Rheological Assessment Research Articles

Impact of Simulated Gastrointestinal Fluid: Viscosity, Surface Tension, and pH on the Dissolution and Rheology Assessment of Viscosity of Two Commercial Candesartan Cilexetil Products.

The aim of this study was to ivnestigate the effect of simulated gastrointestinal viscosity, surface tension, and pH on the dissolution rate of two commercial candesartan cilexetil (CC) products. In vitro dissolution of two commercial CC products and immediate release of 16 mg of CC were applied under two conditions: (1) the requirements of the United States Pharmacopeia (USP) and (2) conditions physiologically related to the gastrointestinal tract mimicking viscous food intake. The solubility of CC in different simulation fluids was also measured. The dissolution media's viscosity, surface tension, and pH were also measured. The viscosity of the gel layer was measured during CC dissolution. The CC dissolution rate was highest in the USP medium. It was found that the media type affected CC dissolution. The non-USP media exhibited a slower dissolution rate than the USP specification. The highest viscosity media lowered the dissolution rate in one of the CC products. Acidic pH showed a significant decrease in dissolution for both CC products. The solubility of CC was affected by solvent type (p value < 0.001). Higher viscosity media slow the dissolution rate of a product, where a gel layer forms on the tablet surface.The results show variation in the dissolution media. This may reveal differences in the dissolution rates of the same drug in different products and media. Considering, viscosity's effect on dissolution might improve patient outcomes when treated with different products.

Supramolecular Peptide Depots for Glucose‐Responsive Glucagon Delivery

ABSTRACTPrecise blood glucose control continues to be a critical challenge in the treatment and management of type 1 diabetes in order to mitigate both acute and chronic complications. This study investigates the development of a supramolecular peptide amphiphile (PA) material functionalized with phenylboronic acid (PBA) for glucose‐responsive glucagon delivery. The PA‐PBA system self‐assembles into nanofibrillar hydrogels in the presence of physiological glucose levels, resulting in stable hydrogels capable of releasing glucagon under hypoglycemic conditions. Glucose responsiveness is driven by reversible binding between PBA and glucose, which modulates the electrostatic interactions necessary for hydrogel formation and dissolution. Through comprehensive in vitro characterization, including circular dichroism, zeta potential measurements, and rheological assessments, the PA‐PBA system is found to exhibit glucose‐dependent assembly, enabling controlled glucagon release that is inversely related to glucose concentration. Glucagon release is accelerated under low glucose conditions, simulating a hypoglycemic state, with a reduced rate seen at higher glucose levels. Evaluation of the platform in vivo using a type 1 diabetic mouse model demonstrates the efficacy in protecting against insulin‐induced hypoglycemia by restoring blood glucose levels following an insulin overdose. The ability to tailor glucagon release in response to fluctuating glucose concentrations underscores the potential of this platform for improving glycemic control. These findings suggest that glucose‐stabilized supramolecular peptide hydrogels hold significant promise for responsive drug delivery applications, offering an approach to manage glucose levels in diabetes and other metabolic disorders.

Supramolecular gel with enhanced immunomodulatory effects presents a minimally invasive treatment strategy for eosinophilic chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is an inflammatory disease characterized by persistent immune dysregulation, which presents considerable limitations in current medical therapy. This study investigates a supramolecular gel (PSPD), which aims to minimize systemic adverse effects through local injection, provide long-lasting anti-inflammatory effects, and modulate the mucosal immune microenvironment. The properties of PSPD were evaluated using rheological experiments. Biocompatibility assessments were conducted through CCK-8 and serum biochemical analyses. The balance between TH17 and Treg was determined using immunofluorescence (IF) and flow cytometry (FC). Additionally, sinus computed tomography (CT), and endoscopy were employed to evaluate mucosal swelling. Rheological assessments revealed that PSPD possesses excellent self-healing and slow-release properties. CCK-8 and serum biochemical assays indicated that PSPD demonstrated superior biocompatibility. In nasal polyps, PSPD significantly inhibited IL17 expression. In an Eosinophilic Chronic Rhinosinusitis (ECRS) rat model, treatment with PSPD led to significant alleviation of nasal mucosal congestion. Furthermore, PSPD modulated the proliferation of TH17 and Treg as well as the expression of cytokines, ultimately reversing the TH17/Treg immune imbalance. This multifunctional gel effectively sustains the modulation of TH17/Treg homeostasis, improving long-term disease management and representing a promising new therapeutic strategy for CRS, particularly in cases of ECRS.

Assessing the Rheological Behavior of Bio-Asphalt Binder with Integrating Biowaste-Derived Activated Carbon

Abstract Current endeavors are being made to develop substitute asphalt binders using different biomass sources for upcoming flexible pavement construction, propelled by sustainability and the escalating expenses of traditional petroleum-centered asphalt. The primary objective of this research is to explore the feasibility of employing activated carbon (ATC) produced from biowaste, specifically walnut shells and sawdust, as a modification for petroleum-based virgin asphalt binders through chemical, physical, and rheological assessments. A comprehensive array of evaluations was carried out, encompassing examinations of homogeneity, physical characteristics, Carbon, Hydrogen, Nitrogen, Sulphur, and Oxygen (CHNSO) analysis, proximate analysis, infrared spectroscopy, multiple stress creep and recovery (MSCR), rheological attributes, and temperature sweep. The CHNSO analysis provided the elemental composition and helped develop molecular formulas for ATC. The results show that binders modified with ATC exhibited a heightening carbon content proportionate to the AC ratio, analyzed at 5%, 10%, and 15%. Temperature sweep tests revealed that adding AC significantly increased binder stiffness in accordance with the complex modulus (G*) and phase angle (δ). This increased rigidity from the ATC modification declines the temperature susceptibility of the modified binders.

Rheology Assessment of Mortar Materials for Additive Manufacturing

Abstract: This review article discusses the relevant rheological tests to evaluate the properties of compositions applied to the 3D printing of concrete (3DCP). These materials must rapidly develop rigidity and resistance, avoiding the collapse of the printed structure, with suitable buildability and other state properties, such as extrudability. A good balance must be maintained between properties and rheological parameters, such as yield stress and viscosity. Cohesion, Young's modulus, and thixotropy are also among the parameters used in these evaluations. The rheological tests addressed are the rheometer, direct shear test, uniaxial unconfined compression test, and penetration test. Their limitations must be taken into account to obtain accurate values of the rheological parameters. It was found that the most used test is the rheometer, and the test that needs to be further studied is the penetration test. Hence, it is recommended to search for a more expeditious method related to the rheological assessment to facilitate obtaining the associated parameters in a simple way.

Efficient Synthesis and Characterization of Antibacterial Xanthan Gum–Based Self‐Healing Hydrogels: Conventional Versus Microwave Treated

ABSTRACTThe development of self‐healing hydrogels with mechanical integrity is vital for biomedical applications. This study synthesizes multi‐network (MN) self‐healing hydrogels using xanthan gum (XG) through conventional and microwave‐assisted methods via free‐radical polymerization. The synthesis materials included XG, acrylamide, acrylonitrile, sodium dodecyl sulfate, ferric chloride hexahydrate, and ammonium persulfate. Conventional synthesis took 60 min at 70°C, while microwave synthesis was completed in 4.5 min at 540 W, enhancing energy and material efficiency. Structural tests like FTIR and SEM confirmed the results. Microwave synthesis produced a layered structure with smaller pores, leading to slower swelling kinetics, and EDX mapping showed higher Fe3+ ion concentrations, indicating better crosslinking. Thermal gravimetric analysis demonstrated that degradation onset temperatures were 184°C for microwave‐assisted synthesis XG hydrogel (MHXG) and 163°C for the water bath XG hydrogel method (HXG), indicating a 20°C enhancement due to the coherent structure induced by microwave treatment. Evaluation of self‐healing capabilities through visual and rheological tests showed significant enhancements in MHXG, which exhibited a self‐healing time of 2 h compared to 1 day required by HXG, attributed to increased crosslink density and hydrogen bonding facilitated by microwave treatment. Rheological assessments confirmed that both hydrogel types maintained their structural integrity and viscoelastic properties after healing. MHXG exhibited a mechanical strength of 21.12 kPa and elasticity of 10 kPa, whereas HXG showed 11.59 kPa and 1 kPa, respectively. Microwave‐treated hydrogel showed enhanced antibacterial effectiveness against Staphylococcus aureus due to better distribution of agents in the matrix. This method for synthesizing XG‐based self‐healing hydrogels is promising for advanced biomedical applications.

Toward Sustainable 3D-Printed Sensor: Green Fabrication of CNT-Enhanced PLA Nanocomposite via Solution Casting.

The current study explores, for the first time, an eco-friendly solution casting method using a green solvent, ethyl acetate, to prepare feedstock/filaments from polylactic acid (PLA) biopolymer reinforced with carbon nanotubes (CNTs), followed by 3D printing and surface activation for biosensing applications. Comprehensive measurements of thermal, electrical, rheological, microstructural, and mechanical properties of developed feedstock and 3D-printed parts were performed and analyzed. Herein, adding 2 wt.% CNTs to the PLA matrix marked the electrical percolation, achieving conductivity of 8.3 × 10-3 S.m-1, thanks to the uniform distribution of CNTs within the PLA matrix facilitated by the solution casting method. Rheological assessments paralleled these findings; the addition of 2 wt.% CNTs transitioned the nanocomposite from liquid-like to a solid-like behavior with a percolated network structure, significantly elevating rheological properties compared to the composite with 1 wt.% CNTs. Mechanical evaluations of the printed samples revealed improvement in tensile strength and modulus compared to virgin PLA by a uniform distribution of 2 wt.% CNTs into PLA, with an increase of 14.5% and 10.3%, respectively. To further enhance the electrical conductivity and sensing capabilities of the developed samples, an electrochemical surface activation treatment was applied to as-printed nanocomposite samples. The field-emission scanning electron microscopy (FE-SEM) analysis confirmed that this surface activation effectively exposed the CNTs to the surface of 3D-printed parts by removing a thin layer of polymer from the surface, thereby optimizing the composite's electroconductivity performance. The findings of this study underscore the potential of the proposed eco-friendly method in developing advanced 3D-printed bio-nanocomposites based on carbon nanotubes and biopolymers, using a green solution casting and cost-effective material extrusion 3D-printing method, for electrochemical-sensing applications.

Thermo-reversible gel synthesized by 4-α-glucanotransferase with sol-gel transition tuned by subtle amylose manipulation

Thermo-reversible gels have garnered significant interest in food, pharmaceutical, cosmetic, and therapeutic delivery sectors. The increasing demand for plant-based ingredients has further propelled research into plant-derived gels. This study investigates the application of 4-α-glucanotransferase from Thermus thermophilus STB20 (Tt4αGT) to synthesize thermo-reversible gels from seven starches. Detailed rheological analyses and fine structural characterizations were conducted to elucidate the mechanisms underpinning gel formation. The results indicate that amylose content and amylopectin chain length distribution are pivotal factors; specifically, an amylose content exceeding 5% is essential for gel formation was proposed for the first time. Modified starches exhibited a higher proportion of both short (DP 6–8) and long chains (DP > 26) compared to their native counterparts. Rheological assessments demonstrated that these gels maintained thermal stability through repeated heating and cooling cycles between 90 °C and 4 °C. Notably, Tt4αGT treatment significantly enhanced gel strength, particularly in tapioca starch (TS), and improved the thickening performance and reversibility of starch. The gel network structure was primarily stabilized by hydrogen bonds, supplemented by electrostatic interactions. These findings highlight the potential of Tt4αGT-treated starches as versatile materials for various industrial applications.

Rheological behavior and release dynamics of pregelatinized pink potato starch modified by stearic acid.

The effects of stearic acid (5 %, 10 %, and 15 % w/w) and pregelatinized pink potato starch (20, 25, and 30 min) on complex formation, physicochemical properties, rheology, and release characteristics were investigated. Moisture content decreased from 14.26 % in pregelatinized starch to 13.25 %, 12.85 %, and 11.45 % in complexes with 5 %, 10 %, and 15 % stearic acid, respectively. Water-holding capacity dropped from 268.68 % to 128.26 %, 95.05 %, and 50.63 %, with increasing stearic acid concentrations. Swelling and solubility power also decreased, with swelling power reducing from 5.57 % to 3.45 % and solubility from 12.75 % to 10.34 %. Micromeritic evaluations showed improved flowability in starch-stearic acid complexes. X-ray diffraction revealed a V-type crystalline complex with characteristic peaks at 7°, 21°, 22°, and 24°, and additional peaks at 7° and 41°. FTIR spectra indicated complex formation with bands around 2917 and 1700 cm−1. FESEM imaging showed intact granules with irregular shapes and protruding amylose fragments. Rheological assessments indicated reduced viscosity and altered viscoelastic properties in the complexes. In-vitro release studies demonstrated controlled drug release, suggesting potential applications for targeted pharmaceutical delivery. This study emphasizes the functional modifications induced by stearic acid in pregelatinized starch, enhancing material properties for industrial and biomedical applications.

Investigation of self-assembly of daucosterol from eleocharis dulcis peel with γ-oryzanol for stabilized water-in-oil emulsion gels

This study investigated the novel application of daucosterol, a natural saponin from eleocharis dulcis peel, in stabilizing emulsion gels with γ-oryzanol. While daucosterol has known health benefits, its ability to stabilize emulsion gels had not yet been explored. This research examined the emulsification properties, microstructure, rheological behavior, stability, and intermolecular interactions of the resulting emulsion gels. Results showed that daucosterol effectively stabilized the emulsion gels, forming structured networks at higher concentrations. FT-IR analysis revealed significant intermolecular hydrogen bonding between daucosterol and γ-oryzanol, and XRD profiles indicated a transition from crystalline to amorphous structures. SEM images displayed denser network formations with increased daucosterol levels. Contact angle measurements demonstrated enhanced hydrophobicity with rising daucosterol concentration, which favored stable water-in-oil emulsions. Rheological assessments confirmed strong thermal stability, robust mechanical properties, and partial thixotropic recovery at higher daucosterol levels. Additionally, daucosterol-stabilized emulsions showed remarkable stability through storage, freeze-thaw cycles, and heat treatments. This stability was attributed to dense, network-like structures that effectively inhibited phase separation and droplet coalescence. Molecular interaction simulations further supported the formation of stable complexes between daucosterol and γ-oryzanol, sustained by hydrogen bonds and van der Waals forces. This study highlights daucosterol's potential as an innovative stabilizer for oil-water emulsion gels.

Interfacial structure modification and enhanced emulsification stability of microalgae protein through interaction with anionic polysaccharides

Microalgae protein (MP) have emerged as a focal point of research within food processing due to its nutritional value and foaming properties. However, its isoelectric point around pH 4 leads to it susceptible to collision, binding, and precipitation. Additionally, MP has poor emulsification properties and only shows stability under strongly alkaline conditions. This study investigated the effects of food-grade anionic polysaccharides (guar gum (GG), gum arabic (GA), low acyl gellan gum (LG), and pectin (PT)) on the molecular structure and emulsification properties of MP. Results indicated that these anionic polysaccharides enhanced the UV absorption of MP near 620 nm, especially at 14 % content, while fluorescence intensity decreased due to amino acid residues masking without structural changes. The addition of polysaccharides resulted in bimodal or multimodal particle size distributions, with LG and PT showing larger particle sizes. At pH 4, negatively charged polysaccharides formed stable complexes with near-neutral MP, improving solution stability via electrostatic repulsion and diminishing turbidity. The droplet distribution analysis indicated that higher anionic polysaccharide ratios (1:4, 1:2, and 1:1) correlated with smaller droplet sizes and increased emulsion stability. Zeta-potential measurements revealed negative charges for emulsions, with LG-MP and PT-MP complexes displaying higher absolute values (15.0 to 20.7 mV) compared to GG-MP and GA-MP complexes, indicating superior stability. Storage stability analysis showed that LG-MP and PT-MP complexes stabilized emulsions had minimal delamination over two weeks. Rheological assessments showed that increasing GG and GA contents from 14 % to 50 % had negligible effects on apparent viscosity, while LG-MP (1:1) complexes stabilized emulsion displayed higher viscosity compared to PT-MP emulsions. Frequency sweep results showed that GG-MP, GA-MP, and LG-MP emulsions had greater elastic moduli (G') than viscous moduli (G"), indicating elastic behavior, whereas PT-MP emulsions transitioned from liquid-like to solid-like behavior as frequency increased. This study illustrates the advantages of high LG and PT content in preventing particle aggregation and enhancing emulsion stability, providing a theoretical and practical foundation for MP applications in food processing.

Development and characterization of PVA-zein/α-tocopherol nonwoven mats for functional wound dressing applications

Wound healing poses significant clinical challenges due to issues like bacterial infections, oxidative stress, and the need for sustained therapeutic delivery. This study aimed to develop and characterize biocompatible nonwoven fibrous mats composed of poly(vinyl alcohol) (PVA) and zein encapsulating α-tocopherol for wound dressing applications. α-Tocopherol was nano-encapsulated in zein proteins using an antisolvent co-precipitation method, followed by its dispersion in PVA solutions. The resulting composition was then processed using a novel, scalable, and inexpensive solution blow spinning (SBS) process that offers higher throughputs to generate non-woven mats. The resulting fibers in the non-woven mats, ranging in diameter from 350 nm to 796 nm, demonstrate uniform morphology, as confirmed by scanning electron microscopy. Fourier transform infrared (FTIR) spectroscopy validated the successful incorporation of α-tocopherol without altering the chemical structure of the PVA-zein matrix. Rheological assessments revealed Newtonian behavior and a decrease in viscosity with higher tocopherol content, enhancing the processability of the mats. Mechanical testing showed that increasing tocopherol content improved tensile strength, elongation, and Young's modulus. The mats exhibited a biphasic release profile with an initial burst and sustained α-tocopherol release over 24 h, fitting the Korsmeyer-Peppas model and hence indicating a diffusion-controlled mechanism. Cytotoxicity assays confirmed high cell viability (>90 %) and enhanced cell spreading, underscoring their biocompatibility. These findings suggest that PVA-zein/tocopherol fiber mats are promising candidates for functional wound dressing materials, offering sustained antioxidant activity and a favorable wound healing environment. Future work will focus on optimizing fiber composition for antimicrobial properties and conducting in vivo studies to validate their clinical efficacy.

Inverse vulcanized sulfur-styrene polymers as effective plasticizers for polystyrene

Inverse vulcanized polymers have demonstrated significant potential as alternatives to conventional petrochemical polymers in various applications, including environmental remediation, where they are used to absorb heavy metals and pollutants from water and soil, and energy devices, such as in the development of high-capacity lithium-sulfur batteries. Despite their promise in these areas, the full application scope of these sulfur-based polymers remains unexplored. There is substantial potential for their use in other fields, such as advanced material coatings, medical devices, and as additives to improve the properties of existing polymers, yet these possibilities have not been thoroughly investigated. This study presents a sulfur-based polymer, synthesized via the inverse vulcanization of sulfur and styrene and partially crosslinked with divinylbenzene, as a novel plasticizer for polystyrene (PS). This polymer blend was prepared using an internal mixer to replace conventional organic-based plasticizers. The selected system was designed to maximize miscibility. Both virgin and plasticized PS were injection molded for comprehensive characterization. Differential Scanning Calorimetry (DSC) confirmed the complete consumption of sulfur, revealing a significant reduction in the glass transition temperature of PS upon the addition of the sulfur-based plasticizer. Morphological analysis showed a homogeneous surface with uniform single-phase morphology, indicating full miscibility of the blend. Tensile tests demonstrated enhanced ductility and reduced stiffness in plasticized PS, with strain at maximum tensile strength and elongation at break increasing by 22.0 % and 28.1 %, respectively. The plasticizer also improved the toughness of PS by 25.2 %. Rheological assessments corroborated the plasticization effect and confirmed the blend's full miscibility. Contact angle measurements indicated increased hydrophilicity of the plasticized PS samples. This newly developed sulfur-based plasticizer proved to be highly effective for PS, showcasing competitive efficiency comparable to commercial plasticizers. This advancement paves the way for new applications in the expanding field of sulfur-based polymers.

Alteration in rheological and digestive properties of O/W emulsions using controlled aggregation of konjac glucomannan and xanthan gum in aqueous phases

The modulation of lipid digestion and emulsion stability remains a pivotal area of research, crucial for developing healthier food products with enhanced sensory and nutritional attributes. This study investigates the influence of konjac glucomannan (KGM) and xanthan gum (XG) on oil-in-water (O/W) emulsions throughout simulated gastrointestinal tract (GIT) digestion, focusing on rheological properties, microstructure evolution, and lipid release kinetics. Three distinct O/W emulsions were formulated with 20 wt% oil content, incorporating either 0.8 wt% XG, a 1:1 mixture of KGM and XG (KGM/XG), or a blend of KGM-XG. Rheological assessments revealed all emulsions exhibited shear-thinning behavior across applied shear rates (0.1–100 1/s). During gastric and small intestinal digestion phases, the KGM-XG emulsion exhibited significantly higher viscosity at higher shear rates (2.512–100 1/s), indicating robust molecular interactions between KGM and XG under digestive conditions. The analysis of microstructure, particle size, and flow behavior showed that the KGM-XG emulsion exhibited significantly (p < 0.05) higher viscosity and smaller particle sizes compared to other systems throughout the digestion process. This finding indicates that KGM-XG emulsion demonstrates a strong resistance to enzymes and digestive fluid during the transition from oral to small intestinal phases. Importantly, the extent of free fatty acid (FFA) release at the end of the small intestinal phase was highest for XG (34.4%), followed by KGM/XG (15.65%) and KGM-XG (13.23%). These findings highlight the potential of KGM-XG emulsions to modulate lipid digestion kinetics, offering applications in designing emulsion-based foods, such as sauces, beverages, and reduced-fat foods.

Synthesis, rheological and thermal studies of Gum ghatti-cl-poly(acrylic acid) hydrogels containing CoFe2O4 nanoparticles

In this work, Gum ghatti-cl-poly(acrylic acid)/CoFe2O4 (GGAACF) hydrogels were synthesized using a free radical polymerization technique, with CoFe2O4 nanoparticles incorporated via a co-precipitation method using nitrates as precursors. Thermal gravimetric analysis (TGA) revealed that the inclusion of CoFe2O4 nanoparticles enhanced the thermal stability of the hydrogels. Swelling studies indicated that the addition of 30 mg of CoFe2O4 nanoparticles maximized water retention. Rheological assessments demonstrated non-Newtonian behavior, with flow curves fitted best by the Power Law model. The incorporation of CoFe2O4 nanoparticles significantly improved the hydrogel’s elasticity and viscosity, as evidenced by a higher storage modulus (G′) compared to the loss modulus (G″) across all frequencies, indicating the elastic nature of the hydrogels. The decrease in complex viscosity with increasing frequency confirmed the pseudoplastic properties of the hydrogels, attributed to the random alignment of CoFe2O4 nanoparticles within the matrix. Tan δ values were below unity at all tested frequencies, underscoring the hydrogels’ strong elastic properties. These findings highlight the effectiveness of rheological analysis in characterizing the viscoelastic behavior of polymer hydrogels, which can be tailored for various applications.

Thermal-responsive soil-hydrogel composite for additive construction

To improve the formability and bonding strength of 3D printing soil, a temperature-stimulating responsive intelligent soil-hydrogel 3D printing formula was innovatively developed by combining soil and gelatin. Varied soil-gelatin composites, featuring different gelatin content by weight of soil (0 %, 0.5 %, 1 %, and 1.5 %), were prepared and cured at 5 °C to facilitate the crosslinking of gelatin. An array of tests, including rheological assessments, compressive tests, and scanning electron microscopy analysis. Were conducted to thoroughly characterize the performance of gelatin-soil composites for 3D printing. Our findings unveiled that, following the cross-linking of gelatin at 5 °C, the gelatin-soil composites exhibited superior formability and bond strength compared to the reference. Furthermore, the soil-gelatin composites demonstrated not only comparable compressive strength to the reference but also enhanced interlayer bond strength. This innovative soil-hydrogel 3D printing formula, combining the versatility of soil and the responsive characteristics of gelatin, presents a promising avenue for advancing the capabilities of 3D printed soil.

Exploring the tunable micro-/macro-structure enabled by alginate-gelatin bioinks for tissue engineering

This study explores the development of optimized alginate-gelatin (AG) bioinks for advanced 3D bioprinting applications, particularly in tissue engineering. Central to our investigation is the establishment of a method for producing AG bioinks with highly tunable viscoelastic properties and the ability to create both macro- and micro-porous scaffolds through a liquid-liquid emulsion technique applied to chemically crosslinked hydrogels and shaped by microextrusion. Our methodology encompasses a comprehensive evaluation of homogenization, pasteurization techniques, and rheological assessments to optimize the mechanical properties of AG hydrogels, ensuring their suitability for bioprinting.The study demonstrates that dynamic homogenization and conventional pasteurization methods yield superior dissolution and sterility of the bioinks, crucial for maintaining optical quality and biological compatibility. Crosslinking optimization significantly enhanced the elasticity and reduced post-crosslinking shrinkage of the hydrogels, a key factor in achieving desired cell viability and function within the engineered tissues. The incorporation of porosity through a controlled liquid-liquid emulsion process was found to enhance cellular interactions and integration within the bioprinted constructs.Our findings confirm that the rheological properties of bioinks play a crucial role in determining bioprintability, with temperature modulation emerging as a key tool for tailoring these characteristics. The biocompatibility and functional performance of the AG hydrogels were validated through in vitro experiments, demonstrating promising cell viability and proliferation. This research lays the groundwork for the development of advanced bioinks capable of supporting complex tissue architectures in regenerative medicine and tissue engineering. By marrying the versatility of alginate and gelatin with innovative fabrication techniques, our study advances the frontier of 3D bioprinting, paving the way for the creation of biomimetic tissues with enhanced physiological relevance and therapeutic potential.

Simplifications of the Short-Term USAT Protocol for Neat and Modified Binders: A Rheological Assessment

Simplifications of the Short-Term USAT Protocol for Neat and Modified Binders: A Rheological Assessment

Investigating the effect of GO‐ZnO nano‐hybrid on the mechanical, rheological, and degradation performance of poly (butylene succinate)

AbstractThis paper reports on preparing two types of graphene oxide‐zinc oxide (GO‐ZnO) nano‐hybrids and their effect on the performance of polybutylene succinate (PBS) matrix. This view synthesized GO, ZnO, and GO‐ZnO nano‐hybrids at 1:1 and 1:2 weight ratios. Subsequently, various spectroscopy and microscopy analyses (FTIR, UV, Raman, AFM, and TEM) were employed to characterize the structure of synthesized nanomaterials. The obtained results revealed that the hybridization was successfully occurred and microstructure of two types of prepared nano‐hybrids are basically different depending on the preparation procedure. Following this, PBS nanocomposites with 0.5, 1, and 1.5 wt% of GO‐ZnO nano‐hybrids (NPs) were produced via the solvent‐blending method. The mechanical, microstructural, rheological, biodegradability and UV‐shielding properties of the fabricated films were then investigated. Mechanical properties showed that addition of 0.5 wt% ZnO‐GO nanohybrids improved elongation at break from 21.6% to 28.7% and increased tensile strength by 20%. However, rheological assessments showed a one‐order‐of‐magnitude decrease in viscosity with the addition of only 0.5 wt%. In degradation analysis, 100 percent of mass loss was observed during 5 weeks for PBS with 1.5 wt% of GO‐ZnO. PBS/GO‐ZnO nanocomposites indicated tailored mechanical properties, biodegradability, suggesting a promising potential in packaging applications.Highlights GO‐ZnO nanohybrids were successfully synthesized. Incorporating GO‐ZnO into PBS improved its hydrolytic degradation The thermal decomposition of PBS was accelerated by the addition of GO‐ZnO. Adding GO‐ZnO nanohybrids to PBS resulted in a drop in viscosity. Nanohybrids with higher ZnO content exhibited greater hydrolytic and thermal degradation.

Development of in situ forming autologous fibrin scaffold incorporating synthetic teriparatide peptide for bone tissue engineering.

This study investigates the potential of an in-situ forming scaffold using a fibrin-based scaffold derived from autologous plasma combined with Synthetic Teriparatide (TP) for bone regeneration application. TP is known for its bone formation stimulation but has limited clinical use due to side effects. This autologous delivery system aims to provide precise, controlled, localized, and long-term release of TP for accelerating bone regeneration. Fibrinogen from autologous plasma was extracted using ethanol, and thrombin was precipitated with ammonium sulfate to create the fibrin scaffold. Characterization of fibrinogen was done through FTIR, SDS-Page, porosity, SEM, degradation, and rheology tests. Viability was assessed by MTT in five groups with different concentrations of TP in fibrin scaffold (50, 100, and 150 µl/ml), fibrin alone, and a control group against HEK and Wharton's jelly cells. The release profile of different concentrations of TP in the fibrin scaffold was also examined. The formation time of the fibrin scaffold was 4 ± 0.2 s. The highest Infrared absorption for fibrinogen was confirmed. Rheology assessment revealed a higher elastic modulus than the viscous modulus. The created fibrin scaffold displayed a consistent three-dimensional microstructure with an interconnected porous network. Cytotoxicity assays demonstrated good biocompatibility and enhanced cell growth with different concentrations of TP in the fibrin scaffold. The TP release increased with higher concentrations, peaking at an average of 61% over 54 h. Autologous plasma-derived fibrin scaffolds incorporating TP exhibit satisfactory release within the scaffold and hold promise as a versatile bone filler for clinical use, facilitating osteoregeneration.