Swelling Rate Research Articles

Abstract 4138380: Cardiac protection of hiPSC-CMs loaded chitosan cardiac patch in myocardial infarcted swine

Background: The low grafting rate of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) following direct injection into the myocardium limits the efficacy of cardiac repair after myocardial infarction (MI). Chitosan-based scaffolds have emerged as functional biomaterials for designing delivery systems in cardiac therapies. This study aimed to enhance the potency of cardiac repair using a hiPSC-CMs loaded chitosan cardiac muscle patch (hCCMP). Methods: The patches were fabricated using chitosan. Characterization of the chitosan patches involved assessing their swelling rate and porosity. The biocompatibility of the hCCMP was analyzed through scanning electron microscopy (SEM) and the CCK8 assay. 16 Yorkshire swine (15-20 kg, 45-50 days of age) were randomly divided into 4 groups (n=4 per group): Sham, MI without further intervention, MI with an empty patch (without hiPSC-CMs), and MI with hCCMP implantation. One and four weeks post-MI, heart function, Infarction size, myocardial perfusion and metabolism were evaluated via cardiac PET-MRI. Engraftment was assessed through human cardiac troponin T staining. Histological analysis including left ventricular anterior wall thickness, cardiac remodeling, angiogenesis, arterialization, and apoptosis in the infarct border area were analyzed using immunofluorescence. Results: SEM showed that the chitosan patch had regular pore size and good 3D structure; porosity was about (96.7±0.37)%. On day3, the patch swelling rate was about (715±64.55)%. SEM, CCK8 assay showed a normal cells growth in the chitosan patch. The hiPSC-CMs grafted well with chitosan patch delivery systems and was associated with significantly improvement in LV function, infarction size, angiogenesis and cardiomyocyte apoptosis in pigs 4 weeks after MI. Conclusions: The 3D chitosan cardiac patch with hiPSC-CMs loaded can enhance the potency of cardiac repair in pigs after MI and present a novel and promising therapic strategy.

Formulation, E-Beam Crosslinking, and Comprehensive Characterisation of Lavender Oil-Enriched Hydrogels

This study focused on the formulation, electron beam (e-beam) crosslinking, and characterisation of hydrogels enriched with lavender oil (LO) to enhance their structural and functional properties for biomedical applications. Stable hydrogels were synthesised using water-soluble polymers and suitable ratios of Tween 80 and Isopropyl alcohol (IPA) as surfactant and co-surfactant, respectively, via e-beam irradiation at doses up to 70 kGy. The most effective crosslinking was achieved with a radiation dose of 30 kGy, depending on the concentrations of surfactants and LO. LO-enriched hydrogels exhibited enhanced superabsorbent swelling (7700% to 18,000%) and faster equilibrium rates than the control hydrogel. Structural analysis revealed a flexible spongiform porous architecture with larger mesh sizes (156 nm to 246 nm) and adequate elastic moduli (130 to 308 Pa). Degradation tests aligned with swelling data, demonstrating a degradation rate of 12% after 35 days, indicating an appropriate balance of stability and degradation. These findings suggest that e-beam technology, in conjunction with LO and surfactant addition, can effectively tailor hydrogel properties for biomedical applications, making them promising candidates for further research in wound care, drug delivery systems, and other biological applications.

Preparation and Performance Evaluation of Small-Molecule Ammonium as a Shale Hydration Inhibitor

In this paper, small-molecule quaternary ammonium salts were synthesized by N-alkylation to inhibit hydration swelling and hydration dispersion. The prepared small-molecule quaternary ammonium salt was characterized by Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA), particle size analysis and Scanning electron microscopy (SEM), and its performance as an inhibitor in clay was evaluated by an anti-swelling test and a linear swelling test. The results show that small-molecule quaternary ammonium salt (TEE-2) synthesized by triethanolamine and epichlorohydrin in ethanol with a molar ratio of 1:1.5 can successfully inhibit the hydration swelling and dispersion of clay. The anti-swelling rate of TEE-2 was 84.94%, the linear swelling rate was 36.42%, and the linear swelling rate of 0.5% TEE-2 was only 29.34%. The hydration swelling of clay in 0.5% TEE-2 solution was significantly inhibited. The hydration inhibition mechanism of the small-molecule quaternary ammonium salt inhibitor 0.5% TEE-2 was analyzed by FTIR, SEM and TGA. It was considered that 0.5% TEE-2 has strong hydration inhibition, which was realized by infiltration and adsorption on the clay surface. Small-molecule quaternary ammonium salts were beneficial for maintaining wellbore stability and reducing the risk of wellbore instability.

Eco-friendly property modulation of biobased gels of carboxymethyl cellulose-integrated poly(tertiary amine)s for the removal of azo-food dyes

Anionic polysaccharide-based gels enable the design of biobased materials with biochemical properties, non-toxic and natural origin. A new set of cationic gels was prepared from carboxymethylcellulose (CMC)-doped tertiary amino functional cationic monomers 2-(dimethylamino)ethyl methacrylate and N-(3-(dimethylamino)propyl) methacrylamide via the formation of semi-interpenetrated network (semi-IPN) at different polymerization temperatures, Tprep. A detailed understanding of the temperature-dependent synthesis and physicochemical response is required for the design of interpenetrating networks with CMC as an adsorbent that provides effective sources for the removal of azo-food dyes such as tartrazine and carmoisine from aqueous solutions. The variation of elasticity and swelling properties with respect to polymerization temperature was investigated. CMC-integration and polymerization temperature played a decisive role in the compressive elasticity. Incorporation of CMC into copolymer matrix led to a significant increase in elasticity of semi-IPNs, while mechanically weaker gels were obtained with increasing Tprep. Addition of CMC increased the swelling modulus of semi-IPNs formed at −18 °C by 2.6-fold. While the transparency changed depending on Tprep and microstructure, addition of CMC decreased the swelling rate of gels at all polymerization temperatures. The compressive modulus decreased with the swelling process in accordance with the Rubber elasticity theory. Semi-IPN gels showed stable swelling against pH-change in aqueous solutions and exhibited excellent pH-sensitivity significantly in low pH. A 4 to 12 fold decrease in maximum volume was observed by varying the pH between 2.1 and 9.8. The correlation between polymerization temperature and removal of azo-food dyes; tartrazine and carmoisine from contaminated wastewater with CMC-based gels was studied. Dynamic adsorption equilibrium was reached in 30 min, and tartrazine and carmoisine removal performances varied between 92.8 % and 98.4 %. respectively. The adsorption data for azo-dyes were evaluated by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Patterson, Sips, and Tooth isotherm models, but were best described by Langmuir and Redlich-Patterson models as they gave the highest correlation. Pseudo-first order, pseudo-second order, Elovich, Avrami kinetic and intra-particle diffusion models were investigated and dye adsorption was represented by pseudo-second-order model. After the adsorption process, semi-IPNs can easily be regenerated and effectively reused over five cycles. The study provided new insights towards the facile and sustainable synthesis of eco-friendly multifunctional CMC-based gels carrying tertiary amino groups for effective removal of azo-based food colorants.

Tragacanth Gum/Trimethyl Chitosan‐Derived Polyelectrolyte Complex as Potential Carriers in Drug Delivery Applications

ABSTRACTA three‐step procedure described in the literature has been used to create N,N,N‐trimethyl Ct a chitosan derivative that is extremely soluble in water. By combining two polymers in aqueous media, this derivative and tragacanth gum were able to form a new polyelectrolyte complex. The TGA, FTIR, and DSC analysis established the development of TMC/XG‐PEC. SEM was used to describe the TMC/TG‐PEC's surface morphology. The features of diffusion and swelling, such as the theoretical equilibrium ratio, initial swelling rate constant, and the process of water transportation into TMC/TG‐PEC, were established. The TMC/TG‐PEC swelling is seen to be pH‐dependent. It swells in the subsequent order: pH 7.4 > 6.8 > 1.2. At pH 1.2, 6.8, and 7.4, the TMC/TG‐PEC swelling ratio was found to be 6.5, 7.7, and 9.6 g/g, respectively. The second‐order kinetics of the swelling process is indicated by the linearity of the plot “t/SR” versus “t”. The TMC/TG‐PEC's n values under various pH circumstances ranged from 0.12 to 0.16, suggesting the Fickian water transport mechanism. The utility of complex as a matrix for KP formulations for sustained‐release tablets was investigated. It was discovered that 90.5% of KP was loaded into PEC. There is evidence that pH influences how much medicine is released. When the medium's pH was altered from acidic to neutral, the KP release was considerably boosted. The TMC/TG‐PEC demonstrated a maximum drug release of 7% in a pH 1.2 medium and between 85% and 90% in a pH 7.4 medium, demonstrating the TMC/TG‐PEC's potential as a matrix substance for the drug's prolonged release formulations of KP. The Fickian drug transport mechanism was indicated by the release exponent n, which was less than 0.5.

Lignin-Chitosan-Based Bioplastics from Oil Palm Empty Fruit Bunches for Seed Coating

Lignin is a hydrophilic-hydrophobic biopolymer known for its antioxidant activity, which could make it a suitable coating material. In this research, a bioplastic based on the combination of alkali lignin from oil palm empty fruit bunches and chitosan was developed for seed coating via a dipping method. Chili seeds were used as a model in this study. The bioplastic was prepared via a modified solvent casting method at lignin:chitosan:glycerol weight ratio of 0.25:1.0:0.2. For the isolated lignin, the antioxidant activity, total phenolic content, methoxyl content, and equivalent weight were measured; for the bioplastic lignin, contact angle, swelling, antioxidant activity, mechanical properties and biodegradability were assessed. The presence of the coating was observed by Cryo-EM while the suitability of lignin-chitosan bioplastics for seed coating was evaluated by the germination rate, root length, height, and dry weight of the sprouts. The results showed that isolated lignin enhances the antioxidant activity of the lignin-chitosan liquid bioplastic by up to 84%. The addition of isolated lignin increased the contact angle and reduced the swelling rate of the bioplastics. The presence of lignin increases the tensile strength and elastic module in the biofilm. The microscopical investigation demonstrated the presence of the coating and no alteration in the seed surface morphology under the coating layer. The application of chitosan-lignin-based bioplastics maintain the quality of the seed during its shelf life. The germination rate of the coated chili seeds increased by up to 100% after one week of storage and 40–80% after five weeks of storage.

Synthesis of Black Seed Oil-loaded-, Alginate-based, pH-sensitive Beads Using Electrospraying Technique.

Black seed oil (BSO), derived from the seeds of the Nigella sativa plant, has garnered attention for its potential anti-cancer properties, particularly in the context of colon cancer. Its active compound, thymoquinone, may help inhibit cancer cell growth and induce apoptosis in colon cancer cells. Additionally, black seed oil's anti-inflammatory and antioxidant effects could contribute to a healthier gut environment, potentially reducing cancer risk. Therefore, this study synthesized pH-sensitive alginate beads to deliver BSO into the colon in a controlled-release manner without releasing the drug at pH 1.2 (stomach), thus providing a well-defined release pattern at pH 6.8. The use of electrospray technology improves process performance by making it easier to formulate small, homogeneous beads with a higher rate of swelling and diffusion in the gastrointestinal medium. The formulated beads were characterized by an ex-vivo mucoadhesive strength test, bead size, sphericity factor (SF), encapsulation efficiency (EE), scanning electron microscope (SEM), in vitro swelling behavior (SB), and in vitro drug release in acidic and buffer media. All these manufactured beads demonstrated modest sizes of 0.58 ± 0.01 mm and spherical shape of 0.03 ± 0.00 mm in this testing. The formulation showed promising floating and releasing properties in vitro. With a very low cumulative percentage of beads, the oil EE of 90.13% ± 0.93% was high, and the release study demonstrated more than 90% in pH 6.8 with good floating nature in the stomach. Additionally, the beads were evenly spaced throughout the intestine. The electrospraying approach used in this protocol can be reproducible, yielding consistent outcomes. Therefore, this protocol can be used for large-scale production for commercialization purposes.

Moulding Test and Process Parameter Optimization of Biomass Seedling Pots for Cow Dung and Corn Stover

In order to determine the optimal moulding process parameters of biomass seedling pots prepared from fermented cow dung mixed with corn stover, the moulding pressure, baking time, and baking temperature of biomass seedling pots were taken as the influencing factors, and the expansion rate, durability rate, wet swelling rate (48 h), and resistance to damage were taken as the evaluation indexes, and the Box–Behnken design of the response surface method was used to analyze the significance of interactions among the different influencing factors in the moulding process of biomass seedling pots and to optimize the moulding process. The experiment was conducted in the Biomass Laboratory of Heilongjiang Bayi Agricultural University. The response surface method Box–Behnken design was used to analyze the significance of the interaction between different influencing factors in the biomass seedling pots moulding process and optimize the moulding process. The results showed that the optimum moulding process conditions obtained using the Box–Behnken design were the following: a moulding pressure of 520.393 kN, baking temperature of 202.870 °C, and baking time of 8.573 min. The model was validated by testing and a response value of 10.522% was obtained for expansion, 99.598% for durability rate, 11.145% for wet swelling (48 h), and 4503.545 N for resistance to damage. The experimental verification showed that the deviation of the actual value obtained under this condition from the predicted value is less than 5%, indicating that the model reproduces well and meets the experimental requirements. Based on the optimal moulding process conditions determined in this experiment, the total porosity, EC, and pH of the Biomass seedling pots were determined to be 67.32%, 1.63 mS/cm, and 6.7, respectively, which met the seedling requirements.

Studies on Distant Hybridization Compatibility between the Azalea (Rhododendron × hybridum hort.) and the Rhododendron decorum Franch. Native to China

Rhododendron resources are abundant in China, and hybridization breeding technology is the primary method for cultivating Rhododendron varieties. In order to optimize the utilization of wild Rhododendron resources for distant hybridization, this study took three horticultural varieties of Rhododendron subgenus Tsutsusi and the Rhododendron decorum Franch. of the subgenus Hymenanthes as the research objects, and the cross-compatibility between subgenera was analyzed from the aspects of pollen tube growth and ovary and seed development. At the same time, the statistics of ovary swelling rate and fruit bearing rate, numbers of capsule seeds, 1000 seed weight of hybrid seeds, germination rate, green seedling rate, and other indexes were analyzed to comprehensively evaluate hybrid fertility. The results showed that there was obvious pre-fertilization and post-fertilization barriers existing in the hybridization of Rhododendron × hybridum hort. and R. decorum. During the growth of pollen tubes, a large amount of callus appeared, which led to the entanglement, distortion, and abnormal development of the pollen tubes; only part of the pollen tubes entered into the ovary or ovule. The pre-fertilization barriers can be overcome by early pollination and delayed pollination. According to the observation of the ovary paraffin section, 45 d after pollination, the seed was shriveled and developed abnormally. The comprehensive evaluation of hybrid fertility showed that ‘Sima’ × R. decorum was fertile, ‘Yin Taohong’ × R. decorum was a weakly fertile, and ‘Little Taohong’ × R. decorum was sterile. This study provided a scientific basis for intergeneric hybridization breeding between the subgenus Tsutsusi and the subgenus Hymenanthes.

Strontium ranelate-loaded human hair keratin-hyaluronic acid hydrogel accelerates wound repair with anti-inflammatory and antioxidant properties

Inflammation and reactive oxygen species (ROS) production often accompany the repair of severe skin wounds, and the management of wounds has always been a clinical challenge, so the design of a hydrogel wound dressing with antioxidant and anti-inflammatory properties is of significant importance. This work incorporated strontium ranelate (SrR) into the keratin/hyaluronic acid (K/HA) hydrogel, which could scavenge ROS and reduce inflammation. The optimized hydrogel exhibits large pore size (217.2 μm), high porosity (57 %), high swelling rate (1759.52 %), and an elastic modulus (3.41 kPa). In the in vitro study, incorporating SrR into hydrogel effectively inhibited oxidative damage in mouse fibroblasts (L929) and improved anti-inflammatory effect in RAW264.7 cells stimulated by lipopolysaccharide. The in vivo study showed that, compared with the control group, the expression of ROS, IL-6 and TNF - α in the K/HA/0.5 mM SrR group were significantly reduced to 31.6 %, 39.7 % and 61.1 %, respectively. The in vivo evaluation in a full-thickness wound defect model demonstrated that K/HA/0.5 mM SrR hydrogel promotes wound healing by attenuating ROS levels, reducing inflammation, and promoting microangiogenesis. In summary, the excellent ROS scavenging and anti-inflammatory properties of SrR make the K/HA/SrR hydrogel a promising and effective strategy for wound healing.

Efficient sealing of cemented sheath: An oil-responsive self-healing latex with toughness enhancement for cement composites

The integrity of the cemented sheath is important to the safe exploration of oil and gas resources. Sealing failure of cement sheath will result in formation fluid channeling and pressure carryover in the annulus. The both toughening and oil-responsive self-healing latex (TOS) was prepared to achieve efficient sealing of cemented sheath, and prolong its service life. The structure and oil swelling behavior of TOS, its toughening and self-healing effects on hardened cement paste (HCP) were analyzed by comprehensive characterizations. Results demonstrated that TOS possessed excellent stability and an oil swelling rate of 1235 %. Cement specimens by curing 28d containing 8 % TOS exhibited a 27.8 % increase in flexural strength, a 48.7 % reduction in elasticity modulus and a 33.8 % reduction in brittleness coefficient. The addition of TOS can effectively improve the toughness of cement. The average pore size of specimens containing 8 % TOS admixture decreased to 9.17 nm. This indicates that TOS enhanced the structural density of cement materials. The crack about 103μm in the cracking specimens with 8 % TOS was almost healed, and the corresponding permeability was reduced 99.1 % after curing in oil. Adsorption and film formation of TOS can resist the cracking of cement sheath, and the oil swelling expansion of film in cement matrix can repair the cracked structure.

Preparation of a chitosan/polyvinyl alcohol-based dual-network hydrogel for use as a potential wound-healing material for the sustainable release of drugs

Treating chronic wounds poses significant challenges in clinical medicine due to bacterial infection, reactive oxygen species (ROS) accumulation, and excessive inflammation. This study aimed to address these issues by developing a wound dressing with antibacterial, antioxidant, and anti-inflammatory properties. Chitosan was functionally modified with acrolein to covalently bind to epigallocatechin gallate (EGCG), enabling a high EGCG load. Subsequently, polyvinyl alcohol (PVA) and EGCG-modified chitosan were crosslinked to prepare a new double-network hydrogel with added cysteine (CSAEC/P50). CSAEC/P50 demonstrated optimal mechanical properties (low swelling rate, high water retention, and optimal flexibility), low hemolysis, high coagulation properties, and antibacterial and antioxidant activities. Cell scratch tests indicated that CSAEC/P50 can promote NIH3T3 cell migration. Immunofluorescence results showed that CSAEC/P50 promoted the transformation of proinflammatory M1 macrophages to anti-inflammatory M2 macrophages. These findings suggest that CSAEC/P50 has significant potential for use in wound dressing applications.

Magnesium oxide nanoparticle reinforced pumpkin-derived nanostructured cellulose scaffold for enhanced bone regeneration

Considering global surge in bone fracture prevalence, limitation in use of traditional healing approaches like bone grafts highlights the need for innovative regenerative strategies. Here, a novel green fabrication approach has reported for reinforcement of physicochemical performances of sustainable bioinspired extracellular matrix (ECM) based on decellularized pumpkin tissue coated with Magnesium oxide nanoparticles (hereafter called DM-Pumpkin) for enhanced bone regeneration. Compared to uncoated scaffold, DM-Pumpkin exhibited significantly improved surface roughness, mechanical stiffness, porosity, hydrophilicity, swelling, and biodegradation rate. Obtained nanoporous structure provides an ideal three-dimensional microenvironment for the attachment, migration and osteo-induction in human adipose-derived mesenchymal stem cells (h- AdMSCs). Calcium deposition and mineralization, alkaline phosphatase activity, and SEM imaging of the cells as well as increased expression of bone-related genes after 21 days incubation confirmed capability of DM-Pumpkin in mimicking the biological properties of bone tissue. The presence of MgONPs had a silencing effect on inflammatory factors and improved wound closure, verified by in vivo studies. Increased expression of collagen type I and osteocalcin in the h- AdMSCs cultured on DM-Pumpkin compared to control further corroborated gained results. Altogether, boosting physicochemical and biological properties of DM-Pumpkin due to surface modification is a promising approach for guided bone regeneration.

Fabrication and characterization of nanohydroxyapatite/chitosan/decellularized placenta scaffold for bone tissue engineering applications

Novel biomaterials are necessary to fabricate biomimetic scaffolds for bone tissue engineering. In the present experiment, we aimed to fabricate and evaluate the osteogenic properties of nanohydroxyapatite/chitosan/decellularized placenta (nHA.Cs.dPL) composite scaffolds. The human placenta was decellularized (dPL), characterized, and digested in pepsin to form the hydrogel. nHA.Cs.dPL scaffolds were fabricated using salt leaching/freeze drying and evaluated for their morphology, chemical composition, swelling, porosity, degradation, mechanical strength, and biocompatibility. Saos-2 cells were seeded on scaffolds, and their osteogenic properties were investigated by evaluating alkaline phosphatase (ALP), osteocalcin (OCN), collagen type 1 (COL I) expression, and calcium deposition under osteogenic differentiation. The dPL was prepared with minimized DNA content and a well-preserved porous structure. Scaffolds were highly porous with interconnected pores and exhibited appropriate swelling and degradation rates supporting saos-2 cell attachment and proliferation. dPL improved scaffold physicochemical features and increased cell proliferation, ALP, OCN, COL I expression, and calcium deposition under osteogenic differentiation induction. nHA.Cs.dPL composite scaffolds provide a 3D microenvironment with superior physicochemical features that support saos-2 cell adhesion, proliferation, and osteogenic differentiation.

Investigation and kinetics of hydrogel scaffold with sustained release ciprofloxacin hydrochloride

AbstractControlled drug delivery is the mechanism that determines the frequency of the drug as well as the side effect that can be occurred. Many approaches studied the encapsulation of the drug in a polymer matrix to achieve a controlled released drug by the effect crosslinking network. In this work, a loaded hydrogel with ciprofloxacin hydrochloride has been prepared as an incremental effect on the antibacterial properties. So, four formulations named, hydrogel 1, hydrogel 2, hydrogel 3, and hydrogel 4 were prepared using different polymers concentrations (chitosan, gelatin, iota carrageenan (IC), and glutaraldehyde as crosslinking agents) ciprofloxacin hydrochloride was used as a drug model. The obtained data revealed that the hydrogels prepared from chitosan/gelatin/IC hydrogels are porous and have interconnected microstructures. The hydrogels structure was evaluated by ATR-IR spectroscopy, EDX, Swelling rate, SEM, porosity, antibacterial properties as well as drug release and kinetics. The hydrogels fractured at stresses of 0.1665 to 0.0358 Kgf / mm2. The swelling rates (SR %) after 24 h. were 412%, 362%, 383%, 375% and 407% for of hydrogel 1, hydrogel 2, hydrogel 3, hydrogel 4 and ciprofloxacin hydrochloride loaded hydrogel 1, respectively. The porosity of the prepared hydrogels was increased as the concentration of IC increased from 72.4 to 78%. Loading of ciprofloxacin hydrochloride was confirmed by the presence of fluorine in the EDX measurement. The ciprofloxacin hydrochloride loaded hydrogel 1 has a sustained release of ciprofloxacin hydrochloride over a time of about 10 h. The first-order kinetic model is the best model for the release of ciprofloxacin hydrochloride from the prepared ciprofloxacin hydrochloride loaded hydrogel 1 with a regression coefficient (R2) of 0.9814. The unloaded samples of hydrogels had almost the same antibacterial properties regardless of the amount of IC. Loading the hydrogel with ciprofloxacin hydrochloride has an incremental effect on the antibacterial properties.

Alginate sulfonamide hydrogel beads for 5-fluorouracil delivery: antitumor activity, cytotoxicity assessment, and theoretical investigation

This study focused on grafting a new monomer (E)-N-(4-(3-(4-bromophenyl) acryloyl) phenyl)-4-methyl benzene sulfonamide (Br-PS) onto sodium alginate (Alg) using a free radical polymerization method. The optimal parameters for the grafting polymerization reaction were investigated, including initiator and monomer concentrations, polymerization reaction duration, and temperature. Additionally, the conversion, graft, and solid content percentages were calculated. The resulting novel poly (Br-PS)-g-Alg was thoroughly analyzed using Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), and scanning electron microscopy (SEM). Moreover, poly (Br-PS)-g-Alg was tested for cytotoxicity and selectivity values on lung cancer cell line (A549), breast cancer cell line (MDA-MB-231), and a normal cell line (MDCK) using the neutral red uptake test. Poly (Br-PS)-g-Alg demonstrated more inhibitory impact (IC50 = 33.37 and 40.9 μg/mL) and high selectivity (selectivity index = 4.83 and 3.94) on the A549 and MDA-MB-231 cell lines, respectively. Furthermore, uniform beads of creative poly (Br-PS)-g-Alg were fabricated, and their swelling rate in various media was studied. These beads could potentially serve as drug carriers for 5-fluorouracil (5-FU). Release experiments in simulated gastric (SGF) and intestinal fluids (SIF) showed a slower 5-FU release pattern in SGF compared to SIF. The proposed structures of poly (Br-PS)-g-Alg were theoretically verified using density functional theory with DFT/B3LYP/6–31(G) basis set, revealing distinct interactions due to the presence of different functional groups. The findings of this study could significantly impact the development of new drug delivery systems.

Recombinant Keratin-Chitosan Cryogel Decorated with Gallic Acid-Reduced Silver Nanoparticles for Wound Healing.

Wound healing is a complex physiological process that can be roughly divided into four stages: hemostasis, inflammation, proliferation, and remodeling. Conventional wound dressings often fail to meet the diverse needs of these healing stages due to their limited functionality. Cryogels, however, possess several attractive properties, such as large, interconnected pores, good mechanical strength, and ease of modification, making them suitable for developing advanced dressings with multiple functions. In this study, we developed a multifunctional cryogel dressing, with biocompatible polysaccharides as the main component, designed to provide a breathable, moist, and antibacterial microenvironment for chronic infected wounds, thereby promoting wound healing. Recombinant keratin 31 (RK31) was combined with chitosan (CS) to produce a CS/RK31 cryogel, referred to as CK. Gallic acid-reduced silver nanoparticles (GA/Ag NPs) were incorporated as the active antibacterial component to create the CS/K31@GA/Ag cryogel, known as CKGA. The cryogel was characterized using scanning electron microscopy (SEM) and a universal testing machine, and its biocompatibility was assessed in vitro. The dynamic hemostatic performance of the cryogel was evaluated with a rat tail amputation bleeding model. Additionally, the antibacterial effects of the cryogel against Staphylococcus aureus and Escherichia coli were tested using agar diffusion assays and turbidimetry. The antioxidant capacity of the CKGA cryogel was also measured in vitro. Finally, the cryogel's ability to promote wound healing was tested in an SD rat model of infected wounds. Characterization results showed that the CKGA cryogel features an interpenetrating porous network structure and exhibits excellent mechanical properties, with a swelling rate of up to 1800%. Both in vitro and in vivo experiments confirmed that the cryogel has good biocompatibility, effectively absorbs exudates, and rapidly stops bleeding. The addition of GA/Ag NPs provided significant antibacterial effects, achieving an inhibition rate of over 99.9% against both S. aureus and E. coli. Furthermore, CKGA cryogels demonstrated a strong scavenging capacity for ROS in a dose-dependent manner. Studies using the SD rat infected wound model showed that the cryogel effectively inhibited bacterial proliferation on wound surfaces, reduced local tissue inflammation, and promoted the healing of infected wounds. The multifunctional cryogel, with its rapid hemostatic, antibacterial, and antioxidant properties, as well as its ability to promote cell proliferation, could be widely used as a wound dressing for the healing of bacterial infections.

Preparation of zwitterionic polymer and its application for dual-functional inhibition in deepwater drilling

During deep-water drilling operations, due to the conditions with low temperature and high pressure in the wellbore, methane hydrate can be easily formed in the presence of methane and plug the wellbore. In addition, the deep-water sediments are dominated by clay-silty with weak cementation, so well instability may be occurred due to clay hydration. In order to inhibit hydrate formation and clay hydration in deepwater drilling, a zwitterionic polymer AADV was synthesized through quaternary copolymerization of AM/AMPS/DMDAAV/VAC. The hydrate inhibition performance of AADV was evaluated in a high-pressure reactor chamber, and the results showed that AADV can delay the hydrate formation time from 330 min in pure water to 2204 min, indicating an excellent inhibition effect of hydrate formation. Meanwhile, 1 % AADV can significantly reduce the linear swelling rate of the calcium-based bentonite to 3.69 % for 10 h and increase the rolling recovery rate to 94.7 %, suggesting an excellent inhibition effect on clay hydration. The mechanism of dual-functional inhibition of AADV was further analyzed. The zwitterionic group in AADV and the hydrophilic amide group can strongly adsorb the water molecules through a strong hydration effect and the hydrogen bonding effect, respectively, which contributes to destroy the water molecules cage structure, and thus to suppress the hydrate formation. Besides, AADV can effectively obstruct mass transfer of methane molecules by increasing the viscosity of the aqueous phase and absorbing on the hydrate surface, leading to hydrate formation inhibition. For the inhibition of clay hydration, the SEM and XRD results proved that AADC inhibits the clay hydration through the film-forming effect. In addition, the contact angle of Na-Bent/AADC composite reached to 55.68° when the polymer concentration increased to 2 %, suggesting that the hydrophobicity of Na-Bent surface can be enhanced after AADC treatment. AADV can wrap around clay particles and form hydrophobic film through adsorption and intercalation, preventing the intrusion of external fluids and inhibiting clay hydration.

Swelling and dissolution behaviors of cellulose in phosphate-based ionic liquids-H2O binary systems: In-situ observation and molecular dynamics simulation

Swelling and dissolution of cellulose in ionic liquids (ILs) as the pretreatment processes are key steps for the high-value conversion and utilization of cellulose. However, the molar ratio of H2O to ILs has a significant effect on the swelling and dissolution of cellulose, and its molecular-scale mechanism is still unclear, which limits screening out the suitable ILs and recovery of ILs from coagulation bath in the spinning process. Herein, three phosphate-based ILs were chosen to couple with water as solvents for swelling and dissolution of cellulose by combining in-situ observation and molecular dynamics (MD) simulation. The results show that the redissolution time of swollen cellulose is greatly reduced, especially [Emim]DEP-H2O has the best swelling and dissolution performance for cellulose due to its high β value and low viscosity. Meanwhile, when the molar ratio of IL to H2O was more than 1: 1, the IL-H2O system still has the ability to dissolve cellulose. While with the molar ratio further decreased, cellulose was no longer dissolved and began to swell, and the fiber diameter obtained the maximum swelling rate with 40.1% at a molar ratio of 1: 3. Moreover, MD simulation was used to calculate the interaction between IL/water/cellulose, which further illustrated that the combination of IL with water molecular has a significant influence on the behavior of cellulose in IL-H2O systems at the molecular scale. Thus, the potential swelling and dissolution mechanism of cellulose in ILs-H2O binary systems was proposed based on experimental and simulation results. Furthermore, the characterization results of swollen cellulose indicate that the crystal structure and degree of polymerization (DP) were almost unchanged, but the specific surface area and pore size increased significantly, and the thermal stability and heat absorption were decreased, all the results prove that the swelling process increased the accessibility of cellulose and benefited to the subsequent dissolution. Consequently, preferable swelling and dissolving parameters of experiments and simulations will provide a new idea for the selection of suitable ILs and the recovery of ILs from a coagulation bath in the dry-wet spinning process.

Developing a multifunctional chitosan composite sponge for managing traumatic injuries

Developing porous hemostatic sponges that are both biosafe and multifunctional remains a complex challenge. Conventional hemostatic techniques often fall short in managing bleeding effectively, leading to severe critical cases such as suboptimal hemostasis, increased infection risk, and complications arising from profuse bleeding. To address these deficits, our study introduces a novel multifunctional nanocomposite sponge that synergistically incorporates chitosan (CS), cellulose (Cel), graphene oxide (GO), and silver (Ag) nanoparticles. The resulting CS/Cel/GO/Ag developed demonstrates a swelling rate exceeding 3000 %, an absorption rate of over 2100 %, and the lowest stress surpassing 20 kPa at an initial 80 % strain. In vitro analyses reveal that the CS/Cel/GO/Ag sponge has excellent cytocompatibility, non-hemolytic nature, and competence in blood cell adherence and bacterial inhibition. In vivo evaluations further demonstrate that compared to conventional hemostatic methods, the sponge substantially enhances hemostatic efficacy, as evidenced by the marked reductions in clotting times and diminished blood loss compared to conventional hemostatic methods. Specifically, the test results of the CS/Cel/GO/Ag sponge across three different models are as follows: for the rat tail amputation model, the clotting time was 99 s, while blood loss was 222 mg; for the rat liver injury model, the clotting time was 129 s. while blood loss was 812 mg; for the rat femoral artery laceration model, the clotting time was 96 s, while blood loss was 758 mg. The compelling attributes of the CS/Cel/GO/Ag sponges position them as a promising solution for the acute management of bleeding. Their excellent performance indicates they have potential role to play in trauma care.