high-temperature resistance and brine tolerance compared with conventional HPAM gels, making them well suited for the harsh environments associated with CO₂ injection. Chromium-based crosslinkers (CrAc and CrCl₃) were investigated because sulfonic acid groups in AMPS can coordinate with trivalent chromium ions, enabling dual ionic crosslinking and the formation of a robust gel network. While organic crosslinked AMPS-HPAM gels have been widely studied, the behavior of chromium-crosslinked AMPS-containing systems, particularly their gelation kinetics under CO₂ exposure, remains less explored. This experimental study evaluates the gelation behavior and stability of chromium-crosslinked AMPS-HPAM gels by examining the effects of the polymer concentration, molecular weight, polymer-crosslinker ratio, temperature, pH, salinity, and dissolved CO₂. The results clarify the crosslinking behavior across a range of formulations and environmental conditions and establish criteria for designing robust gel systems. Gelation times can be controlled from 5 to 10 h, and the resulting gels maintained structural integrity under CO₂ exposure with less than 3.6% dehydration. Long-term thermal testing has shown that the gel remains stable after 10 months at 100 °C, with evaluation still ongoing. These results demonstrate that chromium-crosslinked AMPS-HPAM gels provide both durability and tunability for diverse subsurface conditions.

Dextrin-based nanosponges (D-NS) are promising candidates for oral drug delivery due to their biocompatibility, mucoadhesive properties, and tunable swelling behavior. In this study, pH-sensitive nanosponges were synthesized using β-cyclodextrin (β-CD), GluciDex^®2 (GLU2), and KLEPTOSE^® Linecaps (LC) as building blocks, crosslinked with pyromellitic dianhydride (PMDA) and citric acid (CA). The nanosponges were mechanically size-reduced via homogenization and ball milling, and characterized by FTIR, TGA, dynamic light scattering (DLS), and zeta potential measurements. Swelling kinetics, cross-linking density (determined using Flory-Rehner theory), rheological behavior, and mucoadhesion were evaluated under simulated gastric and intestinal conditions. The β-CD:PMDA 1:4 NS was selected for drug studies due to its optimal balance of structural stability, swelling capacity (~863% at pH 6.8), and highest apomorphine (APO) loading (8.23%) with 90.58% encapsulation efficiency. All nanosuspensions showed favorable polydispersity index values (0.11-0.30), homogeneous size distribution, and stable zeta potentials, confirming suspension stability. Storage at 4 °C for six months revealed no changes in physicochemical properties or apomorphine (APO) degradation, indicating protection by the nanosponge matrix. D-NS exhibited tunable swelling, pH-responsive behavior, and mucoadhesive properties, with nanoparticle-mucin interactions quantified by the rheological synergism parameter (∆G' = 53.45, ∆G″ = -36.26 at pH 6.8). In vitro release studies demonstrated slow, sustained release of APO from D-NS in simulated intestinal fluid compared to free drug diffusion, highlighting the potential of D-NS as pH-responsive, mucoadhesive carriers with controlled drug release and defined nanoparticle-mucin interactions.