Hydrophobic iron oxide nanoparticles: Controlled synthesis and phase transfer via flash nanoprecipitation.

Iron oxide nanoparticles (IONPs) synthesized via thermal decomposition find diverse applications in biomedicine owing to precise control of their physico-chemical properties. However, use in such applications requires phase transfer from organic solvent to water, which remains a bottleneck. Through the thermal decomposition of iron oleate (FeOl), we systematically investigate the impact of synthesis conditions such as oleic acid (OA) amount, temperature increase rate, dwell time, and solvent on the size, magnetic saturation, and crystallinity of IONPs. Solvent choice significantly influences these properties, manipulating which, synthesis of monodisperse IONPs within a tunable size range (10-30 nm) and magnetic properties (75 to 42 Am2Kg-1) is obtained. To enable phase transfer of IONPs, we employ flash nanoprecipitation (FNP) for the first time as a method for scalable and precise size control, demonstrating its potential over conventional methods. Poly(lactic-co-glycolic acid) (PLGA)-coated IONPs with hydrodynamic diameter (Hd) in the range of 250 nm, high colloidal stability and high IONPs loadings up to 43% were obtained, such physicochemical properties being tuned exclusively by the size and hydrophobicity of starting IONPs. They showed no discernible cytotoxicity in human dermal fibroblasts, highlighting the applicability of FNP as a novel method for the functionalization of hydrophobic IONPs for biomedicine.

Semiconducting polymer nanoprodrugs enable tumor-specific therapy via sono-activatable ferroptosis.

Ferroptosis, a recently identified form of cell death, holds promise for cancer therapy, but concerns persist regarding its uncontrolled actions and potential side effects. Here, we present a semiconducting polymer nanoprodrug (SPNpro) featuring an innovative ferroptosis prodrug (DHU-CBA7) to induce sono-activatable ferroptosis for tumor-specific therapy. DHU-CBA7 prodrug incorporate methylene blue, ferrocene and urea bond, which can selectively and specifically respond to singlet oxygen (1O2) to turn on ferroptosis action via rapidly cleaving the urea bonds. DHU-CBA7 prodrug and a semiconducting polymer are self-assembled with an amphiphilic polymer to construct SPNpro. Ultrasound irradiation of SPNpro leads to the production of 1O2 via sonodynamic therapy (SDT) of the semiconducting polymer, and the generated 1O2 activated DHU-CBA7 prodrug to achieve sono-activatable ferroptosis. Consequently, SPNpro combine SDT with the controlled ferroptosis to effectively cure 4T1 tumors covered by 2-cm tissue with a tumor inhibition efficacy as high as 100 %, and also completely restrain tumor metastases. This study introduces a novel sono-activatable prodrug strategy for regulating ferroptosis, allowing for precise cancer therapy.

Physical stimuli-responsive polymeric patches for healthcare.

Many chronic diseases have become severe public health problems with the development of society. A safe and efficient healthcare method is to utilize physical stimulus-responsive polymer patches, which may respond to physical stimuli, including light, electric current, temperature, magnetic field, mechanical force, and ultrasound. Under certain physical stimuli, these patches have been widely used in therapy for diabetes, cancer, wounds, hair loss, obesity, and heart diseases since they could realize controllable treatment and reduce the risks of side effects. This review sketches the design principles of polymer patches, including composition, properties, and performances. Besides, control methods of using different kinds of physical stimuli were introduced. Then, the fabrication methods and characterization of patches were explored. Furthermore, recent applications of these patches in the biomedical field were demonstrated. Finally, we discussed the challenges and prospects for its clinical translation. We anticipate that physical stimulus-responsive polymer patches will open up new avenues for healthcare by acting as a platform with multiple functions.

Prodrug Nanomedicine for Synovium Targeted Therapy of Inflammatory Arthritis: Insights from Animal Model and Human Synovial Joint Fluid.

Many patients cannot tolerate low-dose weekly methotrexate (MTX) therapy for inflammatory arthritis treatment due to life-threatening toxicity. Although biologics offer a target-specific therapy, it raises the risk of serious infections and even cancer due to immune system suppression. We introduce an anti-inflammatory arthritis MTX ester prodrug using a long-circulating biocompatible polymeric macromolecule: folic acid (FA) functionalized hyperbranched polyglycerol (HPG). In vitro the drug MTX is incrementally released through pH and enzymatic degradation over 2 weeks. The role of matrix metalloproteinases (MMPs) in site-specific prodrug activation was verified using synovial fluid (SF) of 26 rheumatology patients and 4 healthy controls. Elevated levels of specific MMPs-markers of joint inflammation-positively correlated with enhanced prodrug release explained by acid-catalyzed hydrolysis of esters by proteases. Intravenously administered 111In-radiolabeled prodrug confirmed by SPECT/CT imaging that it accumulated preferentially in inflamed joints while reducing off-target side-effects in a mouse model of rheumatoid arthritis (RA). Added FA as a targeting vector prolonged prodrug action; prodrug with 4x less MTX applied every 2 weeks was as effective as weekly MTX therapy. The preclinical results suggest a prodrug-based strategy for the treatment of inflammatory joint diseases, with potential for other chronic inflammatory diseases and cancer.

More Efficient Chemical Recycling of Poly(ethylene terephthalate) by Intercepting Intermediates.

The research presented in this paper offers insight into the availability of intermediates in the depolymerization of Polyethylene Terephthalate (PET) to be used as feedstocks to create value added products. Monitoring the dispersity, molecular weight, end groups, and crystallinity of reaction intermediates during the heterogeneous depolymerization of PET offer insight into the mechanism by which the polymer chains evolve during the reaction. Our results show dispersity decreases and crystallinity increases, while the yield of insoluble PET remains high early in the reaction. Our interpretation of this data depicts a mechanism where chain scission targets amorphous tie-chains between crystalline phases. Targeting the tie-chains lowers the Mn of the polymer without changing the amount of recovered polymer flake. Chain scission of tie-chains and isolating highly crystalline PET lowers the dispersity ((D)) of the polymer chains, as the size of the crystalline lamellae guide the molecular weight of the depolymerized oligomers.  When sufficient end groups of PET chains are converted to alcohol groups, the PET flakes break apart into highly crystalline and less disperse polymer. Our results also demonstrate that the oligomeric depolymerization intermediates are readily repolymerized, offering new opportunities to more effectively and efficiently chemically recycle PET.

A novel Co/Zn-ferrite molecularly imprinted polymer-based electrochemical assay for sensing of gallic acid in plant extracts, wine, and herbal supplement.

In this study, a new molecularly imprinted polymer (MIP)-based sensor platform was developed for the electrochemical determination of gallic acid (GAL) in plant extracts, wine, and herbal supplements. Gallic acid is known for its natural antioxidant properties, which play an important role in preventing cell deterioration that can lead to various diseases. In addition, gallic acid has therapeutic potential due to its anticancer, antiinflammatory, antimicrobial, and neuroprotective properties. Accurate analysis of gallic acid in complex matrices, in mixed samples where different components coexist, is necessary to evaluate the efficacy and safety of this compound. Cobalt ferrite-zinc-dihydro caffeic acid (CFO_Zn_DHCA) nanoparticles, sphere-like in shape and 5 ± 1 nm in size, were incorporated into the MIP-based electrochemical sensor design to enhance the active surface area and porosity of the glassy carbon electrode (GCE) surface. The functional monomer chosen for this study was aminophenyl boronic acid (3-APBA). In the GAL/CFO_Zn_DHCA/3-APBA@MIP-GCE sensor, which was developed using photopolymerization (PP), 3-APBA as a functional monomer was designed, and obtained in the presence of basic monomer (HEMA), cross-linker (EGDMA), and initiator (2-hydroxy-2-methyl propiophenone) by keeping it under a UV lamp at 365 nm. It aims to detect GAL in real samples such as Punica granatum (pomegranate) peel, Camellia sinensis (green and black tea leaves), wine, and herbal supplements. Morphological and electrochemical characterizations of the designed GAL/CFO_Zn_DHCA/3-APBA@MIP-GCE sensor were carried out using scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The linear range for the determination of GAL using the indirect method (5.0 mM [Fe(CN)6]-3/-4) was found to be 1.0 × 10-13 M-1.0 × 10-12 M, and the limit of detection (LOD) and limit of quantification (LOQ) for standard solutions were calculated as 1.29 × 10-14 and 4.29 × 10-14 M, respectively. As a result of the study, the developed MIP-based electrochemical sensor was suitable for detecting GAL with high specificity, selectivity, and sensitivity. Recovery studies were performed to determine the practical applicability of the sensor, and the results were satisfactory. This innovative sensor platform stands out as a reliable and sensitive analytical tool for determining GAL.

Formulation development, characterization, and evaluation of sorafenib-loaded PLGA-chitosan nanoparticles.

The basic purpose of this work was to develop environmentally friendly, biodegradable, and biocompatible polymeric nanoparticles of sorafenib that can effectively release the desired drug in a customized and controlled manner for targeting hepatocellular carcinoma. The solvent evaporation technique was employed for the synthesis of sorafenib-loaded PLGA-chitosan nanoparticles, followed by various experimental specifications and compatibility studies using poloxamer 407 as the stabilizer. The best nanoparticles thus synthesized were selected to be used for cytotoxicity investigations through in vitro and in vivo assessments. For the in vitro drug release tests, the dialysis bag diffusion technique was used. For both chitosan nanoparticles and PLGA loaded with sorafenib, a biphasic release pattern was found, exhibiting a protracted release lasting 10 days after a 24-h burst release. As experimental animals, rabbits were utilized to evaluate different in vivo pharmacokinetic properties of the selected formulations. Plasma samples were extracted with acetonitrile and analyzed through the developed HPLC method. Pharmacokinetic parameters such as AUC0-t, Cmax MRT, Vd, and half-life (t1/2) were enhanced significantly (p ≤ 0.001), while clearance was considerably decreased (p ≤ 0.001) for the chosen synthesized nanoparticles in contrast to the commercially accessible sorafenib formulation (Nexavar®). The cytotoxicity of the reference drug and sorafenib-loaded PLGA and chitosan nanoparticles was calculated by performing an MTT assay against HepG2 cell lines. The developed polymeric sorafenib nanoformulations possess the appropriate physicochemical properties, better targeting, surface morphology, and prolonged release kinetics. The pharmacokinetic parameters were improved significantly when the results were compared with commercially available sorafenib formulations.

Multisite Crosslinked Poly(ether-urethane)-Based Polymer Electrolytes for High-Voltage Solid-State Lithium Metal Batteries.

Utilizing solid-state polymer electrolytes (SPEs) in high-voltage Li-metal batteries is a promising strategy for achieving high energy density and safety. However, the SPEs face the challenges such as undesirable mechanical strength, low ionic conductivity and incompatible high-voltage interface. Here, a novel crosslinked poly(ether-urethane)-based SPE with a molecular cross-linked structure is fabricated to create high-throughput Li+ transport pathway. The amino-modified Zr-porphyrin-based metal-organic frameworks (ZrMOF) are introduced as multisite cross-linking nodes and polymer chain extenders. The abundant ether/ketonic-oxygen and Lewis acid sites in the SPE achieve high Li+ conductivity (5.7 × 10-4 S cm-1 at 30 °C) and Li+ transference number (0.84). The interpenetrating cross-linked structure of SPE with robust mechanical strength results in a record cycle life of 8000 h in Li||Li symmetric cell. The high structural stability of ZrMOF and abundant electron-withdrawing urethane/ureido groups in the SPE with high oxidation potential (5.1 V) enables a discharge capacity of 182 mAh g-1 at 0.3 C over 500 cycles in a LiNi0.8Co0.1Mn0.1O2||Li cell. Remarkably, a high energy density of 446 Wh kg-1 in a 1.5-Ah pouch cell is obtained with high loading cathode (≈4 mAh cm-2), demonstrating a great prospect of the current SPE for practical application in solid-state, high-voltage Li-metal batteries.

Three-dimensional source position verification in image-guided high-dose-rate brachytherapy using an XCT-based gel dosimeter.

BACKGROUND: Comprehensive quality assurance (QA) for a seamless workflow of high-dose-rate brachytherapy, from imaging to planning and irradiation, is uncommon, and QA of the source dwell position is performed in one- or two-dimensions. Gel dosimetry using magnetic resonance imaging (MRI) is effective in verifying the three-dimensional distribution of doses for image-guided brachytherapy (IGBT). However, MRI scanners are not readily accessible, and MRI scanning is time-consuming. Nevertheless, X-ray computed tomography (XCT) is available for IGBT planning. PURPOSE: In this study, we designed and developed an efficient method for QA for a seamless workflow of IGBT with a new commercially available XCT-based polymer gel dosimeter. METHODS: To enable direct insertion of brachytherapy applicators, the gelatinizing agent of the dosimeter was modified. A cylindrical polyvinyl chloride jar was filled with the modified gel dosimeter, which was subsequently used to determine the reproducibility of source dwell positions, detectability of source positional errors from intentionally introduced catheter length offsets, effect of looped source transfer tubes on the average displacement, extent of inter-observer variation, and gel robustness following multiple needle-insertions. Three ProGuide sharp needles were inserted into the jar. The dwell time at each point was determined to identify the irradiated volume with a diameter of approximately 10 mm on XCT images. All the times were the same. The plan was delivered using an afterloader with an Ir-192 radioactive source, and the irradiated gel dosimeter was scanned using an XCT scanner. The subtracted images were generated from pre- and post-irradiated images. Volumes with incremented Hounsfield units were manually identified and contoured. The centroid of the volume was defined as the measured source dwell position. Subsequently, planned source dwell positions were extracted from the DICOM file of the plan. Finally, the source dwell positions in plan and irradiated gel were compared in three axes. RESULTS: The hardness of the dosimeter was 1250% greater than that of the previously reported gel dosimeter. Source dwell positions were visually identified in the XCT image. Testing of CT acquisition, planning, irradiation, and analysis was completed in approximately 1 h. In the reproducibility test of source dwell positions, created by inserting three needles (each with three source dwell positions), the average displacements of the source positions from the first source dwell position were within 0.5 mm in all three directions. In the detectability test, displacements were less than 1 mm in the x-y plane but greater than 1 mm in the z-axis, which was the source path direction. When errors of 1-3 mm were intentionally introduced, the measured displacement was within 0.7 mm of the median (range: 0.21-1.65 mm) of intentional errors. When the transfer tube was looped, the source dwell position displaced by approximately 1 mm. After 20 needle-insertions, the source dwell position displacement was within 1 mm. The maximum inter-observer variation of contouring was 0.57 mm. CONCLUSIONS: The XCT-based gel dosimeter enabled verification of three-dimensional source dwell positions for a seamless workflow of IGBT with high precision and efficiency.

Amino Acid-Based Protein-Mimic Hydrogel Incorporating Pro-Regenerative Lipid Mediator and Microvascular Fragments Promotes the Healing of Deep Burn Wounds.

Pro-regenerative lipid mediator 1 (PreM1) is a specialized pro-resolving lipid mediator that promotes wound healing and regenerative functions of mesenchymal stem cells (MSCs), endothelial cells, and macrophages. The healing of third-degree (3°) burns and regenerative functions of MSCs are enhanced by ACgel1, an arginine-and-chitosan-based protein-mimic hybrid hydrogel. Adipose-tissue derived microvascular fragments (MVFs) are native vascularization units and a rich source of MSCs, endothelial cells, and perivascular cells for tissue regeneration. Here we describe an innovative PreM1-MVFs-ACgel1 construct that incorporated PreM1 and MVFs into ACgel1 via optimal design and fabrication. This construct delivered PreM1 to 3°-burn wounds at least up to 7 days-post-burn (dpb), and scaffolded and delivered MVFs. PreM1-MVFs-ACgel1 promoted the healing of 3°-burns in mice, including vascularization and collagen formation. The re-epithelization and closure of 3° burn wounds were promoted by ACgel1, MVFs, PreM1, MVFs-ACgel1, PreM1-ACgel1, or PreM1-MVFs-ACgel1 at certain time-point(s), while PreM1-MVFs-ACgel1 was most effective with 97% closure and 4.69% relative epithelial gap at 13 dpb compared to saline control. The PreM1-ACgel1 and MVFs-ACgel1 also promoted blood vessel regeneration of 3°-burns although PreM1-MVFs-ACgel1 is significantly more effective. These PreM1- and/or MVF-functionalized ACgel1 have nonexistent or minimal graft-donor requirements and are promising adjuvant therapeutic candidates for treating deep burns.

An impedimetric determination of zearalenone on MIP-modified carboceramic electrode.

Zearalenone (ZEN) is a mycotoxin that poses significant risks to human and animal health due to its mutagenic, immunosuppressive, and carcinogenic properties. This study presents a novel analytical method for detecting ZEN using electrochemical impedance spectroscopy (EIS) combined with a molecularly imprinted polymer (MIP). ZEN, used as the template molecule, was incorporated into polypyrrole on screen-printed electrodes (SPE), and a ZEN-sensitive MIP sensor was created through template removal. The modified sensor surfaces were characterized by EIS and scanning electron microscopy (SEM). An impedimetric MIP sensor for ZEN was developed, offering a detection range from 1 pM to 500 pM. The method's limit of detection (LOD) was established at 1 pM (0.3 pg/mL) with a signal-to-noise ratio of 3 (S/N = 3). The method demonstrated high precision and accuracy, with a maximum relative standard deviation (RSD) of less than 4.4% at a 95% confidence level, and relative error (RE) values ranging from -0.8% to -2.7%. The selectivity of the developed MIP sensor was evaluated using ochratoxin A, ochratoxin B, and aflatoxin B1, with no significant interference observed. ZEN recovery from spiked samples was between 95% and 105%, indicating that the method was successfully applied to grain samples, including corn, rice, and wheat.

Design of a molecularly imprinted polymer sensor modified with saffron-based copper nanoflowers for highly selective and sensitive determination of bortezomib.

This work represents the first successful application of a molecularly imprinted polymer (MIP)-based electrochemical sensor for the sensitive and selective determination of the first developed proteasome inhibitor, bortezomib (BOR). BOR is used for the treatment of multiple myeloma, gastrointestinal stromal tumors, and mantle cell lymphoma. It shows its desired effect through the boronate group and can be administered intravenously or subcutaneously. The MIP-based electrochemical sensor design includes the integration of green-synthesized saffron-based copper nanoflowers (CuNFs) from Crocus sativus L. to increase the active surface area and porosity of the glassy carbon electrode (GCE) surface. 2-Acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was selected as the functional monomer along with other MIP components. Detailed characterizations of the developed CuNFs/AMPS/MIP-GCE sensor and CuNFs were performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The indirect measurement approach using 5.0 mM [Fe(CN)6]3-/4- solution was used to determine BOR in the linear range of 2.5 × 10-13 M - 2.5 × 10-12 M (0.25-2.5 pM). The LOD and LOQ values of the sensor obtained at the fM level (29 fM and 96.7 fM), which has a linear response in the commercial human serum sample in the same concentration range, emphasize its sensitivity (1.89 × 1013 and 2.14 × 1013 µA/M for standard solution and serum). The repeatability and reproducibility of the sensor were between 0.87 % and 2.17 %, showing its reliability. The successful performance of the sensor in the presence of metabolites belonging to BOR demonstrates its unique selectivity. The selectivity was demonstrated via relative imprinting factor (IF') values (higher than 3.5) against BOR's metabolites. The stability of the CuNFs/AMPS/MIP-GCE sensor was found to be 5 days.

Boosting the Strength and Toughness of Polymer Blends via Ligand-Modulated MOFs.

Mechanically robust and tough polymeric materials are in high demand for applications ranging from flexible electronics to aerospace. However, achieving both high toughness and strength in polymers remains a significant challenge due to their inherently contradictory nature. Here, a universal strategy for enhancing the toughness and strength of polymer blends using ligand-modulated metal-organic framework (MOF) nanoparticles is presented, which are engineered to have adjustable hydrophilicity and lipophilicity by varying the types and ratios of ligands. Molecular dynamics (MD) simulations demonstrate that these nanoparticles can effectively regulate the interfaces between chemically distinct polymers based on their amphiphilicity. Remarkably, a mere 0.1 wt.% of MOF nanoparticles with optimized amphiphilicity (ML-MOF(5:5)) delivered ≈3.4- and ≈34.1-fold increase in strength and toughness of poly (lactic acid) (PLA)/poly (butylene succinate) (PBS) blend, respectively. Moreover, these amphiphilicity-tailorable MOF nanoparticles universally enhance the mechanical properties of various polymer blends, such as polypropylene (PP)/polyethylene (PE), PP/polystyrene (PS), PLA/poly (butylene adipate-co-terephthalate) (PBAT), and PLA/polycaprolactone (PCL)/PBS. This simple universal method offers significant potential for strengthening and toughening various polymer blends.

Removal of phosphate from wastewater using zirconium/iron embedded chitosan/alginate hydrogel beads: An experimental and computational perspective.

Adsorptive removal of phosphate plays a crucial role in mitigating eutrophication. Herein, the Zr/Fe embedded chitosan/alginate hydrogel bead (Zr/Fe/CS/Alg) is reported as an effective phosphate adsorbent. This polymer nanocomposite is synthesized by the in-situ reduction of the metals on the polymer matrix. The synthesized adsorbent was characterized by the FTIR, SEM-EDX, TGA, BET, and XPS. The adsorbent showed a maximum phosphate adsorption capacity of 221.72 mg/g at pH 3. The experimental data fit well with the Freundlich isotherm and pseudo-second-order kinetics model, indicating a heterogeneous multilayer surface formation and a chemisorption-dominated adsorption process. Density Functional Theory (DFT) and Monte Carlo (MC) calculations revealed high negative adsorption energy due to the chemisorption of phosphate on the adsorbent. Hence, the major interactions such as electrostatic attraction, hydrogen bonding, and inner-sphere complexation of phosphate adsorption and Zr/Fe/CS/Alg hydrogel beads were investigated from the experimental and computational analysis. The negative values of thermodynamic parameters indicated a spontaneous, exothermic, and less random adsorption process. The synthesized adsorbent exhibited excellent selectivity toward phosphate and maintained 73 % efficiency after six adsorption/desorption cycles. The Zr/Fe/CS/Alg hydrogel beads reduced the phosphate concentration in real wastewater samples from 19.02 mg/L to 0.985 mg/L, suggesting that these nanocomposite hydrogel beads could be a promising adsorbent for real-world applications.

In-Situ Coating of Iron with a Conducting Polymer, Polypyrrole, as a Promise for Corrosion Protection.

Iron microparticles were coated with polypyrrole in situ during the chemical oxidation of pyrrole with ammonium peroxydisulfate in aqueous medium. A series of hybrid organic/inorganic core-shell materials were prepared with 30-76 wt% iron content. Polypyrrole coating was revealed by scanning electron microscopy, and its molecular structure and completeness were proved by FTIR and Raman spectroscopies. The composites of polypyrrole/carbonyl iron were obtained as powders and characterized with respect to their electrical properties. Their resistivity was monitored by the four-point van der Pauw method under 0.01-10 MPa pressure. In an apparent paradox, the resistivity of composites increased from the units Ω cm for neat polypyrrole to thousands Ω cm for the highest iron content despite the high conductivity of iron. This means that composite conductivity is controlled by the electrical properties of the polypyrrole matrix. The change of sample size during the compression was also recorded and provides a parameter reflecting the mechanical properties of composites. In addition to conductivity, the composites displayed magnetic properties afforded by the presence of iron. The study also illustrates the feasibility of the polypyrrole coating on macroscopic objects, demonstrated by an iron nail, and offers potential application in the corrosion protection of iron. The differences in the morphology of micro- and macroscopic polypyrrole objects are described.

Effect of Butadiene Rubber Crystallization on Low-Temperature Properties of Butadiene/Silicone Rubber Blends with Potential for Mars Applications.

This study explores the impact of butadiene rubber (BR) crystallization on the low-temperature properties of butadiene/silicone (VMQ) rubber blends (BR/VMQ) designed for Martian applications. Two types of BR, semi-crystalline high-cis Buna CB24 and amorphous Buna CB550, were blended with VMQ, and their mechanical and thermal properties were evaluated. Kinetics of vulcanization, static mechanical properties, dynamical mechanical analysis, thermal shrinkage, and differential scanning calorimetry were utilized. The research demonstrates that the semi-crystalline BR improves mechanical properties but induces greater shrinkage at low temperatures. Conversely, using amorphous BR provided more consistent mechanical properties across the Martian temperature range and reduced material shrink by 6.71% for samples with carbon black, by 8.36% for samples with silica, and by 11.63% for unfilled samples. Future research will be required to evaluate the impact of volume change on the sealing properties of the BR/VMQ blends.

Organic and Metal-Organic Polymer-Based Catalysts-Enfant Terrible Companions or Good Assistants?

This overview provides insights into organic and metal-organic polymer (OMOP) catalysts aimed at processes carried out in the liquid phase. Various types of polymers are discussed, including vinyl (various functional poly(styrene-co-divinylbenzene) and perfluorinated functionalized hydrocarbons, e.g., Nafion), condensation (polyesters, -amides, -anilines, -imides), and additional (polyurethanes, and polyureas, polybenzimidazoles, polyporphyrins), prepared from organometal monomers. Covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and their composites represent a significant class of OMOP catalysts. Following this, the preparation, characterization, and application of dispersed metal catalysts are discussed. Key catalytic processes such as alkylation-used in large-scale applications like the production of alkyl-tert-butyl ether and bisphenol A-as well as reduction, oxidation, and other reactions, are highlighted. The versatile properties of COFs and MOFs, including well-defined nanometer-scale pores, large surface areas, and excellent chemisorption capabilities, make them highly promising for chemical, electrochemical, and photocatalytic applications. Particular emphasis is placed on their potential for CO2 treatment. However, a notable drawback of COF- and MOF-based catalysts is their relatively low stability in both alkaline and acidic environments, as well as their high cost. A special part is devoted to deactivation and the disposal of the used/deactivated catalysts, emphasizing the importance of separating heavy metals from catalysts. The conclusion provides guidance on selecting and developing OMOP-based catalysts.

Thermomechanical and Structural Analysis of Manufactured Composite Based on Polyamide and Aluminum Recycled Material.

The paper presents an analysis of the filler's effect on the machining process and on changes in the thermomechanical properties of polymer composites based on aluminum chips. Composite research samples with a polymer matrix in the form of polyamide 6 were made by the pressing method. Comparative studies were carried out on the changes in thermomechanical properties and structure of the obtained molders with different filler contents and different fractions after the machining process. In order to determine the changes in thermal and mechanical properties, analysis was carried out using the differential scanning calorimetry (DSC) method, thermal analysis of dynamic mechanical properties (DMTA) and a detailed stereometric analysis of the surface. After mechanical processing, roughness amplitude parameters and volumetric functional parameters were determined. In order to analyze the structure, tomographic examinations of the manufactured composite were conducted. In relation to the polymer matrix, a significant increase in the storage modulus of the composites was noted in the entire temperature range of the study. An increase in the enthalpy of melting of the matrix was noted in composites with a lower filler content and a shift in the melting range of the crystalline phase. Significant differences were noted in the study of the composite surfaces in the case of using fillers obtained after machining with different fractions. The dependencies of the functional and amplitude parameters of the surfaces after machining of composite samples prove the change in the functional properties of the surface. The use of aluminum chips in the composite significantly changed the surface geometry.

Advances in the Application of Sulfonated Poly(Ether Ether Ketone) (SPEEK) and Its Organic Composite Membranes for Proton Exchange Membrane Fuel Cells (PEMFCs).

This review discusses the progress of research on sulfonated poly(ether ether ketone) (SPEEK) and its composite membranes in proton exchange membrane fuel cells (PEMFCs). SPEEK is a promising material for replacing traditional perfluorosulfonic acid membranes due to its excellent thermal stability, mechanical property, and tunable proton conductivity. By adjusting the degree of sulfonation (DS) of SPEEK, the hydrophilicity and proton conductivity of the membrane can be controlled, while also balancing its mechanical, thermal, and chemical stability. Researchers have developed various composite membranes by combining SPEEK with a range of organic and inorganic materials, such as polybenzimidazole (PBI), fluoropolymers, and silica, to enhance the mechanical, chemical, and thermal stability of the membranes, while reducing fuel permeability and improving the overall performance of the fuel cell. Despite the significant potential of SPEEK and its composite membranes in PEMFCs, there are still challenges and room for improvement, including proton conductivity, chemical stability, cost-effectiveness, and environmental impact assessments.

Nanocarriers Targeting Circular RNA ADARB1 Boost Radiosensitivity of Nasopharyngeal Carcinoma through Synergically Promoting Ferroptosis.

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck, prevalent in regions such as Southern China and Southeast Asia. Radiotherapy serves as the primary clinical treatment for this carcinoma. However, resistance to radiotherapy is a fundamental cause of treatment failure and patient mortality, with the underlying mechanisms yet to be fully elucidated. We identified a recently characterized circular RNA, circADARB1, which is markedly upregulated in NPC tissues and closely associated with poor prognosis and radiotherapy resistance. Both in vitro and in vivo experiments demonstrated that circADARB1 inhibited ferroptosis, thereby inducing radiotherapy resistance in NPC cells. Building on these findings, we synthesized a biomimetic nanomaterial consisting of semiconducting polymer nanoparticles wrapped in cell membranes, designed to deliver both siRNA targeting circADARB1 and iron ions. The application of this nanomaterial not only efficiently suppressed the expression of circADARB1 and boosted intracellular iron concentrations, but also enhanced ferroptosis induced by radiotherapy, improving the radiosensitivity of NPC cells. Furthermore, our study revealed that circADARB1 upregulated the expression of heat shock protein HSP90B1, which repaired misfolded SLC7A11 and GPX4 proteins triggered by radiotherapy, thereby preserving their stability and biological functions. Mechanistically, SLC7A11 facilitated cysteine transportation into cells and glutathione synthesis, while GPX4 employed glutathione to mitigate intracellular lipid peroxidation induced by radiotherapy, shielding cells from oxidative damage and inhibiting ferroptosis, and ultimately leading to radiotherapy resistance in NPC cells. Our investigation elucidates molecular mechanisms with substantial clinical relevance, highlights the promising application prospects of nanotechnology in precision cancer therapy.