Gels最新文献

Cancer and infectious diseases are two of the world's major public health problems. Gemcitabine (GEM) is an effective chemotherapeutic agent against several types of cancer. In this study, we developed macrocapsules incorporating GEM into a chitosan matrix blended with magnetite and zeolite by ionic gelation. Physicochemical characterization was performed using HRTEM-ED, XRD, FESEM-EDS, FT-IR, TGA, encapsulation efficiency (%E.E.), and release profiles at pHs 7.4 and 5.0. Cell viability tests against A549 and H1299 cell lines, and microbiological properties against staphylococcal strains were performed. Our results revealed the successful production of hemispherical capsules with an average diameter of 1.22 mm, a rough surface, and characteristic FT-IR material interaction bands. The macrocapsules showed a high GEM encapsulation efficiency of over 86% and controlled release over 24 h. Cell viability assays revealed that similar cytotoxic effects to free GEM were achieved with a 45-fold lower GEM concentration, suggesting reduced dosing requirements and potentially fewer side effects. Additionally, the macrocapsules demonstrated potent antimicrobial activity, reducing Staphylococcus epidermidis growth by over 90%. These results highlight the macrocapsules dual role as a chemotherapeutic and antimicrobial agent, offering a promising strategy for treating lung cancer in patients at risk of infectious diseases or who are immunosuppressed.

Enhancing the sensory appeal of jasmine instant tea, particularly its aroma, poses a significant challenge due to the loss of volatile organic compounds during conventional processing. This study introduces a novel approach to address this issue through the application of microencapsulation techniques, aimed at preserving these key aromatic elements. Our investigation focused on the encapsulating agents gelatin, acacia gum, carboxymethylcellulose (CMC), and maltodextrin, chosen for their compatibility with the volatile organic compounds of tea. A statistical analysis was conducted on the analytical results through comprehensive analytical techniques like Principal Component Analysis (PCA), Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), and Variable Importance in Projection (VIP) analysis for microcapsule characterization. The statistical analysis revealed gelatin to be a particularly effective encapsulating medium, preserving an aroma profile more akin to fresh tea. The statistical analysis confirmed the reliability of these findings, highlighting the potential of microencapsulation in refining the quality of jasmine instant tea products. The results of this research suggest that microencapsulation could be instrumental in improving the sensory quality and shelf life of instant tea products, offering new opportunities for product enhancement in the beverage industry.

The fat covered by fat globule membrane is scattered in a water phase rich in lactose and milky protein, forming the original emulsion structure of milk. In order to develop low-fat milk products with good performance or dairy products with nutritional reinforcement, the original emulsion structure of milk can be restructured. According to the type of lipid and emulsion structure in milk, the remolded emulsion structure can be divided into three types: restructured single emulsion structure, mixed emulsion structure, and double emulsion structure. The restructured single emulsion structure refers to the introduction of another kind of lipid to skim milk, and the mixed emulsion structure refers to adding another type of oil or oil-in-water (O/W) emulsion to milk containing certain levels of milk fat, whose final emulsion structure is still O/W emulsion. In contrast, the double emulsion structure of milk is a more complicated structural remodeling method, which is usually performed by introducing W/O emulsion into skim milk (W₂) to obtain milk containing (water-in-oil-in-water) W₁/O/W₂ emulsion structure in order to encapsulate more diverse nutrients. Causal statistical analysis was used in this review, based on previous studies on remodeling the emulsion structures in milk and its gelling products. In addition, some common processing technologies (including heat treatment, high-pressure treatment, homogenization, ultrasonic treatment, micro-fluidization, freezing and membrane emulsification) may also have a certain impact on the microstructure and properties of milk and its gelling products with four different emulsion structures. These processing technologies can change the size of the dispersed phase of milk, the composition and structure of the interfacial layer, and the composition and morphology of the aqueous phase substance, so as to regulate the shelf-life, stability, and sensory properties of the final milk products. This research on the restructuring of the emulsion structure of milk is not only a cutting-edge topic in the field of food science, but also a powerful driving force in promoting the transformation and upgrading of the dairy industry to achieve high-quality and multi-functional dairy products, in order to meet the diversified needs of consumers for health and taste.

Fabricating large-scale porous bioactive glass bone scaffolds presents significant challenges. This study aims to develop formable, in situ setting scaffolds with a practical gelation time of about 10 min by mixing 45S5 bioactive glass with sodium silicate (waterglass) and an acid initiator. The effects of pH (2-11), waterglass concentration (15-50 wt.%), and acid initiator type (phosphoric or boric acid) were examined to optimize gelation kinetics and microstructure. A 10 min gelation time was achieved with boric acid and phosphoric acid at various pH levels by adjusting the waterglass concentration. Exponential and polynomial models were proposed to predict gelation times in basic and acidic environments, respectively. The optical properties of the gels were studied qualitatively and quantitatively, providing insights into gelation kinetics and structure. Acidic gels formed smaller particles in a dense network (pores < 550 nm) with higher light transmittance, while basic gels had larger aggregates (pores ~5 µm) and lower transmittance. As the waterglass concentration decreased, pore size and transmittance converged in both groups. The onset of gelation was detected around 8 min using the derivative of light transmittance. This work identifies the key factors controlling waterglass gelation and their impact on gel structure, enabling the tailored creation of formable, in situ setting bioactive glass bone scaffolds.

Polyvinyl alcohol (PVA) hydrogels have a wide range of applications in the pharmaceutical and biomedicine fields due to their exceptional biophysical properties. The study focuses on preparing and characterizing capsule-shaped PVA hydrogels to enhance their biocompatibility and porosity for controlled glucose release and cell proliferation. The hydrogels were prepared using different concentrations (Cs) and molecular weights (MWs) of PVA, with two different lengths, A (10 mm) and B (20 mm), to control glucose release over 60 min. The preparation process involved PVA gel preparation and PVA hydrogel formation. A total of 500 µL of glucose was injected into all dehydrated hydrogels in groups A and B. Glucose release was studied by immersing the hydrogels in saline at 37 °C with stirring at 500 rpm. The SUP-B15 cell line was grown in six A1 hydrogels for biocompatibility testing. The results indicate that all hydrogels remained stable at 37 °C without degrading. Those with a higher C and MW exhibited a denser and less porous structure, lower glucose storage capacity, and higher elongation at break. Significant differences in glucose release, diffusion speed, and flux were observed, which were more evident in A1 > A4, B1 > B4, and B1 > A1 over 60 min. A1 and B1 had higher values because their higher porosity distribution allowed glucose to diffuse more easily. B1, being larger, has more glucose due to its increased length. The cell growth response and viability at 48 h in contact with the hydrogels was similar to that of the control (4.5 × 10⁵ cells/mL, 98.5% vs. 4.8 × 10⁵ cells/mL, 99.7% viability), thus demonstrating biocompatibility. The hydrogels effectively released glucose over 60 min, with variations based on porosity, C, MW, and length, and demonstrated good biocompatibility with the cell line.

Biosorption, a non-expensive and easy method for removing potentially toxic metal ions from water, has been the subject of extensive research. In this context, this study introduces a novel approach using sodium alginate and chitosan, versatile biopolymers that have shown excellent results as biosorbents. The challenge of maintaining high efficiencies and reuse is addressed by developing alginate/chitosan-based films. These films, prepared using solvent casting and crosslinking methods, form a hydrogel network. The alginate/chitosan-based films, obtained using the eco-friendly polyelectrolyte complex method, were characterized by FTIR, SEM, TGA, and DSC. The study of their swelling pH response, adsorption, and desorption behavior revealed promising results. The adsorption of Pb was significantly enhanced by the presence of both biopolymers (98%) in a shorter time (15 min) at pH = 6.5. The adsorption of both ions followed a pseudo-second-order kinetic and the Langmuir isotherm model. The desorption efficiencies for Cd and Pb were 98.8% and 77.6% after five adsorption/desorption cycles, respectively. In conclusion, the alginate/chitosan-based films present a highly effective and novel approach for removing Cd and Pb from water, with a promising potential for reuse, demonstrating their strong potential in potentially toxic metal removal.

With the increasing development of productivity, new materials that allow for the efficient use of energy are slowly becoming a sought-after goal, as well as a challenge that is currently being faced. For this reason, we have made aerogels as the target of our research and prepared different series (CLPI (1-5)) of cross-linked polyimide aerogels by mixing and cross-linking the heat-insulating cross-linking agent 1,3,5-tris(4-aminobenzylamino)benzene (TAB) with polyamic acid solution. We created a three-dimensional spatial organization by using vacuum freeze-drying and programmed high-temperature drying, then controlled the concentration of the polyamidate solution to investigate the concentration and TAB's influence on aerogel-related properties. Among them, the shrinkage is reduced from 40% in CLPI-1 to 28% in CLPI-5, and it also shows excellent mechanical characteristics, the highest compression strength (CLPI-5) reaches 0.81 MPa and specific modulus reaches 41.95 KN m/Kg. In addition, adding TAB improves the aerogel thermal resistance, T₅ in N₂ from PI-2 519 °C to CLPI-2 556 °C. The three-dimensional network-type structure of the aerogel shows an excellent thermal insulation effect, where the thermal conductivity can be as low as 24.4 mWm^-1 K^-1. Compared with some protective materials, cross-linked polyimide aerogel presents better flame-retardant properties, greatly improving the scope of its application in the industrial protection.

Understanding the niche interactions between blood and bone through the in vitro co-culture of osteo-competent cells and endothelial cells is a key factor in unraveling therapeutic potentials in bone regeneration. This can be additionally supported by employing numerical simulation techniques to assess local physical factors, such as oxygen concentration, and mechanical stimuli, such as shear stress, that can mediate cellular communication. In this study, we developed a Mesenchymal Stem Cell line (MSC) and a Human Umbilical Vein Endothelial Cell line (HUVEC), which were co-cultured under flow conditions in a three-dimensional, porous, natural pullulan/dextran scaffold that was supplemented with hydroxyapatite crystals that allowed for the spontaneous formation of spheroids. After 2 weeks, their viability was higher under the dynamic conditions (>94%) than the static conditions (<75%), with dead cells central in the spheroids. Mineralization and collagen IV production increased under the dynamic conditions, correlating with osteogenesis and vasculogenesis. The endothelial cells clustered at the spheroidal core by day 7. Proliferation doubled in the dynamic conditions, especially at the scaffold peripheries. Lattice Boltzmann simulations showed negligible wall shear stress in the hydrogel pores but highlighted highly oxygenated zones coinciding with cell proliferation. A strong oxygen gradient likely influenced endothelial migration and cell distribution. Hypoxia was minimal, explaining high viability and spheroid maturation in the dynamic conditions.

Poly(3-hydroxybutyrate) (PHB) is a microbially derived polyhydroxyalkanoate that is widely used in biomedical applications. In this study, we investigated the use of acetic acid (aa) as an alternative environmentally friendly solvent for the preparation of gels from PHB (PHB aa) and compared their characteristics with PHB products dissolved in chloroform (PHB chl) using such methods as DSC, FTIR, SEM, rheometry, biodegradation, and cytocompatibility assay. A slight decrease in the degree of the crystallinity of the PHB from 61% to 50.8% was found when the acetic acid was used. This resulted in a greater mass loss for the PHB aa (11%) during enzymatic degradation over 180 days. Gels prepared from PHB in the different solvents showed differences in the microstructure and porosity of the samples, which affected their viscoelastic properties. The storage modulus (G') for the PHB aa gels was higher by 35% compared to that for the PHB chl, and Young's modulus in compression was 101.5 and 41.3 kPa for the PHB aa and PHB chl, respectively. The porosity of the PHB aa was 97.7%, which was 5.2% higher than that for the PHB chl. The presence of low molecular weight polymers in the PHB aa had an effect on mesenchymal stem cells' viability, expressed as a threefold increase in the number of attached cells after 7 days of incubation compared to the PHB chl. Thus, the proposed method of PHB-based materials' preparation is a promising, more environmentally friendly analog of the extensively used method of preparation from chloroform.

Precision in dosing is crucial for optimizing therapeutic outcomes and preventing overdosing, especially in preterm infants. Traditional manual adjustments to adapt the dose often lead to inaccuracies, contamination risks, and reduced precision. To overcome these challenges, semi-solid extrusion 3D printing was used to create personalised gel-based caffeine dosage forms. The hydrogels, made from agar and hydroxypropyl methylcellulose, demonstrated excellent rheological properties, ensuring uniform extrusion and accurate shape retention during and after printing. This gel formulation allowed for precise adjustments of caffeine volume and content tailored to a neonate weighing 1.36 kg, achieving a recovery of 103.46%, well within acceptable limits. Additionally, three production batches confirmed the process's reproducibility with minimal variability. Forced degradation studies showed that both pure caffeine and caffeine in the gel matrix exhibited similar stability profiles, confirming the drug's chemical integrity. The printed gel dosage forms also displayed immediate-release characteristics, with over 80% of caffeine released within 45 min, highlighting their suitability for rapid therapeutic action. These findings emphasise the potential of SSE 3DP and gel-based formulations to produce personalised drug delivery systems with high precision, reproducibility, and reliability.