Gelation Strategy Research Articles

Exploring the gelation potentials of chicken heart batter: From by-product to product

Chicken heart is the by-product of great amount in poultry industry owing to concentrated slaughter development, however, whose potential in food application is unclear. The gelation of chicken heart has great difficulties due to the muscle structure and protein structure of the heart. Therefore, different levels of sodium alginate (SA) were added into chicken heart batter (CHB) to investigate the gelation strategies. The results showed that the cooking loss of chicken heart gel (CHG) decreased by increasing SA level (0.12 %–0.48 %)，along with improved hardness, gumminess and chewiness. The G' and G" of CHB increased along with the SA addition, which mainly relates to hydrophobic interactions and disulfide bonds, followed by ionic bond and hydrogen bond. SA induced increased percentage of immobilized water and bound water. Moreover, the protein-SA interpenetrating network became denser and more uniform along with increased SA in CLSM and SEM images until CHG of 0.48 % SA. To the best of our knowledge, this is the first time that chicken heart is processed into gelation food, which endeavors to promote feed to food by a sustainable proposal.

Thermo-controlled microfluidic generation of monodisperse alginate microspheres based on external gelation.

Droplet-based microfluidic systems have received much attention as promising tools for fabricating monodisperse microspheres of alginate solutions with high accuracy and reproducibility. The immediate and simple ionotropic gelation of alginate, its biocompatibility, and its tunability of mechanical properties make it a favorable hydrogel in the biomedical and tissue engineering fields. In these fields, micron-sized alginate hydrogel spheres have shown high potential as cell vehicles and drug delivery systems. Although on-chip microfluidic gelation of the produced alginate droplets is common, several challenges remain. Complicated chemical and microfabrication processes are required, and the risk of microchannel clogging is high. In the current study, we present an easy-to-use microfluidic external gelation process to produce highly spherical and monodisperse microspheres from very low-concentrated alginate-RGD solution [0.5% (w/v)]. To accomplish this, gelatin, a thermo-sensitive and inexpensive biomaterial, was incorporated into the alginate solution as a sacrificial biomaterial that mediates the off-chip external gelation of the alginate with Ca2+, and avoids droplet coalescence. Utilizing the methodology mentioned above, we successfully generated monodisperse alginate microspheres (AMs) with diameters ranging from 27 μm to 46 μm, with a coefficient of variation of 0.14, from a mixture of Arg-Gly-Asp (RGD)-modified very low viscosity alginate and gelatin. These RGD-AMs were used as microcarriers for human umbilical vein endothelial cells. The described easy-to-use and cost-effective microfluidic off-chip external gelation strategy exhibits comparable advantages to on-chip external gelation and demonstrates superiority over the latter since clogging is impossible.

Hybrid biofabricated blood vessel for medical devices testing

ABSTRACT Current in vitro and in vivo tests applied to assess the safety of medical devices retain several limitations, such as an incomplete ability to faithfully recapitulate human features, and to predict the response of human tissues together with non-trivial ethical aspects. We here challenged a new hybrid biofabrication technique that combines bioprinting and Fast Diffusion-induced Gelation strategy to generate a vessel-like structure with the attempt to spatially organize fibroblasts, smooth-muscle cells, and endothelial cells. The introduction of Fast Diffusion-induced Gelation minimizes the endothelial cell mortality during biofabrication and produce a thin endothelial layer with tunable thickness. Cell viability, Von Willebrand factor, and CD31 expression were evaluated on biofabricated tissues, showing how bioprinting and Fast Diffusion-induced Gelation can replicate human vessels architecture and complexity. We then applied biofabricated tissue to study the cytotoxicity of a carbothane catheter under static condition, and to better recapitulate the effect of blood flow, a novel bioreactor named CuBiBox (Customized Biological Box) was developed and introduced in a dynamic modality. Collectively, we propose a novel bioprinted platform for human in vitro biocompatibility testing, predicting the impact of medical devices and their materials on vascular systems, reducing animal experimentation and, ultimately, accelerating time to market.

A Dual Gelation Strategy Under Gravity‐Enhanced Orientation to Construct Super‐Strong and Tough Bacterial Cellulose Phase Change Fiber for Wearable Heat Supply

A Dual Gelation Strategy Under Gravity‐Enhanced Orientation to Construct Super‐Strong and Tough Bacterial Cellulose Phase Change Fiber for Wearable Heat Supply

Magnetically responsive micro-clustered calcium phosphate-reinforced cell-laden microbead sodium alginate hydrogel for accelerated osteogenic tissue regeneration

The rising prevalence of bone injuries has increased the demand for minimally invasive treatments. Microbead hydrogels, renowned for cell encapsulation, provide a versatile substrate for bone tissue regeneration. They deliver bioactive agents, support cell growth, and promote osteogenesis, aiding bone repair and regeneration. In this study, we synthesized superparamagnetic iron oxide nanoparticles (Sp) coated with a calcium phosphate layer (m-Sp), achieving a distinctive flower-like micro-cluster morphology. Subsequently, sodium alginate (SA) microbead hydrogels containing m-Sp (McSa@m-Sp) were fabricated using a dropping gelation strategy. McSa@m-Sp is magnetically targetable, enhance cross-linking, control degradation rates, and provide strong antibacterial activity. Encapsulation studies with MC3T3-E1 cells revealed enhanced viability and proliferation. These studies also indicated significantly elevated alkaline phosphatase (ALP) activity and mineralization in MC3T3-E1 cells, as confirmed by Alizarin Red S (ARS) and Von Kossa staining, along with increased collagen production within the McSa@m-Sp microbead hydrogels. Immunocytochemistry (ICC) and gene expression studies supported the osteoinductive potential of McSa@m-Sp, showing increased expression of osteogenic markers including RUNX-2, collagen-I, osteopontin, and osteocalcin. Thus, McSa@m-Sp microbead hydrogels offer a promising strategy for multifunctional scaffolds in bone tissue engineering.

Protein Interfacial Gelation toward Shuttle-Free and Dendrite-Free Zn-Iodine Batteries.

Aqueous zinc-iodine (Zn-I2) batteries hold potential for large-scale energy storage but struggle with shuttle effects of I2 cathodes and poor reversibility of Zn anodes. Here, an interfacial gelation strategy is proposed to suppress the shuttle effects and improve the Zn reversibility simultaneously by introducing silk protein (SP) additive. The SP can migrate bidirectionally toward cathode and anode interfaces driven by the periodically switched electric field direction during charging/discharging. For I2 cathodes, the interaction between SP and polyiodides forms gelatinous precipitate to avoid the polyiodide dissolution, evidenced by excellent electrochemical performance, including high specific capacity and Coulombic efficiency (CE) (215 mAh g-1 and 99.5% at 1 C), excellent rate performance (≈170 mAh g-1 at 50 C), and extended durability (6000 cycles at 10 C). For Zn anodes, gelatinous SP serves as protective layer to boost the Zn reversibility (99.7% average CE at 2mA cm-2) and suppress dendrites. Consequently, a 500 mAh Zn-I2 pouch cell with high-loading cathode (37.5 mgiodine cm-2) and high-utilization Zn anode (20%) achieves remarkable energy density (80Wh kg-1) and long-term durability (>1000 cycles). These findings underscore the simultaneous modulation of both cathode and anode and demonstrate the potential for practical applications of Zn-I2 batteries.

A hydrophobic graft-modified PVA hydrogel by michael addition joint with gelation strategy for underwater cardiac sensing

The rapid development of global big health and AI technology has made electrocardiogram (ECG) monitoring in all scenarios more important. While real-time ECG monitoring in the air is easy to realize, underwater ECG monitoring is still challenging for general hydrogels. Herein, we prepared a hydrogel with underwater viscosity, biocompatibility, and excellent mechanical properties by hydrophobic graft-modified of PVA (POV) hydrogel and used it to prepare electrodes for underwater ECG monitoring. The POV hydrogel is very flexible and co-deforms easily with the skin, with a Young's modulus as low as 0.03 MPa and underwater adhesion strength up to 11 KPa. The hydrophobic chain segments within the POV hydrogel give the hydrophobic gel excellent stability, adhesion, and ionic conductivity given by the free ionic groups within the POV hydrogel enable the POV hydrogel to detect and transmit physiological electrical signals. Compared to commercial gel electrodes, this POV electrode has better adhesion, conductivity and stability underwater. The POV gel electrodes can effectively collect real-time ECG signals in the air and underwater. Therefore, this study effectively broaden the application of POV hydrogels in ECG biosensors for underwater cardiac sensing.

Challenges in Application: Gelation Strategies of DAT-Based Hydrogel Scaffolds.

Decellularized adipose tissue (DAT) has great clinical applicability, owing to its abundant source material, natural extracellular matrix microenvironment, and nonimmunogenic attributes, rendering it a versatile resource in the realm of tissue engineering. However, practical implementations are confronted with multifarious limitations. Among these, the selection of an appropriate gelation strategy serves as the foundation for adapting to diverse clinical contexts. The cross-linking strategies under varying physical or chemical conditions exert profound influences on the ultimate morphology and therapeutic efficacy of DAT. This review sums up the processes of DAT decellularization and subsequent gelation, with a specific emphasis on the diverse gelation strategies employed in recent experimental applications of DAT. The review expounds upon methodologies, underlying principles, and clinical implications of different gelation strategies, aiming to offer insights and inspiration for the application of DAT in tissue engineering and advance research for tissue engineering scaffold development.

Gelation of the electron transport layer to improve the thermal stability of efficient perovskite solar cells

We report an gelation strategy in the electron transport layer (ETL) by employing ammonium oxalate (AMO) in SnO2 dispersions. The resulting PSC achieves an improved power conversion efficiency of 21.40% with enhanced thermal stability.

Fast and scalable production of crosslinked polyimide aerogel fibers for ultrathin thermoregulating clothes

Polyimide aerogel fibers hold promise for intelligent thermal management fabrics, but their scalable production faces challenges due to the sluggish gelation kinetics and the weak backbone strength. Herein, a strategy is developed for fast and scalable fabrication of crosslinked polyimide (CPI) aerogel fibers by wet-spinning and ambient pressure drying via UV-enhanced dynamic gelation strategy. This strategy enables fast sol-gel transition of photosensitive polyimide, resulting in a strongly-crosslinked gel skeleton that effectively maintains the fiber shape and porous nanostructure. Continuous production of CPI aerogel fibers (length of hundreds of meters) with high specific modulus (390.9 kN m kg−1) can be achieved within 7 h, more efficiently than previous methods (>48 h). Moreover, the CPI aerogel fabric demonstrates almost the same thermal insulating performance as down, but is about 1/8 the thickness of down. The strategy opens a promisingly wide-space for fast and scalable fabrication of ultrathin fabrics for personal thermal management.

Injectable alginate hydrogel promotes antitumor immunity through glucose oxidase and Fe3+ amplified RSL3-induced ferroptosis

Ferroptosis induced by RAS-selective lethal small molecule 3 (RSL3) can trigger anti-tumor immune responses by reversing the immunosuppressive tumor microenvironment (TME). However, it is challenging to achieve sufficient ferroptosis in the tumor via RSL3 alone. Because of the excellent reactive oxygen species (ROS) production capacity of glucose oxidase (GOx) and Fe3+, we hypothesized that GOx and Fe3+ could increase intracellular lipid peroxidation (LPO) accumulation, and strengthen RSL3-induced ferroptosis in tumor cells. Herein we designed an in-situ gelation strategy based on sodium alginate (SA) to realize localized transport and specific retention of GOx, RSL3, and Fe3+ in tumor tissues. We loaded hydrophobic RSL3 with the tannic acid (TA)/Fe3+ complexes to form nanoparticles (RTF NPs). GOx diluted in the SA solution was blended with RTF NPs to obtain a homogeneous solution. The solution could form hydrogels in the tumor site (RTFG@SA) upon injection. The retained GOx and Fe3+ amplified the induction of ferroptosis by RSL3, augmented immunogenic cell death (ICD) and promoted antitumor immunity. The RTFG@SA hydrogel presented a significant restraint of tumor growth and metastasis in the 4T1 tumor model. This hydrogel could offer an effective means of co-delivery of hydrophilic drugs, hydrophobic drugs, and metal ions.

Formulation of Glutathione-Alginate Microspheres for Diabetes Mellitus Dietary Supplementation

The microsphere is a multi-molecule drug conveyance framework made to accomplish controlled drug conveyance to further develop bioavailability and dependability and target medications to explicit destinations at a given rate. Glutathione as a model for microspheres as dietary supplementation can restore GSH synthesis and lower oxidative stress and oxidant damage in the face of persistent hyperglycemia. The biomedical utilization of glutathione stays restricted because of its moderately short half-life, shaky properties, fast digestion, discharge, and high hydrophilicity. Hence, the motivation behind this study was to get ready GSH utilizing a microsphere with polysorbate 80 and sorbitan monooleate 80, beat skin obstruction capability, and research the properties and delivery profile of GSH-stacked alginate microspheres. It was to do. GSH microspheres were ready by ionotropic gelation technique. The produced microspheres were broken down in vitro for the proficiency of ensnarement (EE%), drug stacking (DL%), molecule size, yield, and medication discharge profile to acquire a streamlined plan. The pre-arranged GSH Microspheres had a high EE% going from (41.50 ± 1.12%) for F1 to (50.36 ± 0.86%) for F2, with little molecule sizes running (2.02 ± 0.09 µm) for F1 to (2.19 ± 0.16 µm) for F2, and drug stacking going from (5.81 ± 0.13%) for F1 to (6.15 ± 0.09%) for F2. The transition profile was tracked down in the scope of 0.018 ± 0.001 µg/cm2/h to 0.030 ± 0.002µg/cm2/h. GSH microspheres were ready by aerosolization utilizing the ionotropic gelation strategy. The GSH microspheres were assessed in vitro for the effectiveness of entanglement (EE%), drug stacking (DL%), molecule size, yield, and medication discharge profile to acquire a streamlined plan

A flexible, highly conductive, tough ionogel electrolyte containing LiTFSI salt and ionic liquid [EMIM][TFSI] based on PVDF-HFP for high-performance supercapacitors

Ionogel electrolytes (IGEs) with chemical and thermal stability properties have attracted considerable attention for all-solid-state energy storage devices, particularly for high-performance supercapacitors (SCs). However, achieving high conductivity, flexibility, and toughness, as well as deformation and impact resistance in special cases, is challenging with the typical polymer based on ionic liquids (ILs). Here, an effective gelation strategy is proposed for the preparation of free-standing LiTFSI/[EMIM][TFSI]/PVDF-HFP ionogels (IGs) by double-additive induced physical cross-linking. The mechanical and electrochemical properties of the IGs can be synergistically optimized by the cross-linking and entanglement of LiTFSI and [EMIM][TFSI] with the PVDF-HFP network. The target IGs simultaneously exhibit excellent deformation capacity (over 50 %), high ionic conductivity (10.3 × 10−3 S cm−1 at 25 °C), hardness (H: 728.6 kPa), and Young's modulus (E: 11.4 MPa), which can exhibit the specific capacitance of 274. 55 F g−1, energy density of 38.13 Wh kg−1 and maximum power density of 2499.93 W kg−1 in the fabricated symmetric supercapacitor. The results will motivate us to further explore their applications for flexible electronic devices, wearable electronic skin, and flexible energy storage.

Solvent triggering assembly of self-supported MXene hydrogel for high performance asymmetric supercapacitors

Constructing 3D porous structure of MXene (Ti3C2Tx) is an efficient approach to prevent nanosheets restacking and realize prominent electrochemical functionality. However, the assembly of self-supported 3D Ti3C2Tx architecture is difficult due to the inherent rigidity and superior hydrophilicity of Ti3C2Tx nanosheets. Herein, a solvent-triggering gelation strategy is developed using polar aprotic N,N-Dimethylformamide and polar protic H2O as co-solvent to enhance hydrogen bonding and Ti-O-Ti covalent bonding between Ti3C2Tx nanosheets. Thereby, self-supported Ti3C2Tx hydrogel (MH12/5:5) in absence of any crosslinkers or substrates has been successfully fabricated. The MH12/5:5 hydrogel exhibits excellent specific capacitance of 384.4 F g1 and superb rate capability of 61 % in a broad current density range of 1–100 A g−1. Asymmetric supercapacitor has been assembled using MH12/5:5 hydrogel as negative electrode and a polyaniline hydrogel as positive electrode, which presents high energy density of 21.2 Wh kg−1. This solvent-triggering gelation strategy points toward a promising direction to develop self-supported MXene hydrogels for high performance energy storage devices.

A hydrogel system for drug loading toward the synergistic application of reductive/heat-sensitive drugs

The preparation of hydrogels as drug carriers via radical-mediated polymerization has significant prospects, but the strong oxidizing ability of radicals and the high temperatures generated by the vigorous reactions limits the loading for reducing/heat-sensitive drugs. Herein, an applicable hydrogel synthesized by radical-mediated polymerization is reported for the loading and synergistic application of specific drugs. First, the desired sol is obtained by polymerizing functional monomers using a radical initiator, and then tannic-acid-assisted specific drug mediates sol-branched phenylboric acid group to form the required functional hydrogel (New-gel). Compared with the conventional single-step radical-mediated drug-loading hydrogel, the New-gel not only has better chemical/physical properties but also efficiently loads and releases drugs and maintains drug activity. Particularly, the New-gel has excellent loading capacity for oxygen, and exhibits significant practical therapeutic effects for diabetic wound repair. Furthermore, owing to its high light transmittance, the New-gel synergistically promotes the antibacterial effect of photosensitive drugs. This gelation strategy for loading drugs has further promising biomedical applications.

Exposing an Environmentally Friendly Gelation Strategy to Fabricate Modern Three-Dimensional M–Ag (M = Pt and Pd) Aerogels with Excellent Green Energy Generation

Exposing an Environmentally Friendly Gelation Strategy to Fabricate Modern Three-Dimensional M–Ag (M = Pt and Pd) Aerogels with Excellent Green Energy Generation

Dynamic Metal-Ligand Coordination-Assisted Ionogels for Deformable Alternating Current Electroluminescent Devices.

Overcoming the trade-off between the mechanical robustness and conductivity of ionic conductors is a crucial challenge for deformable ionotronics. In this work, we propose a simple but effective gelation strategy for selectively improving the mechanical robustness of ionogels without compromising their ionic conductivity. To achieve this, we introduce dynamic metal-ligand coordination chemistry into the ionic liquid (IL)-insoluble domains of a physically crosslinked ionogel network structure. As a result, the overall mechanical property is remarkably improved with the aid of additional chemical crosslinking. This strategy does not require any additional heat/light (UV) treatments to induce chemical crosslinking. The homogeneous physically/chemically dual crosslinked ionogel films can be readily obtained by simply casting a solution containing Ni2+ sources, copolymer gelators, and ILs. The effects of adjusting fundamental parameters on the ionogel properties are investigated systematically. The optimized mechanically robust and highly conductive ionogels are successfully employed as deformable ionic electrodes in alternating-current electroluminescent displays, indicating their high practicality. Overall, these results validate that exploiting metal-ligand coordination dynamic bonding is an extremely straightforward strategy for selectively improving the mechanical characteristics of conductive ionogels, which are promising platforms for deformable ionotronics.

In-situ preparation of chemically-crosslinked polyvinylpyrrolidone gel polymer electrolyte for lithium ion battery via room-temperature electron beam-induced gelation

In this research, we report an initiator-free and room-temperature 2.5 MeV electron beam (EB)-induced gelation strategy to in-situ create polyvinylpyrrolidone-based gel polymer electrolytes (PVP-GPEs) in a fully-assembled lithium ion battery (LIB). A radiation-sensitive liquid precursor consisting of 1-vinyl-2-pyrrolidone (VP), poly (ethylene glycol) diacrylate (PD), and LiClO4 liquid electrolyte (LE) was effectively converted to freestanding PVP-GPEs even at an absorbed dose of 2 kGy (Irradiation time of 6 s). The formed GPE at the absorbed dose of 2 kGy exhibited good thermal stability and mechanical integrity while providing good electrochemical oxidative stability (up to 4.7 V) and ion conductivity (2.03 × 10−3 S/cm at 25 °C). Moreover, the LiCoO2/PVP-GPE/graphite coin cell in-situ prepared at the absorbed dose of 2 kGy showed comparable retention capacity to that of an LE-based coin cell after 50 cycles. The findings of this study suggest that the proposed in-situ quick EB-induced gelation strategy (without use of an initiator and thermal treatment) could be a scalable way to allow high-throughput production of reasonably performing and safe LIBs.

Ga3+ loaded radiation crosslinked gel-Alg-CMC hydrogels for promoting diabetic wound healing.

The metal gallium holds great promise in the fight against infection by disrupting bacterial iron metabolism through a "Trojan horse" technique. It is well worth trying to investigate the potential for gallium-mediated hydrogels for the treatment of infected wounds. In this paper, Ga3+ is innovatively given an important role in hydrogels based on the conventional multi-component hydrogel with metal ion binding gelation strategy. Thus, Ga@Gel-Alg-CMCs hydrogel with broad-spectrum antimicrobial activity is reported on the treatment of infected wounds. The morphology, degradability, and swelling behavior together indicated the excellent physical properties of this hydrogel. Interestingly, in vivo results also showed favorable biocompatibility, slowing down wound infection and promoting diabetic wound healing, making the gallium-doped hydrogel an ideal antimicrobial dressing.

Low Hysteresis Hydrogel Induced by Spatial Confinement

AbstractStress concentration and hysteresis often occur in polymer hydrogels under large deformation, affecting their mechanical properties, and durability. Here, a new spatial confinement gelation strategy is proposed for fabrication of hysteresis‐free polymer hydrogels, and stress concentration is avoided. Experimental results and theoretical calculations confirm that the hydratability difference between salts and polymer chains leads to spatial confinement of the polymer chains by control over the ratio of bound to free water. Spatial confinement acts in place of physical cross‐linking of polymer chains, which slide to dissipate energy and effectively avoid stress concentration and hysteresis, resulting in ultra‐tough hydrogels with fatigue resistance. This is also a universal strategy for preparing polymer hydrogels with different monomers and salts. Taking the prepared PAM‐CaCl2hydrogel, it displays a hysteresis of only 0.13% during load‐unload cycles, even under 1000% strain. This is the lowest value among hydrogels reported to date. Along with excellent fatigue resistance, water retention, antifreeze, and water‐assisted healing ability, this hydrogel shows good performance in fatigue resistant capacitive strain sensors. Moreover, a fishtail‐shaped PAM‐CaCl2hydrogel operates as a bionic muscle to drive a bionic fish at a forward speed of 16.3 cm s−1, when a voltage of 0.1 V is applied.