Core-shell Structure Research Articles

Electrospun scaffold with bioactive polyurethane shell infused with propolis and starch-hyaluronic acid core: An advanced therapeutic platform for skin tissue engineering.

Biological macromolecules such as polysaccharides and proteins, due to their excellent biocompatibility and biodegradability, are ideal for promoting Skin Tissue Engineering (STE) both in vitro and in vivo. In this study, a core-shell electrospun scaffold was fabricated using the coaxial electrospinning method, with Polyurethane (PU) forming the shell and a mixture of Starch (ST), Propolis Extract (PE), and Hyaluronic Acid (HA) forming the core. The scaffold's morphology was characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), confirming the successful formation of a well-defined core-shell structure. The scaffold exhibited a contact angle of 56.7°, reflecting its favorable hydrophilic properties for cellular attachment. Mechanical testing revealed Young's modulus of 8.12MPa and a strain at break of 46%, indicating an optimal balance of mechanical strength and elasticity for STE. Antibacterial tests demonstrated that the core-shell structure exhibited strong antimicrobial activity against Staphylococcus aureus and Escherichia coli, making them a potential candidate. Cytotoxicity assessments showed no toxicity, with L929 fibroblast cells demonstrating enhanced adhesion and proliferation on the core-shell structure compared to control samples. These findings suggest that the PU-shell and ST/PE/HA-core electrospun scaffold represents a promising multifunctional platform for advanced STE and regenerative medicine applications.

Preparation of starch-based oral fast-disintegrating nanofiber mats for astaxanthin encapsulation and delivery via emulsion electrospinning

Developing green and efficient delivery systems to promote bioavailability of bioactive ingredients is a sustained demand in food industry. In this work, the astaxanthin (AST)-loaded starch-based fast-dissolving nanofibers with core-shell structure were prepared by emulsion electrospinning technique without using any organic solvent. To load water-insoluble AST in hydrophilic octenyl succinic anhydride starch (OSAS)/polyvinyl alcohol (PVA) nanofiber matrices, AST-loaded nanoscale emulsions (212.19 ± 5.63 nm) with high encapsulation efficiency (91.54 ± 0.14 %) were prepared as a precursor for emulsion electrospinning, using OSAS/PVA aggregates as an emulsifier. The core-shell structure of nanofibers was revealed by the Transmission electron microscopy (TEM), with average diameter of 509.58 ± 12.77 nm, and 88.64 ± 0.49 % for AST were effectively encapsulated in core layer. Nanofiber mats exhibited high encapsulation efficiency (85.11 ± 1.53 %) and excellent storage stability over 7 d. Meanwhile, amorphous transformation of AST enabled it possess higher water solubility, bioaccessibility, and antioxidant properties (97.72 ± 2.17 %) than free AST in aqueous system. The results demonstrated that the green, nontoxic, and biodegradable nanofiber mats prepared by emulsion electrospinning successfully realized the encapsulation and delivery of AST, with broad application prospects in the food and pharmaceutical fields.

Multistage microfluidic assisted Co-Delivery platform for dual-agent facile sequential encapsulation.

The integration of multiple therapeutic agents within a single nano-drug carrier holds promise for advancing anti-tumor therapies, despite challenges posed by their diverse physicochemical properties. This study introduces a novel multi-stage microfluidic co-encapsulation platform designed to address these challenges. By carefully orchestrating the nano-precipitation process sequence, this platform achieves sequential encapsulation of two drugs with markedly different physicochemical characteristics. Using the multi-stage microfluidic TrH chip, hybrid nanoparticles (HNPs) loaded with paclitaxel (PTX)-simvastatin (SV), PTX-lenvatinib (LV), and SV-LV were synthesized. Unlike conventional Bulk methods and existing commercial microfluidic Tesla and Baffle chips, the HNPs produced here exhibit a core-shell structure and uniform particle size distribution, crucial for enhancing drug delivery efficacy. Notably, this method achieves nearly 100 % encapsulation efficiency for both drugs across a dual-drug feed ratio range from 1:4 to 4:1. Drug loading efficiencies were quantified for PTX-SV/HNPs (14.97 ± 1.19 %), PTX-LV/HNPs (16.58 ± 0.69 %), and SV-LV/HNPs (19.21 ± 2.38 %). PTX-SV/HNPs demonstrated sequential release characteristics of SV and PTX, as confirmed by in vitro drug release experiments. Significantly, PTX-SV/HNPs exhibited superior cytotoxicity against HepG2 cells compared to individual PTX and SV treatments, underscoring their potential in cancer therapy. In conclusion, the developed multi-stage microfluidic platform represents a robust strategy for co-encapsulating drugs with substantial physicochemical disparities, thereby offering a promising avenue for advancing multi-drug delivery in nanomedicine applications.

Shear force-ROS sequential responsive drug delivery system for improving cerebral thrombosis microcirculation and neurological function.

The ischemic strokes seriously threaten human health with high incidence and disability rates. Cerebral embolism and impaired brain function are the two major clinical features of this disease. Therefore, rapid restoration of cerebral blood supply and synchronous improvement of impaired neurological function is the key to treating strokes. Herein, based on the microenvironment of cerebral thrombosis and pathological characteristics of damaged neurons, we constructed a shear force and reactive oxygen species (ROS) dual-responsive system (UK@Fuc/CDPC-PTPCS) for sequential targeted delivery of thrombolytic agent urokinase (UK) and neuroprotective drug cytosolic choline (CDPC). Results proved that after intravenous administration, UK@Fuc/CDPC-PTPCS can quickly locate to cerebral thrombosis site via the active recognition capability of fucoidan (Fuc) to P-selectin overexpressed on activated platelets. Subsequently, the sharply increased blood shear force separated the core-shell structure by breaking the host-guest interaction of β-cyclodextrin (β-CD), so the UK loaded in the shell was first released to rapid thrombolysis and then restored cerebral blood supply. Afterward, the stroke homing peptide (SHp) modified CDPC-PTPCS core actively recognized ischemic damaged neuronal cells. Then high intracellular ROS triggered CDPC release at specific sites to exert neuroprotective effects. This study offered a new therapeutic strategy for ischemic stroke.

A cobalt-aluminium layered double hydroxide with a nickel core-shell structure nanocomposite for supercapacitor applications

A cobalt-aluminium layered double hydroxide with a nickel core-shell structure nanocomposite for supercapacitor applications

Effective protection for cobalt sulfide constructed using a three-layer core-shell structure in biomass carbon for sodium ion batteries

Effective protection for cobalt sulfide constructed using a three-layer core-shell structure in biomass carbon for sodium ion batteries

High-performance delivery capsules co-assembled from lignin and chitosan with avermectin for sustainable pest management.

Inexpensive biomass materials hold great potential for the development of green delivery systems aimed at improving the extremely low utilization efficiency of pesticides. However, current systems face challenges in achieving both high encapsulation rates and drug loading capacities. This study introduces a novel method using chitosan (CS) and sodium lignosulfonate (SL) to co-assemble with avermectin (AVM), a widely used hydrophobic pesticide, forming AVM-CS-SL micro-nano capsules. Engineered under optimized conditions of pH5 and 40°C, the capsules exhibit an AVM encapsulation efficiency of 84.27% and a loading capacity of 90%. The AVM-CS-SL capsules demonstrate multifunctional attributes that enhance pesticide application. The capsules, with an average diameter of 356nm, facilitate stable embedding in leaf grooves and enable effective adhesion to leaf surfaces, thereby improving their resistance to wash-off by rain compared to conventional formulations. Their core-shell structure protects AVM from photodegradation, ensuring long-term stability and efficacy. The capsules also exhibit enhanced bioactivity, with higher mortality rates in Plutella xylostella larvae and low genotoxicity to Vicia faba plants. These findings highlight the strategy of developing multifunctional delivery systems by the co-assembled carrier materials with active ingredients, offering an effective solution for the sustainable development of society and environment.

PH-responsive poly(acrylic acid) coated mesoporous silica nanoparticles for controlled abamectin release: Synthesis, characterization, and agricultural application

BackgroundSmart pesticides, capable of responding to environmental stimuli, hold promise for achieving precise and on-demand release of pesticides, thereby reducing environmental risks and optimizing pesticide utilization. MethodsHerein, we prepared a novel composite nanoparticle with a core-shell structure of poly(acrylic acid)-coated mesoporous silica by distillation precipitation polymerization method, which is simple and efficient. Then, abamectin was successfully loaded by impregnation adsorption, and a novel pH-responsive controlled-release pesticide formulation, Abamectin-MSN@PAA, was prepared. SignificantFindings In this work, Abamectin-MSN@PAA exhibited a loading content of 23.79 % and an average particle size of approximately 272.1 nm. Notably, the formulation demonstrated acid-responsive release kinetics, with cumulative release percentages of 85.91 %, 69.03 %, and 53.44 % observed at pH values of 5, 7, and 9, respectively, after 96 h. Moreover, Abamectin-MSN@PAA effectively preserved abamectin from degradation under UV light exposure. In comparison with abamectin suspension, Abamectin-MSN@PAA exhibited superior adhesion to radish leaves and demonstrated increased aphid mortality in bioassay experiments. Following 7 days of drug spraying, the aphid survival rate was 26.67 % for Abamectin (40 mg L−1) and only 18.3 % for Abamectin-MSN@PAA (40 mg L−1). These findings underscore the potential of pH-responsive poly(acrylic acid)-coated mesoporous silica nanoparticles as a versatile platform for controlled pesticide delivery, thereby enhancing pesticide bioavailability and efficacy in agriculture.

Room-Temperature Selective Detection of H2 by Pd Nanoparticle-Decorated SnO2@WO3 Core-Shell Hollow Structures.

Sensitive H2 sensors play key roles in the large-scale and safe applications of H2. In this study, we developed novel ternary Pd-loaded SnO2@WO3 core-shell structures by hydrothermal and in situ reduction methods. The compositions of the optimized ternary core-shell structures (Pd-SW-2) are prepared on the basis of the optimal binary core-shell structures (SW-X) according to the sensing performances to H2. Gas sensing tests reveal that the sensing performances (e.g., sensing response and response/recovery time) to H2 are gradually improved after the formation of core-shell structures and the modification of Pd nanoparticles. 10Pd-SW-2 exhibits the highest response (370 times and 204 times higher than those of SnO2 and SW-2, respectively) and the shortest response and recovery time (19/53 s) to 100 ppm of H2 at 25 °C among the as-prepared ternary and binary composites. Combined with the morphology, XPS, electrochemical, H2-TPR, and O2-TPD analyses, the underlying reasons for the improved sensing performance of 10Pd-SW-2 are attributed to (1) the unique core-shell hollow structure and appropriate Pd particle sizes and distribution, (2) abundant oxygen vacancies, (3) the electron sensitization resulting from the energy band structure, and (4) the excellent chemical sensitization originated from the interaction between Pd/PdHx/PdO and H2.

Half-Covered ‘Glitter-Cake’ AM@SE Composite: A Novel Electrode Design for High Energy Density All-Solid-State Batteries

All-solid-state batteries (ASSBs) are pursued due to their potential for better safety and high energy density. However, the energy density of the cathode for ASSBs does not seem to be satisfactory due to the low utilization of active materials (AMs) at high loading. With small amount of solid electrolyte (SE) powder in the cathode, poor electrochemical performance is often observed due to contact loss and non-homogeneous distribution of AMs and SEs, leading to high tortuosity and limitation of lithium and electron transport pathways. Here, we propose a novel cathode design that can achieve high volumetric energy density of 1258 Wh L-1 at high AM content of 85 wt% by synergizing the merits of AM@SE core-shell composite particles with conformally coated thin SE shell prepared from mechanofusion process and small SE particles. The core-shell structure with an intimate and thin SE shell guarantees high ionic conduction pathway while unharming the electronic conduction. In addition, small SE particles play the role of a filler that reduces the packing porosity in the cathode composite electrode as well as between the cathode and the SE separator layer. The systematic demonstration of the optimization process may provide understanding and guidance on the design of electrodes for ASSBs with high electrode density, capacity, and ultimately energy density.

Ultrabright and Stable Red Perovskite Nanocrystals in Micro Light-Emitting Diodes Using Flow Chemistry System.

Addressing the challenges of the efficiency and stability of red perovskite nanocrystals is imperative for the successful deployment of these materials in displays and lighting applications. the structural dynamic changes of red perovskite quantum dots (PQDs) are explored using a flow chemistry system to solve the above hurdles. First, the ultrabright red-emitting PQDs of CsPb(Br,I)3 are achieved by adjusting ligand distribution (oleic acid and oleyamine) in combination with different flow rates and equivalence ratios. The PQDs exhibit an impressive photoluminescence quantum yield (PLQY) of 95%. In addition, as mentioned in numerous previous studies, the severe instability of mixed halide perovskites is due to halide immigration. Therefore, in this paper, zinc, which has a lower dissociation energy than lead is utilized, as a reagent to provide more halide ions in the synthesis to enhance the stability of PQDs. As a result, a CsPb(Br,I)3@Cs4Pb(Br,I)6 core-shell structure with outstanding stability and 92% PLQY is obtained. The simple method for synthesizing the core-shell structure of CsPb(Br,I)3@Cs4Pb(Br,I)6 paves the way for the production of perovskite micro light-emitting diodes for commercial applications.

Synergistic Intramolecular Charge Transfer Promotes Au Nanoclusters with Enhanced NIR-II Photoluminescence.

Gold nanoclusters (Au NCs) protected by molecular ligands represent a new class of second-generation near-infrared (NIR-II) luminescent materials that have been widely studied. However, the photoluminescence efficiencies of most NIR-II emitting Au NCs in aqueous solution are generally lower than 0.2%, and to fully exploit the advantages of AuNCs in the NIR-II region, improving their photoluminescence efficiency has become an urgent need. Considering the holistic nature of the core-shell structure of Au NCs, herein, we propose a synergistic intramolecular charge transfer (ICT) strategy to enhance the luminescence. The NIR-II fluorescence quantum yield of Au NCs was increased 6-fold to 5.59% by the synergistic effect of heteroatomic copper doping and ligand p-MBA deprotonation. Experimental characterization results show that the strong p-π conjugation between d10 metal and the deprotonated p-MBA enhances the charge transfer between the metal core and ligand. The synergistic ICT process strongly suppressed the nonradiative process, thereby enhancing the emission intensity. Our findings provide a facile method for understanding the integrity of the core-shell structure of Au NCs and regulating their photoluminescence properties.

Design of Litchi-Like Al/PTFE with Superior Reactivity and Application in Solid Propellants.

The combustion efficiency and reactivity of aluminum (Al) particles, as a crucial component in solid propellants, are constrained by the inert oxide layer aluminum oxide (Al2O3). Polytetrafluoroethylene (PTFE) can remove the oxide layer, however, carbon deposition generated during the reaction process still limits the reaction efficiency of Al/PTFE fuel. Here, a litchi-like Al/PTFE fuel with the nano-PTFE islands distributed on the Al particles surface is successfully designed, based on localized activation and synergistic reaction strategies, to solve the Al2O3 layer and carbon deposition. This unique PTFE-coated structure can achieve localized activation of Al by surface etching, creating reaction channels, and exposing the active Al. Such a channel network promotes the circulation of fluorine and oxygen, stimulating the synergistic reactions of Al-F and Al-O and energy output. Regulating the PTFE content can maximize the elimination of carbon deposition and achieve the full combustion reaction of Al/PTFE. The maximum flame area and pressure output of the litchi-like Al/PTFE fuel increased by 241.9%, 734.7%, 118.4%, and 265.2%, respectively, compared with traditional physical mixture and core-shell structure Al/PTFE fuels. The localized activation and synergistic effects of litchi-like structure effectively transform carbon waste into a valuable resource, introducing a novel approach for the propellants.

Nanoscale visualization of crack tips inside molten corium-concrete interaction debris using 3D-FIB-SEM with multiphase positional misalignment correction.

Characterizing molten corium-concrete interaction (MCCI) fuel debris in Fukushima reactors is essential to develop efficient methods for its removal. To enhance the accuracy of microscopic observation and focused ion beam (FIB) microsampling of MCCI fuel debris, we developed a three-dimentional FIB scanning electron microscopy (SEM) technique with a multiphase positional misalignment (MPPM) correction method. This system automatically aligns voxel positions, corrects contrast, and removes artifacts from a series of over 500 SEM images. The MPPM correction method, which focuses on time-modulated contrast, considerably reduces charge-up artifacts in glass phases, enabling 3D morphological observation and analytical transmission electron microscopy of crack tips in two types of MCCI debris at the 3D/nanoscale for the first time. In the Fe-ZrSiO4-based debris, metallic balls composed of Fe, Cr2O3, and ZrO2 with dimples on the surface of about 2-58 µm in diameter were observed at the crack tips. In the (Zr, U)SiO4 based debris, a core-shell structure composed of a (U, Zr)O2 core with a diameter of about 1-5 μm and a (Zr, U)SiO4 shell with a diameter of about 2-9 μm in complex molten corium-concrete interaction fuel debris at the crack tips.

Preparation and Characterization of Waterborne Multihydroxy Crosslinked Polyurethane Hybrid Core–Shell Emulsion

ABSTRACTThe use of waterborne polyurethane (WPU) is becoming increasingly prevalent in the effort to address the issue of glare. However, WPU continues to exhibit certain limitations in terms of its performance, including deficiencies in mechanical properties, and low chemical resistance. Consequently, this study employed polyacrylate (PA) modification to create waterborne polyurethane/acrylate (WPUA) hybrid emulsions with a core–shell structure, aiming to enhance their optical properties. Furthermore, different types of alcohol crosslinkers were added to investigate their effects on the optical and mechanical properties of the coatings. Accordingly, this paper presented the design and preparation of a multihydroxyl crosslinking modified antiglare core–shell PU@PA heteropolymer resin utilizing five different hydroxyl‐containing crosslinking agents: polyhydroxy alcohols, trimethylolpropane, pentaerythritol, xylitol, and dipentaerythritol. The impact of selecting crosslinkers with varying hydroxyl numbers as well as optimizing their concentrations on particle size, gloss, and tensile strength of WPUA was thoroughly examined. Results revealed that with xylitol as the crosslinker at a mass fraction of 0.9%, the emulsion's average particle size was 680.6 nm, the gloss of the coating reached 42.8 GU, and the tensile strength was 22.31 MPa. The resulting functional WPUA exhibited excellent optical and mechanical properties, offering new insights for the development of antiglare coatings.

Internal Nanocavity Regulation of Embedded Rare Earth Up-Conversion Nanoparticles for H2O2 Production Operable at Up to 780 nm.

Semiconductor photocatalysts embedded with rare earth upconversion nanoparticles (REUPs) are a promising strategy to improve their photoresponse range, but their photocatalytic performance within the near-infrared (NIR) region is far from satisfactory. Here, a method is reported to improve the photocatalytic activity by adjusting the nanocavity of upconversion nanoparticles inside a semiconductor. Two types of CdS embedded with NaYF4:Yb,Er photocatalysts with core-shell structure (no cavity) (NYE/CdS) and yolk-shell structure (empty cavity) (NYE@CdS) are synthesized by different methods. Experimental and theoretical analysis indicates that the yolk-shell structure NYE@CdS can enhance the local fluorescence-induced electric field within the hollow cavity, and realize more effective energy transfer from REUPs to CdS. Notably, the H2O2 production performance of NYE@CdS reaches 0.33mmol g-1 h-1 under NIR light irradiation (λ > 780nm), exceeding most of the reported photocatalysts. This research will provide new ideas for the design of high-efficiency photocatalysts for H2O2 production.

Rational Design of Core–Shell Structured Pd@MIL-100(Fe) for Efficient Visible Light-Initiated Syntheses of Secondary Amines from Nitro Aromatics and Benzyl Alcohols

Rational Design of Core–Shell Structured Pd@MIL-100(Fe) for Efficient Visible Light-Initiated Syntheses of Secondary Amines from Nitro Aromatics and Benzyl Alcohols

Supercooled Liquids in a Core-Shell Coordination Structure for Practical Long-Term Energy Storage.

Mutual acquisition of phase-stability and controllable phase-transition becomes a predominant criterion of phase-change materials for the practical long-term energy storage but seems contradictory always. Here a strategy combining coordination and hydrogen bonds hierarchically to create a supercooled liquid in a core-shell coordination structure is reported, addressing that demand successfully. This new material is composed of a Mn-methylurea complex (MM) core and the hierarchically bonded erythritols shell. MM glass core with a viscosity of 108 Pa·s determines its thermal phase-stability. As discovered, the ingenious ligand-exchange between erythritol and Cl- ion coordinated with MM core accounts for this effectively reversible phase-transition. This can be triggered by a small shear-stress of 10Pa within tens of seconds, exhibiting good practicability. Thermodynamics and kinetics of phase-transition are explored.

Integration of Asymmetric Multi-Path Hollow Structure and Multiple Heterogeneous Interfaces in Fe3O4@C@NiO Nanoprisms Enabling Ultra-Low and Broadband Absorption.

A reasonable construction of hollow structures to obtain high-performance absorbers is widely studied, but it is still a challenge to select suitable materials to improve the low-frequency attenuation performance. Here, the Fe3O4@C@NiO nanoprisms with unique tip shapes, asymmetric multi-path hollow cavity, and core-shell heteroepitaxy structure are designed and synthesized based on anisotropy and intrinsic physical characteristics. Impressively, by changing the load of NiO, the composites achieve strong absorption, broadband, low-frequency absorption: the reflection loss of -55.8 dB and the absorption bandwidth of 9.9 GHz covers both low and high frequency (2.9-6.1 and 11.3-18 GHz). The constructed anisotropic hollow and heterointerface nanoprisms can optimize impedance matching for low-frequency absorption (3.8-7.9 GHz) almost completely covering the 5G band. Especially, the influence of hollow path on the interface polarization and ferromagnetic coupling behavior is revealed through the simulation of electric and magnetic field distribution using the High-Frequency Structure Simulator (HFSS). In addition, HFSS simulation shows that the Radar Cross-Sectional (RCS) value of the absorber at any angle is <-10 dB m2, which meets the complex requirements in practical application. This research paves a new way for the development of efficient low-frequency absorbers based on composition and structure design.

Intra-Mesopore Immunoassay Based on Core-Shell Structured Magnetic Hierarchically Porous ZIFs.

It is crucial yet challenging to sensitively quantify low-abundance biomarkers in blood for early screening and diagnosis of various diseases. Herein, an analytical model of intra-mesopore immunoassay (IMIA) was proposed, which was competent to examine various biomarkers at the femtomolar level. The success is rooted in the design of an innovative superparamagnetic core-shell structure with Fe3O4 nanoparticles (NPs) at the core and hierarchically porous zeolitic imidazolate frameworks as a shell (Fe3O4@HPZIF-8), achieved through a soft-template directed self-assembly coupled with confinement growth mechanism. Such a unique configuration conceptualized IMIA where the HPZIF-8 shell served as a solid carrier to cover capture antibodies while the Fe3O4 core assisted its rapid separation. The large pore channels not only provided a stable microenvironment to maintain the recognition ability of captured antibodies but also enhanced their coating density, thus promoting the probability of capturing and binding target antigens, significantly improving immunoassay (IA) sensitivity. The practical clinic IA for cTnI (Cardiac Troponin I, biomarker of acute myocardial infarction (AMI)) in human serums was exemplified. The developed IMIA could accurately quantify slight fluctuations in cTnI concentrations in the serums of AMI patients at different stages after symptom onset with more than 100-fold enhancement of limit of detection (LOD) in comparison to conventional plate-based enzyme-linked immunosorbent assay (ELISA). Such high sensitivity of IMIA makes it a powerful tool for the accurate diagnosis of different diseases by altering the type of primary capture antibody.