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Viscosity, or the thickness, of aerosols plays a key role in atmospheric processes like ice formation, water absorption, and heterogeneous kinetics. However, the viscosity of sea spray aerosols (SSA) has not been widely studied. This research explored the relationship between particle size and viscosity of authentic SSA particles through particle bounce, atomic force microscopy analysis, and predictive viscosity modeling from molecular composition. The study found that 40 nm SSA particles had estimated viscosities around 104 Pa·s and bounce fractions three times higher than 100 and 200 nm particles with less than 102 Pa·s at a relative humidity (RH) of 60%. Additional studies revealed the Kelvin effect and particle density, influenced by particle size, have a greater impact on size-dependent bounce fractions than changes in RH across impactor stages. While changes in the level of surfactants can impact particle bounce, the increased viscosity in smaller SSA is attributed to the formation of gel-like phase states caused by cation-organic cross-links between divalent calcium ions and organic anions enriched in the smaller particles. This work shows the smallest gel-like SSA particles observed in the field are highly viscous, which has implications for cloud formation, secondary aerosol growth, and pollutant transport in coastal environments.

Mucus plugs occlude airways to obstruct airflow in asthma. Studies in patients and in mouse models show that mucus plugs occur in the context of type 2 inflammation, and studies in human airway epithelial cells (HAECs) show that IL-13-activated cells generate pathologic mucus independently of immune cells. To determine how HAECs autonomously generate pathologic mucus, we used a magnetic microwire rheometer to characterize the viscoelastic properties of mucus secreted under varying conditions. We found that normal HAEC mucus exhibited viscoelastic liquid behavior and that mucus secreted by IL-13-activated HAECs exhibited solid-like behavior caused by mucin cross-linking. In addition, IL-13-activated HAECs shows increased peroxidase activity in apical secretions, and an overlaid thiolated polymer (thiomer) solution shows an increase in solid behavior that was prevented by peroxidase inhibition. Furthermore, gene expression for thyroid peroxidase (TPO), but not lactoperoxidase (LPO), was increased in IL-13-activated HAECs and both TPO and LPO catalyze the formation of oxidant acids that cross-link thiomer solutions. Finally, gene expression for TPO in airway epithelial brushings was increased in patients with asthma with high airway mucus plug scores. Together, our results show that IL-13-activated HAECs autonomously generated pathologic mucus via peroxidase-mediated cross-linking of mucin polymers.

After traumatic brain injury, the brain extracellular matrix undergoes structural rearrangement due to changes in matrix composition, activation of proteases, and deposition of chondroitin sulfate proteoglycans by reactive astrocytes to produce the glial scar. These changes lead to a softening of the tissue, where the stiffness of the contusion core and peripheral pericontusional regions becomes softer than that of healthy tissue. Pioneering mechanotransduction studies have shown that soft substrates upregulate intermediate filament proteins in reactive astrocytes; however, many other aspects of astrocyte biology remain unclear. Here, we developed a platform for the culture of cortical astrocytes using polyacrylamide (PA) gels of varying stiffness (measured in Pascal; Pa) to mimic injury-related regions in order to investigate the effects of tissue stiffness on astrocyte reactivity and morphology. Our results show that substrate stiffness influences astrocyte phenotype; soft 300 Pa substrates led to increased GFAP immunoreactivity, proliferation, and complexity of processes. Intermediate 800 Pa substrates increased Aggrecan+, Brevican+, and Neurocan+ astrocytes. The stiffest 1 kPa substrates led to astrocytes with basal morphologies, similar to a physiological state. These results advance our understanding of astrocyte mechanotransduction processes and provide evidence of how substrates with engineered stiffness can mimic the injury microenvironment.

Tardigrades are microscopic animals that survive desiccation by inducing biostasis. To survive drying tardigrades rely on intrinsically disordered CAHS proteins, which also function to prevent perturbations induced by drying in vitro and in heterologous systems. CAHS proteins have been shown to form gels both in vitro and in vivo, which has been speculated to be linked to their protective capacity. However, the sequence features and mechanisms underlying gel formation and the necessity of gelation for protection have not been demonstrated. Here we report a mechanism of fibrillization and gelation for CAHS D similar to that of intermediate filament assembly. We show that in vitro, gelation restricts molecular motion, immobilizing and protecting labile material from the harmful effects of drying. In vivo, we observe that CAHS D forms fibrillar networks during osmotic stress. Fibrillar networking of CAHS D improves survival of osmotically shocked cells. We observe two emergent properties associated with fibrillization; (i) prevention of cell volume change and (ii) reduction of metabolic activity during osmotic shock. We find that there is no significant correlation between maintenance of cell volume and survival, while there is a significant correlation between reduced metabolism and survival. Importantly, CAHS Ds fibrillar network formation is reversible and metabolic rates return to control levels after CAHS fibers are resolved. This work provides insights into how tardigrades induce reversible biostasis through the self-assembly of labile CAHS gels.

Nanotechnology is very important in targeting drug delivery, which shows much more interest of researchers. Many orally administered drugs are ineffective as desired because certain side effects such as systemic toxicities, slow onset of action, first pass effect, poor bioavailability etc. Topical route in combination with nanotechnology on the other hands offers bundle of benefits. It can provide predictive and controlled drug release, by pass first pass effect, improves drug bioavailability, pain free route, steady state blood concentration etc. There are many factors, such as the type of nonionic surfactant used, method of preparation, the temperature of hydration, etc. which affect the noisome based nano-carrier formation. But application of niosomes in the gel form make it more convenient to use by enhancing its bioavailability and reducing the side effects. Although these benefits make topical drug delivery system a better route for drug administration but certain barriers such as permeation through skin always challenging. In this review article, we have made an attempt to incorporate all the basic details of noisome gels based on methods of preparation, characterization, way to overcome the barriers and their applications along with novel advancements taken place in the field of nanotechnology. [ABSTRACT FROM AUTHOR]

Shredded mattress waste was valorised into an insulation material via the addition of a cellulose/urea gel. The addition of the cellulose-based gel was found to successfully bond the miscellaneous shred, creating a composite with a unique pore structure. The composites were tested for their thermal conductivity to explore their use as insulation materials in construction applications. From the testing, the thermal conductivity was found to range between 49 and 60 mW/mK depending on the composition and processing steps. While some of the produced composites showed poor thermal resistance not suitable for an insulation product, we report that additional processing resulted in thermal conductivities that were lower than the existing commercial insulation product (45 mW/mK). Numerical simulations revealed that it is possible to further reduce the thermal conductivity of the samples by optimising the porosity and pore sizes. Hence, there is a strong promise of recycling a common waste product into sustainable building insulation products with further optimisations. [ABSTRACT FROM AUTHOR]

Reducing salt in food without compromising its quality is a huge challenge. Some review articles have been recently published on saltiness perception in some colloidal systems such as emulsions. However, no published reviews are available on saltiness perceptions of gel-based matrices, even though salt release and perception in these systems have been extensively studied. This article reviews the recent advances in salt perception in gel-based systems and provides a detailed analysis of the main factors affecting salt release. Strategies to enhance saltiness perception in gels and emulsion-filled gels are also reviewed. Saltiness perception can be improved through addition of biopolymers (proteins and polysaccharides) due to their ability to modulate texture and/or to adhere to or penetrate through the mucosal membrane on the tongue to prolong sodium retention. The composition of the product and the distribution of salt within the matrix are the two main factors affecting the perception of salty taste. Food structure re-design can lead to control the level of interaction between the salt and other components and change the structure, which in turn affects the mobility and release of the salt. The change of ingredients/matrix can affect the texture of the product, highlighting the importance of sensory evaluation. [ABSTRACT FROM AUTHOR]

Cellulose ethers represent a class of water-soluble polymers widely utilized across diverse sectors, spanning from healthcare to the construction industry. This experimental study specifically delves into aqueous solutions of carboxymethylcellulose (CMC), a polymer that undergoes gel formation in acidic environments due to attractive interactions between hydrophobic patches along its molecular chain. We use rheometry to determine the linear viscoelastic properties of both CMC solutions and acid-induced gels at various temperatures. Then, applying the time-temperature superposition principle, we construct master curves for the viscoelastic spectra, effectively described by fractional models. The horizontal shift factors exhibit an Arrhenius-like temperature dependence, allowing us to extract activation energies compatible with hydrophobic interactions. Furthermore, we show that acid-induced CMC gels are physical gels that display a reversible yielding transition under external shear. In particular, we discuss the influence of pH on the non-linear viscoelastic response under large-amplitude oscillatory shear. Overall, our results offer a comprehensive description of the linear and non-linear rheological properties of a compelling case of physical hydrogel involving hydrophobic interactions. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy), as a highly conductive polymer, is limited in application due to the difficulty of uniform dispersion in hydrogels. To improve the compatibility of PPy with hydrogels, xanthan gum (XG) is employed as an emulsifier to homogeneously disperse pyrrole (Py) in water. XG is used as a template for in situ polymerization, and PPy is coated on XG to form nanoparticles (PX) with a core‐shell structure, enabling the nanoparticles to be dispersed uniformly in water for a long time. PX nanoparticles are combined with pure hydrophobic association hydrogel (HA) to form a HA/PX nanocomposite hydrogel. The HA/PX2% nanocomposite hydrogels exhibiting high toughness (equivalent to 5.1 MJ/m3) and high sensitivity (GF = 11.07 for 600%–1400% strain range) are prepared by combining dynamic hydrophobic cross‐linking sites, as well as hydrogen bonding between PX nanoparticles and the cross‐linked network. The test results show that the HA/PX nanocomposite hydrogel strain sensor has excellent strain sensing durability (800 cycles of 100% strain) and has the ability to accurately detect human joint movements for voice recognition and handwriting recognition. The nanocomposite hydrogel is a new method for the preparation of flexible electronic materials, which has great promise for application in the field of strain sensors. [ABSTRACT FROM AUTHOR]

We report the successful assembly of a tripeptide in the presence of nanodiamonds (NDs) into nanocomposite hydrogels. While the presence of NDs does not hinder peptide self‐assembly and gelation kinetics are not affected, NDs improve the viscoelastic properties and significantly increase the elastic moduli of the peptide hydrogels. Increased resistance of the gels against applied stress can also be attained depending on the amount of NDs loaded in the nanocomposite. Raman micro‐spectroscopy and TEM confirmed the presence of NDs on the surface, and not in the interior, of peptide nanofibers. Peptide‐ND non‐covalent interactions are also probed by Raman and Fourier‐transformed infrared spectroscopies. Overall, this work enables the embedding of NDs into nanocomposite hydrogels formed through the self‐assembly of a simple tripeptide at physiological pH, and it provides key insights to open the way for their future applications in biomaterials, for instance exploiting their luminescence and near‐infrared responsiveness. [ABSTRACT FROM AUTHOR]

Multi‐responsive, self‐healing hydrogels were developed utilizing positively charged polysaccharides, chitosan, and water‐soluble chitosan. This fabrication employed free‐radical synthesized polyacrylic acid and polymethacrylic acid along with the cross‐linker FeCl3, resulting in the generation of polyelectrolyte metal complexes, which enhances the properties of the chitosan‐based hydrogels, particularly their mechanical strength, self‐healing ability, thermal stability, swelling behavior, porous structure, cell viability, and even anticancer activity. Characterization and stability assessment of the hydrogels were performed using FT‐IR, nuclear magnetic resonance, gel permeation chromatography, scanning electron microscopy, rheometer, x‐ray diffraction, thermogravimetric analysis, DSC, and UV spectroscopy. FT‐IR measurements indicated that the facile complexation of the cross‐linker's metal ions (Fe3+) with the carboxylate (COO−), amino (NH), and hydroxyl (OH) groups of the polymers and chitosan chains facilitated rapid gelation. Furthermore, the sustained release of the drug levofloxacin (up to 80%) was observed to increase with increasing pH due to the hydrogels' anionic nature. Biocompatibility and cytotoxicity tests were conducted using the MTT assay on splenocytes and Dalton Lymphoma cancer cell lines. These tests demonstrated the promising potential of these hydrogels for drug delivery applications. [ABSTRACT FROM AUTHOR]

Background/Objectives: Sodium aescinate (SA) is commonly used topically due to its anti-inflammatory, anti-edematous, and anti-swelling properties. However, the clinical application of SA is limited by strong irritation, and cannot be used on the damaged skin and mucous membrane. This study aimed to investigate whether arginine hydrochloride (Arg·HCl) could reduce the rectal mucosal irritation of SA through the formation of a gel. Methods: Molecular docking was first used to explore potential interactions between SA and Arg·HCl. Gels for rectal administration were then formulated by combining SA with various ratios of Arg·HCl (from 1:0 to 1:10). In vitro tests, including pH, centrifuge stability, viscosity, and spreadability analysis, were conducted. The optimal gel formulation was determined based on rectal mucosal irritation tests and anti-inflammatory experiments. Additionally, the anti-hemorrhoidal characteristics and safety of the optimal gel in terms of acute toxicity and dermal sensitivity were evaluated. Results: The optimal SA to Arg·HCl ratio of 1:6 (F5-SA gel) was identified, significantly reducing rectal mucosal irritation while enhancing anti-inflammatory activity. The F5-SA gel demonstrated high efficacy against hemorrhoids, notably promoting anal ulcer healing. When administered rectally to rabbits at a dose of 132 mg·kg−1·d−1 (198 times the recommended therapeutic dose), no other obvious side effects were observed except a significant reduction in food intake on the day of administration. In addition, the gel did not induce dermal sensitivity. Conclusions: The F5-SA gel is a promising formulation that can reduce irritation and toxic side effects, and enhance the therapeutic effect to some extent, ultimately achieving a safer and more effective rectal delivery system for SA. [ABSTRACT FROM AUTHOR]

Background: Psoriatic arthritis (PsA), a chronic inflammatory disease, mainly affects the joints, with approximately 30% of psoriasis patients eventually developing PsA. Characterized by both innate and adaptive immune responses, PsA poses significant challenges for effective treatment. Recent advances in drug delivery systems have sparked interest in developing novel formulations to improve therapeutic outcomes. The current research focuses on the development and evaluation of a nanosponge-loaded, cyclo-oxygenase-2 (COX-2) inhibitor-based topical gel for the treatment of PsA. Methods: Nanosponges (NSs) were prepared by using beta-cyclodextrin as a polymer and dimethyl carbonate (DMC) as a crosslinker by melting, and gels were prepared by employing carbopol and badam gum as polymers. Results: Solubility studies confirmed that the prepared nanosponges were highly soluble. FT-IR studies confirmed the formation of hydrogen bonds between lumiracoxib and beta-cyclodextrin. SEM confirmed that the prepared formulations were roughly spherical and porous in nature. The average particle size was 190.5 ± 0.02 nm, with a zeta potential of −18.9 mv. XRD studies showed that the crystallinity of lumiracoxib decreased after encapsulation, which helped to increase its solubility. The optimized nanosponges (NS2) were incorporated in an optimized gel (FG10) to formulate a nanosponge-loaded topical gel. The optimized gel formulation exhibited a homogeneous consistency, with a pH of 6.8 and a viscosity of 1.15 PaS, indicating its suitability for topical application and stability. The in vitro diffusion studies for the topical gel showed drug release of 82.32% in 24 h. The optimized formulation demonstrated significant antipsoriatic activity, as confirmed through cytotoxicity studies conducted on HaCaT cells. Conclusions: On the basis of the findings, it can be concluded that the prepared nanosponge-loaded topical gel formulation presents a promising solution for the effective management of PsA, offering enhanced drug solubility, sustained release, and improved therapeutic potential. [ABSTRACT FROM AUTHOR]

Understanding mass transport in the alteration layers of glass surfaces is a crucial component of the safety assessment of nuclear waste glass. In this work, we model such an alteration layer as a silicate gel with water through a molecular dynamics (MD) simulation with a reactive force field. Gels with various water contents (WCs) ranging from 5.1 to 30.7wt%$30.7 \,{\rm wt}\%$ are produced via high‐temperature annealing with water and silica. It is found that an increase in the water content destroys the polymerized structure of the silicate network and promotes the formation of silanol groups. The pore size and water connectivity formed by the silicate networks are investigated for the modeled gels. Gel with a WC of 5.7wt%$5.7 \,{\rm wt}\%$ is composed of isolated water in the pores; in contrast, pores filled with interconnected water are formed in gel with a WC of 30.7wt%$30.7 \,{\rm wt}\%$. The water diffusivity in the modeled gel is calculated using the mean‐squared displacement at various temperatures. An attempt is made to formulate a linear relationship between the water diffusivity and porosity derived from the MD simulation. The porosity is calculated using a probe atom with a radius, which was optimized from a linear relationship between the water diffusivity and porosity. This approach successfully explains the water diffusivity in terms of the porosity. Random walk (RW) simulations for the structures derived from the MD simulations are performed to determine the geometrical effects of the pores. The diffusivity obtained from RW simulation is compared with the results of the MD simulations, which include chemical interactions such as the formation and breakage of hydrogen bonds. This comparison highlights how geometrical effects and chemical interactions contribute to water diffusivity depending on the WC. [ABSTRACT FROM AUTHOR]

Low‐molecular‐weight (LMW) gelators are a versatile class of compounds able to self‐assemble and to form supramolecular materials, such as gels. The use of LMW peptides to produce these gels shows many advantages, because of their wide structure tunability, the low‐cost and effective synthesis, and the in vivo biocompatibility and biodegradability, which makes them optimal candidates for release and delivery applications. In addition, in these materials, the binding of the hosts may occur through a variety of noncovalent interactions, which are also the main factors responsible for the self‐assembly of the gelators, and through specific interactions with the fibers or the pores of the gel matrix. This review aims to report LMW gels based on amino acid and peptide derivatives used for the release of many different species (drugs, fragrances, dyes, proteins, and cells) with a focus on the possible strategies to incorporate the cargo in these materials, and to demonstrate how versatile these self‐assembled materials are in several applications. [ABSTRACT FROM AUTHOR]

Altrenogest is a key regulatory hormone for intensive and batch management of reserve sows in breeding farms. As a synthetic hormone, altrenogest could make ovaries stay at the initial stage of follicles and inhibit estrus and ovulation in animals. However, the currently used oral altrenogest solution needs to be administered continuously every day for more than two weeks in clinical practice. In this study we developed a phospholipid-based injectable gel carrying altrenogest to decrease the number of administrations, sustain release of the drug, and enhance therapeutic efficacy for clinical use. The altrenogest gel had a viscosity of 100 cP before phase transition and over 1,000,000 cP after phase transition. In vitro, altrenogest can be continuously released from gel for over two weeks. The pharmacokinetic results showed that the AUC (0–∞) of the altrenogest gel was almost double that of the altrenogest solution. The MRT (0–∞) was 40.92 ± 7.21 h and the t1/2 of the altrenogest gel was 80.03 ± 20.79 h. The altrenogest gel demonstrated excellent fluidity, ease of injectability, high drug-loading capacity, and appropriate sustained-release characteristics both in vitro and in vivo, making it a potential drug delivery system for swine production. [ABSTRACT FROM AUTHOR]

This paper provides a solid foundation for understanding the synthesis, properties, and applications of cellulose-based gels. It effectively showcases the potential of these gels in diverse applications, particularly in biomedicine, and highlights key synthesis methods and properties. However, to push the field forward, future research should address the gaps in understanding the environmental impact, mechanical stability, and scalability of cellulose-based gels, while also considering how to overcome barriers to their industrial use. This will ultimately allow for the realization of cellulose-based gels in large-scale, sustainable applications. [ABSTRACT FROM AUTHOR]

Natural deep eutectic solvents (NaDES) were employed for the extraction of bilberry and green tea leaves. This study explored the incorporation of these NaDES extracts into various carrier systems: hydrogels, emulsions, and emulgels stabilized with hydroxyethyl cellulose or xanthan gum. The results demonstrated that, when combined with synthetic UV filters, the NaDES extracts significantly enhanced the SPF and improved the antioxidant properties of the formulation. Although NaDES extracts cannot fully replace synthetic UV filters (homosalate, ethylhexyl methoxycinnamate, and benzophenone-4), they can serve as effective UV boosters, significantly enhancing the SPFs of formulations containing UV filters. Hence, the SPF of the formulation could be improved without increasing the concentrations of synthetic filters. Moreover, NaDES extracts, unlike UV filters, significantly increased the antioxidant potential of the formulations. Among the carriers, hydrogels with xanthan gum and emulgels with hydroxyethyl cellulose achieved the highest SPFs when containing both NaDES extracts and synthetic filters. A texture analysis further revealed that the NaDES extracts positively impacted the mechanical properties of the formulations by increasing their cohesiveness, thus enhancing their physical stability under mechanical pressure. These findings pave the way for further research into NaDES-based formulations, including in vivo testing, to optimize and confirm their efficacy on human skin and validate NaDES extracts as eco-friendly ingredients in cosmetics, with antioxidant and UV boosting potential. [ABSTRACT FROM AUTHOR]

Polysaccharide-based carriers as biomaterials for drug delivery have been inspiring scientists for years due to their exceptional characteristics, such as nontoxicity, biocompatibility, and degradability, as they are able to protect pharmaceutically active molecules and provide their controlled/modified release. This review focuses on selected drug delivery systems based on natural polymers, namely fucoidan, pullulan, dextran, and pectin, with the aim of highlighting published patent documents. The information contained in patents is very important because it is usually not published in any other document and is much less discussed as the state of the art in the scientific literature. The Espacenet—European Patent Office database and the International Patent Classification were used for the research to highlight the specific search procedure. The presented analysis of the innovative state of the art includes an overview from the first patent applications to the latest granted patents in this field. [ABSTRACT FROM AUTHOR]

The purpose of teeth whitening is the removal of intrinsic or extrinsic discoloration via mechanical or chemical techniques that restore the teeth to their natural shade or lighten it, depending on the chosen method. Both the abrasive particles used in mechanical procedures and the oxidant agents applied in chemical bleaching are effective if they are used according to the stain aetiology, however, the risks associated with these products (e.g. potential tooth wear, sensitivity, damage of the enamel or dentin organic matrix) are not negligible. As a response to these issues, current research in the tooth whitening field is directed towards the development of safer whitening products such as dentifrices with lower abrasive index, natural bleaching agents, or laser-assisted whitening procedures that require shorter exposure time for optimal results. This review aims to provide a description of the currently available teeth whitening techniques and their limitations, as well as the novel alternatives that promise similar or superior results with less potential side effects. For a better understanding of the subject, the structure of the tooth, the causes of teeth discoloration as well as the mechanisms of action and chemistry behind the abrasive agents and peroxide-based whitening processes were also discussed.

INTRODUCTION. The examination of protocols for clinical trials of locally applied and locally acting medicinal products highlights challenges that developers face when selecting the design, endpoints, population, comparison groups, and sample size. An analysis of the most common errors in clinical trial protocols will help minimise the number of comments from protocol reviewers and accelerate the process of bringing novel medicinal products to the pharmaceutical market.AIM. This study aimed to analyse the results of evaluating clinical trials of locally applied and locally acting medicinal products conducted with due consideration of the recent additions to the Rules for Conducting Bioequivalence Studies of Medicinal Products within the Eurasian Economic Union (EAEU); assess the main advantages of the added requirements and the challenges remaining in protocol development; and make recommendations for the most effective application of existing laws and regulations.DISCUSSION. The Rules for Conducting Bioequivalence Studies of Medicinal Products within the EAEU were supplemented with Appendices 11, 12, and 13 in August 2023. Since then, protocol reviewers have accumulated sufficient experience in the examination of clinical trial protocols for locally applied and locally acting medicinal products. This article presents the most frequent comments made during the examination of clinical trial protocols and provides recommendations for corrective actions. The most challenging aspects of drafting a protocol for a clinical trial of a locally applied and locally acting medicinal product include the selection and justification of primary/secondary endpoints and the calculation and justification of the population size. The difficulty is probably due to the lack of a detailed description of study characteristics in EAEU laws and regulations. Locally applied and locally acting corticosteroids are the least challenging medicinal products in terms of protocol drafting because EAEU legislation and scientific publications provide the most detailed guidance for them.CONCLUSIONS. The analysis of protocols for clinical trials of locally applied and locally acting medicinal products, relevant EAEU requirements, and applicable international guidelines identified several major challenges, including the selection of primary/secondary endpoints, the characterisation of the trial population, and the justification of the sample size. The recommendations presented in this article will help applicants in planning clinical trials aimed at accelerating the launch of medicinal products into the pharmaceutical market.

The concentration of harmful metal ions is growing globally, which raises the risk to both human and ecological health. The use of "adsorption" technique has been found to be very effective, for the removal of toxic metal ions. Among other things, hydrogels as an adsorbent work effectively for the removal of toxic metal ions and other aquatic pollutants. The newly designed potato starch‐xanthate (SX) based hydrogel (SX‐modified hydrogel) has been synthesized using a mixture of acrylamide (AAm) and acrylic acid (AA) monomers, with the help of free‐radical graft copolymerization technique. The synthesized SX‐modified hydrogel has been characterized by several analytical techniques, namely, UV–visible (UV–vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), thermogravimetric (TG) analysis, point of zero charge (ΔpHPZC) analysis, x‐ray diffraction (XRD) analysis, and scanning electron microscope (SEM) analysis. The main objective of the current work is to remove the Cu2+ and Co2+ ions from wastewater using SX‐modified hydrogel as well as to study the swelling and water retention properties of the SX‐modified hydrogel. The swelling ratio of SX‐modified hydrogel has been found to be 312.31, 374.01, and 410.20 g/g at optimum pH 10, temperature 35°C, time 675 min in gray wastewater, tap water, and distilled water, respectively. The maximum percentage removal of Cu2+ and Co2+ ions by SX‐modified hydrogel has been found as 97.7% and 94.2%, respectively, at optimum conditions. The Langmuir isotherm model fits best with the experimental data, with maximum adsorption capacity of 515.46 mg/g for Cu2+ and 483.09 mg/g for Co2+ ions, respectively. The kinetic studies suggest that the adsorption process is governed by the second order kinetic model with rate constant of 2.06 × 10−4 g/(mg min) for Cu2+ and 1.79 × 10−4 g/(mg min) for Co2+ ions, respectively. The negative ΔG values suggest the adsorption process is spontaneous in nature. In addition, the positive ΔH values support the adsorption process is endothermic in nature. The SX‐modified hydrogel showed a remarkable desorption efficiency with 96.7% for Cu2+ and 92.5% for Co2+ ions and reusability for four consecutive adsorption–desorption cycles. It can be concluded that the SX‐modified hydrogel has showed an effective, economical, easy, low energy consuming, and significant potential in the treatment of wastewater containing heavy metal ions. [ABSTRACT FROM AUTHOR]

This study reports the reversible solubility switching of a polymer triggered by non‐phototoxic visible light. A photochromic polymerizable azobenzene monomer with four methoxy groups at the ortho‐position (mAzoA) was synthesized, exhibiting reversible photoisomerization between trans‐ and cis‐states using green (546 nm) and blue light (436 nm). Free radical copolymerization of hydrophilic dimethylacrylamide (DMAAm) with mAzoA produced a light‐responsive random copolymer (P(mAzoA‐r‐DMAAm)) that shows a reversible photochromic reaction to visible light. Optimizing mAzoA content resulted in P(mAzoA10.7‐r‐DMAAm)3.0 kDa exhibiting LCST‐type phase separation in PBS (pH 7.4) with trans‐ and cis‐states at 39.2 °C and 32.9 °C, respectively. The bistable temperature range of 6.3 °C covers 37 °C, suitable for mammalian cell culture. Reversible solubility changes were demonstrated under alternating green and blue light at 37 °C. 1H NMR indicated significant retardation of thermal relaxation from cis‐ to trans‐states, preventing undesired thermal mechanical degradation. Madin Darby Canine Kidney (MDCK) cells adhered to the P(mAzoA‐r‐DMAAm) hydrogel, confirming its non‐cytotoxicity and potential for biocompatible interfaces. This principle is useful for developing hydrogels that can reversibly stimulate cells mechanically or chemically in response to visible light. [ABSTRACT FROM AUTHOR]

Background/Objectives: Cytolytic vaginosis or, classically, Doderlein's cytolysis is characterized by significant growth of species of the Lactobacillus genus, which leads to high amounts of lactic acid in the vaginal environment. Lactobacillus crispatus has been proposed as a key pathogen in this clinical condition. The symptomatology of cytolytic vaginosis is commonly confused with that of vulvovaginal candidosis, leading to inadequate and ineffective azole therapies. Nevertheless, historically, the use of sodium bicarbonate intimate baths was an effective way to reduce the symptoms of cytolytic vaginosis. Methods: In this study, four HPMC gel prototypes were developed, containing sodium bicarbonate concentrations ranging from 4% to 7% (w/w). These gels were evaluated for their physicochemical properties, antimicrobial activity, interference with lactobacilli adhering to cells, and cellular and tissue biocompatibility. Results: The gels presented pH values of around 9.0, and osmolality between 706 mOsm/kg (F4) and 1065 mOsm/kg (F7). The viscosity upon heating to physiologic temperature and dilution with simulated vaginal fluid was highly affected by the concentration of sodium bicarbonate. Gels with higher sodium bicarbonate concentrations (F6 and F7) were not shown to be stable in these conditions. All formulations exhibited effective antimicrobial activity against seven L. crispatus strains, with MIC values ranging from 6.25% to 25% (v/v) in terms of dilution. Additionally, the 4% (w/w) gel significantly interfered with the adhesion of L. crispatus to epithelial cells in competition and exclusion assays, reducing adhesion by more than 90% in relation to the control. Cytotoxicity tests on the Hec-1A, HeLa, and VK2/E6E7 cell lines indicated that the F4 and F5 gels demonstrated lower cytotoxicity levels compared to those with higher concentrations. Furthermore, ex vivo assays using porcine vaginal tissue confirmed that the 4% gel was non-toxic at a 25% (v/v) dilution. Conclusions: Based on these results, the 4% (w/w) sodium bicarbonate gel (F4) emerges as a promising therapeutic option for cytolytic vaginosis, offering effective bacterial interference, favourable physicochemical properties, and biocompatibility suitable for vaginal application. [ABSTRACT FROM AUTHOR]

In recent years, in addition to the positive effects of probiotics and prebiotics on health, increasing research has shown that postbiotics also have significant potential in the health field. Postbiotics are bioactive components produced by probiotic bacteria during fermentation and may exhibit antimicrobial activity. This study investigated the antimicrobial effects of liposomal postbiotics formulated in gel. Various postbiotic-containing liposomal systems have been developed and optimized to prepare formulations. Optimized liposomes and liposomal postbiotic-containing gel forms were examined in terms of particle size, polydispersity index, zeta potential, structural properties, encapsulation efficiency, permeability, release profiles, and stability. Finally, the antimicrobial activities of the postbiotics and the optimum gel formulation LG1 were evaluated on Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus hirae, and Candida albicans strains using disk diffusion and microdilution methods. The optimum liposome formulation L1 was determined to have a particle size of 185.32 ± 0.80 nm, a polydispersity index of 0.206 ± 0.012, a zeta potential of 35.0 ± 0.5 mV, and an encapsulation efficiency of 17.52%. Its permeability was determined as 51.52% at the end of 6 h. In vitro release studies showed that the drug release profile was in accordance with first-order kinetics and suitable for controlled release. The findings show that formulated postbiotics have similar antimicrobial activity to free postbiotics. These results suggest that liposomal gel formulations support the antimicrobial effects of postbiotics while providing advantages of use. In conclusion, the findings contribute to a better understanding of the antimicrobial potential of postbiotics and lipogelosomal postbiotics and optimize their use in pharmaceutical applications. [ABSTRACT FROM AUTHOR]

A new design policy to synthesize nanogel molecules having desired dimensions under unperturbed state is proposed. Miniemulsion copolymerization of vinyl and divinyl monomers, both conventional free‐radical polymerization and ideal living polymerization, is used to illustrate the method. For the network formation dynamics, the newly proposed model that takes into account the size and structure dependence of cross‐linking/cyclization reactions is employed. The master curve relationship that indicates the maximum average dimensions for randomly cross‐linked networks is used as a guideline and the network dimension is controlled by the magnitude of network maturity index NMI, which is the average number of cycle rank per primary chain. By appropriately sizing the NMI, it is possible to synthesize network polymers with dimensions equal to or greater than the maximum dimensions achievable with a homogeneous, randomly cross‐linked network polymer of the same cycle rank and molecular weight. The current strategy of designing and controlling 3D size is applicable regardless of the reaction mechanism of network formation and will also be applied to the synthesis of macro‐gels. [ABSTRACT FROM AUTHOR]

Numerous studies have reported in the past that the use of protein‐encoding DNA hydrogels as templates for cell‐free protein synthesis (CFPS) leads to better yields than the use of conventional templates such as plasmids or PCR fragments. Systematic investigation of different types of bulk materials from pure DNA hydrogels and DNA hydrogel composites using a commercially available CFPS kit showed no evidence of improved expression efficiency. However, protein‐coding DNA hydrogels were advantageously used in microfluidic reactors as immobilized templates for repetitive protein production, suggesting that DNA‐based materials offer potential for future developments in high‐throughput profiling or rapid in situ characterization of proteins. [ABSTRACT FROM AUTHOR]

Efficient synthesis of H2O2 via photocatalytic oxygen reduction without sacrificial agents is challenging due to inadequate proton supply from water and difficulty in maintaining O−O bond during O2 activation. Herein, we developed a straightforward strategy involving a proton‐rich hydrogel cross‐linked by metal ions [M(n)], which is designed to facilitate the selective production of H2O2 through proton relay and metal ion‐assisted detachment of crucial intermediates. The hydrogel comprises CdS/graphene and alginate cross‐linked by metal ions via O=C−O−M(n) bonds. Efficient O2 reduction and hydrogenation occurred, benefitting from the collaboration between proton‐rich alginate and the photocatalytically active CdS/graphene. Meanwhile, the O=C−O−M(n) bonds enhance the electron density of α‐carbon sites on graphene, crucial for O2 activation and *OOH intermediate detachment, preventing deeper O−O bond cleavage. The role of metal ions in promoting *OOH desorption was demonstrated through Lewis acidity‐dependent activity, with Y(III) having the highest activity, followed by Lu(III), La(III), and Ca(II). [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate) (PHB) is a microbially derived polyhydroxyalkanoate that is widely used in biomedical applications. In this study, we investigated the use of acetic acid (aa) as an alternative environmentally friendly solvent for the preparation of gels from PHB (PHB aa) and compared their characteristics with PHB products dissolved in chloroform (PHB chl) using such methods as DSC, FTIR, SEM, rheometry, biodegradation, and cytocompatibility assay. A slight decrease in the degree of the crystallinity of the PHB from 61% to 50.8% was found when the acetic acid was used. This resulted in a greater mass loss for the PHB aa (11%) during enzymatic degradation over 180 days. Gels prepared from PHB in the different solvents showed differences in the microstructure and porosity of the samples, which affected their viscoelastic properties. The storage modulus (G′) for the PHB aa gels was higher by 35% compared to that for the PHB chl, and Young's modulus in compression was 101.5 and 41.3 kPa for the PHB aa and PHB chl, respectively. The porosity of the PHB aa was 97.7%, which was 5.2% higher than that for the PHB chl. The presence of low molecular weight polymers in the PHB aa had an effect on mesenchymal stem cells' viability, expressed as a threefold increase in the number of attached cells after 7 days of incubation compared to the PHB chl. Thus, the proposed method of PHB-based materials' preparation is a promising, more environmentally friendly analog of the extensively used method of preparation from chloroform. [ABSTRACT FROM AUTHOR]

Gels, specifically hydrogels and aerogels, have emerged as versatile materials with profound implications in pharmaceutical sciences. This comprehensive review looks into detail at hydrogels and aerogels, providing a general introduction to gels as a foundation. The paper is then divided into distinct sections for hydrogels and aerogels, each delving into their unique formulations, advantages, disadvantages, and applications. In the realm of hydrogels, we scrutinize the intricacies of formulation, highlighting the versatile advantages they offer. Conversely, potential limitations are explored, paving the way for a detailed discussion on their applications, with a specific focus on their role in antimicrobial applications. Shifting focus to aerogels, a thorough overview is presented, followed by a detailed explanation of the complex formulation process involving sol–gel chemistry; aging; solvent exchange; and drying techniques, including freeze drying, supercritical drying, and ambient-pressure drying (APD). The intricacies of drug loading and release from aerogels are addressed, providing insights into their pharmaceutical potential. The advantages and disadvantages of aerogels are examined, accompanied by an exploration of their applications, with a specific emphasis on antimicrobial uses. The review culminates in a comparative analysis, juxtaposing the advantages and disadvantages of hydrogels and aerogels. Furthermore, the current research and development trends in the applications of these gels in pharmaceutical sciences are discussed, providing a holistic view of their potential and impact. This review serves as a comprehensive guide for researchers, practitioners, and enthusiasts, seeking a deeper understanding of the distinctive attributes and applications of hydrogels and aerogels in the ever-evolving research concerning pharmaceutical sciences. [ABSTRACT FROM AUTHOR]

Gelatin is a promising biopolymer for edible coatings thanks to its low cost and gelling properties. However, its weak mechanical properties limit its use. This study aimed to develop a gelatin coating with tomato extract, analyzing its antioxidant activity and rheological properties for food applications. Gelatin concentrations (2, 5, and 7%) were evaluated, and it was determined that 7% with 7.5% glycerol was the optimal mixture. Three concentrations of tomato extract (0.5, 1, and 1.5%) were added, and antioxidant activity was evaluated using the ABTS technique, as well as the interaction of components through FT-IR and physicochemical analysis. The results showed that there were no significant differences in terms of their physicochemical characterization, maintaining a pH of 5 and a yellowish hue. The FT-IR spectra indicated there were hydrogen bond interactions between gelatin and the extract. The antioxidant capacity was higher with the 1.5% extract, achieving an inhibition of 58.9%. It was found that the combination of the different materials used improved the rheological (specifically the viscosity and stability of the material) and antioxidant properties of the gelatin. These findings suggest that modified gelatin coatings may be effective in extending the shelf life of foods. [ABSTRACT FROM AUTHOR]

DNA hydrogels hold significant promise for biomedical applications and can be synthesized through enzymatic Rolling Circle Amplification (RCA). Due to the exploratory nature of this emerging field, standardized RCA protocols specifying the impact of reaction parameters are currently lacking. This study varied template sequences and reagent concentrations, evaluating RCA synthesis efficiency and hydrogel mechanical properties through quantitative PCR (qPCR) and indentation measurements, respectively. Primer concentration and stabilizing additives showed minimal impact on RCA efficiency, while changes in polymerase and nucleotide concentrations had a stronger effect. Concentration of the circular template exerted the greatest influence on RCA productivity. An exponential correlation between hydrogel viscosity and DNA amplicon concentration was observed, with nucleobase sequence significantly affecting both amplification efficiency and material properties, particularly through secondary structures. This study suggests that combining high‐throughput experimental methods with structural folding prediction offers a viable approach for systematically establishing structure‐property relationships, aiding the rational design of DNA hydrogel material systems. [ABSTRACT FROM AUTHOR]

We report the use of wet‐spinning to 3D‐print gels from low‐molecular‐weight gelators (LMWGs) based on the 1,3 : 2,4‐dibenzylidenesorbitol (DBS) scaffold. Gel stripes assembled from DBS‐CONHNH2 and DBS‐COOH are printed, and their conductivities assessed. Printed gels based on DBS‐CONHNH2 can be loaded with Au(III), which is reduced in situ to form embedded gold nanoparticles (AuNPs). The conductivity of these gels increases because of electron transport mediated by the AuNPs, whereas the conductivity of DBS‐COOH, which does not promote AuNP formation, remains lower. We then fabricate multi‐component gel patterns comprised of spatially well‐defined domains of printed DBS‐CONHNH2/AuNP (higher conductivity) and DBS‐COOH (lower conductivity) resulting in soft multi‐domain materials with differential conductivity. Such materials have future prospects in applications such as soft nanoelectronics or tissue engineering. [ABSTRACT FROM AUTHOR]

This study introduces a technique for decontaminating radioactive surfaces by employing a gel, herein termed as radiation decontamination gel with eutectic liquids (RADGEL), composed of a deep eutectic solvent and polyvinyl alcohol, with the goal of enabling reuse of the surface post‐decontamination. The decontamination effectiveness of RADGEL underwent thorough evaluation through trials conducted on different simulated surfaces, achieving decontamination efficiency up to 99.9% for alpha as well as gamma radionuclides. The various parameters influencing decontamination factors such as amount of complexing agent used, polymer film thickness, nature, and magnitude of radioactivity, as well as surface characteristics of substrates to be decontaminated were optimized. Additionally excellent mechanical strength of RADGEL, affirms its potential as practically efficient, cost‐effective, and safe option for surface decontamination. The Fourier‐transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analysis suggest RADGELs capability for both physical and chemical interactions with contaminants, thus highlighting its comprehensive decontamination efficacy. The outcomes of this study carry substantial implications for the decontamination of surfaces contaminated with various types of radionuclides. [ABSTRACT FROM AUTHOR]

Polyelectrolyte (PE) gels, distinguished by their unique stimuli-responsive swelling behavior, serve as the basis of broad applications, such as artificial muscles and drug delivery. In this work, we present a theoretical model to analyze the electrostatics and its contribution to the swelling behavior of PE gels in salt solutions. By minimizing the free energy of PE gels, we obtain two distinct scaling regimes for the swelling ratio at equilibrium with respect to the salt concentration. We compare our predictions for the swelling ratio with experimental measurements, which show excellent agreement. In addition, we employ a finite element method to assess the applicability range of our theoretical model and assumptions. We anticipate that our model will also provide valuable insights into drug adsorption and release, deformation of red blood cells, 4D printing and soft robotics, where the underlying mechanism of swelling remains enigmatic. [ABSTRACT FROM AUTHOR]

1H spin–lattice relaxation experiments have been performed for gels based on fish collagen in order to analyze water dynamics. The covered frequency range ranges from 10 kHz to 10 MHz; in some cases, the temperature has varied as well. The relaxation data have been reproduced in terms of two models of water motion—a model including two relaxation contributions associated with the diffusion of water molecules on the macromolecular surfaces and a second model being just a phenomenological power law. The concept of surface diffusion has led to a very good agreement with the experimental data and a consistent set of parameters, with the diffusion coefficients being about five orders of magnitude slower compared to bulk water for one of the pools and considerably faster for the second one (smaller by factors between 2 and 20 compared to bulk water). In some cases, the attempt to reproduce the data in terms of a power law has led to a good agreement with the experimental data (the power law factor varying between 0.41 and 0.57); however, in other cases, the discrepancies are significant. This outcome favors the concept of surface diffusion. [ABSTRACT FROM AUTHOR]

Nanocellulose has emerged as a widely utilized building block in nanostructured materials due to its availability, sustainability, large surface area, and high stiffness and aspect ratio. The wet or dry elastoplastic properties of these materials are determined by the fibrils' stiffness, chemical properties, hemicellulose content, and the number of fibril contacts. However, the specific contributions and relative importance of each factor remain unclear. Therefore, this work was devoted to systematically comparing the material properties of gels, aerogels, and wet and dry sheets prepared from CNFs with different aspect ratios, chemical functionality, and hemicellulose content. The fibrils were prepared by chemical and mechanical processing of different pulps. By preserving the native structure as much as possible, higher aspect ratio fibrils can be obtained, which allows for the development of more mechanically robust materials. The results demonstrate that higher aspect ratios lead to more interconnected networks at a lower solids concentration, resulting in a more evenly distributed stress and longer-range stress transfer, yielding stiffer and more ductile materials. The most important finding was that the aspect ratio influences the network formation, resulting in different network topologies. The results were also compared to earlier published data and integrated into a theoretical beam-bending model for a complete elastoplastic description of the network properties, including the influence of fibril aspect ratio and chemical functionality. This information improves our understanding and description of nanofibril networks for which general models have been missing. It can be used to optimize nanofibril preparation and, hence, the resulting eco-friendly materials. [ABSTRACT FROM AUTHOR]

Despite the numerous ongoing research studies in the area of conducting polymer-based electrode materials for supercapacitors, the implementation has been inadequate for commercialization. Further understanding is required for the design and synthesis of suitable materials like conducting polymer-based gels as electrode materials for supercapacitor applications. Among the polymers, conductive polymer gels (CPGs) have generated great curiosity for their use as supercapacitors, owing to their attractive qualities like integrated 3D porous nanostructures, softness features, very good conductivity, greater pseudo capacitance, and environmental friendliness. In this review, we describe the current progress on the synthesis of CPGs for supercapacitor applications along with their morphological behaviors and thermal properties. We clearly explain the synthesis approaches and related phenomena, including electrochemical approaches for supercapacitors, especially their potential applications as supercapacitors based on these materials. Focus is also given to the recent advances of CPG-based electrodes for supercapacitors, and the electrochemical performances of CP-based promising composites with CNT, graphene oxides, and metal oxides is discussed. This review may provide an extensive reference for forthcoming insights into CPG-based supercapacitors for large-scale applications. [ABSTRACT FROM AUTHOR]

In recent times, there has been a significant surge in research interest surrounding thermo-responsive water-soluble polyacrylamides, primarily due to their intriguing capability to undergo significant solubility changes in water. These polymers exhibit the remarkable ability to shift from a soluble to an insoluble state in response to temperature variations. The capacity of these polymers to dynamically respond to temperature changes opens up exciting avenues for designing smart materials with tunable properties, amplifying their utility across a spectrum of scientific and technological applications. Researchers have been particularly captivated by the potential applications of thermo-responsive water-soluble polyacrylamides in diverse fields such as drug delivery, gene carriers, tissue engineering, sensors, catalysis, and chromatography separation. This study reports the construction and functionalization of polymer gels consisting of a polymer network of polyacrylamide derivatives with nano-sized structural units. Specifically, thermo-responsive polymer gels were synthesized by combining well-defined star-shaped polymers composed of polyacrylamide derivatives with a multifunctional initiator and linking method through a self-accelerating click reaction. The polymerization system employed a highly living approach, resulting in polymer chains characterized by narrow molecular weight distributions. The method’s high functionality facilitated the synthesis of a temperature-responsive block copolymer gel composed of N-isopropyl acrylamide (NIPA) and N-ethyl acrylamide (NEAA). The resulting polymer gel, comprising star-shaped block copolymers of NIPA and NEAA, showcases smooth volume changes with temperature jumps.