Carolina Buitrago-Arias, Piedad Gañán-Rojo, Mabel Torres-Taborda
et al.
Feeding a growing population under the pressures of climate change requires solutions that safeguard yields while strengthening agricultural resilience. Integrated Crop Management (ICM)—which combines precise fertilization, efficient water use, and targeted pest control—offers a promising framework. Hydrogels, with their water retention and controlled release properties, can enhance ICM by improving fertilizer efficiency, reducing water loss, and supporting soil health. Despite extensive research, their optimal use in agriculture remains unclear, and limitations continue to restrict large-scale adoption. To address this gap, this study applies the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology alongside bibliometric analysis to examine hydrogel applications in ICM from 2000 to 2024. Ninety Scopus-indexed publications were analyzed across four domains: pesticides, nutritional growth inputs, soil conditioners, and bioactive substances. The results reveal a marked increase in hydrogel structural complexity, greater diversity in characterization methods, ongoing reliance on high-impact pesticides despite advances in bio-based hydrogels, and persistent gaps in assessing environmental impacts and regulatory compliance. These findings underscore the need for stronger collaboration between academia and industry to translate hydrogel research into effective, sustainable agricultural practices under changing climatic conditions.
Hydrogel microneedles (HMNs) have emerged as a transformative platform for minimally invasive drug delivery and biosensing, offering enhanced bioavailability, controlled drug release, and real-time biomarker detection. By leveraging swelling hydrogels, nanomaterial integration, and stimuli-responsive properties, HMNs provide precision medicine capabilities across diverse therapeutic and diagnostic applications. However, challenges remain in mechanical stability, as hydrogel-based MNs must balance flexibility with sufficient strength for skin penetration. Drug retention and controlled release require optimization to prevent premature diffusion and ensure sustained therapeutic effects. Additionally, biosensing accuracy is influenced by variability in interstitial fluid extraction and signal transduction. Clinical translation is hindered by regulatory hurdles, scalability concerns, and the need for extensive safety validation in human trials. This review critically examines the key materials, fabrication techniques, functional properties, and testing frameworks of HMNs while addressing these limitations. Furthermore, we explore future research directions in smart wearable MNs, AI-assisted biosensing, and hybrid drug–device platforms to optimize transdermal medicine. Overcoming these barriers will drive the clinical adoption of HMNs, paving the way for next-generation patient-centered therapeutics and diagnostics.
Oral administration remains the most patient-friendly drug delivery route, yet its efficacy is limited by physiological barriers including gastric degradation and inefficient cellular uptake. pH-responsive nanogels have shown promise for gastrointestinal drug delivery, though their effectiveness is often constrained by poor membrane interaction. Inspired by natural membrane-anchoring mechanisms, a series of comb-like anionic polymers were designed via grafting alkylamines of different chain lengths (C<sub>10</sub>, C<sub>14</sub>, C<sub>18</sub>) at varying densities (10–30%) onto a biodegradable poly(L-lysine isophthalamide) (PLP) backbone. These pH-responsive comb-like polymers self-assembled into nanogels for loading the hydrophobic chemotherapeutic agent camptothecin. The alkyl length and grafting density significantly influenced pH-responsive behavior, membrane disruption, and drug release profiles. The optimal formulation—the nanogel prepared with PLP grafted 30% C<sub>14</sub>—achieved a high drug-loading capacity, ideal particle size and stability, and offered superior protection in acidic conditions (only 7 ± 5% release at pH 1.2 over 24 h), while enabling rapid intestinal release (78 ± 2% at pH 7.4 within 24 h). The nanogels significantly enhanced cellular uptake, cytoplasmic delivery, and cytotoxicity against colorectal carcinoma cells. This study demonstrates the key role of hydrophobic modification in designing effective oral nanocarriers, providing a promising platform for the treatment of intestinal diseases.
Hydrogels exhibit remarkable physicochemical properties, including high water absorption and retention capacities, as well as controlled release behavior. Their inherent biodegradability, biocompatibility, and non-toxicity make them suitable for a wide range of applications. Cellulose, a biodegradable, renewable, and abundantly available polysaccharide, is a viable source for hydrogel preparation. Ionizing radiation, using electron-beam (EB) or gamma (γ) irradiation, provides a promising approach for synthesizing hydrogels. This study reviews recent advancements in cellulose-based hydrogels, focusing on cellulose and its derivatives, brief information regarding ionizing radiation, comparison between EB and γ-irradiation, synthesis and modification through ionizing radiation technology, and their environmental and agricultural applications. For environmental remediation, these hydrogels have demonstrated significant potential in water purification, particularly in the removal of heavy metals, dyes, and organic contaminants. In agricultural applications, cellulose-based hydrogels function as soil conditioners by enhancing water retention and serving as carriers for agrochemicals.
Achilleas Kechagias, Areti A. Leontiou, Yelyzaveta K. Oliinychenko
et al.
In this study, aligned with the principles of the circular economy and sustainability, novel eugenol@natural zeolite (EG@NZ) and citral@natural zeolite (CT@NZ) nanohybrids were developed. These nanohybrids were successfully incorporated into a pork gelatin (Gel)/glycerol (Gl) composite matrix using an extrusion–compression molding method to produce innovative active packaging films: Gel/Gl/xEG@NZ (where x = 5, 10, and 15%wt.) and Gel/Gl/xCT@NZ (where x = 5 and 10%wt.). All films exhibited zero oxygen barrier properties. Release kinetic studies showed that both EG@NZ and CT@NZ nanohybrids adsorbed up to 58%wt. of their respective active compounds. However, EG@NZ exhibited a slow and nearly complete release of eugenol, whereas CT@NZ released approximately half of its citral content at a faster rate. Consequently, the obtained Gel/Gl/xEG@NZ films demonstrated significantly higher antioxidant activity as measured by the 2,2-diphenyl-1-picrylhydrazylradical (DPPH) assay and superior antibacterial effectiveness against <i>Escherichia coli</i> and <i>Listeria monocytogenes</i> compared to their CT-based counterparts. Overall, the Gel/Gl/xEG@NZ films show strong potential for applications as active pads for fresh pork ham slices, offering zero oxygen permeability, enhanced antioxidant and antibacterial properties, and effective control of total viable count (TVC) growth, maintaining a low and steady rate beyond the 10th day of a 26-day storage period.
<i>Cutibacterium acnes</i> is linked to the prevalent inflammatory skin disorder known as Acne Vulgaris (AV). Some topical agents exhibit unfavorable side effects like dryness and skin inflammation, and antimicrobial resistance (AMR) poses an increasing risk to effective AV management. This study develops and characterizes stable topical essential oil (EO)-loaded microemulgels with in vitro validated antimicrobial activities against <i>C. acnes</i> ATCC 6919, providing a solid scientific basis for their effectiveness. These microemulgels, with their potential to serve as an alternative to AMR-prone synthetic agents, could revolutionize the field of acne treatment. The MICs of the EOs (citronella, tea tree, and lemongrass) against <i>C. acnes</i> were determined. EO-loaded microemulgels were developed using a blend of microemulsion and carbopol/hyaluronic acid gel in a ratio of 1:1 and characterized, and their stability was observed over three months. The MICs of citronella, tea tree, and lemongrass EOs were 0.08, 0.16, and 0.62% <i>v</i>/<i>v</i>, respectively. The microemulgels were whitish and smooth, with characteristic EO odors. They demonstrated pH values ranging between 4.81 ± 0.20 and 5.00 ± 0.03, good homogeneity, a spreadability of 9.79 ± 0.6 and 12.76 ± 0.8 cm<sup>2</sup>, a viscosity of 29,500 and 31,130 cP, and retained stability at 4, 25, and 40 °C. EO-loaded microemulgels were developed with the potential of <i>C. acnes</i> management. The formulation shows adequate potential for further pharmaceutical development towards translational adoption in acne management.
Wiriya Charoenchokpanich, Pratchaya Muangrod, Sittiruk Roytrakul
et al.
Due to its excellent biocompatibility and ease of biodegradation, jellyfish gelatin has gained attention as a hydrogel. However, hydrogel produced from jellyfish gelatin has not yet been sufficiently characterized. Therefore, this research aims to produce a jellyfish gelatin-based hydrogel. The gelatin produced from desalted jellyfish by-products varied with the part of the specimen and extraction time. Hydrogels with gelatin: glutaraldehyde ratios of 10:0.25, 10:0.50, and 10:1.00 (<i>v</i>/<i>v</i>) were characterized, and their cefazolin release ability was determined. The optimal conditions for gelatin extraction and chosen for the development of jellyfish hydrogels (JGel) included the use of the umbrella part of desalted jellyfish by-products extracted for 24 h (WU24), which yielded the highest gel strength (460.02 g), viscosity (24.45 cP), gelling temperature (12.70 °C), and melting temperature (22.48 °C). The quantities of collagen alpha−1(XXVIII) chain A, collagen alpha−1(XXI) chain, and collagen alpha−2(IX) chain in WU24 may influence its gel properties. Increasing the glutaraldehyde content in JGel increased the gel fraction by decreasing the space between the protein chains and gel swelling, as glutaraldehyde binds with lateral amino acid residues and produces a stronger network. At 8 h, more than 80% of the cefazolin in JGel (10:0.25) was released, which was higher than that released from bovine hydrogel (52.81%) and fish hydrogel (54.04%). This research is the first report focused on the production of JGel using glutaraldehyde as a cross-linking agent.
Cultivated meat, also known as cell-based or clean meat, utilizes mesenchymal stem cells to cultivate mature cell types like adipocytes, which are pivotal for imparting the desired taste and texture. The delivery of differentiated cells, crucial in cultivated meat production, is facilitated through extensive exploration of 3D culturing techniques mimicking physiological environments. In this study, we investigated the adipogenic differentiation potential of bovine umbilical cord stem cells (BUSCs), sourced from discarded birth tissue, and assessed the feasibility of delivering differentiated cells for cultivated meat using gelatin methacrylate (GelMA) as a carrier for adipose tissue. Various adipogenic inducers, previously reported to be effective for human mesenchymal stem cells (hMSCs), were evaluated individually or in combination for their efficacy in promoting the adipogenesis of BUSCs. Surprisingly, while the traditional adipogenic inducers, including insulin, dexamethasone, isobutylmethylxantine (IBMX), indomethacin, and rosiglitazone, showed no significant effect on the adipogenic differentiation of BUSCs, efficient differentiation was achieved in the presence of a fatty acid cocktail. Furthermore, we explored methods for the delivery of BUSCs. Differentiated cells were delivered either encapsulated in GelMA hydrogel or populated on the surface of GelMA microparticles (MPs) as the adipose component of cultivated meat. Our findings reveal that after adipogenic induction, the lipid production per cell was comparable when cultured either within hydrogel or on MPs. However, GelMA-MPs supported better cell growth compared to hydrogel encapsulation. Consequently, the overall lipid production is higher when BUSCs are delivered via GelMA-MPs rather than encapsulation. This study not only systematically evaluated the impact of common adipogenic inducers on BUSCs, but also identified GelMA-MPs as a promising carrier for delivering bovine adipocytes for cultivated meat production.
As the market for plant-based meat analogs grows, the development of plant-based animal fat analogs has become increasingly important. In this study, we propose an approach by developing a gelled emulsion based on sodium alginate, soybean oil (SO), and pea protein isolate. Formulations containing 15% to 70% (<i>w</i>/<i>w</i>) SO were successfully produced without phase inversion. The addition of more SO resulted in pre-gelled emulsions with a more elastic behavior. After the emulsion was gelled in the presence of calcium, the color of the gelled emulsion changed to light yellow, and the formulation containing 70% SO exhibited a color most similar to actual beef fat trimming. The lightness and yellowness values were greatly influenced by the concentrations of both SO and pea protein. Microscopic images revealed that pea protein formed an interfacial film around the oil droplets, and the oil was more tightly packed at higher oil concentrations. Differential scanning calorimetry showed that lipid crystallization of the gelled SO was influenced by the confinement of the alginate gelation, but the melting behavior was like that of free SO. FTIR spectrum analysis indicated a potential interaction between alginate and pea protein, but the functional groups of SO were unchanged. Under mild heating conditions, gelled SO exhibited an oil loss similar to that observed in actual beef trims. The developed product has the potential to mimic the appearance and slow-rendering melting attribute of real animal fat.
Drilling cuttings from the rock formation generated during the drilling process are generally smashed to fine particles through hydraulic cutting and grinding using a drilling tool, and then are mixed with the drilling fluid during circulation. However, some of these particles are too small and light to be effectively removed from the drilling fluid via solids-control equipment. These small and light solids are referred to as low gravity solids (LGSs). This work aimed to investigate the effect of LGSs on the performance of oil-based drilling fluid (OBDF), such as the rheological properties, high-temperature and high-pressure filtration loss, emulsion stability, and filter cake quality. The results show that when the content of LGSs reached or even exceeded the solid capacity limit of the OBDF, the rheological parameters including the plastic viscosity, gel strength, and thixotropy of OBDF increased significantly. Furthermore, the filtration of OBDF increases, the filter cake becomes thicker, the friction resistance becomes larger, and the stability of emulsion of OBDF also decreases significantly when the concentration of LGSs reached the solid capacity limit of OBDF (6–9 wt% commonly). It was also found that LGSs with a smaller particle size had a more pronounced negative impact on the drilling fluid performance. This work provides guidance for understanding the impact mechanism of LGSs on drilling fluid performance and regulating the performance of OBDF.
<p>A clear legal test for equality is impossible, as it should be. Indeed were the test clear, it could not be for equality. It would have to be for something other than equality — in effect, for inequality. The abstract character of equality is not a new idea. In fact, the Supreme Court of Canada’s first decision under section 15 of the Canadian Charter of Rights and Freedoms recognized equality as “an elusive concept” that “lacks precise definition.” Why, then, do judges continue to demand such definition over thirty years later? The answer, at times, is politics.</p>
This article examines the career of Erasmus Purling, an English engineer who wrote a short alchemical treatise in 1657. After serving the Royalist cause in the late 1640s, he joined the Commonwealth forces in the early 1650s. He then attempted to manufacture and market a tin alloy supposedly resembling silver, first in England, where he was opposed by the London pewterers and imprisoned. In 1657, he was granted a monopoly privilege from the French Crown for his invention, which he promoted in his alchemical pamphlet. This publication, as well the other works he used to promote his discoveries, attracted the hostility of Parisian pewterers. They attempted to bring his enterprise, and transmutational alchemy in general, into disrepute. Despite this, Purling's pewter sold well, attracted influential investors, and was even protected by a second privilege obtained in 1659. At the Restoration, Purling returned to England, where he tried to implement similar projects, probably without success. Nevertheless, his troubled and little-known career illustrates several facets of alchemical entrepreneurship in the seventeenth century, including conflicting relationships within the world of crafts and trades and ambiguous relationships with state administrations on the eve of the reign of Louis XIV.
Polyglycerol dendrimers (PGD) exhibit unique properties such as drug delivery, drug solubilization, bioimaging, and diagnostics. In this study, PGD hydrogels were prepared and evaluated as devices for controlled drug release with good solubilization properties. The PGD hydrogels were prepared by crosslinking using ethylene glycol diglycidylether (EGDGE). The concentrations of EGDGE and PGDs were varied. The hydrogels were swellable in ethanol for loading paclitaxel (PTX). The amount of PTX in the hydrogels increased with the swelling ratio, which is proportional to EGDGE/OH ratio, meaning that heterogeneous crosslinking of PGD made high dense region of PGD molecules in the matrix. The hydrogels remained transparent after loading PTX and standing in water for one day, indicating that PTX was dispersed in the hydrogels without any crystallization in water. The results of FTIR imaging of the PTX-loaded PGD hydrogels revealed good dispersion of PTX in the hydrogel matrix. Sixty percent of the loaded PTX was released in a sink condition within 90 min, suggesting that the solubilized PTX would be useful for controlled release without any precipitation. Polyglycerol dendrimer hydrogels are expected to be applicable for rapid release of poorly water-soluble drugs, e.g., for oral administration.
Hamud A. Altaleb, Abdulwahab Salah, Badr M. Thamer
Innovative and facile methods for the preparation of metal nanoparticles (MNPs) with A highly uniform distribution and anchored on a unique substrate are receiving increasing interest for the development of efficient and low-cost catalysts in the field of alternative and sustainable energy technologies. In this study, we report a novel and facile metal-ions adsorption-pyrolysis method based on a hydrogel nanocomposite for the preparation of well-distributed nickel nanoparticles on 3D porous carbon frameworks (Ni@PCFs). The pyrolysis temperature effect on electrocatalytic activity toward methanol oxidation and catalyst stability was investigated. Physicochemical characterizations (SEM, TEM, and XRD) were used to determine the morphology and composition of the prepared electrocatalyst, which were then linked to their electrocatalytic activity. The experimental results indicate that the catalyst synthesized by pyrolysis at 800 °C (Ni@PCFs-8) exhibits the highest electrocatalytic activity for oxidation of methanol in alkaline media. Additionally, prepared Ni@PCFs-8 displays a remarkable increase in electrocatalytic activity after activation in 1 M KOH and excellent stability. The adsorption-pyrolysis pathway ensures that the Ni NPs are trapped in the PCFs, which can provide highly reactive surface sites. This work may provide a facile and effective strategy for preparing uniformly distributed metallic NPs on a 3D PCF substrate with high catalytic activity for energy applications.
Insecticides and rodenticides form the basis of integrated pest management systems worldwide. As pest resistance continues to increase and entire groups of chemical active ingredients are restricted or banned, manufacturers are looking for new options for more effective formulations and safer application methods for the remaining pesticide ingredients. In addition to new technological adaptations of mainstream formulations in the form of sprays, fumigants, and dusts, the use of gel formulations is becoming increasingly explored and employed. This article summarizes information on the current and potential use of gel (including hydrogel) and paste formulations against harmful arthropods or rodents in specific branches of pest management in the agricultural, food, stored product, structural wood, urban, medical, and public health areas. Due to the worldwide high interest in natural substances, part of the review was devoted to the use of gels for the formulation of pesticide substances of botanical origin, such as essential or edible oils. Gels as emerging formulation of so called “smart insecticides” based on molecular iRNA disruptors are discussed.