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Pancreatic ductal adenocarcinoma (PDAC) accounts for about 90% of all pancreatic cancer cases. Five-year survival rates have remained below 12% since the 1970s, in part due to the difficulty in detection prior to metastasis (migration and invasion into neighboring organs and glands). Mechanical memory is a concept that has emerged over the past decade that may provide a path toward understanding how invading PDAC cells "remember" the mechanical properties of their diseased ("stiff", elastic modulus, E ≈ 10 kPa) microenvironment even while invading a healthy ("soft", E ≈ 1 kPa) microenvironment. Here, we investigated the role of mechanical priming by culturing a dilute suspension of PDAC (FG) cells within a 3D, rheologically tunable microgel platform from hydrogels with tunable mechanical properties. We conducted a suite of acute (short-term) priming studies where we cultured PDAC cells in either a soft (E ≈ 1 kPa) or stiff (E ≈ 10 kPa) environment for 6 h, then removed and placed them into a new soft or stiff 3D environment for another 18 h. Following these steps, we conducted RNA-seq analyses to quantify gene expression. Initial priming in the 3D culture showed persistent gene expression for the duration of the study, regardless of the subsequent environments (stiff or soft). Stiff 3D culture was associated with the downregulation of tumor suppressors (LATS1, BCAR3, CDKN2C), as well as the upregulation of cancer-associated genes (RAC3). Immunofluorescence staining (BCAR3, RAC3) further supported the persistence of this cellular response, with BCAR3 upregulated in soft culture and RAC3 upregulated in stiff-primed culture. Stiff-primed genes were stratified against patient data found in The Cancer Genome Atlas (TCGA). Upregulated genes in stiff-primed 3D culture were associated with decreased survival in patient data, suggesting a link between patient survival and mechanical priming.

Hematopoietic stem cells (HSCs) are the apical cells of the hematopoietic system, giving rise to cells of the blood and lymph lineages. HSCs reside primarily within bone marrow niches that contain matrix and cell‐derived signals that help inform stem cell fate. Aspects of the bone marrow microenvironment have been captured in vitro by encapsulating cells within hydrogel matrices that mimic native mechanical and biochemical properties. Hydrogel microparticles, or microgels, are increasingly being used to assemble granular biomaterials for cell culture and noninvasive delivery applications. Here, we report the optimization of a gelatin maleimide hydrogel system to create monodisperse gelatin microgels via a flow‐focusing microfluidic process. We report characteristic hydrogel stiffness, stability, and swelling characteristics as well as encapsulation of murine hematopoietic stem and progenitor cells, and mesenchymal stem cells within microgels. Microgels support cell viability, confirming compatibility of the microfluidic encapsulation process with these sensitive bone marrow cell populations. Overall, this work presents a microgel‐based gelatin maleimide hydrogel as a foundation for future development of a multicellular artificial bone marrow culture system. [ABSTRACT FROM AUTHOR]

While precipitation polymerization allows the synthesis of microgels with controlled functional‐group distributions, the structural development of these microgels during the polymerization process still remains unclear. In this study, microgels with different reactivity ratios between the monomer and charged co‐monomer are prepared by precipitation polymerization, and the evolution of their size, thermoresponsive behavior, and surface properties during polymerization are evaluated. In particular, the surface properties of the microgels are analyzed quantitatively using the softness parameter and the surface charge density is calculated using Ohshima's equation. The results allowed describing the structural changes of microgels during precipitation polymerization well and provided design guidelines for functional microgels with controlled functional group distributions. [ABSTRACT FROM AUTHOR]

[Display omitted] In this paper, microgels with uniform particle size were prepared by physically cross-linking the hydrophobically modified chitosan (h -CS) with sodium phytate (SP). The effects of cross-linking density on the interfacial adsorption kinetics, viscoelasticity, stress relaxation, and micorheological properties of the hydrophobically modified chitosan microgels (h -CSMs) at the oil–water interface were extensively investigated by the dilatational rheology, compressional rheology, and particle tracing microrheology. The results were correlated with the particle size, morphology, and elasticity of the microgels characterized by dynamic light scattering and atomic force microscopy. It was found that with the increase of cross-linking density, the h -CSMs changed from a polymer-like state to ultra-soft fussy spheres with higher elastic modulus. The compression isotherms demonstrated multi-stage increase caused by the interaction between the shells and that between the cores of the microgels successively. As the increase of cross-linking density, the h -CSMs diffused slower to the oil–water interface, but demonstrating faster permeation adsorption and rearrangement at the oil–water interface, finally forming interfacial layers of higher viscoelastic modulus due to the core-core interaction. Both the initial tension relaxation and the microgel rearrangement after interface expansion became faster as the microgel elasticity increased. The interfacial microrheology demonstrated dynamic caging effect caused by neighboring microgels. This article provides a more comprehensive understanding of the behaviors of polysaccharide microgels at the oil-water interface. [ABSTRACT FROM AUTHOR]

Concentrated emulsions and foams and microgels are comprised of deformable particles making these materials display complex rheological behavior that includes a yielding transition from an elastic solid to viscous fluid. Most studies of this class of soft matter involve shear flows and only a few report both shear and normal stresses. Here, we report measurements of the shear stress and two normal stress differences for a Carbobol microgel, which is usually classified as simple yield stress fluid, subjected to constant shear rate flows. Similar to our previous study, the shear stress evolves through the yield point in a manner indicative of simple yield stress fluid behavior while the normal stress differences evolve in a reproducibly chaotic manner. We also find that the evolution of the stresses is dependent on the whether the microgel has been in a state of relaxation or recovery prior to the measurement. [ABSTRACT FROM AUTHOR]

Solubility enhancement of poorly aqueous-soluble drugs, like Terbinafine (TBN), is a critical challenge in formulating effective dosage forms. This study focused on developing β-cyclodextrin (β-CD) and polyacrylamide (PAM)-based microgels to address the solubility issue of TBN, classified as a biopharmaceutics classification system class II drug. The microgels were crafted through free radical polymerization, employing methylene bisacylamide as a cross-linker and methacrylic acid as a monomer, initiated by ammonium persulfate. Comprehensive characterizations, including Fourier transform infrared, thermo-gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, powder X-ray diffractometry analysis, Zeta size, and Zeta potential, were conducted. In vitro studies, such as drug release and swelling, were performed at pH 1.2. Toxicity analysis in rabbits revealed zero toxicity. These β-CD/PAM microgels successfully enhanced the solubility of TBN.

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The biophysical heterogeneity of the bone–cartilage interface requires complex materials to mimic differences in bone density, extracellular matrix composition, and mineralization. Biomaterial approaches to repair osteochondral tissue typically use multilayer scaffolds, which require multistep fabrication and may undergo delamination at the construct interface. This work describes the development of functionalized microgels for the repair of osteochondral tissues using an N‐cadherin peptide, bone morphogenetic protein‐2 (BMP‐2) peptide, and changes in stiffness to create pro‐osteogenic and prochondrogenic microgels. Microgels, when annealed into a scaffold, outperforms bulk hydrogel controls evidenced by upregulation of osteogenic and chondrogenic markers in mesenchymal stromal cells (MSCs). The macroporous void space present in microgel anneals scaffolds enabled robust cell proliferation and extracellular matrix (ECM) deposition throughout the entire scaffold. A bilayer functionalized annealed microgel scaffold is then created and the ability to spatially control the differentiation of MSCs is assessed. Osteochondral bilayer scaffolds exhibit distinct regions of osteogenic and chondrogenic protein expression as a function of microgel population upon immunostaining for osteocalcin and aggrecan, respectively. Spatial transcriptomics confirm osteogenic and chondrogenic genes are upregulated in their respective microgel regions. These studies highlight the tunable and functionalizable nature of microgels and the importance of macroporous void space. [ABSTRACT FROM AUTHOR]

The polymer obtained from hydrophilic monomers can be transformed into a hydrogel via cross-linking by different cross-linkers. Hydrogels are three-dimensional networks that can absorb several times their weight and swell in water/swelling media, improving the media's viscosity as a thickener. The cross-linked poly(acrylic acid) microparticles prepared via precipitation polymerization technique are often synthesized by radical polymerization and have carboxylic functional groups in their structure, which make the hydrogel properties such as swelling capacity, particle morphology, and viscosity be controlled by physical factors such as solvent, neutralizer, pH, pKa, zeta potential, and ionic strength of the swelling media, as well as synthetic factors including comonomer, cross-linker, and network type. In this paper, the effects of crucial factors on the synthetic and swelling steps are elaborated to facilitate the achievement of poly(acrylic acid)-based xerogels having desirable rheological properties, such as swelling/viscosity optimization, which is the primary purpose of a thickener in any swelling media. [ABSTRACT FROM AUTHOR]

Widespread use of plant protection agents in agriculture is a major cause of pollution. Apart from active ingredients, the environmental impact of auxiliary synthetic polymers should be minimized if they are highly persistent. An alternative to synthetic polymers is the use of natural polysaccharides, which are abundant and biodegradable. In this study, we explore pectin microgels functionalized with anchor peptides (P‐MAPs) to be used as an alternative biobased pesticide delivery system. Using copper as the active ingredient, P‐MAPs effectively prevented infection of grapevine plants with downy mildew under semi‐field conditions on par with commercial copper pesticides. By using anchor peptides, the microgels tightly bind to the leaf surface, exhibiting excellent rain fastness and prolonged fungicidal activity. Finally, P‐MAPs are shown to be easily degradable by enzymes found in nature, demonstrating their negligible long‐term impact on the environment. [ABSTRACT FROM AUTHOR]

Abstract Delivery of therapeutic stem cells to treat bone tissue damage is a promising strategy that faces many hurdles to clinical translation. Among them is the design of a delivery vehicle which promotes desired cell behavior for new bone formation. In this work, we describe the use of an injectable microporous hydrogel, made of crosslinked gelatin microgels, for the encapsulation and delivery of human mesenchymal stem cells (MSCs) and compared it to a traditional nonporous injectable hydrogel. MSCs encapsulated in the microporous hydrogel showed rapid cell spreading with direct cell–cell connections whereas the MSCs in the nonporous hydrogel were entrapped by the surrounding polymer mesh and isolated from each other. On a per-cell basis, encapsulation in microporous hydrogel induced a 4 × increase in alkaline phosphatase (ALP) activity and calcium mineral deposition in comparison to nonporous hydrogel, as measured by ALP and calcium assays, which indicates more robust osteogenic differentiation. RNA-seq confirmed the upregulation of the genes and pathways that are associated with cell spreading and cell–cell connections, as well as the osteogenesis in the microporous hydrogel. These results demonstrate that microgel-based injectable hydrogels can be useful tools for therapeutic cell delivery for bone tissue repair.

Abstract Background Colorectal cancer (CRC) incidence is increasing in recent years due to intestinal flora imbalance, making oral probiotics a hotspot for research. However, numerous studies related to intestinal flora regulation ignore its internal mechanisms without in-depth research. Results Here, we developed a probiotic microgel delivery system (L.r@(SA-CS)2) through the layer-by-layer encapsulation technology of alginate (SA) and chitosan (CS) to improve gut microbiota dysbiosis and enhance anti-tumor therapeutic effect. Short chain fatty acids (SCFAs) produced by L.r have direct anti-tumor effects. Additionally, it reduces harmful bacteria such as Proteobacteria and Fusobacteriota, and through bacteria mutualophy increases beneficial bacteria such as Bacteroidota and Firmicutes which produce butyric acid. By binding to the G protein-coupled receptor 109A (GPR109A) on the surface of colonic epithelial cells, butyric acid can induce apoptosis in abnormal cells. Due to the low expression of GPR109A in colon cancer cells, MK-6892 (MK) can be used to stimulate GPR109A. With increased production of butyrate, activated GPR109A is able to bind more butyrate, which further promotes apoptosis of cancer cells and triggers an antitumor response. Conclusion It appears that the oral administration of L.r@(SA-CS)2 microgels may provide a treatment option for CRC by modifying the gut microbiota.

Progress in the discovery of potent antibodies for therapeutic and research purposes has been accelerated by mining the antibody repertoire of plasma cells and plasmablasts. Magnetic activated cell sorting (MACS) is a well recognized method for cell sorting, however, secreted IgGs rapidly diffuse away from cells, therefore requiring specialized technique to compartmentalize individual cells and capture their secretions for MACS isolation. To this end, a scalable method to prepare hydrogel‐based microcontainers for single cell culture and subsequent sorting based on their secreted IgG products at high‐throughput level are described. In situ crosslinkable microgels featuring tunable viscosity are fabricated to act as soft compartments that accommodate delicate primary cells and capture secreted proteins, while providing solid supports after solgel transition to enable immune recognition with chemically functionalized magnetic nanorods in aqueous medium for MACS separation. Splenocytes are sorted based on antigen‐specific IgG production from mice immunized with an antibiotic target ceftriaxone sodium, enriching a population of 220 000 000 to 800 000 prevalence following sorting. This enrichment ratio is substantially higher than conventional fluorescence activated cell sorting (FACS) methods, likely due to the multivalency of the antigen‐conjugated magnetic nanorods. [ABSTRACT FROM AUTHOR]

This study investigated the characteristic and foaming properties of microgels derived from aquafaba, a byproduct generated during chickpea cooking processes. Two distinct approaches were employed for microgel production: a top-down method involving the mechanical disintegration of aquafaba gels through household blending and subsequent high-pressure homogenization and a bottom-up method incorporating an additional shearing step during the gelation of aquafaba. The resulting microgels, when spray-dried, exhibited a raisin-like morphology. Upon rehydration, particle size measurements indicated a prevalence of large microgel particles (D[4,3] values of 16, 10 ± 1, 27 and 13, 70 ± 3, 96 µm for top-down and bottom-up methods, respectively). Fourier transform infrared spectroscopy analysis revealed increased starch crystallinity in microgels produced via the top-down method. At the same time, no significant differences in protein secondary structures were observed between aquafaba powder and microgels. Despite similar particle sizes and structural changes, the impact of the foaming agent type (aquafaba powder vs. microgels) and whipping time on foam properties were demonstrated. Notably, aquafaba microgels resulted in higher foam overrun values (between 709.40 and 962.90%) than those reported in the literature, surpassing traditional protein sources such as egg white and whey protein. However, regarding foam stability, aquafaba powder samples outperformed microgels produced through both top-down and bottom-up methods, regardless of whipping time. The introduction of an ultrasonic bath treatment was found to be necessary to enhance the foam stability of microgel suspensions. To further optimize foaming properties and justify the additional cost associated with microgel production, future research should focus on understanding the adsorption mechanisms of aquafaba microgels at the air–water interface. This investigation will contribute valuable insights into improving foaming characteristics, making aquafaba microgels a promising alternative for various food applications. [ABSTRACT FROM AUTHOR]

Combinations of synthetic polymers, such as poly(N-isopropylacrylamide) (PNIPAM), with natural biomolecules, such as keratin, show potential in the field of biomedicine, since these hybrids merge the thermoresponsive properties of PNIPAM with the bioactive characteristics of keratin. This synergy aims to produce hybrids that can respond to environmental stimuli while maintaining biocompatibility and functionality, making them suitable for various medical and biotechnological uses. In this study, we exploit keratin derived from wool waste in the textile industry, extracted via sulfitolysis, to synthesize hybrids with PNIPAM microgel. Utilizing two distinct methods—polymerization of NIPAM with keratin (HYB-P) and mixing preformed PNIPAM microgels with keratin (HYB-M)—resulted in hybrids with 20% and 25% keratin content, respectively. Dynamic light scattering (DLS) and transmission electron microscopic (TEM) analyses indicated the formation of colloidal systems with particle sizes of around 110 nm for HYB-P and 518 nm for HYB-M. The presence of keratin in both systems, 20% and 25%, respectively, was confirmed by spectroscopic (FTIR and NMR) and elemental analyses. Distinct structural differences were observed between HYB-P and HYB-M, suggesting a graft copolymer configuration for the former hybrid and a complexation for the latter one. Furthermore, these hybrids demonstrated temperature responsiveness akin to PNIPAM microgels and pH responsiveness, underscoring their potential for diverse biomedical applications. [ABSTRACT FROM AUTHOR]

Microgel-enhanced asymmetric hydrogels containing a thermosensitive layer and a non-thermosensitive layer are constructed. Actuators exhibiting outstanding response properties and multiple mechanosensors possessing high sensitivity are demonstrated. [Display omitted] Thermosensitive hydrogels have found extensive applications in soft devices, but they often suffer from limited functionalities, low response rate and small response amplitude. In this work, double layered asymmetrical hydrogels composed of a thermosensitive layer and a non-thermosensitive layer are developed to simultaneously achieve high-performance mechanosensing and actuating properties in a single hydrogel. In thermosensitive layer, thermosensitive microgels are introduced to construct hierarchical structure, which accounts for the enhanced thermosensitive behaviors by cooperative responsiveness. In non-thermosensitive layer, poly(acrylamide- co -acrylic acid) (P(AM- co -AA)) hydrogel is constructed. KCl is introduced as conductive component. Mechanosensors for monitoring various mechanical stimuli in daily life have been fabricated utilizing such hydrogels and high gauge factors (GF) have been achieved, 0.38 for resistive strain sensors, 9.40 kPa−1 for piezoresistive pressure sensors and 3.92 kPa−1 for capacitive pressure sensors. Because of the asymmetrical structure, such hydrogels also exhibit outstanding actuating properties with a fast response rate of 863°/min and a bending amplitude about 360°. Interestingly, grasping-releasing of target objects utilizing an octopus-shaped hydrogel actuator and temperature alerting based on hydrogel actuator are also demonstrated. Overall, the double layered asymmetrical ionic hydrogels have provided a new clue to construct hydrogel devices with multiple functionalities and enhanced response properties. [ABSTRACT FROM AUTHOR]

Cells integrate many mechanical and chemical cues to drive cell signalling responses. Because of the complex nature and interdependency of alterations in extracellular matrix (ECM) composition, ligand density, mechanics, and cellular responses it is difficult to tease out individual and combinatorial contributions of these various factors in driving cell behavior in homeostasis and disease. Tuning of material viscous and elastic properties, and ligand densities, in combinatorial fashions would enhance our understanding of how cells process complex signals. For example, it is known that increased ECM mechanics and transforming growth factor beta (TGF‐β) receptor (TGF‐β‐R) spacing/clustering independently drive TGF‐β signalling and associated myofibroblastic differentiation. However, it remains unknown how these inputs orthogonally contribute to cellular outcomes. Here, we describe the development of a novel material platform that combines microgel thin films with controllable viscoelastic properties and DNA origami to probe how viscoelastic properties and nanoscale spacing of TGF‐β‐Rs contribute to TGF‐β signalling and myofibroblastic differentiation. We found that highly viscous materials with non‐fixed TGF‐β‐R spacing promoted increased TGF‐β signalling and myofibroblastic differentiation. This is likely due to the ability of cells to better cluster receptors on these surfaces. These results provide insight into the contribution of substrate properties and receptor localisation on downstream signalling. Future studies allow for exploration into other receptor‐mediated processes. [ABSTRACT FROM AUTHOR]

This work reports preparing thermal responsive poly (N‐isovinylcaprolactam) (PNVCL) microgel based films for cell growth and detachment. PNVCL microgels of hydrated size ranging from 386 to 815 nm (25 °C) and different crosslinking degree are prepared. The PNVCL microgels can be rapidly and massively deposited on glass by spin coating method. Atomic force microscopy (AFM) and water contact angle (WCA) are used to study the influence of crosslinking degree and particle size on the surface morphology, stability, and hydrophilicity of PNVCL microgel film. The cell activity of the desorbed cells is quantitatively characterized employing human normal lung epithelial cells (BEAS‐2B). The results show that BEAS‐2B cells can be desorbed quickly from the film in 30 min, and the optical density (OD) value of desorbed cells incubated after 3 d increases by approximately 52% compared to the control group. This study broadens the selection of temperature‐sensitive film for cell harvesting, and provides a new tool for the quantitative characterization of desorbed cells. [ABSTRACT FROM AUTHOR]

Smart hydrogels responsive to external stimuli are promising for various applications such as soft robotics and smart devices. High mechanical strength and fast response rate are particularly important for the construction of hydrogel actuators. Herein, tough hydrogels with rapid response rates are synthesized using vinyl‐functionalized poly(N‐isopropylacrylamide) (PNIPAM) microgels as macro‐crosslinkers and N‐isopropylacrylamide as monomers. The compression strength of the obtained PNIPAM hydrogels is up to 7.13 MPa. The response rate of the microgel‐crosslinked hydrogels is significantly enhanced compared with conventional chemically crosslinked PNIPAM hydrogels. The mechanical strength and response rate of hydrogels can be adjusted by varying the proportion of monomers and crosslinkers. The lower critical solution temperature (LCST) of the PNIPAM hydrogels could be tuned by copolymerizing with ionic monomer sodium methacrylate. Thermo‐responsive bilayer hydrogels are fabricated using PINPAM hydrogels with different LCSTs via a layer‐by‐layer method. The thermo‐responsive fast swelling and shrinking properties of the two layers endow the bilayer hydrogel with anisotropic structures and asymmetric response characteristics, allowing the hydrogel to respond rapidly. The bilayer hydrogels are fabricated into clamps to grab small objects and flowers that mimicked the closure of petals, and it shows great application prospects in the field of actuators. [ABSTRACT FROM AUTHOR]

Thermoresponsive microgels are a kind of soft and wet material exhibiting various potential applications such as smart windows. As a concept of proof, poly(N‐isopropylacrylamide) based thermoresponsive microgel shows excellent promise in thermochoromic smart windows. While relatively expensive monomers lead to an unacceptable cost when they are used as building materials. In this work, efforts are made to exploration of an alternative for poly(N‐isopropylacrylamide) reducing the cost of thermoresponsive microgels. For this purpose, industrial chemicals acrylamide (AM) and diacetone acrylamide (DAAM) are employed to synthesize microgels through free radical precipitation polymerization. Although both homopolymers of acrylamide and diacetone acrylamide are not thermoresponsive. Their copolymers exhibit typical lower solution temperature solution (LCST) behaviors, which confirm the feasibility of the envisaged. Further, the influence of synthetic conditions including monomer ratio, concentration of surfactant, and polymerization temperature, on the size and responsive temperature of microgels is investigated. Ultimately, cost‐effective thermoresponsive microgels are prepared with adjustable diameters from 1.6 to 4.5 µm and responsive temperature from 19.3 to ≈70.0 °C. [ABSTRACT FROM AUTHOR]

Wastewater treatment plant effluent is considered an important hotspot of dissolved organic matter. The behavior and transformation of dissolved effluent organic matter (dEfOM) regulate particle sedimentation, pollutant fate, microbial attachment, and biofilm formation. However, studies have so far focused on the transformation of marine and riverine organic matter, and the current knowledge of dEfOM behavior is still limited. Fluctuations in water conditions, especially temperature, may directly alter the size, assembly speed, and structure of microgels, thereby potentially disturbing fate and the transportation of organic matter. In this study, we firstly investigated the effects of temperature on the behavior and capacity of dEfOM assembly into microgels and the possible mechanism. The microgel size and granularity of dEfOM were monitored by flow cytometry. Our results suggest that, with regard to microgels, a higher temperature leads to a higher assembly capacity but also a decrease in the size distribution. By contrast, assembly at 4 °C reduces the relative assembly capacity but increases the microgel size and granularity. The size distribution of the formed microgels at the various temperatures was ordered as follows: 4 °C > 20 °C > 35 °C. The size reduction in dEfOM assembly may be closely tied to the enhancement of hydrophobic interactions. The reduction in microgel granularity in warm conditions (35 °C) in terms of the effluent water may be caused by thermally induced condensation. Overall, the findings demonstrate the effects of temperature on dEfOM assembly and can facilitate further relevant studies on aquatic organic particle formation during current global warming scenarios.

The size of acrylamide‐based microgels can be decreased by addition of ionic surfactants during the classical dispersion polymerization. Nevertheless, the mechanism of such syntheses is not well understood yet. Here, a "Limited Aggregation Model" is proposed by analogy with the limited coalescence mechanism occurring for Pickering emulsion stabilization. In such a model, nuclei aggregate until a constant, high enough surfactant surface coverage is reached, which ensures colloidal stability. Consequently, the total surface of the growing particles, linked to the inverse of their size, is linearly dependent on the surfactant concentration. This law is verified if the surfactant/polymer particle interaction is high enough to guarantee a "total adsorption" of the surfactants onto the particles. This simple model fits very well with all the data extracted from the literature, including very different synthesis conditions. Finally, it not only permits to predict the microgels size, but it is also an interesting tool to investigate the role of each synthesis parameter like initiator, solvent or polymer. For instance, it shows that the surfactant role is not linked to its charge, proving that a phenomenon complementary to the electrostatic repulsion, related to the surfactant tail, ensures the colloidal stability of the growing collapsed microgels. [ABSTRACT FROM AUTHOR]

Ethylhexyl methoxycinnamate (EHMC) is frequently employed as a photoprotective agent in sunscreen formulations. EHMC has been found to potentially contribute to health complications as a result of its propensity to produce irritation and permeate the skin. A microgel carrier, consisting of poly(ethylene glycol dimethacrylate) (pEDGMA), was synthesized using interfacial polymerization with the aim of reducing the irritation and penetration of EHMC. The thermogravimetric analysis (TGA) indicated that the EHMC content accounted for 75.72% of the total composition. Additionally, the scanning electron microscopy (SEM) images depicted the microgel as exhibiting a spherical morphology. In this study, the loading of EHMC was demonstrated through FTIR and contact angle tests. The UV resistance, penetration, and skin irritation of the EHMC-pEDGMA microgel were additionally assessed. The investigation revealed that the novel sunscreen compound, characterized by limited dermal absorption, had no irritant effects and offered sufficient protection against ultraviolet radiation. [ABSTRACT FROM AUTHOR]

Magnetic Fe3O4 nanoparticles have attached attention in bone tissue engineering because of their superior magnetism and great biocompatibility. However, some disadvantages such as the potential risk of agglomeration impair their applications. Here, we proposed a hybrid magnetic nanocomposite microgel by the integration of Fe3O4 nanoparticles and digital lighting processing (DLP) three‐dimensional (3D) printing technology. The 3D‐printed microgels could be precisely customized by printing the mixture of gelatin methacryloyl (GelMA) solution and polydopamine‐coated Fe3O4 nanoparticles, in which polydopamine decoration improved the hydrophilicity and distribution of the incorporated Fe3O4. The degradable microgels could be injected through a 22‐G needle while retaining their original shape after injection. Interestingly, the addition of Fe3O4 nanoparticles into GelMA solution displayed improved printing accuracy. Moreover, these magnetic microgels were biocompatible in vitro and in vivo. After induction within osteogenic medium, addition of nanoparticles upregulated the osteogenic gene expression of rat bone mesenchymal stem cells (BMSCs). In a word, this work provides a magnetic microplatform, which shows great potential in bone tissue engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] Microgel–enzyme coatings were fabricated onto graphite substrates (highly oriented pyrolytic graphite or graphite- based screen-printed electrodes) via two-stage sequential procedure, which consists in adsorption of a pH- and temperature-sensitive copolymer microgel, followed by electrostatic immobilization of glucose oxidase into the microgel film. The microgel–enzyme coatings were examined by means of atomic force microscopy showing remarkable coverage of graphite surface by the microgels and visualizing the immobilized enzyme. Finally, amperometry was applied to reveal the effect of the polymeric (microgel) matrix on temperature behavior of glucose oxidase in the microgel– enzyme coatings. [ABSTRACT FROM AUTHOR]

[Display omitted] The stability of purely aqueous emulsions (W/W) formed by mixing incompatible polymers, can be achieved through the Pickering effect of particles adsorption at the interface. However, there is, as yet, no guideline regarding the chemical nature of the particles to predict whether they will stabilize a particular W/W emulsion. Bis-hydrophilic soft microgels, made of copolymerized poly(N -isopropylacrylamide) (pNIPAM) and dextran (Dex), act as very efficient stabilizers for PEO/Dextran emulsions, because the two polymers have an affinity for each polymer phase. The ratio between both components of the microgels is varied in order to modulate the bis-hydrophilic balance, the content of Dex compared to pNIPAM varying from 0 to 60 wt%. The partition between the two aqueous phases and the adsorption of microgels at the W/W interface is measured by confocal microscopy. The stability of emulsions is assessed via turbidity measurements and microstructural investigations under sedimentation or compression. The adsorption of particles and their partitioning is found to evolve progressively as a function of bis-hydrophilic balance. At room temperature, the stability of the resulting W/W emulsions also depends on the bis-hydrophilic balance with a maximum of stability for the particles containing 50%wt of Dex, for the Dex-in-PEO emulsions, while the PEO-in-Dex become stable above this value. The thermo-responsiveness of the microgels translates into stability inversion of the emulsions below 50 wt% of Dex in the microgels, whereas above 50 wt%, no emulsion is stable. This work paves the way of a guideline to design efficient and responsive W/W stabilizers. [ABSTRACT FROM AUTHOR]

In-stent restenosis (ISR) after percutaneous coronary intervention is a major reason for limited long-term patency due to complex neointimal proliferation caused by vascular injury. Drug-coated balloon (DCB) has been developed to treat various cardiovascular diseases including ISR by providing anti-proliferative drugs into blood vessel tissues. However, a significant proportion of the drug is lost during balloon tracking, resulting in ineffective drug delivery to the target region. In this study, we report an everolimus-coated balloon (ECB) using everolimus-loaded gelatin-hydroxyphenyl propionic acid microgel (GM) with enhanced everolimus delivery to vascular walls for long-term patency. GM with high drug loading (> 97%) was simply prepared by homogenizing enzyme-mediated crosslinked hydrogels. The optimal condition to prepare GM-coated ECB (GM-ECB) was established by changing homogenization time and ethanol solvent concentration (30 ∼ 80%). In vitro sustained everolimus release for 30 d, and cellular efficacy using smooth muscle cells and vascular endothelial cells were evaluated. Additionally, an in vivo drug transfer levels of GM-ECB using rabbit femoral arteries were assessed with reduced drug loss and efficient drug delivery capability. Finally, using ISR-induced porcine models, effective in vivo vascular patency 4 weeks after treatment of ECBs was also confirmed. Thus, this study strongly demonstrates that GM can be used as a potential drug delivery platform for DCB application. We report an ECB using everolimus-loaded GM prepared by homogenization of enzymatic cross-linked hydrogel. GM showed efficient drug loading (> 97 %) and controllable size. GM-ECB exhibited potential to deliver everolimus in a sustained manner to target area with drug efficacy and viability against SMC and EC. Although GM-ECB had much lower drug content compared to controls, animal study demonstrated enhanced drug transfer and reduced drug loss of GM-ECB due to the protection of encapsulated drugs by GM, and the possible interaction between GM and endothelium. Finally, vascular patency and safety were assessed using ISR-induced porcine models. We suggest an advanced DCB strategy to alleviate rapid drug clearance by bloodstream while improving drug delivery for a long-term vascular patency. [Display omitted] [ABSTRACT FROM AUTHOR]

Prevention of recurrence/metastasis and tissue regeneration are critical for post-surgery treatment of malignant tumors. Here, to address these needs, a novel type of microgel co-loading cryo-shocked cancer cells, immunoadjuvant, and immune checkpoint inhibitor is presented by microfluidic electrospray technology and liquid nitrogen treatment. Owing to the encapsulation of cryo-shocked cancer cells and immunoadjuvant, the microgels can recruit dendritic cells and activate them in situ, and evoke a robust immune response. Moreover, with the combination of the immune checkpoint inhibitor, the antitumor immune response is further enhanced by inhibiting the interaction of PD1 and PDL1. With this, the excellent anti-recurrence and anti-metastasis efficacy of the microgels are demonstrated in an orthotopic breast cancer mouse model. Besides, because of the excellent biocompatibility and appropriate degradation performance, the microgels can provide support for normal cell adhesion and growth, which is beneficial to tissue reconstruction. These properties indicate the great value of the cryo-shocked cancer cell microgels for efficient tumor postoperative combination immunotherapy and tissue regeneration.

Soybean protein isolate microgel (SPIM) was prepare by extreme acid combined with heat induction. The structural changes and molecular interactions of the protein, and the microstructure and gel properties of the microgel were explored by fluorescence spectroscopy, infrared spectroscopy, and atomic force microscopy, and the effects of different heat induction temperatures (25, 45, 55, 65, 75 and 85 ℃) on the structure and properties of the microgel were evaluated. The results showed that the relative content of β-sheet increased during the formation of SPIM, and electrostatic interaction, hydrophobic interaction and hydrogen bonding were involved in the self-assembly of microgels. In addition, with increasing temperature, the surface hydrophobicity index of SPIM increased first and then decreased, and that the thermal stability gradually increased. Compared with extreme acid, the specific surface area, emulsifying activity, emulsion stability and water-holding capacity of the microgel formed by extreme acid combined with heat induction at 75 ℃ were significantly increased (P < 0.05). Overall, extreme acid combined with heat induction is an effective method to regulate the structure and properties of protein microgels, and the quality of microgels can be improved by precise temperature control.

The aim of this study was to prepare poly-N-isopropylmethacrylamide-co-acrylic acid-acrylamide [p-(NIPMAM-co-AA-AAm)] via precipitation polymerization in an aqueous medium. Rhodium nanoparticles were formed in the microgel network by an in-situ reduction technique with the addition of sodium borohydride as a reducing agent. Pure p-(NIPMAM-co-AA-AAm) and hybrid microgels [Rh-(p-NIPMAM-co-AA-AAm)] microgels were examined by using UV–Visible, FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), DLS (Dynamic Light Scattering) and XRD (X-Ray Diffraction) techniques. The catalytic activities of the hybrid microgel [Rh-(p-NIPMAM-co-AA-AAm)] for the degradation of azo dyes such as alizarin yellow (AY), congo red (CR), and methyl orange (MO) were compared and the mechanism of the catalytic action by this system was examined. Various parameters including the catalyst amount and dye concentration influenced the catalytic decomposition of azo dyes. In order to maximize the reaction conditions for the dye's quick and efficient decomposition, the reaction process was monitored by spectroscopic analysis. The rate constants for reductive degradation of azo dyes were measured under various conditions. When kapp values were compared for dyes, it was found that [Rh-(p-NIPMAM-co-AA-AAm)] hybrid microgels showed superior activity for the degradation of MO dyes compared to the reductive degradation of CR and AY.

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present study, hydrogel emulsion particles made by emulsion templating method were used in order to encapsulate a-tocopherol. An oil-in-water-in-oil emulsion was used as mold to make microgel particles. The aim of this study was to investigate the effect of partial replacement of whey protein with iota-carrageenan (0, 0.2 and 0.4 wt%) on emulsion properties, hydrogel particles and release of a-tocopherol. The results showed that the introduction of iota-carrageenan in the formulation increased the apparent viscosity of the simple emulsions, droplet size increased from 2.69 μm in emulsions containing whey protein alone to 2.95 and 2.71 μm in emulsions containing 0.2 and 0.4 of iota-carrageenan. Replacing 0.2 and 0.4% of iota-carrageenan reduced the zeta potential from -43.93 mV to -46.56 and -46.68 mV, respectively. The introduction of iota-carrageenan in the formulation also reduced the particle size and reduced the encapsulation efficiency of a-tocopherol in hydrogel emulsion particles. Addition of iota-carrageenan to the formulation of hydrogel particles reduces the release rate of a-tocopherol in simulated gastric fluid from 30.36% in particles containing whey protein alone to 28.90 and 28.22% in particles containing 0.2 and 0.4% of iota-carrageenan, respectively. The results of this study showed that replacing part of the whey protein with iota-carrageenan improved the release and delivery of the lipophilic bioactive compound to the intestine in hydrogel emulsion particles.

Combinations of synthetic polymers, such as poly(N-isopropylacrylamide) (PNIPAM), with natural biomolecules, such as keratin, show potential in the field of biomedicine, since these hybrids merge the thermoresponsive properties of PNIPAM with the bioactive characteristics of keratin. This synergy aims to produce hybrids that can respond to environmental stimuli while maintaining biocompatibility and functionality, making them suitable for various medical and biotechnological uses. In this study, we exploit keratin derived from wool waste in the textile industry, extracted via sulfitolysis, to synthesize hybrids with PNIPAM microgel. Utilizing two distinct methods—polymerization of NIPAM with keratin (HYB-P) and mixing preformed PNIPAM microgels with keratin (HYB-M)—resulted in hybrids with 20% and 25% keratin content, respectively. Dynamic light scattering (DLS) and transmission electron microscopic (TEM) analyses indicated the formation of colloidal systems with particle sizes of around 110 nm for HYB-P and 518 nm for HYB-M. The presence of keratin in both systems, 20% and 25%, respectively, was confirmed by spectroscopic (FTIR and NMR) and elemental analyses. Distinct structural differences were observed between HYB-P and HYB-M, suggesting a graft copolymer configuration for the former hybrid and a complexation for the latter one. Furthermore, these hybrids demonstrated temperature responsiveness akin to PNIPAM microgels and pH responsiveness, underscoring their potential for diverse biomedical applications.

Single-cell manipulation is the key foundation of life exploration at individual cell resolution. Constructing easy-to-use, high-throughput, and biomimetic manipulative tools for efficient single-cell operation is quite necessary. In this study, a facile and efficient encapsulation of single cells relying on the massive and controllable production of droplets and collagen–alginate microgels using a microfluidic device is presented. High monodispersity and geometric homogeneity of both droplet and microgel generation were experimentally demonstrated based on the well-investigated microfluidic fabricating procedure. The reliability of the microfluidic platform for controllable, high-throughput, and improved single-cell encapsulation in monodisperse droplets and microgels was also confirmed. A single-cell encapsulation rate of up to 33.6% was achieved based on the established microfluidic operation. The introduction of stromal material in droplets/microgels for encapsulation provided single cells an in vivo simulated microenvironment. The single-cell operation achievement offers a methodological approach for developing simple and miniaturized devices to perform single-cell manipulation and analysis in a high-throughput and microenvironment-biomimetic manner. We believe that it holds great potential for applications in precision medicine, cell microengineering, drug discovery, and biosensing.

Carboxymethyl chitosan (CMCh) is a unique polysaccharide with functional groups that can develop positive and negative charges due to the abundant numbers of amine and carboxylic acid groups. CMCh is widely used in different areas due to its excellent biocompatibility, biodegradability, water solubility, and chelating ability. CMCh microgels were synthesized in a microemulsion environment using divinyl sulfone (DVS) as a crosslinking agent. CMCh microgel with tailored size and zeta potential values were obtained in a single stem by crosslinking CMCh in a water-in-oil environment. The spherical microgel structure is confirmed by SEM analysis. The sizes of CMCh microgels varied from one micrometer to tens of micrometers. The isoelectric point of CMCh microgels was determined as pH 4.4. Biocompatibility of CMCh microgels was verified on L929 fibroblasts with 96.5 ± 1.5% cell viability at 1 mg/mL concentration. The drug-carrying abilities of CMCh microgels were evaluated by loading Vancomycin (Van) antibiotic as a model drug. Furthermore, the antibacterial activity efficiency of Van-loaded CMCh microgels (Van@CMCh) was investigated. The MIC values of the released drug from Van@CMCh microgels were found to be 68.6 and 7.95 µg/mL against E. coli and S. aureus, respectively, at 24 h contact time. Disk diffusion tests confirmed that Van@CMCh microgels, especially for Gram-positive (S. aureus) bacteria, revealed long-lasting inhibitory effects on bacteria growth up to 72 h. [ABSTRACT FROM AUTHOR]

The mean‐square radius of gyration Rg2 and the graph diameter D of highly heterogeneous network polymers formed in emulsion vinyl/divinyl copolymerization are investigated to find a linear relationship, Rg2 = a D. The proportionality coefficient, a, is dominated by the cycle (circuit) rank, kc, or the number of intramolecular cross‐links. The magnitude of a is slightly larger than that for the random cross‐linked network polymers, but the functional form of a (kc) is simply proportional to that for the random networks proposed earlier. This relationship makes it possible to determine Rg2 based on D and kc, enabling quick estimation of Rg2 for large network polymers. It is found that the contraction factor g of the present heterogeneous network polymer is larger than that for the homogeneous networks formed through random cross‐linking of polymer chains. The ratio of these two contraction factors is kept constant, irrespective of the magnitude of kc. [ABSTRACT FROM AUTHOR]

This work demonstrated the hybridization of the PEG-g-PNIPAm copolymer microgel with the anti-inflammatory drug-loaded nanoMOFs that can achieve excellent tribological performance and anti-inflammatory effect for the synergistic therapy of OA. The incorporation of PEG chains into the PNIPAm microgel matrix to grow on the nanoMOFs greatly improved the high-temperature aqueous dispersion stability, facilitated the aqueous lubricating performance, and supported temperature-modulated tribological properties. [Display omitted] • Developed hybrid microgel nanocarriers of PEG-g-PNIPAm copolymer-coated nanoMOFs. • Demonstrated reversibly thermo-sensitive swelling-collapsing behavior of the hybrid. • Achieved excellent aqueous lubrication using nanoMOF@PEG-g-PNIPAm as additives. • Regulated OA-related genes and protein expression of chondrocyte with inflammation. This paper demonstrates the hybridization of copolymer microgel with drug-loaded metal–organic frameworks nanoparticles that can achieve excellent aqueous lubricating performance and anti-inflammatory effect for synergistic treatment of osteoarthritis (OA). Poly(ethylene glycol)- graft -poly(N -isopropylacrylamide) (PEG-g-PNIPAm) microgel layer is grown on the MIL-101(Cr) surface via one-pot soap-free emulsion polymerization method. The lower critical solution temperature of the MIL-101(Cr)@PEG-g-PNIPAm hybrid is raised significantly by incorporating PEG chains into the PNIPAm microgel matrix, which greatly enhances the high-temperature aqueous dispersion stability. The hybrid microgel demonstrated reversibly thermo-sensitive swelling-collapsing behavior to modulate the optical properties and hydrodynamic size. Using as aqueous lubricating additives, the hybrid reduces over 64% and 97% in friction coefficient and wear volume. Also, the hybrid supports desirable temperature-controlled lubrication modulation due to their reversible thermo-responsive behavior, which is benefit to joint lubrication of OA. After encapsulating anti-inflammatory diclofenac sodium (DS), the DS-MIL-101(Cr)@PEG-g-PNIPAm shows thermo-responsive drug release in aqueous media, which can improve the drug-delivery efficiency. By co-culturing the DS-loaded hybrid with human normal chondrocytes, we demonstrate good biocompatibility and anti-inflammatory effect on the chondrocytes with inflammation by regulating the expression of OA-related genes and proteins. Our work establishes multifunctional MOFs-based hybrid microgel systems for advanced colloids modulation and biomedical application. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel approach to surface modification, which consists of the adsorption of microgel–enzyme complexes preformed in solution, is highlighted. Accordingly, the microgel–enzyme complexes were formed due to the electrostatic interaction of the oppositely charged interacting components, that is, a cationic poly(N-isopropylacrylamide)-based microgel and glucose oxidase taken as a model enzyme. The spontaneous adsorption of the prepared microgel–enzyme complexes, examined by means of quartz crystal microbalance with dissipation monitoring and atomic force microscopy, was observed, resulting in the formation of well-adhered microgel–enzyme coatings. Further, the preformed microgel–enzyme complexes were adsorbed onto the modified graphite-based screen-printed electrodes, and their enzymatic responses were determined by means of amperometry, demonstrating a remarkable analytical performance toward the quantification of β-D-glucose in terms of high sensitivity (0.0162 A × M−1 × cm−2), a low limit of detection (1 μM), and an expanded linear range (1–2000 μM). The fabricated microgel–enzyme biosensor constructs were found to be very stable against manifold-repeated measurements. Finally, the pH- or salt-induced release of glucose oxidase from the adsorbed preformed microgel–enzyme complexes was demonstrated. The findings obtained for the microgel–enzyme coatings prepared via adsorption of the preformed microgel–enzyme complexes were compared to those found for the microgel–enzyme coatings fabricated via a previously exploited two-stage sequential adsorption, which includes the adsorption of the microgel first, followed by the electrostatic binding of glucose oxidase by the adsorbed microgel. [ABSTRACT FROM AUTHOR]

Objective: to study the effectiveness of correcting the morphofunctional characteristics of the liver in an experimental model of chronic liver disease (CLD), using implanted cell-engineered constructs (CECs).Materials and methods. Experiments were carried out on male Wistar rats (n = 80) aged 6–8 months with an initial weight of 230–250 g. CLD was modeled by inoculating the rats with 60% CCl4 oil solution for 42 days based on a modified scheme. Microgel based on recombinant spidroin rS1/9 was used as a matrix for CECs fabrication. Allogeneic liver cells (LCs) and multipotent bone marrow-derived mesenchymal stem cells (BM-MSCs) from a healthy donor were used as the cellular component of the CECs. The effectiveness of the corrective effect of the implanted CECs was assessed in an experimental CLD model (n = 60) in two groups of rats: Group 1 (control, n = 20, 1 mL of saline solution was injected into the damaged liver parenchyma) and Group 2 (experimental, n = 40, CECs containing allogenic LCs and BM-MSCs in a 5 : 1 ratio in a volume of 1 mL were implanted into the damaged liver parenchyma). For long-term monitoring of the CEC state, the CECs were labeled by additional inclusion in Cytodex-3. The effectiveness of the regulatory effect of CECs on regenerative processes in the liver was evaluated using biochemical, morphological and morphometric techniques, as well as by flow cytometry at 90 days after implantation.Results. In the control group, the mortality rate in CLD was 25%. There was no death in the experimental group with CLD after CEC implantation. The CECs were found to have a corrective effect on the biochemical and morphological parameters of the liver in CLD during 90 days of follow-up, with concomitant preservation of structural cellular homeostasis in the implanted CECs. Conclusion. Implantation of CECs in the liver facilitates effective correction of CLD by activating regenerative processes in the damaged liver, which is due to long-term preservation of structural cellular homeostasis in the CECs.

In this paper, selenated konjac glucomannan (SeKGM) and sulfhydrated sodium al- ginated (TSA) were prepared, following crosslinking using calcium lactate (CL) and obtaining SeKGM-TSA/Ca2+ microgel. Then SeKGM-TSA/Ca2+ @Q was fabricated after querce-tin (Q) loading. Fourier transform infrared spectroscopy (FT-IR) was selected to confirm the chemical structure of microgel, and the morphology of microgel was observed by TEM. The SeKGM-TSA/Ca2+ @Q microgel possessed an uniform spherical morphology with a particle size of 88.8±13. 56 nm. Moreover, OH scavenging rate, mucoadhesion behavior andin vitro Q release behavior of microgel were investigated. the results showed that the · OH scavenging rate of SeKGM-TSA/Ca2+ @Q was 50. 2% +1. 12% and the adhesion to mucin was up to 141.0±0. 46 mg. This work proposed a meaningful strategy for intestinal targeted delivery of Q by using microgel with acidproof. intestinal adhesive properties and ROS scavenging effect. [ABSTRACT FROM AUTHOR]

Soy-based yoghurt alternatives were highly requested by consumers over the last few years. However, their texture does not always fulfil consumers' demands as such yoghurt alternatives are often perceived as too firm or too soft, sandy, or fibrous. In order to improve the texture, fibres, for example, in the form of microgel particles (MGP), can be added to the soy matrix. MGP are expected to interact with soy proteins, creating different microstructures and, thus, different gel properties after fermentation. In this study, pectin-based MGP were added in different sizes and concentrations, and the soy gel properties after fermentation were characterised. It was found that the addition of 1 wt.% MGP influenced neither the flow behaviour nor the tribological/lubrication properties of the soy matrix, regardless of the MGP size. However, at higher MGP concentrations (3 and 5 wt.%), the viscosity and yield stress were reduced, the gel strength and cross-linking density decreased, and the water-holding capacity was reduced. At 5 wt.%, strong and visible phase separation occurred. Thus, it can be concluded that apple pectin-based MGP serve as inactive fillers in fermented soy protein matrices. They can, therefore, be used to weaken the gel matrix purposely to create novel microstructures. [ABSTRACT FROM AUTHOR]

In the present study, hydrogel emulsion particles made by emulsion templating method were used in order to encapsulate α-tocopherol. An oil-in-water-in-oil emulsion was used as mold to make microgel particles. The aim of this study was to investigate the effect of partial replacement of whey protein with iota-carrageenan (0, 0.2 and 0.4 wt%) on emulsion properties, hydrogel particles and release of α-tocopherol. The results showed that the introduction of iota-carrageenan in the formulation increased the apparent viscosity of the simple emulsions, droplet size increased from 2.69 μm in emulsions containing whey protein alone to 2.95 and 2.71 μm in emulsions containing 0.2 and 0.4 of iota-carrageenan. Replacing 0.2 and 0.4% of iota-carrageenan reduced the zeta potential from -43.93 mV to -46.56 and -46.68 mV, respectively. The introduction of iota-carrageenan in the formulation also reduced the particle size and reduced the encapsulation efficiency of α-tocopherol in hydrogel emulsion particles. Addition of iota-carrageenan to the formulation of hydrogel particles reduces the release rate of α-tocopherol in simulated gastric fluid from 30.36% in particles containing whey protein alone to 28.90 and 28.22% in particles containing 0.2 and 0.4% of iota-carrageenan, respectively. The results of this study showed that replacing part of the whey protein with iota-carrageenan improved the release and delivery of the lipophilic bioactive compound to the intestine in hydrogel emulsion particles. [ABSTRACT FROM AUTHOR]

[Display omitted] Water-in-water (W/W) emulsions formed by mixing incompatible polymers in aqueous solution can in some cases be stabilized by adding particles that adsorb spontaneously at the W/W interface. The importance of the contact angle of the particles with the interface on the stability of W/W emulsions is still an outstanding issue. We hypothesize that if the contact angle with the continuous phase is smaller than 90°, particles can bridge dispersed droplets, which enhances the stability of the emulsion. The W/W emulsions consisted of a dispersed poly(ethylene oxide) (PEO) phase in a continuous dextran phase or vice versa. Gelatin microgels were added and their contact angle was varied by varying the pH. The morphology during aging was observed by microscopy. The contact angle of the microgels with the PEO phase varied between 110° close to neutral pH and 0° at pH 3 and pH 11. The W/W emulsions were stable only when the contact angle with the continuous phase was smaller than 90°. In this case, microgels could form bridges between dispersed droplets creating a network of droplets. [ABSTRACT FROM AUTHOR]

In this study, oleogels were prepared by the emulsion-template method using egg-white protein microgel as a gelator and xanthan gum (XG) as thickener. The physicochemical properties of the emulsion and oleogels were investigated. The adsorption of protein on the surface of the oil droplet reached saturation when the protein microgel concentration reached 2%. The excess protein combined with XG and accumulated on the outer layer of the oleogel, which prevented the emulsion from flocculation, enhanced the oil-holding capacity of the oleogel, and had a positive effect on preventing the oxidation of oil. When the concentration of XG was less than 0.4%, the EWP microgel, combined with the XG, stabilized the emulsion. As the concentration of XG was greater than 0.4%, excessive XG in the emulsion improved the viscosity and mechanical properties of the emulsion to prevent the aggregation of oil droplets. However, the change in XG concentration had no significant effect on the oxidation of the oil. [ABSTRACT FROM AUTHOR]