Preparation Of Hydrogels Research Articles

Scalable Preparation of Polyzwitterionic Hydrogels Based on Hydration Shielding‐Accelerated Redox Self‐Catalytic Polymerization (HS‐A‐RP)

Traditional synthesis methods for polyzwitterionic hydrogels involve harsh conditions, such as thermal or UV irradiation, prolonged durations, and high monomer concentrations. Herein, we address these challenges at the meantime by proposing a novel chemical method, called hydration‐shielding accelerated self‐catalytic polymerization (HS‐A‐RP), facilitating the preparation of polyzwitterionic hydrogels. The discovery is that polyvinyl alcohol (PVA) chains can generate hydration shielding around hydrated zwitterionic monomers, promoting their effective aggregation and rapid crosslinking polymerization under the assistance of silver ions (Ag+)‐potassium persulfate (S2O82‐) redox catalyst. The HS‐A‐RP method performs under mild condition (‐5℃ to 37℃) without extra energy, overcomes the critical monomer polymerization concentration limitation (wt%: 0.3%), and completes within an ultra‐short polymerization time (<60 s). The prepared polyzwitterionic hydrogels possesses a denser network and superior mechanical properties compared to those prepared by traditional thermal/UV methods, exhibiting good anti‐swelling behavior, excellent lubrication performance, and significant antibacterial and anti‐fouling properties. These significant advances endow HS‐A‐RP with attractive application potentials in manufacturing functional hydrogel coatings for biomedical device, in situ encapsulation of thermally sensitive materials, and excellent sand fixation abilities. Moreover, HS‐A‐RP method is suitable for scalable manufacture and decorative coating of polyzwitterionic hydrogels on diverse substrates in extreme environmental conditions.

Scalable Preparation of Polyzwitterionic Hydrogels Based on Hydration Shielding-Accelerated Redox Self-Catalytic Polymerization (HS-A-RP).

Traditional synthesis methods for polyzwitterionic hydrogels involve harsh conditions, such as thermal or UV irradiation, prolonged durations, and high monomer concentrations. Herein, we address these challenges at the meantime by proposing a novel chemical method, called hydration-shielding accelerated self-catalytic polymerization (HS-A-RP), facilitating the preparation of polyzwitterionic hydrogels. The discovery is that polyvinyl alcohol (PVA) chains can generate hydration shielding around hydrated zwitterionic monomers, promoting their effective aggregation and rapid crosslinking polymerization under the assistance of silver ions (Ag+)-potassium persulfate (S2O82-) redox catalyst. The HS-A-RP method performs under mild condition (-5℃ to 37℃) without extra energy, overcomes the critical monomer polymerization concentration limitation (wt%: 0.3%), and completes within an ultra-short polymerization time (<60 s). The prepared polyzwitterionic hydrogels possesses a denser network and superior mechanical properties compared to those prepared by traditional thermal/UV methods, exhibiting good anti-swelling behavior, excellent lubrication performance, and significant antibacterial and anti-fouling properties. These significant advances endow HS-A-RP with attractive application potentials in manufacturing functional hydrogel coatings for biomedical device, in situ encapsulation of thermally sensitive materials, and excellent sand fixation abilities. Moreover, HS-A-RP method is suitable for scalable manufacture and decorative coating of polyzwitterionic hydrogels on diverse substrates in extreme environmental conditions.

The effectiveness test of film forming hydrogel (FFH) of Yellow Root Extract (Arcangelisia flava (L.) Merr) on healing burns of male white mice (Mus Musculus)

The Burns are conditions where skin tissue is lost due to direct contact with heat energy. Therefore, a preparation was developed as film forming hydrogel (FFH) from yellow root extract. Yellow roots contain alkaloids, flavonoids, and saponins, which can improve wound healing. This study aims to determine the effect of the concentration of yellow root extract on wound diameter percentage and increasing the number of fibroblast cells and epithelial thickness. This research uses a true experimental laboratory with a design pre-post test study method on mice aged 2-3 months weighing 20-35 g. Samples were taken using a random sampling technique and divided into five treatment groups, namely formula 1 (F1) with 0.5% yellow root extract, formula 2 (F2) with 1% yellow root extract (F2), formula 3 (F3) with 1.5% yellow root extract, bioplacentonÒ (positive control), normal saline 0.9% (negative control). Treatment of mice for 14 days. The observation parameters were measuring the diameter of the burn wound using the Morton method and the percentage of burn wound healing. The number of fibroblast cells and epithelial thickness were observed at 400x magnification by taking five fields of view in a zig-zag manner. This research shows that the film forming hydrogel (FFH) preparations from yellow root extract with a 1.5% yellow root extract (F3) are the most effective for healing burn wounds. This can be seen from the diameter of the wound, the percentage of wound healing, the increase in fibroblasts, and the thickness of the epithelium.

Preparation and Characterization of Dual-Network Multifunctional Hydrogels Based on Peach Gum Polysaccharides: Ultrafast Self-Healing Ability, Favorable Mechanical Tunability, and Controlled Release Properties

Natural hydrogels have attracted considerable attention due to advantages of moisturizing, biocompatibility, and plasticity. In this study, a dual-network oxidized peach gum polysaccharide–carboxymethyl chitosan (OPGC) hydrogels with ultrafast self-healing ability was constructed by self-assembly using oxidized peach gum polysaccharide (OPGP) and carboxymethyl chitosan (CMCS). After complete fracture, OPGC hydrogels rapidly self-healed within 30 s due to the dual-network structure formed by the hydrogen bonds between the OPGP molecules and the Schiff base bonds between them and the CMCS. Meanwhile, the hydrogels exhibited good injectability and biocompatibility. With the increase of CMCS from 0.5 wt% to 2.5 wt%, the gel formation time of OPGC hydrogels was drastically shortened from 12 min to 3 min, while the strength and water-holding capacity were enhanced. Furthermore, experimental in vitro and in vivo animal studies demonstrated excellent drug loading capacity of OPGC hydrogels, and the release rate of bactericide could be controlled by adjusting the content of CMCS. The OPGC hydrogels have outstanding properties for potential applications in the health and medical fields.

Dendrimers-Based Hydrogels and Nanogels for Drug Delivery

Abstract: Current developments in nanotechnology provide an alternative therapy for various diseases by utilizing customized medicine. Among some of the nanoscale superstructures made of the hydrophilic or amphiphilic polymeric matrix are nanogels. At the same time, hydrogels are the first biomaterials created for insertion into the human body and have several biological uses. Owing to the advantages of nanogels and hydrogel, including biocompatibility, hydrophilicity, controlled drug release, and intelligent drug delivery, another macromolecule called dendrimer is incorporated into the nanogel and hydrogel for synergistic effects. In this review, we focus on the applications of dendrimer-based hydrogels and nanogels as carriers for targeted delivery of drugs. We also present the synthetic processes, different characterization methods, and challenges in incorporating the dendrimer and the drug during the preparation of nanogel and hydrogel. In recent years, the most widely used dendrimers for hydrogel formation have been reported to be poly(amidoamine) (PAMAM), phosphorous, peptide, and polyester dendrimers. Dendrimer-based hydrogel and nanogels show various applications in the treatment of a wide range of diseases, such as glaucoma, cancer, and microbial diseases. The self-cleaving mechanism of dendrimer hydrogels (DH) leads to enhanced and sustained delivery of the drugs in the treatment of cancer. Recent studies show the use of doxorubicinconjugated nanogel-based PAMAM dendrimer as a capable nanocarrier for the delivery of drugs in the treatment of cancer.

Hybrid three-dimensional printing and encapsulation process for cellulose hydrogel sensors.

Hybrid three-dimensional printing and encapsulation process for cellulose hydrogel sensors.

Effect of light shielding on the photoinhibition of nitrifying bacteria immobilized on a light-shielding hydrogel.

Microalgae-nitrifying bacterial consortia have attracted attention as energy-efficient nitrogen removal methods that do not require aeration. However, the photoinhibition of nitrifying bacteria is a hurdle to their practical application. We have developed a 'light-shielding hydrogel' that mitigates the photoinhibition of nitrifying bacteria, and it demonstrated the performance of high ammonia removal even under strong light irradiation. However, the effect of carbon black (CB) concentration in hydrogel and its optimization have not yet been examined. In this study, the light-shielding effect was evaluated by measuring the light transmitted through a light-shielding hydrogel layer and comparing the experimental and theoretical values. Increasing the CB concentration from 0.1 to 0.5% effectively reduced the light transmission from 13 to 2.5% at a thickness of 1 mm. The actual nitrification activity and the theoretical activity determined from the light transmission were close in the range of 900-1,600 μmol photons m-2 s-1 of irradiated light intensity. Based on these results, the theoretical predictions obtained in this study may contribute to the prediction of photoinhibition mitigation. Therefore, it is expected to provide suitable conditions for optimizing the preparation of light-shielding hydrogels and pave the way for their application in outdoor wastewater treatment processes.

Nanozymes meet hydrogels: Fabrication, progressive applications, and perspectives.

Nanozymes meet hydrogels: Fabrication, progressive applications, and perspectives.

Fast fabrication of stimuli-responsive MXene-based hydrogels for high-performance actuators with simultaneous actuation and self-sensing capability.

Fast fabrication of stimuli-responsive MXene-based hydrogels for high-performance actuators with simultaneous actuation and self-sensing capability.

A carboxymethyl chitosan /trans-2-hexenal Schiff's base gel with controlled density using dynamic imine bonds: pH-controlled release and extended duration.

A carboxymethyl chitosan /trans-2-hexenal Schiff's base gel with controlled density using dynamic imine bonds: pH-controlled release and extended duration.

All-in-one: Harnessing multifunctional natural polysaccharide spray hydrogel loaded with polyphenol-metal nanoparticles for fruit preservation.

All-in-one: Harnessing multifunctional natural polysaccharide spray hydrogel loaded with polyphenol-metal nanoparticles for fruit preservation.

Transdermal Film-Forming Hydrogel Loaded with Nigella Sativa and Trigonella foenum-graecum Extracts for Enhanced Wound Healing

Topical wound treatment using conventional hydrogels is easily lost due to friction so that treatment is less effective, this can inhibit wound healing which causes chronic wounds. Convensional hydrogel containing a combination of N. sativa and T. foenum-graecum alcohol extracts at concentrations of 10% and 5% showed that the preparation was able to healing process of burns in diabetic rats better than single extracts. Compared to conventional preparations, topical Film Forming Hydrogel (FFH) preparation is capable of forming thin sheets some time after applications. A good FFH preparation has strong adhesion and can be adjusted to the shape of the wound so that it is expected to increase the effectiveness of wound healing, including wounds in patients with diabetes mellitus. This study aimed to formulate FFH preparation containing active ingredient combination of Nigella sativa L. and Trigonella foenum-graecum L. extract. The combination of polyvinyl alcohol (PVA) and carboxymethyl chitosan (CMCh) was used as base, while 96% ethanol and a variation of propylene glycol (PG) content served as solvent and plasticizer, respectively. The experiment was carried out to obtain FFH preparation with desired physical, chemical, and mechanical characteristics, including pH, viscosity, swelling ratio, tensile strength, and elongation. Furthermore, homogeneity of the preparation was assessed through the analysis of Fourier Transform Infrared (FITR) Spectroscopy functional groups, and the stability of physicochemical characters was determined during a 30-day storage period. The results showed that all variations of PG levels of 10%, 16%, and 22% in the test formulations met the physicochemical, and mechanical requirements of FFH preparation. Only F1-Extract meets the minimum standard of 70% for the elongation parameter, and could release the drug gradually. The FFH formulation with active ingredients of N. sativa extract of 10%, T. foenum-graecum of 5%, PG content of 10% (F2-Extract), with a combination of PVA-CMCh at a ratio of 1:1 of 43% each, and 96% ethanol of 4% produced an optimal FFH preparation. Stability test results showed that F2-E and F3-E also had stable pH, viscosity, and swelling ratio at 30 days of storage.

Review: Advances in multifunctional hydrogels based on carbohydrate polymer and protein in the treatment of diabetic wounds.

Review: Advances in multifunctional hydrogels based on carbohydrate polymer and protein in the treatment of diabetic wounds.

Review on the Preparation and Performance of Polyacrylamide-Based Composite Hygroscopic Hydrogels for Atmospheric Water Harvesting

With the rapid global economic development and population growth, the shortage of freshwater resources has become increasingly severe. Particularly in arid and semi-arid regions, the scarcity of freshwater poses a serious threat to local economic development and residents' lives. Therefore, the development of efficient water collection technologies is particularly important. Atmospheric Water Harvesting (AWH) technology, as an innovative method for obtaining water resources, has received extensive attention in recent years. This technology converts water vapor from the air into liquid water, providing a new approach to solving the problem of freshwater shortage. Among various AWH technologies, adsorption-based atmospheric water harvesting stands out due to its low energy consumption and wide applicability. This technology utilizes hygroscopic materials to adsorb water vapor from the air and release it for collection using low-grade energy sources such as solar energy. Polyacrylamide-based composite hygroscopic hydrogels, as a novel type of hygroscopic material, exhibit great potential in the field of adsorption-based atmospheric water harvesting due to their excellent hygroscopic and photothermal conversion properties. This review summarizes the preparation methods, performance characteristics, and research progress of polyacrylamide-based composite hygroscopic hydrogels in atmospheric water harvesting.

New Trends in Preparation and Use of Hydrogels for Water Treatment

Hydrogel-based wastewater treatment technologies show certain outstanding features, which include exceptional efficiency, sustainability, reusability, and the precise targeting of specific contaminants. Moreover, it becomes possible to minimize the environmental impact when using these materials. Their flexibility, low energy consumption, and adaptability to meet specific requirements for different purposes offer significant advantages over traditional methods like activated carbon filtration, membrane filtration, and chemical treatments. Recent advancements in hydrogel technology, including new production methods and hybrid materials, enhance their ability to efficiently adsorb contaminants without altering their biocompatibility and biodegradability. Therefore, innovative materials that are ideal for sustainable water purification were developed. However, these materials also suffer from several limitations, mostly regarding the scalability, long-term stability in real-world systems, and the need for precise functionalization. Therefore, overcoming these issues remains a challenge. Additionally, improving the efficiency and cost-effectiveness of regeneration methods is essential for their practical use. Finally, assessing the environmental impact of hydrogel production, use, and disposal is crucial to ensure these technologies are beneficial in the long run. This review summarizes recent advancements in developing polymer-based hydrogels for wastewater treatment by adsorption processes to help us understand the progress made during recent years. In particular, the studies presented within this work are compared from the point of view of the synthesis method, raw materials used such as synthetic/natural or hybrid networks, and the targeted class of pollutants—dyes or heavy metal ions. In several sections of this paper, discussions regarding the most important properties of the newly emerged adsorbents, e.g., kinetics, the adsorption capacity, and reusability, are also discussed.

Biocomposite Complex Hydrogels With Antimicrobial Activity Suitable for Wound Healing

ABSTRACTSkin defects caused by injuries such as burns that exceed a certain diameter no longer heal spontaneously and require more complex interventions. Hydrogels have received special attention due to their unique ability to block the penetration of bacteria into wounds as they can absorb contaminated exudates and exhibit a high degree of flexibility. This study is focused on the preparation and characterization of novel antibacterial biocomposite hydrogels based on two carbohydrates, alginate and hyaluronic acid (HA), with immobilized ZnO NPs and curcumin‐loaded electrospun nanofibers to improve the efficacy of the wound healing process. The hydrogel matrix was obtained after crosslinking HA and alginate in the presence of the DMT‐MM activator. Hydrogels were physicochemically characterized by FT‐IR, scanning electron microscopy (SEM), UV–Vis spectroscopy, and the swelling degree was also investigated. It appeared that the swelling behavior of the biocomposite hydrogels was influenced by the amount of ZnO NPs and by the presence of nanofibers. Biodegradability, hemolysis, cell viability, antimicrobial, and in vitro irritability tests were carried out to assess their biological properties. The obtained results highlighted that these hydrogels are biodegradable, hemocompatible, non‐cytotoxic, and non‐irritating and have good antimicrobial activity. Based on the obtained results, these materials might be interesting candidates for wound healing treatment.

Smart hydrogel: A new platform for cancer therapy.

Smart hydrogel: A new platform for cancer therapy.

The Effect of the Conformation Process on the Physicochemical Properties of Carboxymethylcellulose-Starch Hydrogels.

This study discusses the preparation of biopolymeric hydrogels (a biomaterial) via different techniques, such as casting and extrusion, to compare the effects of the process and the use of citric acid as a crosslinker on the morphology, physicochemical properties, and degree of swelling of the hydrogel. Casting is widely used for its low cost and space-saving nature, but upscaling is problematic. Extrusion offers a way to produce materials in large quantities; these materials can undergo mechanical and thermal energy, which can significantly alter their properties. The samples obtained by extrusion had porous surfaces, which are critical for the water penetration and swelling of superabsorbent hydrogels. In contrast, the hydrogels produced by casting did not form pores, resulting in a lower degree of swelling. Extrusion increased the degree of swelling threefold due to the formation of pores, influencing water absorption and diffusion dynamics, especially in samples with higher starch content, where crosslinking occurred more effectively.

Standardisation of Vitexin and Isovitexin in Ficus deltoidea var. Kunstleri (FDK) Extract and Anti-Hyperlipidaemic Properties of FDK Hydrogel in High Cholesterol Diet-Induced Early and Established Atherosclerosis Rabbits

Hyperlipidaemia is a major risk factor for cardiovascular disease (CVD) due to its role in forming atherosclerotic plaques. Finding natural products with anti-hyperlipidaemic properties is important for preventing atherosclerosis. Ficus deltoidea var kunstleri extract (FDK) is traditionally used to regulate blood glucose and blood pressure, however its effect on lowering lipid is scarce. Previous study showed neutral effects of FDK extract on lipids. Hydrogel delivery is commonly used to enhance absorption of active compounds therefore enhancing their therapeutic effect. This study aimed to develop a FDK hydrogel from standardised FDK extract and evaluate its effectiveness in lowering lipids and atherogenic index (AI) in high cholesterol (HC)-induced-early and established atherosclerosis rabbits. Standardised FDK extract against vitexin and isovitexin was produced according to a standard guideline using Liquid chromatography-tandem mass spectrometry (LCMS/MS) method prior to the preparation of FDK hydrogel (FDKH). Forty-rabbits were fed with 1 % high cholesterol diet for 4 and 8 weeks to induce early and established atherosclerosis, respectively. Each group was subdivided into 4 intervention arms: 1) FDKH 125 mg/kg; 2) FDKH 250 mg/kg; 3) Simvastatin 5 mg/kg; and 5) placebo for 8 weeks. Lipid profile and atherogenic index (AI) were measured at the baseline (B0), post-HC diet and post-treatment in both early and established atherosclerosis rabbits. Quantitative analysis of FDK using LC-MS/QQQ reveals the presence of 3.5 ± 0.04 mg/g of vitexin and 3.1 ± 0.8 mg/g isovitexin, respectively. In the early atherosclerotic group, at week 12, all treatment groups showed significant reductions in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) compared to week 4. The reductions varied by treatment type. FDKH 250 mg/kg resulted in the highest reductions in TC and LDL-C, followed by FDKH 125 mg/kg and simvastatin, which is still higher than placebo. Interestingly, simvastatin led to the greatest reduction in TG, followed by FDKH 125 mg/kg and FDKH 250 mg/kg. In the established atherosclerotic group, FDKH 250 mg/kg again demonstrated the highest reductions in TC, LDL-C and TG levels, confirming its efficacy in more advanced stages of atherosclerosis. Both FDKH dosages significantly improved AI compared to the placebo, with FDKH 250 mg/kg showing the lowest AI value. These findings suggest that FDKH, particularly at the 250 mg/kg dosage, is highly effective in reducing lipid levels and improving AI, indicating its potential as a potent alternative to traditional treatments like simvastatin. Further clinical trials are warranted to confirm these results and explore the long-term effects and safety of FDKH in humans. In conclusion, FDKH have significant potential to mitigate serum lipid and atherogenesis in both early and established atherosclerosis rabbits. This advancement represents a promising adjunct treatment option, offering a natural and effective solution for hyperlipidaemia. HIGHLIGHTS Ficus deltoidea var kunstleri (FDK) extract was successfully standardised using a validated LC-MS/QQQ method against 2 major bioactive components, vitexin and isovitexin. Treatment with FDK hydrogel (FDKH) led to a significant reduction of TC, LDL and TG and atherogenic index in high cholesterol-induced-early and established atherosclerosis rabbits. FDKH have significant potential to mitigate serum lipid and atherogenesis in both early and established atherosclerosis rabbits. This study suggests a promising adjunct treatment option of FDKH, offering a natural and effective solution for hyperlipidaemia. GRAPHICAL ABSTRACT

Tough, highly conductive and frost-resistant chitosan based hydrogel for flexible sensor.

Tough, highly conductive and frost-resistant chitosan based hydrogel for flexible sensor.