Preparation Of Hydrogels Research Articles

Innovative composite fluidized hydrogel GAC particles for effective membrane fouling mitigation and membrane integrity protection

Membrane filtration is recognized as an environmentally friendly and cost-efficient technology for water treatment, but membrane fouling is still a significant challenge that increases maintenance costs and reduces membrane lifespan. Particle scouring can effectively mitigate fouling with lower energy consumption. This study investigates the use of fluidized granular activated carbon (GAC) particles encapsulated with hydrogel layers to enhance fouling mitigation in microfiltration systems treating surface water. The proposed hydrogel-modified GAC particles aim to balance scouring efficiency with membrane integrity. The results demonstrate that optimizing hydrogel preparation conditions significantly enhanced the mechanical strength and surface hydrophilicity of GAC particles. The incorporation of hydrogel layers notably improved membrane fouling mitigation, reducing transmembrane pressure (TMP) by 19.3 %, 27.1 %, and 34.3 % for layer thicknesses of 0.5 mm, 1.0 mm, and 1.5 mm, respectively. The hydrodynamic behavior of fluidized GAC particles was significantly improved, enhancing the effectiveness of fouling mitigation in water treatment processes. Additionally, the hydrogel layer effectively protected membrane integrity and inhibited carbon release, ensuring minimal damage and stable permeability. This study underscores the pivotal role of hydrogel layers in improving the performance and longevity of membrane filtration systems, when fluidized GAC particles are used for membrane fouling control.

Environmentally stable and rapidly polymerized tin-tannin catalytic system hydroxyethyl cellulose hydrogel for wireless wearable sensing

In recent years, flexible sensors constructed mainly from hydrogels have played an indispensable role in several fields. However, the traditional hydrogel preparation process involves complex and time-consuming steps and the freezing or volatilization of water in the water gel in extreme environments greatly limits the further use of the sensor. Therefore, an ionic conductive hydrogel (SnHTD) was designed, which was composed of tannic acid (TA), metal ions Sn2+, hydroxyethyl cellulose (HEC), and acrylamide (AM) in a deep eutectic solvent (DES) and water binary solvent. It is worth noting that the gel time is shortened to less than 3 min by introducing the Sn-TA redox system. The addition of DES makes the hydrogel have a wide temperature tolerance range (−20 to 60 °C) and the ability to store for a long time (30 days). The introduction of HEC increased the tensile stress of hydrogel from 140.17 kPa to 219.89 kPa. Additionally, the hydrogel also has high conductivity, repeatable adhesion and UV shielding properties. In general, this research opens up a new way for room temperature polymerization of environmentally resistant hydrogel materials and effectively meets the growing demand for wireless wearable sensing.

Synthesis of Cellulose-Based Hydrogel-Nanocomposites for Medical Applications.

This study focused on synthesizing a cellulose-based hydrogel nanocomposite as a green hydrogel by adding a microcrystalline cellulose (MC) solution to carboxymethyl cellulose sodium (CMC-Na) with citric acid as a cross-linker. Y2O3 nanoparticles were incorporated during hydrogel preparation in different ratios (0.00% (0 mmol), 0.03% (0.017 mmol), 0.07% (0.04 mmol) and 0.10% (0.44 mmol)). FTIR analysis confirmed the cross-linking reaction, while XRD analysis revealed the hydrogels' amorphous nature and identified sodium citrate crystals formed from the reaction between citric acid and CMC-Na. The swelling test in deionized water (pH 6.5) at 25 °C showed a maximum swelling percentage of 150% after 24 h in the highest nanoparticle ratio. The resulting cellulose hydrogels were flexible and exhibited significant antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The synthesized cellulose-based hydrogel nanocomposites are eco-friendly and suitable for medical applications.

Preparation and evaluation of gastrodin microsphere-loaded Gastrodia elata polysaccharides composite hydrogel on UVB-induced skin damage in vitro and in vivo

Skin damage from sun exposure is a common issue among outdoor workers and is primarily caused by ultraviolet rays. Upon absorption of these rays, the skin will experience inflammation and cell apoptosis. This study explored the concept of 'Combination of medicine and adjuvant' by utilizing Gastrodia elata polysaccharide, a key component of Gastrodia elata Bl.‌, to develop a new hydrogel material. Oxidized Gastrodia elata polysaccharide (OGEP) and carboxymethyl chitosan (CMCS) was use to prepare a biocompatible, biodegradable and self-healing hydrogel OGEP/CMCS (OC). And this hydrogel was further loaded with Gastrodin-containing microspheres (GAS/GEL) to create GAS/GEL/OGEP/CMCS (GGOC) hydrogel. Characterization studies revealed that OC and GGOC hydrogels exhibited favorable mechanical properties, antioxidant activity and biocompatibility. The experiments showed that OC and GGOC hydrogels could regulate mitochondrial membrane potential, prevent mitochondrial breakage, inhibit proinflammatory factors, prevent NF-κB protein activation and regulate apoptosis-related pathways. This study highlighted the application potential of Gastrodia elata polysaccharide as a ‘Combination of medicine and adjuvant’ and the anti-UVB damage effect of the prepared hydrogel.

Preparation, structural characterization, and functional properties of wheat gluten amyloid fibrils-chitosan double network hydrogel as delivery carriers for ferulic acid

It has been demonstrated that ferulic acid (FA) can be effectively encapsulated using wheat gluten amyloid fibrils (AF) and chitosan (CS) in a double network hydrogel (DN) form, with cross-linking mediated by Genipin (GP). Within this system, the DN comprising gluten AF-FA and CS-FA exhibited optimal loading metrics at a formulation designated as DN8, achieving a load efficiency of 88.5 % and a load capacity of 0.78 %. Analysis through fluorescence quenching confirmed that DN8 harbored the highest quantity of FA. Fourier-transform infrared spectroscopy (FTIR) further verified a significant increase in β-sheet content post-hydrogel formation, enhancing the binding capacity for FA. Rheological assessments indicated a transition from solution to gel, delineating the phase state of the DN. Comprehensive in vitro digestion studies revealed that DN8 provided superior sustained release properties, exhibited the highest total antioxidant capacity, and displayed potent inhibitory activities against angiotensin I converting enzyme (ACE) and acetylcholinesterase (Ach-E). Additionally, the DN significantly bolstered the stability of FA against photothermal degradation. Collectively, these findings lay foundational insights for the advancement of the wheat gluten AF-based delivery system for bioactive compounds and provided a theoretical basis for the development of functional foods.

Preparation and Characterization of Chitosan-Modified Bentonite Hydrogels and Application for Tetracycline Adsorption from Aqueous Solution.

The "sol-gel method" was used to prepare spherical chitosan-modified bentonite (SCB) hydrogels in this study. The SCB hydrogels were characterized and used as sorbents to remove tetracycline (TC) from aqueous solutions. The adsorbents were characterized by SEM, XRD, FTIR, TG, and BET techniques. Various characterization results showed that the SCB adsorbent had fewer surface pores and a specific surface area that was 96.6% lower than the powder, but the layered mesoporous structure of bentonite remained unchanged. The adsorption process fit to both the Freundlich model and the pseudo-second-order kinetic model showed that it was a non-monolayer chemical adsorption process affected by intra-particle diffusion. The maximum monolayer adsorption capacity determined by the Langmuir model was 39.49 mg/g. Thermodynamic parameters indicated that adsorption was a spontaneous, endothermic, and entropy-increasing process. In addition, solid-liquid separation was easy with the SCB adsorbent, providing important reference information for the synthesis of SCB as a novel and promising adsorbent for the removal of antibiotics from wastewater at the industrial level.

A simple and universal approach for fabricating bioactive self-stacked hydrogels with enhanced therapeutic efficacy

Despite significant advancements in self-stacked hydrogels of herbal small molecules in recent years, the emergence of new pharmacological small molecule self-stacked hydrogel systems remains largely reliant on serendipity and painstaking efforts. To address this challenge, we proposed a ‘bioactive bivalent metal ions-coordinated pharmacological small molecules’ strategy. This approach enabled the preparation of triterpenoid betulinic acid-based self-stacked hydrogels with excellent injectable and self-healing properties via a simple two-step method. We extended this strategy to self-stacking hydrogels based on other pentacyclic triterpene small molecules, anthraquinone small molecules, flavonoid small molecules and synthetic steroid small molecules. This universal strategy is capable of extracting hydrophobic pharmacological small molecules to construct novel self-stacked biomaterials in a cost-effective, efficient, large-scale, and environmentally friendly manner. Importantly, we successfully synthesized Mg2+-coordinated betulinic acid (BA-Mg) self-stacked hydrogel at low concentrations in the bacterial cellulose (termed BC) hydrogel network, overcoming the mechanical limitations of self-stacked hydrogels for biomedical applications. The BA-Mg/BC hybrid hydrogel demonstrated exceptional biocompatibility, anti-inflammatory, and angiogenic properties, significantly accelerating the skin wound healing process through the synergistic pharmacological effects of Mg2+ and BA.

Engineering the nanozyme hydrogel beads by polyvinyl alcohol/chitosan encapsulation with recyclable and sustainable catalytic activity for visual analysis of hydrogen peroxide

BackgroundHydrogen peroxide (H2O2) plays a vital role in human health and have been regarded as a crucial analyte in metabolic processes, redox transformations, foods research and medical fields. Especially, the long-time and excessive digestion of H2O2 may even cause severe diseases. Although conventional instrumental methods and nanozymes-based colorimetric methods have been developed to accomplish the quantitative analysis of H2O2, the drawbacks of instrument dependence, cost-effectiveness, short lifespan, non-portable and unsustainable detection efficacies will limit their applications in different detection scenarios. ResultsHerein, to address these challenges, we have proposed a novel strategy for nanozyme (RuO2) hydrogel preparation by the solid support from cross-linked polyvinyl alcohol (PVA) and chitosan (CS) to both inherit the dominant peroxidase-like (POD) activity and protect the RuO2 from losing efficacies. Taking advantages from the hydrogel, the encapsulated RuO2 were further prepared as the regularly spherical beads (PCRO) to exhibit the sustainable, recyclable, and robust catalysis. Moreover, the intrinsic color interferences which originated from RuO2 can be avoided by the encapsulation strategy to promote the detection accuracy. Meanwhile, the high mechanical strength of PCRO shows the high stability, reproducibility, and cyclic catalysis to achieve the recyclable detection performance and long lifetime storage (40 days), which enables the sensitively detection of H2O2 with the detection limit as lower to 15 μM and the wide detection linear range from 0.025 to 1.0 mM. SignificanceOn the basis of the unique properties, PCRO has been further adopted to construct a smartphone detection platform to realize the instrument-free and visual analysis of H2O2 in multi-types of milk and real water samples through capturing, processing, and analyzing the RGB values from the colorimetric photographs. Therefore, PCRO with the advanced detection efficacies holds the great potential in achieving the portable and on-site analysis of targets-of-interest.

Preparation and Characterization of Hydrogels Fabricated From Chitosan and Poly(vinyl alcohol) for Tissue Engineering Applications.

In this study, we report on the preparation, characterization, and cytocompatibility of hydrogels for biomedical applications made from two different molecular weights of chitosan (CS) blended with poly(vinyl alcohol) (PVA) and chemically cross-linked with tetraethyl orthosilicate (TEOS) followed by freeze-drying. A series of CS-PVA hydrogels were synthesized with different amounts of chitosan (1%, 2%, and 3% by weight). The structure of these CS-PVA hydrogels was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The hydrogel samples were also characterized for tensile strength, contact angle, swelling behavior, and degradation at physiological body temperature. Their physicochemical properties, biocompatibility, and cell viability when cultured with human dermal fibroblasts were assessed using alamarBlue and live/dead assays and compared to optimize their functionality. SEM analysis showed that the concentration and molecular weight of the chitosan component affected the pore size. Furthermore, the contact angle decreased with increasing chitosan content, indicating that chitosan increased its hydrophilic properties. The in vitro degradation study revealed a nonlinear time-dependent relationship between chitosan concentration or molecular weight, and the rate of degradation was affected by the pore size of the hydrogel. All of the CS-PVA hydrogels exhibited good cell proliferation, particularly with the high molecular weight chitosan samples.

Multifunctional Hydrogel Based on Silk Fibroin Promotes Tissue Repair and Regeneration

AbstractThe creation of functional hydrogels with robust load‐bearing capacity adaptable to complex tissue regeneration remains challenging. Silk fibroin (SF) is a natural biomaterial with excellent mechanical strength and cell adhesion capacity, possessing tremendous potential to solve the aforementioned dilemma. The excellent biodegradability and biocompatibility and the molecular structure with multiple modifiable moieties provide opportunities for the injectability and multifunctionality of hydrogels. Furthermore, the incorporation of other polymers or active ingredients can improve the basic properties, confer biological activities and pharmacological effects, and provide the prerequisites for hydrogels to fulfill specific requirements. Therefore, SF‐based hydrogels are widely applied in tissue repair and regeneration, especially in bone, skin, nerve, liver, myocardium, and cornea, which have effectively addressed the challenges of scaffolds' lack of cell adhesion sites, excessive degradation, as well as the lack of efficient, long‐lasting antimicrobial properties. This review outlines the properties of SF, discusses the types of materials commonly used in the preparation of hydrogels and their characteristics, and describes the current construction methods of SF hydrogels. Simultaneously, recent advancements in applying SF‐based multifunctional hydrogels within biological tissues are explored, with a focus on their role in tissue repair, highlighting the repair mechanism of SF based on bone and skin.

Acid-mediated strategies designed for stretchable and durable polyacrylamide/sodium alginate dual-network hydrogels toward flexible capacitors and wearable sensors

The utilization of acid as a synthesis assistant provides an effective means to regulate the structure of hydrogels, thereby simplifying the design and preparation process of multifunctional hydrogels. However, there remains a dearth of discourse concerning the utilization of this convenient acid-mediated strategy, which possesses the potential to directly govern molecular interactions within gel networks for rational structure and property design. Herein, we describe the preparation of flexible dual-network conductive hydrogels using polyacrylamide (PAM) and sodium alginate (SA) as substrates, driven by the strategy of acid-mediated (HCI, H2SO4, and H2C2O4) in detail for the first time. Especially, the structure-activity relationship of hydrogels was elucidated through a comparative analysis of molecular dynamics (MD) simulations and empirical properties, thereby enhancing the understanding of this field. Furthermore, extensive investigations have been conducted to explore the distinct impacts of acid ions and concentrations. The acid-mediated method exhibits superior versatility and operability compared to the filler modification method, thereby enabling a more convenient acquisition of conductive and robust hydrogels suitable for flexible capacitors and wearable sensors. Consequently, this study presents a straightforward, efficient, and cost-effective universal strategy for targeted functional hydrogel design.

Development of Clindamycin-Releasing Polyvinyl Alcohol Hydrogel with Self-Healing Property for the Effective Treatment of Biofilm-Infected Wounds.

Self-healing hydrogels have good mechanical strength, can endure greater external force, and have the ability to heal independently, resulting in a strong bond between the wound and the material. Bacterial biofilm infections are life-threatening. Clindamycin (Cly) can be produced in the form of a self-healing hydrogel preparation. It is noteworthy that the antibacterial self-healing hydrogels show great promise as a wound dressing for bacterial biofilm infection. In this study, we developed a polyvinyl alcohol/borax (PVA/B) self-healing hydrogel wound dressing that releases Cly. Four ratios of PVA, B, and Cly were used to make self-healing hydrogels: F1 (4%:0.8%:1%), F2 (4%:1.2%:1%), F3 (1.6%:1%), and F4 (4%:1.6%:0). The results showed that F4 had the best physicochemical properties, including a self-healing duration of 11.81 ± 0.34 min, swelling ratio of 85.99 ± 0.12%, pH value of 7.63 ± 0.32, and drug loading of 98.34 ± 11.47%. The B-O-C cross-linking between PVA and borax caused self-healing, according to FTIR spectra. The F4 formula had a more equal pore structure in the SEM image. The PVA/B-Cly self-healing hydrogel remained stable at 6 ± 2 °C for 28 days throughout the stability test. The Korsmeyer-Peppas model released Cly by Fickian diffusion. In biofilm-infected mouse wounds, PVA/B-Cly enhanced wound healing and re-epithelialization. Our results indicate that the PVA/B-Cly produced in this work has reliable physicochemical properties for biofilm-infected wound therapy.

Recent Advances in Hydrogel Technology in Delivering Mesenchymal Stem Cell for Osteoarthritis Therapy.

Osteoarthritis (OA), a chronic joint disease affecting over 500 million individuals globally, is characterized by the destruction of articular cartilage and joint inflammation. Conventional treatments are insufficient for repairing damaged joint tissue, necessitating novel therapeutic approaches. Mesenchymal stem cells (MSCs), with their potential for differentiation and self-renewal, hold great promise as a treatment for OA. However, challenges such as MSC viability and apoptosis in the ischemic joint environment hinder their therapeutic effectiveness. Hydrogels with biocompatibility and degradability offer a three-dimensional scaffold that support cell viability and differentiation, making them ideal for MSC delivery in OA treatment. This review discusses the pathological features of OA, the properties of MSCs, the challenges associated with MSC therapy, and methods for hydrogel preparation and functionalization. Furthermore, it highlights the advantages of hydrogel-based MSC delivery systems while providing insights into future research directions and the clinical potential of this approach.

Preparation of Multifunctional Hydrogels with In Situ Dual Network Structure and Promotion of Wound Healing.

As an emerging biomedical material, wound dressings play an important therapeutic function in the process of wound healing. It can provide an ideal healing environment while protecting the wound from a complex external environment. A hydrogel wound dressing composed of tilapia skin gelatin (Tsg) and fucoidan (Fuc) was designed in this article to enhance the microenvironment of wound treatment and stimulate wound healing. By mixing horseradish peroxidase (HRP), hydrogen peroxide (H2O2), tilapia skin gelatin-tyramine (Tsg-Tyr), and carboxylated fucoidan-tyramine in agarose (Aga), using the catalytic cross-linking of HRP/H2O2 and the sol-gel transformation of Aga, a novel gelatin-fucoidan (TF) double network hydrogel wound dressing was constructed. The TF hydrogels have a fast and adjustable gelation time, and the addition of Aga further enhances the stability of the hydrogels. Moreover, Tsg and Fuc are coordinated with each other in terms of biological efficacy, and the TF hydrogel demonstrated excellent antioxidant properties and biocompatibility in vitro. Also, in vivo wound healing experiments showed that the TF hydrogel could effectively accelerate wound healing, reduce wound microbial colonization, alleviate inflammation, and promote collagen deposition and angiogenesis. In conclusion, TF hydrogel wound dressings have the potential to replace traditional dressings in wound healing.

Evaluation of Antioxidant, Antibacterial and Enzyme-Inhibitory Properties of Dittany and Thyme Extracts and Their Application in Hydrogel Preparation

Evaluation of Antioxidant, Antibacterial and Enzyme-Inhibitory Properties of Dittany and Thyme Extracts and Their Application in Hydrogel Preparation

Preparation of Dual-Network Conductive Hydrogels As Wearable Flexible Strain Sensors Using One-Pot Method and Soaking Strategy

Preparation of Dual-Network Conductive Hydrogels As Wearable Flexible Strain Sensors Using One-Pot Method and Soaking Strategy

A green, ROS-scavenging and anti-bacterial hydrogel loading MnO2-curcumin nanocomposite for the full-thickness wound healing

Recently, nanozymes have been widely applied for the enhancement of reactive oxygen species (ROS) and hypoxia, which is a major obstacle to the quick repairing of skin wound. However, their intrinsic low bioavailability and biosafety is still a great challenge for the broad introduction in the wound healing. Meanwhile, the fabrication of hydrogel wound dressing mostly accompany the complicated polymer modification, synthetic polymer usage and following pollution and health risk. Nanocellulose (CNC) has been remarked as a good candidate for functional hydrogel dressing, however, its role is generally confined to a simple mechanical reinforce or Schiff base participant in the oxidized form. With this regards, in the present paper, we first developed a ROS-scavenging, MnO2-curcumin nanocomplex stabilized by bovine serum albumin (BSA) (called BMC NPs). Dopamine was oxidative polymerized on the nanocellulose chain to form the CNC-polydopamine (CNC-PDA) in a facile way, and cross-linked quickly with thiol-fortified gelatin (Gel-SH) via the catechol-thiol addition to produce the adhesive, self-healing and hemostatic hydrogel. The CNC-PDA + Gel-SH hydrogel loading BMC NPs showed an excellent anti-oxidant, and anti-bacterial capacity. In vivo full-thickness wound experiment also confirmed that CNC-PDA + Gel-SH + BMC NPs hydrogel has a good re-epithelization, collagen synthesis, ROS clearance and anti-inflammation with the NIR treatment. Our result demonstrates the promising effect of nanocomposite -biomolecule conjugate in the wound healing as well as the great potential of PDA-coating chemistry in the hydrogel preparation.

Preparation of a high-performance conductive lignocellulose hydrogel by directly using non-detoxified bisulfite-pretreated corncob

Biomass-based hydrogels have become a research hotspot because of their better biocompatibility. However, the preparation of biomass hydrogels is complicated, and they often need to be modified by introducing other substances. In this study, corncob pretreated with bisulfite (125–185 °C) was used as a raw material to prepare lignocellulose hydrogels. The results showed that directly using the pretreated sample without the washing step lowered the total hydrogel costs while preserving the lignosulfonate (LS) produced during pretreatment. The best tensile (54.1 kPa) and compressive (177.7 kPa) stresses were obtained for the hydrogel prepared from non-detoxified pretreated corncob at 165 °C (NCH-165). The sulfonic acid groups in LS could enhance the interaction between plant cellulose, thus improving its mechanical properties. The capacitor assembled from NCH-165 achieved an energy density of 236.1 Wh/kg at a power density of 499.7 W/kg and a high coulombic efficiency of more than 99 % after 2000 charge/discharge cycles. In conclusion, the present study simplifies the pathway for the preparation of flexible, conductive, and anti-freezing hydrogels by directly utilizing a non-detoxified bisulfite-pretreated corncob.

Preparation of High-Performance Barium Titanate Composite Hydrogels by Deep Eutectic Solvent-Assisted Frontal Polymerization.

This study aimed to develop composite hydrogels with exceptional piezoelectric properties and pressure sensitivity. To achieve the objective, this study created a deep eutectic solvent (DES) by mixing choline chloride (ChCl), acrylamide (AM), and acrylic acid (AA). Barium titanate nanoparticles (BTNPs) were incorporated as fillers into the deep eutectic solvents (DES) to synthesize the composite hydrogels using frontal polymerization (FP). The mechanical and piezoelectric properties of the resulting composite hydrogels were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). This study found that the BTNPs/P(AM-co-AA) composite hydrogels exhibited excellent mechanical and piezoelectric properties. This is attributed to the high dielectric constant of BTNPs and the electrode polarization phenomenon when subjected to pressure. With a BTNPs content of 0.6 wt%, the maximum compressive strength increased by 3.68 times compared with the hydrogel without added BTNPs. Moreover, increasing the BTNPs content to 0.6 wt% resulted in a 1.48 times increase in generated voltage under the same pressure, compared with the hydrogel with only 0.2 wt% BTNPs. This study provides a method for preparing composite hydrogels with outstanding piezoelectric properties and pressure sensitivity.

Properties of Chitin and Its Regenerated Hydrogels from the Insect Zophobas morio Fed Citrus Biomass or Polystyrene.

The potential of insects as a recycling tool has recently attracted attention. In this study, chitin was extracted with 1 M HCl for 24 h at 20 °C, followed by 1 M NaOH for 5 h at 90 °C, and bleached with 2.5% v/v NaOCl for 2 h at 20 °C from Zophobas morio (ZM) insects fed citrus waste biomass (OP) or polystyrene foam (PS). The highest survival rate was found in the OP group. The properties of the resulting chitin material are reported, as well as the preparation of hydrogels using a DMAc/LiCl solvent. All chitins obtained were α-chitin. The degrees of deacetylation, crystallinity, molecular weight, and solubility in DMAc/LiCl were similar between the PS and biomass feeds, and they showed similar viscosities in the DMAc/LiCl solution. All hydrogels obtained had similar properties and viscoelastic behavior, indicating that the resultant chitins and their hydrogels from ZM were similar between those fed with citrus biomass and those fed with PS.