Flexible Piezoresistive Sensors Based on PPy Granule-Anchored Multilayer Fibrous Membranes with a Wide Operating Range and High Sensitivity.

The employment of flexible piezoresistive sensors has sparked growing interest within the realm of wearable electronic devices, specifically in the fields of health detection and e-skin. Nevertheless, the advancement of piezoresistive sensors has been impeded by their limited sensitivity and restricted operating ranges. Consequently, it is imperative to fabricate sensors with heightened sensitivity and expanded operating ranges through the utilization of the appropriate methodologies. In this paper, piezoresistive sensors were fabricated utilizing electrospun polyvinylidene fluoride/polyacrylonitrile/polyethylene-polypropylene glycol multilayer fibrous membranes anchored with polypyrrole granules as the sensing layer, while electrospun thermoplastic polyurethane (TPU) fibers were employed as the flexible substrate. The sensitivity of the sensor is investigated by varying the fiber diameter of the sensing layer. The experimental findings reveal that a concentration of 14 wt % in the spinning solution exhibits high sensitivity (996.7 kPa-1) within a wide working range (0-10 kPa). This is attributed to the favorable diameter of the fibers prepared at this concentration, which facilitates the uniform in situ growth of pyrrole. The highly deformable TPU flexible fibers and multilayer sensing layer structure enable different linear responses across a broad pressure range (0-1 MPa). Furthermore, the sensor demonstrates good cyclic stability and can detect human movements under different pressures. These results suggest that the piezoresistive sensor with a wide operating range and high sensitivity has significant potential for future health monitoring and artificial intelligence applications.

Clinical and biochemical evaluation of rituximab as add on therapy in neuromyelitis optica spectrum disorders.

OBJECTIVE: This study assesses the efficacy of rituximab in the treatment of neuromyelitis optica spectrum disorders (NMOSD). METHODS: The study initially included 40 patients with NMOSD diagnosed, after excluding patients who did not meet the complete inclusion criteria. Patients in the conventional group received routine clinical treatment, while patients in the study group received additional treatment with rituximab on the basis of the conventional treatment. Baseline data and clinically relevant indicators were collected for all patients, and the efficacy was compared between the two groups. RESULTS: Baseline data were comparable between the two groups (p > 0.05). The EDSS scores after clinical treatment in the study group were lower than those in the conventional group, and the difference in EDSS scores before and after treatment was higher than that in the conventional group (p < 0.05). The difference in visual acuity correction before and after treatment was not significant between the two groups (p > 0.05). Laboratory indicators in the study group after clinical treatment were superior to those in the conventional group (all p < 0.05). The recurrence rate after clinical treatment in the study group was significantly lower than that in the conventional group (p < 0.05). Adverse reactions after clinical treatment in the study group were less than those in the conventional group (p < 0.05). CONCLUSION: This study found that rituximab demonstrated significant efficacy in the acute attacks and recurrence prevention of NMOSD, emphasizing its relatively good safety and tolerability. It highlights the potential of rituximab in treating NMOSD and provides valuable insights for future disease management.

G-triplex/hemin DNAzyme mediated colorimetric aptasensor for Escherichia coli O157:H7 detection based on exonuclease III-assisted amplification and aptamers-functionalized magnetic beads.

Escherichia coli O157: H7 (E. coli O157: H7) is one of the most common foodborne pathogens and is widespread in food and the environment. Thus, it is significant for rapidly detecting E. coli O157: H7. In this study, a colorimetric aptasensor based on aptamer-functionalized magnetic beads, exonuclease III (Exo III), and G-triplex/hemin was proposed for the detection of E. coli O157: H7. The functional hairpin HP was designed in the system, which includes two parts of a stem containing the G-triplex sequence and a tail complementary to cDNA. E. coli O157: H7 competed to bind the aptamer (Apt) in the Apt-cDNA complex to obtain cDNA. The cDNA then bound to the tail of HP to trigger Exo III digestion and release the single-stranded DNA containing the G-triplex sequence. G-triplex/hemin DNAzyme could catalyze TMB to produce visible color changes and detectable absorbance signals in the presence of H2O2. Based on the optimal conditions, E. coli O157: H7 could be detected down to 1.3 × 103 CFU/mL, with a wide linear range from 1.3 × 103 to 1.3 × 107 CFU/mL. This method had a distinguished ability to non-target bacteria, which showed good specificity. In addition, the system was successfully applied to detect E. coli O157: H7 in milk samples.

Mild-temperature responsive nanocatalyst for controlled drug release and enhanced catalytic therapy.

Owing to the advantages of the in situ production of toxic agents through catalytic reactions, nanocatalytic therapy has arisen as a highly potential strategy for cancer therapeutics in recent years. However, the insufficient amount of endogenous hydrogen peroxide (H2O2) in the tumor microenvironment commonly limits their catalytic efficacy. Here, we employed carbon vesicle nanoparticles (CV NPs) with high near-infrared (NIR, 808 nm) photothermal conversion efficiency as carriers. Ultrafine platinum iron alloy nanoparticles (PtFe NPs) were grown in situ on the CV NPs, where the highly porous nature of the resultant CV@PtFe NPs was employed to encapsulate a drug, ß-lapachone (La), and phase-change material (PCM). As a multifunctional nanocatalyst CV@PtFe/(La-PCM) NPs can exhibit a NIR-triggered photothermal effect and activate cellular heat shock response, which upregulates the downstream NQO1 via HSP70/NQO1 axis to facilitate bio-reduction of the concurrently melted and released La. Moreover, sufficient oxygen (O2) is supplied by CV@PtFe/(La-PCM) NPs catalyzed at the tumor site to reinforce the La cyclic reaction with abundant H2O2 generation. This promotes the bimetallic PtFe-based nanocatalysis, which breaks H2O2 down into highly toxic hydroxyl radicals (•OH) for catalytic therapy. Our results show that this multifunctional nanocatalyst can be used as a versatile synergistic therapeutic agent with NIR-enhanced nanocatalytic tumor therapy by tumor-specific H2O2 amplification and mild-temperature photothermal therapy, which holds promising potential for targeted cancer treatment. STATEMENT OF SIGNIFICANCE: We present a multifunctional nanoplatform with mild-temperature responsive nanocatalyst for controlled drug release and enhanced catalytic therapy. This work aimed at not only reduce the damage to normal tissues caused by photothermal therapy, but also improves the efficiency of nanocatalytic therapy by stimulating endogenous H2O2 production through photothermal heat. In vitro and in vivo confirmed that CV@PtFe/(La-PCM) NPs exhibited powerful and overall antitumor effects. This formulation may provide an alternative strategy for the development of the mild- photothermal enhanced nanocatalytic therapy effect in solid tumor.

In Situ Fabrication of Silver Peroxide Hybrid Ultrathin Co-Based Metal-Organic Frameworks for Enhanced Chemodynamic Antibacterial Therapy.

Bacterial-induced infectious diseases have always caused an unavoidable problem and lead to an increasing threat to human health. Hence, there is an urgent need for effective antibacterial strategies to treat infectious diseases. Current methods are often ineffective and require large amounts of hydrogen peroxide (H2O2), with harmful effects on normal healthy tissue. Chemodynamic therapy (CDT) provides an ideal infection microenvironment (IME)-activated paradigm to tackle bacterial-related diseases. To take full advantage of the specificity of IME and enhanced CDT for wounds with bacterial infection, we have designed an intelligent antibacterial system that exploits nanocatalytic ZIF-67@Ag2O2 nanosheets. In this system, silver peroxide nanoparticles (Ag2O2 NPs) were grown on ultrathin zeolitic imidazolate framework-67 (ZIF-67) nanosheets by in situ oxidation, and then, ZIF-67@Ag2O2 nanosheets with the ability to self-generate H2O2 were triggered by the mildly acidic environment of IME. Lamellar ZIF-67 nanosheets were shown to rapidly degrade and release Co2+, allowing the conversion of less reactive H2O2 into the highly toxic reactive oxygen species hydroxyl radicals (•OH) for enhanced CDT antibacterial properties. In vivo results revealed that the ZIF-67@Ag2O2 nanosheet system exhibits excellent antibacterial performance against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The proposed hybrid strategy demonstrates a promising therapeutic strategy to enable antibacterial agents with IME-responsive nanocatalytic activity to circumvent antibiotic resistance against bacterial infections.

A comparison of study on intestinal barrier protection of polysaccharides from Hericium erinaceus before and after fermentation.

The intestinal barrier protects the host from harmful substances. This paper investigated two polysaccharides extracted from the Hericium erinaceus before and after fermentation (HEP and FHEP). The effects of two polysaccharides on the intestinal barrier were investigated in cell and mice models. The results showed that polysaccharides had a protective effect against acrylamide-induced injury in IEC-6 cell. Compared with HEP, FHEP significantly increased TEER and paracellular permeability (P < 0.05). Both polysaccharides the expression of alter tight junction (TJ) and mucin (MUC) as observed in cell Western Bolt (WB). Polysaccharides also enhance the intestinal barrier function in mice by improving cyclophosphamide induced cytokines level, TJ and MUC expression, and gut microbiota. The results showed that FHEP significantly increased IgA, IgG, and IgM levels while decreasing TNF-, IL-1, and IL-6 levels (P < 0.05). The immunohistochemical results showed that both polysaccharides significantly increased the expression of occludin, ZO-1, ZO-2, claudin-3, claudin-4, MUC2 and decreased claudin-2. In parallel, polysaccharides could alter the composition of the gut microbiota, indicating that increased in Bacteriodetes, Firmicutes and decreased in Klebsiella and Shigella. This work provides important views on the protective effect of fermented polysaccharides on the intestinal barrier, and provides a potential mechanism for the beneficial health properties of these biomacromolecules.

Muscle cytotoxicity and immuno-reactivity analysis of the porous carbon nanospheres fabricated by high temperature calcination.

Carbon-based nanomaterials have a high specific surface area, biocompatibility, and controlled mesopore structures. These characteristics make carbon nanospheres excellent carriers for drugs, biological dyes, photosensitizers, etc. Nevertheless, little is known about the impact of topological features on the surface of carbon nanomaterials on their in vivo immunoreactivity. In this study, we fabricated mesoporous carbon nanoparticles (MCNs) and solvent-processable carbon vesicles (CVs) by high-temperature calcination. The hematoxylin and eosin (H&E) staining suggested CVs' relatively poor dispersion capacity compared to MCNs and carbon precursors (CPs), leading to more severe muscle inflammation and necrosis. Immunostaining and Fluorescence Activated Cell Sorter (FACS) analysis further showed that both MCNs and CVs triggered a transient immune response in transplanted muscle and muscle-draining lymph nodes, but did not alter muscle resistance to exogenous viruses. In conclusion, this study provides insights into how carbon nanoparticles modulate the activation of immune responses in vivo.

A multifunctional nanocatalytic system based on Chemodynamic-Starvation therapies with enhanced efficacy of cancer treatment.

A multi-functional nanocatalytic system based on combined therapies has attracted considerable research attention in recent years due to its potential in the treatment of cancer. Herein, ZnO2@Au@ZIF-67 nanoparticles (NPs) based on hydroxyl radical (•OH) mediated chemodynamic therapy (CDT) and glucose-exhausting starvation therapy (ST) were constructed. Specifically, in the acidic tumor microenvironment (TME), the pH responsive decomposition of the shell ZIF-67 triggered the release of the Fenton-like catalyst Co2+, after which the exposed zinc peroxide (ZnO2) reacted with H2O (H+) to generate O2 and hydrogen peroxide (H2O2). The generated O2 could alleviate hypoxia in the TEM and interact with ultra-small Au NPs originally coated on ZnO2 to catalyze intracellular glucose and to produce another source of H2O2. While the glucose consumption caused the starvation of tumor cells, the generated H2O2 from dual sources reacted with the catalyst Co2+ to generate highly toxic •OH for CDT. Systematic in vitro and in vivo experiments were carried out to evaluate this nanocatalytic system, and the results showed an enhanced efficacy of this cancer therapy.

Polymersomes as virus-surrogate particles for evaluating the performance of air filter materials.

The development of antivirus air filter materials has attracted considerable interests due to the pandemic of coronavirus disease 2019 (COVID-19). Filtration efficiency (FE) of these materials against virus is critical in the assessment of their use in disease prevention. Due to the high cost and biosafety laboratory required for conducting research using actual virus samples, surrogates for virus are commonly used in the filtration test. Here, we explore the employment of polymersomes (polymeric vesicles) as a new type of surrogate. The polymersomes are hollow shell nanoparticles with amphiphilic bilayer membranes, which can be fabricated in nanosized, and possess similar size and structural features to virus. The performance of commercial KN95 mask and surgical mask with micro-sized fibers, and electrospun polyvinylidene fluoride (PVDF) and polyacrylonitrile (PAN) nanofibers were chosen to be evaluated. The filtration tests against fluorescent-labeled virus-surrogate particles (VSPs), i.e. polymersomes, allowed the determination of the FE of the multilayered filter materials in a layer-specific manner. The results suggested the importance of hydrophobicity in designing the nanofibrous filter materials. The employment of VSPs in filtration performance evaluation allows a cost-effective way to estimate the FE against virus, providing guidance on future development of air filter materials.

Photothermal-responsive fiber dressing with enhanced antibacterial activity and cell manipulation towards promoting wound-healing.

For chronic persistent skin injuries, functional wound dressings with improved antibacterial action and cell control are extremely appealing. In this study, we design and fabricate a composite fiber dressing with near-infrared (NIR) laser-induced hyperthermia and transformable topographies that can protect the wound from bacterial infection while also encouraging cell recruitment and tissue regeneration. Polycaprolactone/gelatin (PCL/Gel) with melting point close to photothermal temperature were electrospun as the supporting matrix. The zeolitic imidazolate framework-8 (ZIF-8)-derived nanocarbon was synthesized as NIR laser-triggered nanoagent and then electrospun within oriented PCL/Gel fibers to enable the inorganic/polymer composite fiber dressing with photo-to-thermal conversion effect and drug loading capability. The composite fiber dressing exhibits excellent photothermal performance and stage-specific transformable topographies (photothermal-triggered melting behavior of oriented PCL/Gel fibers) after multiple laser irradiations, which can generate local massive heat and abundant drug release for synergistic sterilization, as well as direct cell migration and adhesion/spreading to promote tissue regeneration. Furthermore, in vivo testing demonstrates that the photothermal-responsive fiber dressing accelerates wound closure process by synergistically improving antibacterial and cell manipulation. Overall, this composite fiber dressing offers a promising integrated wound healing strategy.

Micro-and-nanometer topological gradient of block copolymer fibrous scaffolds towards region-specific cell regulation.

Regulating cell behavior and function by surface topography has drawn significant attention in tissue engineering. Herein, a gradient fibrous scaffold comprising anisotropic aligned fibers and isotropic annealed fibers was developed to provide a controllable direction of cell migration, adhesion, and spreading. The electrospun aligned fibers were engraved to create surface gradients with micro-and-nanometer roughness through block copolymer (BCP) self-assembly induced by selective solvent vapor annealing (SVA). The distinct manipulation of cell behavior by annealed fibrous scaffolds with tailored self-assembled nanostructure and welded fibrous microstructure has been illustrated by in situ/ex situ small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and in vitro cell culture. Further insights into the effect of integrated gradient fibrous scaffold were gained at the level of protein expression. From the perspective of gradient topology, this region-specific scaffold based on BCP fibers shows the prospect of guiding cell migration, adhesion and spreading and provides a generic method for designing biomaterials for tissue-engineering.

Can Photothermal Post-Operative Cancer Treatment Be Induced by a Thermal Trigger?

One of the current challenges in the post-operative treatment of breast cancer is to develop a local therapeutic vector for preventing recurrence and metastasis. Herein, we develop a core-shell fibrous scaffold comprising phase-change materials and photothermal/chemotherapy agents, as a thermal trigger for programmable-response drug release and synergistic treatment. The scaffold is obtained by in situ growth of a zeolitic imidazolate framework-8 (ZIF-8) shell on the surface of poly(butylene succinate)/lauric acid (PBS/LA) phase-change fibers (PCFs) to create PCF@ZIF-8. After optimizing the core-shell and phase transition behavior, gold nanorods (GNRs) and doxorubicin hydrochloride (DOX) co-loaded PCF@ZIF-8 scaffolds were shown to significantly enhance in vitro and in vivo anticancer efficacy. In a healthy tissue microenvironment at pH 7.4, the ZIF-8 shell ensures the sustained release of DOX. If the tumor recurs, the acidic microenvironment induces the decomposition of the ZIF-8 shell. Under the second near-infrared (NIR-II) laser treatment, GNR-induced thermal not only directly destroys the relapsed tumor cells but also accelerates DOX release by inducing the phase transition of LA. Our study sheds light on a well-designed programmable-response trigger, which provides a promising strategy for post-operative recurrence prevention of cancer.

Visible-blind ultraviolet narrowband photomultiplication-type organic photodetector with an ultrahigh external quantum efficiency of over 1 000 000.

A visible-blind ultraviolet (UV) photodetector can detect UV signals and is not interfered with by visible light or infrared light in the environment. In order to realize high-performance visible-blind UV organic photodetectors (OPDs), we design photomultiplication-type (PM-type) OPDs by using a novel strategy. Firstly, wide bandgap organic semiconductor materials, which do not absorb visible light, are selected as donors to absorb UV light. Secondly, a very small amount of C60 is used as an acceptor to trap photogenerated electrons. These accumulating electrons near the Al electrode form a potential, which leads to band bending and narrowing of the interface barrier, thereby assisting hole-tunneling injection to form a multiplication. The fabricated visible-blind UV PM-type OPDs with donor/acceptor doping ratio of 50 : 1 exhibit a narrowband response with full-width at half-maximum (FWHM) of approximately 36 nm, an ultrahigh external quantum efficiency of 1.08 × 106% and a remarkable specific detectivity of 1.28 × 1014 jones at 335 nm wavelength under -14 V bias. The UV-to-visible rejection ratio exceeds 103 by adjusting the donor/acceptor mixing ratios. The devices made with other wide bandgap organic materials also showed similar performance, indicating that this device structure provides an effective method for the preparation of high-performance visible-blind UV PM-type OPDs. In addition, we prepared a flexible visible-blind UV PM-type OPD based on a PET substrate and integrated it with a flexible OLED to fabricate a wearable UV monitor, which can visually detect the intensity of UV light.

Curcumin suppresses doxorubicin-induced cardiomyocyte pyroptosis via a PI3K/Akt/mTOR-dependent manner.

BACKGROUND: Doxorubicin (DOX) is one of the most effective anti-neoplastic drugs although its clinical use is limited by the severe cardiotoxicity. Apoptosis and defective autophagy are believed to contribute to DOX-induced cardiotoxicity. Here we explored the effect of curcumin (Cur) on DOX-induced cardiac injury and the mechanism involved with a focus on oxidative stress, autophagy and pyroptosis. METHODS: Kunming mice were challenged with DOX (3 mg·kg-1, i.p. every other day) with cohorts of mice receiving Cur at 50, 100, 200 and 400 mg·kg-1 via gavage daily. Serum levels of cardiac enzymes, such as aspartate amino transferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and heart homogenate oxidative stress markers, such as superoxide dismutase (SOD) and malondialdehyde (MDA) were determined. Echocardiographic and cardiac contraction were examined. Apoptosis, pyroptosis, autophagy and Akt/mTOR-signalling proteins were detected using western blot or electron microscopy. Cardiac contractile properties were assessed including peak shortening, maximal velocity of shortening/relengthening (± dL/dt), time-to-PS, and time-to-90% relengthening (TR90). Superoxide levels were evaluated using DHE staining. GFP-LC3 was conducted to measure autophagosomes. RESULTS: Our study showed that Cur protected against cardiotoxicity manifested by a significant decrease in serum myocardial enzymes and improvement of anti-oxidative capacity. Cur inhibited autophagy and offered overt benefit for cardiomyocyte survive against DOX-induced toxicity. Cur attenuated DOX-induced cardiomyocyte pyroptosis as evidenced by NLR family pyrin domain containing 3 (NLRP3), Caspase-1, and interleukin-18 levels. DOX impaired cardiac function (reduced fractional shortening, ejection fraction, increased plasma cTnI level and TR90, decreased PS and ± dL/dt), the effects of which were overtly reconciled by 100 mg·kg-1 but not 50 mg·kg-1 Cur. H9c2 cells exposure to DOX displayed increased intracellular reactive oxygen species (ROS) and autophagy, the effects of which were nullified by Cur. Autophagy activator rapamycin cancelled off Cur-induced protective effects. CONCLUSIONS: Our finding suggested that Cur rescued against DOX-induced cardiac injury probably through regulation of autophagy and pyroptosis in a mTOR-dependent manner.

Prokineticin 2 (PK2) Rescues Cardiomyocytes from High Glucose/High Palmitic Acid-Induced Damage by Regulating the AKT/GSK3ß Pathway In Vitro.

Prokineticin 2 (PK2) is a small 8 kDa protein that participates in many physiological processes, such as angiogenesis, inflammation, and neurogenesis. This experiment investigated the effect of PK2 on high glucose/high palmitic acid-induced oxidative stress, apoptosis, and autophagy in cardiomyocytes and the AKT/GSK3ß signalling pathway. H9c2 cells were exposed to normal and high concentrations (33 mM) of glucose and palmitic acid (150 µM) with or without PK2 (10 nM) for 48 h. Reactive oxygen species were detected using the fluorescent probes DCFH-DA and DHE. Changes in apoptosis were assessed using flow cytometry, and autophagosomes were detected using Ad-GFP-LC3. Apoptotic proteins, such as Cleaved Caspase3, Bax, and Bcl-2; autophagy proteins, including Beclin-1 and LC3B; and PK2/PKR/AKT/GSK3ß signals were evaluated using western blotting. Cardiomyocytes exposed to high glucose/high palmitic acid exhibited increases in intracellular ROS, apoptosis, and autophagosomes, and these increases were robustly prevented by PK2. In addition, high glucose/high palmitic acid remarkably suppressed PK2, PKR1, and PKR2 expression and p-AKT/AKT and p-GSK3ß/GSK3ß ratios, and these effects were significantly prevented by PK2. Moreover, an AKT1/2 kinase inhibitor (AKT inhibitor, 10 µM) blocked the effects of PK2 on the changes in cardiomyocyte exposure to high glucose/high palmitic acid. These results suggest that PK2 attenuates high glucose/high palmitic acid-induced cardiomyocyte apoptosis by inhibiting oxidative stress and autophagosome accumulation and that this protective effect is most likely mediated by the AKT-related signalling pathway.

Superhydrophobic hierarchical fiber/bead composite membranes for efficient treatment of burns.

One of the current challenges in burn wound care is the development of multifunctional dressings that can protect the wound from bacteria or organisms and promote skin regeneration and tissue reconstitution. To this end, we report the design and fabrication of a composite electrospun membrane, comprised of electrospun polylactide: poly(vinyl pyrrolidone)/polylactide: poly(ethylene glycol) (PLA:PVP/PLA:PEG) core/shell fibers loaded with bioactive agents, as a functionally integrated wound dressing for efficient burns treatment. Different mass ratios of PLA:PVP in the shell were screened to optimize mechanical, physicochemical, and biological properties, in addition to controlled release profiles of loaded antimicrobial peptides (AMPs) from the fibers for desirable antibacterial activity. Fibroblasts were shown to readily adhere and proliferate when cultured on the membrane, indicating good in vitro cytocompatibility. The introduction of PLA beads by electrospraying on one side of the membrane resulted in biomimetic micro-nanostructures similar to those of lotus leaves. This designer structure rendered the composite membranes with superhydrophobic property to inhibit the adhesion/spreading of exogenous bacteria and other microbes. The administration of the resulting composite fibrous membrane on burnt skin in an infected rat model led to faster healing than a conventional product (sterile silicone membrane) and control detailed herein. These composite fibrous membranes loaded with bioactive drugs provide an integrated strategy for promoting burn wound healing and skin regeneration. STATEMENT OF SIGNIFICANCE: To address an urgent need in complex clinical requirements on developing a new generation of wound dressings with integrated functionalities. This article reports research work on a hierarchical fiber/bead composite membranes design, which combines a lotus-leaf-like superhydrophobic surface with drugs preloaded in the core and shell of fibers for effective burn treatment. This demonstrates a balance between simplified preparation processes and increased multifunctionality of the wound dressings. The creation of hierarchically structured surfaces can be readily achieved by electrospinning, and the composite dressings possessed a considerable mechanical strength, effective wound exudate absorption and permeability, good biocompatibility, broad antibacterial ability and promoting wound healing etc. Thus, our work unveils a promising strategy for the development of functionally integrated wound dressings for burn wound care.

A comprehensive review of electrospinning block copolymers.

Electrospinning provides a versatile and cost-effective route for the generation of continuous nanofibres with high surface area-to-volume ratio from various polymers. In parallel, block copolymers (BCPs) are promising candidates for many diverse applications, where nanoscale operation is exploited, owing to their intrinsic self-assembling behaviour at these length scales. Judicious combination of BCPs (with their ability to make nanosized domains at equilibrium) and electrospinning (with its ability to create nano- and microsized fibres and particles) allows one to create BCPs with high surface area-to-volume ratio to deliver higher efficiency or efficacy in their given application. Here, we give a comprehensive overview of the wide range of reports on BCP electrospinning with focus placed on the use of molecular design alongside control over specific electrospinning type and post-treatment methodologies to control the properties of the resultant fibrous materials. Particular attention is paid to the applications of these materials, most notably, their use as biomaterials, separation membranes, sensors, and electronic materials.

Photoelectrochemical immunoassay of lipoprotein-associated phospholipase A2 via plasmon-enhanced energy transfer between gold nanoparticles and CdS QDs/g-C3N4.

A facile and feasible photoelectrochemical (PEC) immunoassay based on plasmon-enhanced energy transfer between gold nanoparticles (AuNPs) and CdS quantum dots (QDs)/g-C3N4 nanosheets was developed for the ultrasensitive detection of lipoprotein-associated phospholipase A2 (Lp-PLA2). To construct such a sensing platform, the immunosensor was prepared by immobilizing Lp-PLA2 on a CdS QDs/g-C3N4-modified electrode. A competitive-type immunoreaction was utilized for Lp-PLA2 detection, with AuNP-labeled anti-Lp-PLA2 antibody used as the competitor. Introducing AuNPs with the specific antibody for the antigen target Lp-PLA2 led to heavy quenching of the photocurrent of CdS QDs/g-C3N4 due to the plasmon-enhanced energy transfer between AuNPs and CdS QDs. The quenching efficiency decreased with increasing target Lp-PLA2 concentration. Under optimal conditions, the PEC immunosensor presented a good photocurrent response to the target Lp-PLA2 in the dynamic linear range of 0.01-300 ng mL-1, with a low detection limit of 5.3 pg mL-1. Other biomarkers and natural enzymes did not interfere with response of this system. The reproducibility and accuracy of this method for the analysis of human serum specimens were evaluated, and the results given by the method developed here were found to closely correspond to the results obtained with commercial Lp-PLA2 ELISA kits. Importantly, this protocol offers promise for the development of exciton-plasmon interaction-based PEC detection systems. Graphical abstract ᅟ.