Gels最新文献

To address the limitations of pure silk fibroin (SF) hydrogels, such as poor mechanical strength and rapid degradation, a fully "green" composite hydrogel was developed by integrating bamboo nanofibrillated cellulose (BNC) with SF and crosslinked using the natural agent genipin. The composite formed a stable interpenetrating network, as confirmed by means of SEM and FTIR. This structure led to significantly enhanced mechanical properties (increased storage modulus and pronounced shear-thinning behavior), moderate swelling, and a controllable degradation rate. In vitro biocompatibility assays demonstrated that the BNC-SF hydrogel was non-cytotoxic and excellently supported the adhesion, spreading, and proliferation of L929 fibroblasts. Notably, it exhibited a strong pro-migratory effect in a scratch assay. This work presents a high-performance, injectable scaffold material derived entirely from natural sources, showing great potential for tissue engineering and regenerative medicine applications.

The effect of mixed soy and whey protein in the matrix on properties and digestion characteristics of emulsion-filled gels was investigated. Different matrix protein concentrations (8-14%) with a composite soy and whey protein (SW) ratio of 5:5 were screened using gel hardness. The better-performing gel (13%) was selected for matrix composition studies. Soy and whey composite protein mixed at different ratios (S/W = 0/10, 3/7, 5/5, 7/3, and 10/0) was dispersed into another soy-whey (S/W = 6/4) composite emulsion and gelled thermally. Different hybrid protein ratios in the matrix can alter the textural and rheological properties and, consequently, the digestion kinetics of mixed plant-animal gel systems. The storage modulus was highest at an S/W ratio of 0/10. The hardness of gel with the S/W ratio matrix of 0/10 was 3.10 and 9.60 times higher than that of 5/5 and 10/0 (p < 0.05). The SW ratio did not affect water-holding capacity or springiness (p > 0.05). All the gels had swelling ability below 10% except SW 10/0 (around 60%). Gels with an S/W of 5/5 exhibited a lower hydrolysis degree and rate during gastric digestion, while the reverse occurred during intestinal digestion. The compact gel network might limit pepsin's accessibility to cleavage sites.

Fibrin hydrogels are biocompatible but often lack instructive cues needed to sustain chondrocyte phenotype and cartilage-like matrix formation; therefore, we investigated whether a tricomposite fibrin hydrogel incorporating decellularized articular cartilage matrix (dACM) and decellularized amniotic membrane matrix (dAMM) enhances human articular chondrocyte performance in vitro. Human articular chondrocytes were encapsulated in tricomposite or fibrin-only hydrogels and cultured for 28 days, evaluating degradation kinetics, viability and cell density, histological remodeling (H&E, Masson's trichrome, Safranin O), immunohistochemistry for type II collagen, aggrecan, and type I collagen, and qPCR of SOX9, COL2A1, ACAN, RUNX2, COL1A2, and COL10A1. The tricomposite remained cytocompatible (~99% viability), supported marked cell expansion (~250% by day 28), and degraded more slowly than fibrin controls. It increased chondrogenic gene expression (SOX9 >3-fold vs. control by day 28; sustained COL2A1 at 1.5-2-fold; early ACAN at 3-5-fold) while attenuating off-target transcriptional programs (RUNX2 ~50% of control, reduced COL1A2, and negligible COL10A1). Consistently, histology showed progressive lacuna-like morphology and proteoglycan-rich matrix accumulation, accompanied by strong type II collagen and aggrecan immunoreactivity and reduced type I collagen. Overall, adding dACM and dAMM to fibrin improved hydrogel biofunctionality and promoted hyaline-like extracellular matrix assembly, supporting further evaluation of this cell-instructive platform for focal articular cartilage repair.

Poly(ethylene glycol) (PEG) and poly(2-hydroxy ethyl methacrylate) are polymers used for many biomedical applications due to their biocompatibility, non-toxicity, and antibiofouling properties. In this work, a new comb-like hydrogel based on 2-hydroxyethyl methacrylate (HEMA) grafted onto a polyethylene glycol network (net-PEG) was synthesized by gamma radiation from Co⁶⁰ in two steps. First, PEG (Mw = 20,000) was crosslinked at 30 kGy, and then HEMA was grafted, varying the concentration (5-20% v/v) and irradiation dose (2.5-15 kGy). Results of infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed the incorporation of HEMA onto net-PEG. Moreover, the properties of comb-like hydrogel (net-PEG)-g-HEMA were studied through swelling kinetics, drug loading and release, antimicrobial activity, and biocompatibility assays. The findings showed a different behavior in swelling kinetics and drug delivery depending on HEMA grafting. Comb-like hydrogel with 30 and 66% grafting could load more ciprofloxacin (2 mg g^-1) than net-PEG (1.5 mg g^-1) but only release 38 and 48% at 24 h, respectively. In addition, all drug-loaded hydrogels displayed inhibition for Gram-negative bacteria (E. coli) and a cell viability superior of 95% using mouse embryonic fibroblasts (BALT/T3). Comb-like hydrogel has potential application in the biomedical field such as in wound dressings or controlled drug delivery systems.

Phenolic aerogels offer low thermal conductivity, excellent thermal stability, and high char yield, but they suffer from intrinsic brittleness, low compressive modulus, and limited compressive strain. To overcome these limitations, phenolic aerogels modified with graphene oxide were synthesized and their structural, mechanical, and thermal insulation properties were evaluated. The GO fillers were uniformly dispersed in the phenolic matrix without disrupting its porous structure. Mechanical testing revealed that the modified aerogel achieved a compressive modulus of 265.52 MPa, representing a 67% increase over the pure phenolic aerogel's value of 158.49 MPa, and a compressive strength of 40.19 MPa, compared to 6.18 MPa, for the pure sample. At the same time, the composite maintained good thermal insulation performance, with a thermal conductivity of 0.063 W·m^-1·K^-1. This work demonstrates a feasible approach to tailoring the structure-property relationship of phenolic aerogels via GO modification, supporting their potential use in high-temperature insulation and lightweight structural applications.

Despite their numerous advantages, polyphenolic compounds are characterized by low bioavailability during gastrointestinal digestion and high sensitivity to technological processes during food preparation and storage. Therefore, numerous studies conducted over the past decade have identified overcoming these challenges as the undisputed goal of fully utilizing their functional properties. One solution to these challenges is the use of gelling agents. Their use as carriers for polyphenolic compounds has improved their stability during digestion and subsequent technological applications. This study analyzed the latest available scientific reports to determine the effect of combining polyphenolic compounds with gelling agents on the bioavailability, biological activity, and subsequent technological applications of the resulting ingredients.

Novel highly compressible and stretchable nanocomposite (NC) hydrogels were obtained by the free radical polymerization of N-vinylformamide (NVF) in aqueous solution in the presence of Laponite XLG (XLG) as the crosslinker and 2,2'-azobis(2-methylpropionitrile) as the initiator. The expected composition of the NC hydrogels was proved by FTIR, TEM, XRD, and TGA analyses. Swelling degree (SD) and mechanical measurements showed that the properties of the PNVF NC hydrogels were largely different from those of both PNVF hydrogels covalently crosslinked by N,N'-methylenebisacrylamide (MBA) and equivalent poly(N-vinyl-2-pyrrolidone) (PNVP) NC hydrogels. After an initial fast swelling stage, the PNVF NC hydrogels displayed a slow, but steady, SD increase with time, unlike the MBA-crosslinked and NVP hydrogels, which exhibited a much smaller SD change during their second swelling stage. The mechanical testing of the synthesized hydrogels by uniaxial compressive and tensile measurements showed much higher compressibility (>90%) and stretchability (up to ≈840%) in the PNVF NC hydrogels than both PNVP and MBA-crosslinked PNVF hydrogels (compressibility < 80%; stretchability up to ≈114%). Cyclic compression tests revealed higher values for both elastic character and mechanical stability in the PNVF NC hydrogels in comparison to the MBA-crosslinked and PNVP ones. These different mechanical properties were explained by the PNVF NC gels possessing a network made of homogeneously distributed crosslinking sites and flexible polymer chains, thus avoiding extensive chain breakage up to larger stress values. The PNVF NC hydrogels described here may find applications for water purification, due to their high clay content, as well as in the biomedical field based on the biocompatibility of both the polymer and crosslinking agent.

The selective removal of trace heteroatomic contaminants from fuel remains a critical challenge for clean combustion and refinery upgrading, particularly due to the chemical stability and structural similarity of sulfur- and nitrogen-containing aromatics. Herein, a surface-engineered graphene oxide aerogel functionalized with cyclodextrin (β-CD-CONH-GO) is developed via covalent grafting to introduce well-defined host-guest recognition sites within a porous framework. Spectroscopic and microscopic characterizations confirm successful functionalization, preserved aerogel morphology, and accessible hybrid interfaces. The removal process for monocyclic, bicyclic, and tricyclic impurities is governed by synergistic molecular inclusion within the cyclodextrin cavity, interfacial hydrogen bonding, and secondary confinement provided by the aerogel porosity. Thus, the β-CD-CONH-GO exhibits efficient adsorption toward representative bicyclic impurities, and the removal performance follows the order of indole > quinoline > benzothiophene. Kinetic analysis demonstrates pseudo-second-order adsorption behavior, indicating chemisorption dominated by cooperative host-guest recognition and hydrogen bonding. It possesses removal selectivity even in mixed systems containing structurally similar aliphatic and aromatic competitors and maintains > 95% efficiency after five regeneration cycles via ethanol extraction, confirming superb durability. This study demonstrates a feasible pathway to design adsorbents for deep fuel refining and highlights cyclodextrin-based graphene hybrid aerogels as promising candidates for separations.

In the last half-century, capillary gel electrophoresis (CGE) became a versatile and high-performance analytical platform for the separation of complex biomolecular mixtures featuring rapid separations, high efficiency, and small sample consumption. Integrating a pore-size gradient mechanism in CGE makes it possible to achieve enhanced selectivity of polyionic macromolecules such as SDS-proteins and nucleic acids. This review provides a comprehensive overview of the theoretical foundations and operational principles of capillary pore-size gradient gel electrophoresis (CGGE), including the physicochemical basis of gradient formation, the influence of pore-size distributions on analyte mobility, and the challenges of generating stable, reproducible gradients in narrow-bore capillaries. Instrumental considerations such as capillary surface treatment, gradient filling and polymerization strategies, temperature and voltage control, detection modalities, and method-development frameworks are discussed in detail, emphasizing their critical impact on analytical performance and reproducibility. Key application areas in bioanalytical chemistry are highlighted, covering nucleic acid analysis and peptide/protein characterization. CGGE offers unique analytical advantages where fine molecular discrimination, tunable selectivity, and high resolution in a broad molecular weight range are required.

Calcium is a key macroelement involved in a range of physiological processes in the body, and its concentration in blood is an important diagnostic indicator in various diseases. This work presents a novel rapid method for the point-of-care determination of total calcium content in patient blood, by applying a drop of capillary blood from a finger onto a hydrogel. Gelatin hydrogel, modified with an optical sensor for calcium, Arsenazo III, was used as a platform for the separation of blood into plasma and erythrocytes. A comparative analysis of various types of hydrogel materials (polyacrylamide, PVA, Fmoc-FF, carbomer, carbopol, gelatin) was performed, demonstrating that among the studied systems, only gelatin hydrogel is suitable as a platform for the determination of calcium in blood plasma. The binding of calcium ions from blood plasma with the calcium sensor embedded in the hydrogel leads to a change in the absorption spectrum of the system, enabling photometric determination of calcium concentrations below and above the normal range in blood plasma. Therefore, this rapid assay allows monitoring of calcium metabolism disorders in the human organism. The method is characterized by its speed, simplicity of sample preparation, and potential for integration into clinical practice.