Robust magnetic ZnO-Fe2O3 Z-scheme hetereojunctions with in-built metal-redox for high performance photo-degradation of sulfamethoxazole and electrochemical dopamine detection.

This work reports synthesis of a dual-function facile heterojunction and investigation of role of the charge transfer dynamism between individual semiconductor components for superior photocatalytic and electrochemical sensing application. The bio-benevolent and sturdy ZnO/Fe2O3 heterojunctions were utilized for visible light facilitated photo-degradation of sulfamethoxazole (SMX) antibiotic and electrochemical sensing of dopamine drug (DA). The fabricated heterojunction were characterized for structural, optical, and magnetic properties. Structural studies revealed the formation of nano heterojunction containing both phases. Magnetic studies confirmed the highly pure magnetic nature of photocatalysts. ZnO/30 wt%Fe2O3 heterojunction (S2) shows 95.2% SMX degradation under visible light and high retention of performance under solar light. The scavenging experiments infer that OH radicals are the active species responsible for degradation. A Z-scheme photocatalytic mechanism was predicted for higher performance with protection of high potential VB of ZnO and CB of Fe2O3 for high generation of reactive oxygen species. LC-MS was employed to predict a plausible degradation route. The sample modified glassy carbon electrodes (GCE) were used for electrochemical sensing of dopamine via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The S2 junction exhibited 0.18 µM limit of detection with concentration range of 1 µM-50 µM. The stability test was successfully carried out at room temperature for 15 days. In addition, the S2 modified electrodes were spiked in real urine samples and good results were obtained. DPV reveals that S2 modified electrode is best sensor for dopamine sensing among all synthesized heterojunctions. The detection mechanism was also discussed in detail. The in-built metal redox i.e Zn2+/Zn+ and Fe3+/Fe2+ facilitate the Z-scheme transfer, improve the charge transfer capacity and reduce the recombination. This study is beneficial because it reports utilization of popular and well-tested semiconductor metal oxides to form heterojunctions with dual capabilities of environmental detoxification and cost-effective electrochemical detection of biomolecules.

Electrochemical immunosensing of tumor markers.

The rising incidence and mortality rates of cancer have led to a growing need for precise and prompt early diagnostic approaches to effectively combat this disease. However, traditional methods employed for detecting tumor cells, such as histopathological and immunological techniques, are often associated with complex procedures, high analytical expenses, elevated false positive rates, and a dependence on experienced personnel. Tracking tumor markers is recognized as one of the most effective approaches for early detection and prognosis of cancer. While onco-biomarkers can also be produced in normal circumstances, their concentration is significantly elevated when tumors are present. By monitoring the levels of these markers, healthcare professionals can obtain valuable insights into the presence, progression, and response to treatment of cancer, aiding in timely diagnosis and effective management. This review aims to provide researchers with a comprehensive overview of the recent advancements in tumor markers using electrochemical immunosensors. By highlighting the latest developments in this field, researchers can gain a general understanding of the progress made in the utilization of electrochemical immunosensors for detecting tumor markers. Furthermore, this review also discusses the current limitations associated with electrochemical immunosensors and offers insights into paving the way for further improvements and advancements in this area of research.

Exosomes and Their Bioengineering Strategies in the Cutaneous Wound Healing and Related Complications: Current Knowledge and Future Perspectives.

Exosomes, as therapeutically relevant cell-secreted extracellular vesicles, have attracted enormous interest because they participate in intercellular communication and facilitate wound healing. Stem cell-derived exosomes exhibit similar biological effects to source cells with the exception of low immunogenicity and no tumorigenicity, as well as superior efficacy in promoting wound healing. Exosomes accelerate wound healing by promoting angiogenesis and cell proliferation, as well as balancing inflammatory responses. Particularly, when exosomes are genetically modified or used in combination with materials, they can exhibit better comprehensive therapeutic properties, such as enriching active ingredients, targeted delivery, and physiological barrier to penetration, which are not available in traditional single products. Besides, exosomes have also been considered for diagnostic and therapeutic uses related to wounds, such as repairing complex wounds, enhancing graft success, treating related complications, and serving as diagnostic biomarkers. However, their clinical applications still face challenges, as reliable commercial products are not yet available. This review will focus on recent research advances that describe the characteristics and isolation of exosomes, introduce the sources of exosomes suitable for wound repair and related complications, illustrate the value of engineered exosomes and their development directions in the future, and provide evidence for the potential therapeutic application of exosomes in wound healing, as well as discuss potential risks, challenges, and solutions for future applications.

Dynamically bonded, tough, and conductive MXene@oxidized sodium alginate: chitosan based multi-networked elastomeric hydrogels for physical motion detection.

Biopolymer-based conductive hydrogels (HGs) are promising candidates for preparing environmentally friendly flexible electronics. However, it is still a great challenge to synthesize biopolymer-based tough, self-healable, and fast strain recoverable HGs. Herein, a facile strategy is demonstrated to synthesize stretchable, self-recoverable, conductive, and tough HGs strain sensors through the formation of multi-dynamic interactions (i.e., imine bond formation, hydrogen bonds, ionic bonds, and electrostatic bonds) and strong covalent interactions between MXene (Ti3C2Tx), oxidized sodium alginate (OSA), chitosan (CS), polyacrylamide (PAAm), Fe(III) and PEDOT:PSS. Thus, obtaining dynamically and covalently bonded nanocomposite hydrogels (NCHGs) with controllable interfacial interactions exhibited a high mechanical strength (0.91 MPa), toughness (2.99 MJ/m3), stretchability (820 %), elasticity (>600 %) and conductivity (1.31 S/m). In addition, the presence of Fe(III) ions and conducting fillers endows excellent repeatability with high stability in resistance change upon bending or stretching with ultra-broad sensitivity up to 11-gauge factor and consisting lowest resistance change up to 0.5 %.

Advancing Inorganic Microcapsule Fabrication through Frozen-Assisted Interfacial Reactions Utilizing Liquid Marbles.

Inorganic microcapsules (IMs) have gained significant attention as versatile platforms for delivering functional agents in various fields. Traditional template-dependent methods employing hard templates often involve complex and harsh template removal processes. Achieving IMs with diverse composition and structure remains challenging with current preparation strategies. Therefore, in this work, we have for the first time demonstrated an extremely facile and efficient liquid-marbles-based template approach for fabricating pure inorganic microcapsules via interfacial reaction in a mild aqueous solution. The water-water reaction interface is created by changing the wettability of the liquid marble (LM) surface through the icing-melting process. The composition and function of the inorganic shell could be easily adjusted by varying the inorganic reagent species of the interfacial reaction, the hydrophobic particle of the shell, and the reaction environment according to the specific requirements of the application field. Such an approach provides a flexible platform for material preparation.

ISX9 loaded thermoresponsive nanoparticles for hair follicle regrowth.

There is a high demand for an optimal drug delivery system to treat androgenetic alopecia. Topical application of ISX9, which is a neurogenesis inducer, has been found to stimulate hair follicle (HF) regrowth by upregulating the Wnt/ß-catenin signaling pathway, an essential pathway involved in initiating HF growth and development. In the present study, a temperature-sensitive, biopolymer-based, biocompatible, and eco-friendly drug-delivery system was synthesized. This system comprised chitosan-grafted poly(glycidyl methacrylate-co-N-isopropyl acrylamide) (Poly(GMA-co-NIPAAm)@CS-PGNCS) as the shell component and PF127 as the core polymer. The hydrophobic nature of the PF127 block copolymer efficiently dissolved the partially water-soluble drug, ISX9, and the thermos-responsive shell polymer effectively released the drug at a definite skin temperature. The optimized spherical nanoparticles demonstrated the lowest critical solution temperature (LCST) at 32 ± 2 °C with a diameter of 100-250 nm, which delivered encapsulated ISX9 with greater precision than topical ISX9. In a series of in vivo experiments, we demonstrated that ISX9-coated TBNPs upregulated the expression of ß-catenin, active ß-catenin, Wnt target genes, stemness marker genes, proliferating cell nuclear antigen, HF stem cell markers, and HF markers including VEGF, TGF, and IGF-1 more effectively than topical ISX9. These results suggest that TBNPs could be employed as a platform for effective transdermal delivery of various hydrophobic drugs.

Correction: Reactions of [60]fullerene with alkynes promoted by OH.

[This corrects the article DOI: 10.1039/D2RA01300B.].

Reactions of [60]fullerene with alkynes promoted by OH.

In the current work, the reactions of [60]fullerene with alkynes promoted by OH- (base) are addressed. The treatment of C60 with alkynes in the presence of TBAOH produces alkynylation products (R-C60-H) with high selectivity in o-DCB at 100 °C. Plausible reaction mechanisms were proposed. This work provides a convenient and environmental friendly method for the functionalization of fullerenes.

Novel nanofibrous membrane-supporting stem cell sheets for plasmid delivery and cell activation to accelerate wound healing.

The integration of biomaterials with cells for high overall performances is vitally important in tissue engineering, as scaffold-free cell sheet lacks enough mechanical performance and cell viability while cell-free scaffold possesses limited biological functions. In this study, we propose a new strategy to strengthen cell sheets and enhance cell activity for accelerating wound healing based on a novel sandwich structure of cell sheet-plasmid@membrane-cell sheet (CpMC). Specifically, the CpMC contains two adipose-derived stem cell (ADSC) sheets on outer surfaces and an electrospun gelatin/chitosan nanofibrous membrane (NFM) encapsulating vascular endothelial growth factor (VEGF) plasmids in between. The physicochemical properties of NFM including swelling, stiffness, strength, elasticity, and biodegradation can be tailored by simply adjusting the ratio between gelatin and chitosan to be 7:3 which is optimal for most effectively supporting ADSCs adhesion and proliferation. The swelling/biodegradation of NFM mediates the sustained release of encapsulated VEGF plasmids into adjacent ADSCs, and NFM assists VEGF plasmids to promote the differentiation of ADSCs into endothelial, epidermal, and fibroblast cells, in support of the neoangiogenesis and regeneration of cutaneous tissues within 2 weeks. The proposed membrane-supporting cell sheet strategy provides a new route to tissue engineering, and the developed CpMC demonstrates a high potential for clinical translation.

Rheological Behavior of Blends of Metallocene Catalyzed Long-Chain Branched Polyethylenes. Part I: Shear Rheological and Thermorheological Behavior.

Long-chain branched metallocene-catalyzed high-density polyethylenes (LCB-mHDPE) were solution blended to obtain blends with varying degrees of branching. A high molecular LCB-mHDPE was mixed with low molecular LCB-mHDPE at varying concentrations. The rheological behavior of those low molecular LCB-mHDPE is similar but their molar mass and molar mass distribution are significantly different. Those blends were characterized rheologically to study the effects of concentration, molar mass distribution, and long-chain branching level of the low molecular LCB-mHDPE. Owing to the ultra-long relaxation times of the high molecular LCB-mHDPE, the blends exhibited a clearly more long-chain branched behavior than the base materials. The thermorheological complexity analysis showed an apparent increase in the activation energies Ea determined from G', G″, and especially δ. Ea (δ), which for LCB-mHDPE is a peak function, turned out to produce even more pronounced peaks than observed for LCB-mPE with narrow molar mass distribution and also LCB-mPE with broader molar mass distribution. Thus, it is possible to estimate the molar mass distribution from the details of the thermorheological complexity.

Potential biodegradable face mask to counter environmental impact of Covid-19.

On the eve of the outbreak of the COVID-19 pandemic, there is a tremendous increase in the production of facemasks across the world. The primary raw materials for the manufacturing of the facemasks are non-biodegradable synthetic polymers derived from petrochemicals. Disposal of these synthetic facemasks increases waste-load in the environment causing severe ecological issues for flora and fauna. The synthesis processes of the polymers from the petrochemical by-products were also not eco-friendly, which releases huge greenhouse and harmful gases. Therefore, many research organizations and entrepreneurs realize the need for biodegradable facemasks to render similar performance as the existing non-biodegradable masks. The conventional textile fabrics made of natural fibers like cotton, flax, hemp, etc., can also be used to prepare facemasks with multiple layers in use for general protection. Such natural textile masks can be made anti-microbial by applying various herbal anti-microbial extracts like turmeric, neem, basil, aloe vera, etc. As porosity is the exclusive feature of the masks for arresting tiny viruses, the filter of the masks should have a pore size in the nanometre scale, and that can be achieved in nanomembrane manufactured by electrospinning technology. This article reviews the various scopes of electrospinning technology for the preparation of nanomembrane biomasks. Besides protecting us from the virus, the biomasks can be useful for skin healing, skincare, auto-fragrance, and organized cooling which are also discussed in this review article.

In-situ crosslinked hydrogel based on amidated pectin/oxidized chitosan as potential wound dressing for skin repairing.

Hydrogel can provide a favorable moisture environment for skin wound healing. In this study, a novel in-situ crosslinked injectable hydrogel was prepared using the water-soluble amidated pectin (AP) and oxidized chitosan (OC) through Schiff-base reaction without any chemical crosslinker. The influence of AP content on the properties of the hydrogel was systemically investigated. It showed that gelation time, pore structure, swelling capability and degradability of the hydrogel can be tuned by varying the content of amine and aldehyde groups from AP and OC. All the porous hydrogels with various AP contents (65%, 70%, and 80%) presented desirable gelation time, swelling property, high hemocompatibility and biocompatibility. Particularly, AP-OC-65 hydrogel presented superior swelling capability and better hemo- and bio-compatibility, owing to more residual amine sites in the hydrogel. Therefore, the injectable AP-OC-65 hydrogel has a greater potential for application to wound dressing or skin substitute.

Fabrication of Highly Robust and Conductive Ion Gels Based on the Combined Strategies of Double-Network, Composite, and High-Functionality Cross-Linkers.

A robust hybrid ion gel is fabricated utilizing the combined strategies of double-network (DN), composite, and high-functionality cross-linkers. The charged poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) constructs the DN skeleton, with graphene oxide (GO) and N,N'-methylenebisacrylamide (MBA) being the cross-linkers for the first and second networks, respectively. The ionic liquid, either 1-ethyl-3-methylimidazolium dicyanamide ([EMIm][DCA]) or 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), is locked in the network to offer the high conductivity. Compared to the DN PAMPS ion gel without nanoparticles and the hybrid DN ion gel with unconnected silica nanoparticles, the present ion gel exhibits a significantly higher tensile strength (3.2 ± 0.1 MPa) and an excellent compressive strength (26 ± 1 MPa). The [EMIm][DCA] ion gel has a high conductivity close to that of its neat ionic liquids. The conductivity of the gel is sensitive to deformation and temperature, which leads to potential applications in sensing body movements, pulse, and temperature change.

Oxidized chitosan modified electrospun scaffolds for controllable release of acyclovir.

Developing a novel scaffold carrier with a sustained and controllable release profile of drug is essential to promote the effective transdermal delivery for acyclovir (ACY). In this work, electrospun polyacrylonitrile nanofibers (PAN NFs) was chemically modified with oxidized chitosan (OC). The modified fibrous scaffold was further loaded with the ACY for drug released investigation. FT-IR and NMR results revealed that the conversion of the functional group for each step has successfully occurred on the surface of the fibers. Through the in-vitro drug release and kinetic study, it demonstrated that ACY could be sustainably and controlled released from the OC modified scaffold following the Korsmeyer-Peppas model with a Fickian diffusion mechanism. The human adipose-derived stem cells and the blood combability evaluation confirmed the obtained scaffold possessed excellent cell biocompatibility and hemocompatibility. It could be concluded that the resultant OC modified scaffold based on electrospun PAN NFs opened a new potential option for the topical/transdermal drug delivery of ACY.

Nano silver-embedded electrospun nanofiber of poly(4-chloro-3-methylphenyl methacrylate): use as water sanitizer.

Water contaminated with microorganisms causes numerous diseases and is a major concern for public health. In search of a simple material which can provide clean water free from pathogens, nanofibers of poly(4-chloro-3-methylphenyl methacrylate, abbreviated as CMPMA, and nano Ag-doped poly(CMPMA) composite nanofibers were used to decontaminate water from microorganisms such as Escherichia coli and Bacillus subtilis. Nanofibers were prepared by electrospinning. X-ray diffraction (XRD) and transmission electron microscopy (TEM) provide the diameters of the Ag nanoparticles which are in the range 18-21 and 13-18 nm. The diameter of the poly(CMPMA) and nano Ag-doped poly(CMPMA) composite nanofiber is seen to vary between 400 and 700 nm with the change of the processing parameters. Optimum parameters for uniform nanofibers have been obtained. The morphology of the fibers is derived from scanning electron microscopy (SEM). The superiority of the nano Ag-doped poly(CMPMA) composite nanofiber was established.