Greater Swelling Research Articles

Adsorption of Diclofenac Sodium and Tetracycline From Aqueous Solution Using PVA Films Prepared with Modal/Cotton Fiber Wastes

AbstractIn this study, fiber‐polymer composite films were prepared by adding 0.5 g, 1.0 g, and 1.5 g of modal/cotton (50 : 50) waste to 10 % PVA film, and the properties of the films were revealed by SEM, FTIR analyzes and swelling percentage. It is observed that the strength of the bonds in the FTIR analysis decreases when modal/cotton fibers are added to the PVA film. While a 406 % swelling is achieved in the PVA film, the swelling percentages of the films decrease when modal/cotton fibers are added to the PVA film, and a greater swelling is observed at pH 9 compared to pH 5. The adsorption efficiency of tetracycline and diclofenac sodium on the films was researched at different pH levels and film doses. Tetracycline removal reached its highest value at pH 9, while diclofenac sodium removal reached its highest value at pH 5. Langmuir and Freundlich isotherm models were determined for tetracycline and diclofenac sodium adsorption. Tetracycline removal is better described by the Freundlich isotherm model, whereas diclofenac sodium removal fits the Langmuir isotherm model better. As a result, films prepared with modal/cotton waste not only provide tetracycline and diclofenac sodium removal but also contribute to waste recycling by utilizing waste fiber materials.

Graphene Oxide (GO)-Based Bioink with Enhanced 3D Printability and Mechanical Properties for Tissue Engineering Applications.

Currently, a major challenge in material engineering is to develop a cell-safe biomaterial with significant utility in processing technology such as 3D bioprinting. The main goal of this work was to optimize the composition of a new graphene oxide (GO)-based bioink containing additional extracellular matrix (ECM) with unique properties that may find application in 3D bioprinting of biomimetic scaffolds. The experimental work evaluated functional properties such as viscosity and complex modulus, printability, mechanical strength, elasticity, degradation and absorbability, as well as biological properties such as cytotoxicity and cell response after exposure to a biomaterial. The findings demonstrated that the inclusion of GO had no substantial impact on the rheological properties and printability, but it did enhance the mechanical properties. This enhancement is crucial for the advancement of 3D scaffolds that are resilient to deformation and promote their utilization in tissue engineering investigations. Furthermore, GO-based hydrogels exhibited much greater swelling, absorbability and degradation compared to non-GO-based bioink. Additionally, these biomaterials showed lower cytotoxicity. Due to its properties, it is recommended to use bioink containing GO for bioprinting functional tissue models with the vascular system, e.g., for testing drugs or hard tissue models.

Fabrication and characterization of tamarind seed gum based novel hydrogel for the targeted delivery of omeprazole magnesium

The tamarind seed gum based novel hydrogel was fabricated by varying concentration of polymer, monomer and crosslinker for the targeted delivery of omeprazole magnesium at stomach pH of 1.5. The free radical graft copolymerization of 2-acrylamido-2-methyl propane sulfonic acid with tamarind seed gum backbone resulted in hydrogel. The formation of sulfonic acid pendant groups in hydrogel was observed by the existence of an infrared absorption band at 1152 cm−1 for SO group. The conversion to semicrystalline nature on incorporation of drug evidenced by powder X-ray diffraction studies with peaks at 2θ = 20.4° 31.5° and 52.2°. The scanning electron microscopy images showed bigger voids which narrowed down for drug loaded matrix, supported by the presence of a peak for magnesium in the energy dispersive X-ray spectroscopy. The greatest swelling was observed at pH 7 with second-order rate constant 1.5371 (g/g)/min and drug release was found to be 97.85 ± 1 % over 1200 min at pH 1.5. The drug release transport was found combination of diffusion and erosion of polymer chain to be super case II diffusion and Hill equation model was good fit. The hydrogel drug conjugate found to be non-toxic at tested concentrations (17 mg/50 mg) on in-vivo testing in Drosophila model.

Effects of Solvents Used for Conservation/Restoration Treatments on Damaged Linden Panels of Cultural Heritage Assets

Heritage objects with wooden supports can degrade in inappropriate storage conditions or when microclimate factors contribute to the development of biological attacks. Another issue regarding the deterioration of artifacts is the lack of a full understanding of material properties and their behavior during restoration treatments. In this paper, we note the strengthening treatments of artifacts with severely damaged wood and the various treatments against bio-pests. The influence of solvent on dimensional changes was observed for water, acetone, and white spirit. Acetone was found to cause the greatest swelling and deformation of the treated panels. The present work highlights the importance of choosing not only the correct types of solvents for the solubilization of synthetic resins, as well as those used in conservation-restoration treatments, but also the effects they have on polychrome wood panels that have been degraded by xylophagous insects.

GUDUCHI KSHEER BASTI AND AYURVED MANAGEMENT OF VĀTARAKTA- CASE REPORT

Etiological factors like, Aghat, Yanayana, Jalkrida Vishamashanam, Ajirnashana, Adhyashana, Diwaswap, consumption of Lavana, Amla, Katu, Kshara and Vidhahi food etc, Vata and Rakta get vitiated and Rakta causes Margavrodha to Vata and the disease Vatarakta occurs. The Rakta gets vitiated by Vatadosha later gravitates towards the foot and small joints. This vicious amalgamation of vitiated Vata and Rakta is called Vatarakta. Vatarakta can even be correlated to Gout on the basis of etiopathology. A 54-year-old male patient approached the OPD with the chief complaints of: Right great toe swelling, pain along with mild discoloration. Left feet small joints pain with burning sensation without swelling. Right elbow joint pain while movements. General weakness was also seen. All the above complaints were in the last 6 months. The patient gets partial relief in symptoms with febuxostat and pain killers which precipitate in hyperacidity and disturbed bowel. So patients are willing to avoid allopathy medicine. In our Panchakarma IPD patient was given combination of Ayurved medicines and Panchakarma therapy as schedule of Guduchi ksheer basti (Enema with drugs having Guduchi, Milk) for 15 days, and later was shifted on Ayurveda Shaman medicines on discharge for further 2 weeks and the results were remarkably seen. Hence this study was taken to prove that Ayurvedic management has remarkable results in Vatarakta (Gout). Observation and results were drawn on the basis of assessment criteria. Discussion was done on the basis of entire observations during research. Conclusion was drawn on the basis of result.

Xanthan-Gum/Pluronic-F-127-Based-Drug-Loaded Polymeric Hydrogels Synthesized by Free Radical Polymerization Technique for Management of Attention-Deficit/Hyperactivity Disorder.

Smart and intelligent xanthan gum/pluronic F-127 hydrogels were fabricated for the controlled delivery of atomoxetine HCl. Different parameters such as DSC, TGA, FTIR, XRD, SEM, drug loading, porosity, swelling index, drug release, and kinetics modeling were appraised for the prepared matrices of hydrogels. FTIR confirmed the successful synthesis of the hydrogel, while TGA and DSC analysis indicated that the thermal stability of the reagents was improved after the polymerization technique. SEM revealed the hard surface of the hydrogel, while XRD indicated a reduction in crystallinity of the reagents. High gel fraction was achieved with high incorporated contents of the polymers and the monomer. An increase in porosity, drug loading, swelling, and drug release was observed with the increase in the concentrations of xanthan gum and acrylic acid, whereas Pluronic F-127 showed the opposite effect. A negligible swelling index was shown at pH 1.2 and 4.6 while greater swelling was observed at pH 7.4, indicating a pH-responsive nature of the designed hydrogels. Furthermore, a higher drug release was found at pH 7.4 compared to pH 1.2 and 4.6, respectively. The first kinetics order was followed by the prepared hydrogel formulations. Thus, it is signified from the discussion that smart xanthan gum/pluronic F-127 hydrogels have the potential to control the release of the atomoxetine HCl in the colon for an extended period of time.

Influence of cyclic water content changes during long-term storage on the mechanical stability of wood pellets

In the case of wood pellets, a water content >10 wt.-% should not be exceeded, as they begin to break even under low mechanical loads. However, during storage, they are exposed to different environmental conditions, including rising and falling humidity. In this study, by humidifying and re-drying wood pellets, it was found that their loss of stability at high humidity is reversible and they can recover to a high degree at subsequent low humidity. However, exceeding the saturation vapor pressure and a pellet water content >12 wt.-% leads to much greater swelling and loss of stability. In this case, pellets recover significantly less during subsequent drying. Long-term tests with multiple cycles of humidification <12 wt.-% have shown that pellets with high density and stability in their original state suffer a significant loss of stability within the first 10 cycles, while pellets with high porosity didn't change during long-term storage.

Synthesis and Evaluation of Alginate-Based Nanogels as Sustained Drug Carriers for Caffeine.

The objective of this study is to design a polymeric network of nanogels for sustained release of caffeine. Therefore, alginate-based nanogels were fabricated by a free-radical polymerization technique for the sustained delivery of caffeine. Polymer alginate was crosslinked with monomer 2-acrylamido-2-methylpropanesulfonic acid by crosslinker N',N'-methylene bisacrylamide. The prepared nanogels were subjected to sol-gel fraction, polymer volume fraction, swelling, drug loading, and drug release studies. A high gel fraction was seen with the increasing feed ratio of polymer, monomer, and crosslinker. Greater swelling and drug release were observed at pH 4.6 and 7.4 as compared to pH 1.2 due to the deprotonation and protonation of functional groups of alginate and 2-acrylamido-2-methylpropanesulfonic acid. An increase was observed in swelling, loading, and release of the drug with the incorporation of a high feed ratio of polymer and monomer, while a reduction was seen with the increase in crosslinker feed ratio. Similarly, an HET-CAM test was used to evaluate the safety of the prepared nanogels, which showed that the prepared nanogels have no toxic effect on the chorioallantoic membrane of fertilized chicken eggs. Similarly, different characterizations techniques such as FTIR, DSC, SEM, and particle size analysis were carried out to determine the development, thermal stability, surface morphology, and particle size of the synthesized nanogels, respectively. Thus, we can conclude that the prepared nanogels can be used as a suitable agent for the sustained release of caffeine.

Design, Development and in vitro Evaluation of Hydrogels Prepared by Free Radical Polymerization of Acrylic Acid (AAc) Containing a Model Antidiabetic Drug

Abstract: Introduction: The controlled release of medicaments in the management of diabetes is desirable to have a better therapeutic activity of the drug. Objectives: In the present study hydrogels were prepared as a controlled drug delivery system taking Rosiglitazone as a model drug. Materials and Methods: Hydrogels were created using the Free Radical Polymerization approach, with the crosslinker N, N′-Methylene bisacrylamide serving as a binding agent for the polymerization. To create a polymeric network, ammonium persulphate has been used as a polymerization inducer for AAc to poly (acrylic acid) in the existence of polyvinyl alcohol (PVP). A maximum of fifteen formulations were created with various concentrations of polymers and crosslinking agents to test the swelling, diffusion coefficients, ESR, and in vitro drug release properties of the drugs tested. The FT-IR and DSC techniques were used to determine the drug's compatibility with the polymers. The XRD studies were carried out to understand the nature of the drug contained within the hydrogel formulation. The morphologies of the surface were determined using SEM. Results and Discussion: A greater swelling was observed in the basic pH range and a marginal swelling was observed in the acidic pH range according to the swelling studies. The ESR affirmed that the pH of the hydrogels was indeed a factor in the swelling of the gels. The results of the diffusion study revealed that the diffusion coefficient has risen as a result of the reduction in cross-linker concentration and the increase in acrylic acid concentration in the solution. The in vitro release of drug data revealed that the swelling has been increased as a result of the increased concentration of acrylic acid, which resulted in the increased release of the drug. However, when the concentrations of PVP and cross-linker were increased, it was discovered that the drug release was decreased. Conclusion: AAc-PVP based hydrogel was found to be a promising controlled drug delivery system for the treatment of Rosiglitazone, according to the findings of this study. Keywords: Hydrogels, PVP Acrylic acid, Free Radical Polymerization, Antidiabetic Drug.

Hydromechanical characterisation of a highly expansive clay

The hydromechanical properties of a South African expansive clay are reported. In this study,swell potential and swell pressure were assessed by two oedometric approaches, namely, the loading after wetting test and the wetting after loading test. The data indicate that predictions of swell pressure from the two approaches remain similar, whereas greater predictions of heave are obtained for the loading after wetting approach. It is also observed that the magnitude of predicted heave from the loading after wetting test is dependent on the soaking stress considered, with greater swell being obtained for lower soaking stresses. Measurements of primary drying and wetting curves illustrate appreciable hysteresis in the intermediate suction range (≈17 MPa). The discrepancy of this finding with that of a previous study is attributed to differences in fabric. Additionally, when examining the volumetric response of a sample subjected to a drying and wetting path, negligible hysteresis is observed when void ratio is plotted as a function of gravimetric water content. Conversely, when the shrinkage/swell curves are plotted in terms of suction, irreversibly volumetric changes are apparent.

Preparation and in-vitro characterization of 5-aminosalicylic acid loaded hydrogels for colon specific delivery

The aim of the current investigation was to prepare and characterize the novel pH-sensitive hydrogels of pluronic F127 and sodium polystyrene sulfonate for the controlled delivery of 5-aminosalicylic acid to colon. Pluronic F127 and sodium polystyrene sulfonate were crosslinked with acrylic acid by N,N′-Methylene bisacrylamide. Various studies including porosity, drug loading, swelling, and drug release were performed for the fabricated hydrogels. Greater swelling and drug release were observed at high pH 7.4 as compared to pH 4.6 and 1.2, thus depicted pH-sensitive nature of developed hydrogel. Characterizations such as Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), were performed in order to evaluate the crosslinking, thermal stability, crystallinity, and surface morphology of the fabricated hydrogel, respectively. The toxicity of the developed drug carrier system was investigated by the HET-CAM test and revealed no toxic effects on the chorioallantoic membrane of the chicken egg. Conclusively, the fabricated hydrogel could be applied as a potential alternate to conventional dosage forms for controlled release of 5-aminosalicylic acid for prolonged period of time.

Preparation, In Vitro Characterization, and Cytotoxicity Evaluation of Polymeric pH-Responsive Hydrogels for Controlled Drug Release.

The aim of the current investigation was based on the development of pH-responsive hydrogels of chondroitin sulfate, carbopol, and polyvinyl alcohol polymerized with acrylic acid in the presence of ammonium persulfate and ethylene glycol dimethylacrylate for controlled drug delivery. A free radical polymerization technique was used for the preparation of these pH-responsive hydrogels. The gel fraction of the prepared hydrogels was increased with the increase in the chondroitin sulfate, carbopol, polyvinyl alcohol, and acrylic acid content, while the sol-fraction was decreased. Swelling and drug release studies were performed in various pH conditions. Greater swelling and drug release were observed at high pH values (pH 4.6 and 7.4) as compared to low pH value (pH 1.2), representing the pH-responsive nature of the synthesized hydrogels. Porosity and drug loading were increased with the incorporation of high concentrations of hydrogel contents except polyvinyl alcohol, which showed reverse effects. Similarly, biodegradation study reported a slow degradation rate of the prepared hydrogels with the increase in hydrogel constituents. Cytotoxicity study proved the safe use of developed hydrogels as no toxic effect was shown on T84 human colon cancer cells. Similarly, various characterizations, including Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy, were performed for prepared hydrogels. Hence, we could demonstrate that the prepared hydrogels can be used as a promising drug carrier for the controlled delivery of drugs.

Highly Responsive Chitosan-Co-Poly (MAA) Nanomatrices through Cross-Linking Polymerization for Solubility Improvement.

In this study, we report the highly responsive chitosan-based chemically cross-linked nanomatrices, a nano-version of hydrogels developed through modified polymerization reaction for solubility improvement of poorly soluble drug simvastatin. The developed nanomatrices were characterized for solubilization efficiency, swelling studies, sol-gel analysis, in vitro drug release studies, DSC, FTIR, XRD, SEM, particle size analysis, and stability studies. An in vivo acute toxicity study was conducted on female Winstor rats, the result of which endorsed the safety and biocompatibility of the system. A porous and fluffy structure was observed under SEM analysis, which supports the great swelling tendency of the system that further governs the in vitro drug release. Zeta sizer analyzed the particle size in the range of 227.8 ± 17.8 nm. Nano sizing and grafting of hydrophilic excipients to the nanomatrices system explains this shift of trend towards the enhancement of solubilization efficiency, and, furthermore, the XRD results confirmed the amorphous nature of the system. FTIR and DSC analysis confirmed the successful grafting and stability to the system. The developed nanomatrices enhanced the release characteristics and solubility of simvastatin significantly and could be an effective technique for solubility and bioavailability enhancement of other BCS class-II drugs. Due to enhanced solubility, efficient method of preparation, excellent physico-chemical features, and rapid and high dissolution and bio-compatibility, the developed nanomatrices may be a promising approach for oral delivery of hydrophobic drugs.

Imidazolium Gemini ionic liquids for regulating facilely the swelling and dispersion of montmorillonite in water

The imidazolium Gemini ionic liquids (IL), with alkyl groups ranging from butyl to tetradecyl as tail chains and polyoxyethylene group as linker chain, were synthesized and used as novel efficient modifiers for flexibly controlling the swelling and dispersion of Na-montmorillonite (NaMt). The correlation between swelling behavior and structure of imidazolium Gemini IL was investigated. Too long or too short tail chains caused greater swelling, obtaining smaller particle size and reductive face-to-face stacking degree of layers. Based on the change of water contact angles, the increased stability of modified Mt in water indicated that the hydrophobicity of the tail chains played an important role in impeding the entry of water molecules into the interlayer. Zeta potential, Fourier transform infrared spectra and X-ray photoelectron spectroscopy validated the cation exchange between imidazolium Gemini IL and Na+, and confirmed the adsorption site. The molecular arrangement and intercalation were determined through adsorption behavior, interlayer space of Mt and simulation of molecular size. The imidazolium Gemini IL covered the Mt layers in monolayer, finally taking lateral (short tail chains) or paraffin (long tail chains) arrangement. The investigation will provide useful guidance for modifying Mt to obtain desirable properties and broadening the practical application of Mt hybrids.

Biocompatible Sulphonated PEEK Spheres: Influence of Processing Conditions on Morphology and Swelling Behavior

This work aimed to develop and evaluate the influence of processing variables on the morphology and swelling of sulfonated poly(ether ether ketone) (SPEEK) spheres for possible applications as a biomaterial. We used the drip method to obtain spheres with the polymer starting solutions SPEEK-6 (w/v: 6%) and SPEEK-10 (w/v: 10%), drip rates (20 and 30 mL/h), and drip heights (5 and 10 cm) in experimental planning. The samples were characterized by Fourier-transform infrared spectroscopy (FTIR), optical microscopy (OM), the absorption capacity of phosphate-buffered saline (PBS) by swelling (%), and statistical analysis of data through Design of Experiments (DOE). The obtained results evidenced that the processing variables influenced the morphology and swelling. Spheres with a bigger concentration of the polymer solution presented a greater degree of sulfonation (DS). We verified that the diameter of the spheres was directly related to the variable height and the sphericity was associated with the speed and viscosity of the solution. Bigger and more pores in a greater amount were observed in the spheres with a greater DS, influencing the behavior of the swelling in PBS. The better variable combinations with a high DS, regular sphericity, a smaller diameter, and greater swelling were the samples S2-10-20-5 e S10-10-20-5. The cytotoxicity indicated that the best samples obtained in the experimental planning (S2-10-20-5 and S10-10-20-5) were not toxic. In that regard, the evaluated spheres presented cell viability and swelling capacity, suggesting their possible applications as biomaterials.

Fabrication and In Vitro Evaluation of pH-Sensitive Polymeric Hydrogels as Controlled Release Carriers.

The purpose of the current investigation was to develop chondroitin sulfate/carbopol-co-poly(acrylic acid) (CS/CBP-co-PAA) hydrogels for controlled delivery of diclofenac sodium (DS). Different concentrations of polymers chondroitin sulfate (CS), carbopol 934 (CBP), and monomer acrylic acid (AA) were cross-linked by ethylene glycol dimethylacrylate (EGDMA) in the presence of ammonium peroxodisulfate (APS) (initiator). The fabricated hydrogels were characterized for further experiments. Characterizations such as Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Powder X-ray diffractometry (PXRD), and Fourier transform infrared spectroscopy (FTIR) were conducted to understand the surface morphology, thermodynamic stability, crystallinity of the drug, ingredients, and developed hydrogels. The swelling and drug release studies were conducted at two different pH mediums (pH 1.2 and 7.4), and pH-dependent swelling and drug release was shown due to the presence of functional groups of both polymers and monomers; hence, greater swelling and drug release was observed at the higher pH (pH 7.4). The percent drug release of the developed system and commercially available product cataflam was compared and high controlled release of the drug from the developed system was observed at both low and high pH. The mechanism of drug release from the hydrogels followed Korsmeyer–Peppas model. Conclusively, the current research work demonstrated that the prepared hydrogel could be considered as a suitable candidate for controlled delivery of diclofenac sodium.

Nanowire Architectures Improve Ion Uptake Kinetics in Conjugated Polymer Electrochemical Transistors.

Organic electrochemical transistors are believed to face an inherent material design tension between optimizing for ion mobility and for electronic mobility. These devices transduce ion uptake into electrical current, thereby requiring high ion mobility for efficient electrochemical doping and rapid turn-on kinetics and high electronic mobility for the maximum transconductance. Here, we explore a facile route to improve operational kinetics and volumetric capacitance in a high-mobility conjugated polymer (poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)], DPP-DTT) by employing a nanowire morphology. For equivalent thicknesses, the DPP-DTT nanowire films exhibit consistently faster kinetics (∼6-10× faster) compared to a neat DPP-DTT film. The nanowire architectures show ∼4× higher volumetric capacitance, increasing from 7.1 to 27.7 F/cm3, consistent with the porous structure better enabling ion uptake throughout the film. The nanowires also exhibit a small but energetically favorable shift in a threshold voltage of ∼17 mV, making the nanostructured system both faster and energetically easier to electrochemically dope compared to neat films. We explain the variation using two atomic force microscopy methods: in situ electrochemical strain microscopy and nanoinfrared imaging via photoinduced force microscopy. These data show that the nanowire film's structure allows greater swelling and ion uptake throughout the active layer, indicating that the nanowire architecture exhibits volumetric operation, whereas the neat film is largely operating via the field effect. We propose that for higher-mobility materials, casting the active layer in a nanowire form may offer faster kinetics, enhanced volumetric capacitance, and possibly lower threshold voltage while maintaining desirable device performance.

Sustainable composite material based on surface-modified rape straw and environment-friendly adhesive

An energy efficient and sustainable composite building material based on rape straw and environment-friendly adhesive is designed. Bone glue with sodium lignosulfonate is used as the binder. Rape straw particles are modified using water and sodium hydroxide treatment. A wide range of functional properties is analyzed, and a detailed characterization of microstructure is performed. The experimental results show that the surface treatment by both water and sodium hydroxide improves the interface adhesion between rape straw and bone glue. The primary consequence is then an increase of both bulk- and matrix density, as compared with the reference material. The best mechanical properties are achieved for the water-treated samples. The sodium hydroxide treatment is found to influence negatively sorption isotherms and to cause greater swelling in a comparison with other composites. The effect of straw surface treatment on thermal and water vapor diffusion properties is not evidenced. The significant swelling of all designed composites at the relative humidities higher than 75% limits their practical applications. They are supposed to be used in dry environments, typically for cladding and insulation in construction, or for packaging purposes.

The Elusive Structure of Magadiite, Solved by 3D Electron Diffraction and Model Building

In addition to a great swelling ability, layered silicates also allow the functionalization of their interlayer region to form various robust green materials that are used as CO2 adsorbents, drug carriers, or catalysts. Here, the unique magadiite structure, which has resisted elucidation despite many attempts and applications the material offers, is finally described. A material-specific strategy allowed the use of 3D electron diffraction which led to the success of deciphering the atomic structure. In order to enable an ab initio structure solution of the electron beam sensitive material, a sodium-free dehydrated form of magadiite was synthetically isolated, and, from that, it was subsequently possible to derive a structure model for the sodium form of magadiite, later successfully refined against powder X-ray diffraction data. Furthermore, a geometry optimization and simulations of spectroscopic data with DFT methods confirm the obtained crystal structure of sodium magadiite. These results finally prompted a detailed description of the layers and of the chemically active interlayer region and provide a huge impact toward the design of new and more efficient materials based on functionalized magadiite and related structures.

Accelerating ESD-induced gastric ulcer healing using a pH-responsive polyurethane/small intestinal submucosa hydrogel delivered by endoscopic catheter.

Endoscopic submucosal dissection (ESD) is the standard treatment for early-stage gastric cancer, but the large post-operative ulcers caused by ESD often lead to serious side effects. Post-ESD mucosal repair materials provide a new option for the treatment of post-ESD ulcers. In this study, we developed a polyurethane/small intestinal submucosa (PU/SIS) hydrogel and investigated its efficacy for accelerating ESD-induced ulcer healing in a canine model. PU/SIS hydrogel possessed great biocompatibility and distinctive pH-sensitive swelling properties and protected GES-1 cells from acid attack through forming a dense film in acidic conditions in vitro. Besides, PU/SIS gels present a strong bio-adhesion to gastric tissues under acidic conditions, thus ensuring the retention time of PU/SIS gels in vivo. In a canine model, PU/SIS hydrogel was easily delivered via endoscopy and adhered to the ulcer sites. PU/SIS hydrogel accelerated gastric ulcer healing at an early stage with more epithelium regeneration and slight inflammation. Our findings reveal PU/SIS hydrogel is a promising and attractive candidate for ESD-induced ulcer repair.