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The characterisation of novel materials presents a challenge that requires new and original developments. To face some of these demands for making measurements at the nanoscale, a new microsphere-assisted white light interference nanoscope performing local reflectance mapping is presented. This technique presents the advantages of being non-destructive, full-field and label-free. A 145 μm diameter microsphere, glued to the end of an optical fiber, is inserted inside the white light interference microscope to improve the lateral resolution from 940 nm to 520 nm. The acquisition and the Fourier transform processing of a stack of interference images superimposed on the virtual image produced by the microsphere allows the extraction of the local reflectance over a wavelength range of 460 nm to 900 nm and a field of view of 8 μm in diameter. The enhancement in the lateral resolution of the reflectance is demonstrated through the spectral distinction of neighboring ripples on a laser-textured colored stainless-steel sample that cannot be resolved without the microsphere, on regions with a surface of 279 × 279 nm2 horizontally spaced 279 nm apart. Future improvements could potentially lead to a lateral resolution of reflectance measurement over a 100 nm diameter area in air, paving the way to sub-diffraction reflectance mapping. [ABSTRACT FROM AUTHOR]

It is of great importance to study the detachment/attachment behaviors of cells (cancer cell, immune cell, and epithelial cell), as they are closely related with tumor metastasis, immunoreaction, and tissue development at variety scales. To characterize the detachment/attachment during the interaction between cells and substrate, some researchers proposed using cell traction force (CTF) as the indicator. To date, various strategies have been developed to measure the CTF. However, these methods only realize the measurements of cell passive forces on flat cases. To quantify the active CTF on nonflat surfaces, which can better mimic the in vivo case, we employed elastic hydrogel microspheres as a force sensor. The microspheres were fabricated by microfluidic chips with controllable size and mechanical properties to mimic substrate. Cells were cultured on microsphere and the CTF led to the deformation of microsphere. By detecting the morphology information, the CTF exerted by attached cells can be calculated by the in‐house numerical code. Using these microspheres, the CTF of various cells (including tumor cell, immunological cell, and epithelium cell) were successfully obtained on nonflat surfaces with different curvature radii. The proposed method provides a versatile platform to measure the CTF with high precision and to understand the detachment/attachment behaviors during physiology processes. [ABSTRACT FROM AUTHOR]

Silica microspheres have been demonstrated as the optical micro-cavity for laser generation based on whispering-gallery modes (WGM). They can achieve a high-quality factor (Q) within a tiny volume. Traditionally, complex processes are needed to process a coating containing photoluminescent elements, with enough thickness and uniformity, for laser generation. We developed a novel sol-gel fabrication method of Er3+/Yb3+doped silica microspheres with a homogeneous doping concentration over the entire microsphere volume. The sol-gel precursors were doped with 1–2 mol% Er3+ and/or Yb3+. The viscosity of the precursor was controlled at around 4000 cP, and gel fibers can be conveniently drawn from the precursor. After firing at 1000 °C for 1 h, transparent fibers with diameters of 40–180 µm were obtained. The fiber tips were quickly melted into microspheres using a CO2 laser. The diameters of microspheres were determined by the fiber diameter and laser parameters, such as laser power and irradiation time duration. Typically, the microspheres had diameters between 90 to 160 µm. The emission spectrum under 357 nm and 527 nm excitation showed characteristic Er3+ emission peaks, that match the literature well. The UV-VIS spectra confirm the photoluminescence results and showed both Er3+ and Yb3+ characteristic absorptions. The optical behaviors of the microspheres indicate that the Er3+ and Yb3+ were well dispersed in the silica matrix and the microspheres had typical optical activities of Er3+/Yb3+ glasses. Highlights: Silica microspheres, fabricated using laser melting, with homogeneously doped Er3+/Yb3+. No need for multiple layers of Er3+/Yb3+ sol-gel coatings. Microspheres demonstrated strong optical activities with Er3+/Yb3+ doping. [ABSTRACT FROM AUTHOR]

Piezoelectric energy harvesters (PEHs) developed from electrospun polyvinylidene fluoride (PVDF) fibers offer flexibility and superior piezoelectric output, making them promising for self‐powered systems and sensors. Nonetheless, the electromechanical conversion efficiency of conventional electrospun PVDF fibers is impeded by their limited pressure‐strain range. Herein, elastic porous PVDF microspheres are introduced in‐situ via electrospinning to craft a piezoelectric membrane with higher compressive strain. The PVDF microspheres are uniformly embedded between the fibers in a sandwich fashion, and their dimension is easily tunable by varying spinning solution's concentration. Moreover, the micropores on the PVDF microspheres created by removing pre‐mixed SiO2 template not only elevates the β crystal content of PVDF to 82.19%, but also improves the compressibility, significantly boosting the piezoelectric output. The microsphere alloyed PVDF PEH delivers a piezoelectric output of 33.0 V and a power density of 8 μW/cm2, over 5.8 times that of conventional electrospun PVDF membrane, and can consistently charge lithium‐ion batteries. Our research unveils a novel strategic path to modify fiber structured PEHs, advancing their applications in self‐powered systems. [ABSTRACT FROM AUTHOR]

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Conventional dosage forms cannot address drawbacks such as poor bioavailability and stability of some drugs meant to be absorbed from upper part of the gut. Gastroprotective floating microspheres have shown great success in addressing these issues. One of the unresolved issues associated with gastroprotective floating microspheres is quantitative efficiency of the system in fasted and fed conditions. Allicin is a defence compound present in Allium sativum plant, commonly known as Garlic. It is one of the chief Phytobioactive compounds present in Allium species, such as, white garlic, alpine leek, field garlic, wild garlic and elephant garlic. It is a sulphur containing volatile compound that is primarily responsible for the characteristic taste and smell of Allium species. It accounts for 70% w/w of the total thiosulfinates present in fresh garlic. In the present investigation allicin loaded gastroretentive microspheres were prepared in six different batches viz., GFM 1, GFM 2, GFM 3, GFM 14, GFM 5 and GFM 6 by ionic gelation method using varying the ratio of selected excipients and the prepated microsphere were evaluated. The results indicates that GFM 5 showed maxim drug release and considered as best formulation. [ABSTRACT FROM AUTHOR]

As effective treatments for sarcopenia other than exercise have not yet been established, research is needed on treatment methods using drugs that can control muscle atrophy. Therefore, in this study, we aimed to assess the use of intramuscular sustained-release drug delivery systems and direct intramuscular injection for the control of muscle atrophy. First, we evaluated the inhibitory effects of camphor on skeletal muscle atrophy in vitro. L6 skeletal muscle cells were analyzed by WST-1 cell viability, 3D tomographic lipid accumulation, and mitochondrial length. These results indicated that camphor significantly regulates L6 cell atrophy. Next, we established poly(lactic-co-glycolic acid) (PLGA)-based microspheres loaded with camphor (PLGA-camphor), with each PLGA-camphor microsphere have a size of ~ 66–75 μm. Camphor was released ~ 93.29% over 10 days. Finally, we administered the PLGA-camphor by intramuscular injection in the starved fed mice model and performed immunohistological and histological analyses. The results indicate that PLGA-camphor is able to significantly regulate skeletal muscle atrophy in vivo. Our results suggest that PLGA-camphor may affect skeletal muscle atrophy. In the present study, our research findings indicate that camphor significantly reduces muscle atrophy in vitro. It used gravity to load camphor into PLGA-based microspheres, which were 66–75 μm in size. The sustained release properties of PLGA-camphor microsphere were shown to release 93.29% of camphor over ten days. When directly injected into the muscle of mice with muscular dystrophy, the PLGA-camphor microsphere resulted in a noteworthy reduction in muscle atrophy, particularly in the starved-induced muscle atrophy model mice. Our results suggest that PLGA-camphor microsphere could be a promising method for addressing skeletal muscle atrophy. [ABSTRACT FROM AUTHOR]

As a typical endocrine disrupter, bisphenol A (BPA) in the environment could damage the reproductive and endocrine system of humans and mammals. Hence, the precise removal of BPA from the environment becomes increasingly urgent. In this work, we employ Pickering emulsion polymerization to prepare the molecularly imprinted polymer (MIP) microspheres containing specific binding sites for the precise recognition of BPA through the non-covalent molecular imprinting strategy. In the process of polymerization, TiO2 nanoparticles are used as the sole emulsifier to build the Pickering oil/water emulsion system followed by the radical polymerization. The template molecules of BPA could be eluted from the polymer microspheres by continuous Soxhlet extraction. The obtained MIP microspheres were characterized with the help of optical microscope and field emission scanning electron microscope, respectively. The MIP microspheres present regularly spherical structures with a relative broad size distribution. The chemical structure and thermal stability of MIP and non-imprinted polymer (NIPs) microspheres also were investigated by Fourier transform infrared spectroscopy and thermogravimetry, respectively. The formation of specific imprinted sites on the MIPs was validated through a batch of rebinding experiments, including the binding kinetics, binding isotherm and selective experiment. Moreover, the obtained MIP microspheres could be regenerated and recycled at least five cycles without significant loss of binding capacity. The MIP microspheres would have broad application prospects in the environmental and analytical field. [ABSTRACT FROM AUTHOR]

Abstract The characterisation of novel materials presents a challenge that requires new and original developments. To face some of these demands for making measurements at the nanoscale, a new microsphere-assisted white light interference nanoscope performing local reflectance mapping is presented. This technique presents the advantages of being non-destructive, full-field and label-free. A 145 μm diameter microsphere, glued to the end of an optical fiber, is inserted inside the white light interference microscope to improve the lateral resolution from 940 nm to 520 nm. The acquisition and the Fourier transform processing of a stack of interference images superimposed on the virtual image produced by the microsphere allows the extraction of the local reflectance over a wavelength range of 460 nm to 900 nm and a field of view of 8 μm in diameter. The enhancement in the lateral resolution of the reflectance is demonstrated through the spectral distinction of neighboring ripples on a laser-textured colored stainless-steel sample that cannot be resolved without the microsphere, on regions with a surface of 279 × 279 nm2 horizontally spaced 279 nm apart. Future improvements could potentially lead to a lateral resolution of reflectance measurement over a 100 nm diameter area in air, paving the way to sub-diffraction reflectance mapping.

Effective treatment of infection in chronic wounds is critical to improve patient outcomes and prevent severe complications, including systemic infections, increased morbidity, and amputations. Current treatments, including antibiotic administration and antimicrobial dressings, are challenged by the increasing prevalence of antibiotic resistance and patients’ sensitivity to the delivered agents. Previous studies have demonstrated the potential of a new antimicrobial agent, Gallium maltolate (GaM); however, the high burst release from the GaM-loaded hydrogel gauze required frequent dressing changes. To address this need, we developed a hydrogel foam-based wound dressing with GaM-loaded microspheres for sustained infection control. First, the minimal inhibitory and bactericidal concentrations (MIC and MBC) of GaM against two Staphylococcus aureus strains isolated from chronic wounds were identified. No significant adverse effects of GaM on dermal fibroblasts were shown at the MIC, indicating an acceptable selectivity index. For the sustained release of GaM, electrospraying was employed to fabricate microspheres with different release kinetics. Systematic investigation of loading and microsphere size on release kinetics indicated that the larger microsphere size and lower GaM loading resulted in a sustained GaM release profile over the target 5 days. Evaluation of the GaM-loaded hydrogel dressing demonstrated cytocompatibility and antibacterial activities with a zone of inhibition test. An equine distal limb wound model was developed and utilized to demonstrate the efficacy of GaM-loaded hydrogel foam in vivo. This antimicrobial hydrogel foam dressing displayed the potential to combat methicillin-resistant S. aureus (MRSA) infection with controlled GaM release to improve chronic wound healing.

Due to fossil fuel depletion and increasing pollution, researchers are now finding ways to develop alternative fuels. Recently, hydrogen became the most focused alternative that can act as a future fuel. Electrochemical water splitting is the cleanest method of producing oxygen and hydrogen from water. Costly noble metal-based materials are used for water splitting and oxygen generation, so there is a strong need to replace platinum with non-precious materials for water splitting. The morphology of the material has a considerable impact on its physical properties and performance. In this research work, we have synthesized flower-shaped nickel cobalt sulfide (NCS-AA) material via a facile hydrothermal method. The material was characterized using SEM and EDS for morphology observation and elemental analysis. The SEM results showed the formation of a flower-type morphology with a diameter of 500 nm to 2 µm and EDS analysis confirmed the presence of Ni, Co, and S. Further, electrochemical analysis was carried out to analyze its performance in oxygen evolution reaction (OER) by performing CV, LSV, and CA analysis techniques. NCS-AA demonstrated good OER activity with an overpotential of ~ 320 mV and a Tafel slope of 115 mV/dec versus a reversible hydrogen electrode for 10 mA/cm2 current density. Further, the stability of NCS-AA materials at 50 mA/cm2 and 200 mA/cm2 was excellent as examined using the chronopotentiometry technique. [ABSTRACT FROM AUTHOR]

Abstract Macrophage metabolism dysregulation, which is exacerbated by persistent stimulation in infectious and inflammatory diseases, such as diabetic infectious bone defects (DIBD), eventually leads to the failure of bone repair. Here, we have developed an injectable, macrophage-modulated GAPDH-Silence drug delivery system. This microsphere comprises chondroitin sulfate methacrylate (CM) and methacrylated gelatin (GM), while the dimethyl fumarate (DMF)-loaded liposome (D-lip) is encapsulated within the microsphere (CM@GM), named D-lip/CM@GM. Triggered by the over-expressed collagenase in DIBD, the microspheres degrade and release the encapsulated D-lip. D-lip could modulate metabolism by inhibiting GAPDH, which suppresses the over-activation of glycolysis, thus preventing the inflammatory response of macrophages in vitro. While beneficial for macrophages, D-lip/CM@GM is harmful to bacteria. GAPDH, while crucial for glycolysis of staphylococcal species (S. aureus), can be effectively countered by D-lip/CM@GM. We are utilizing existing drugs in innovative ways to target central metabolism for effective eradication of bacteria. In the DIBD model, our results confirmed that the D-lip/CM@GM enhanced bacteria clearance and reprogrammed dysregulated metabolism, thereby significantly improving bone regeneration. In conclusion, this GAPDH-Silence microsphere system may provide a viable strategy to promote diabetic infection bone regeneration.

The low energy density, unsatisfied cycling performance, potential safety issue and slow charging kinetics of the commercial lithium-ion batteries restrained their further application in the fields of fast charging and long-haul electric vehicles. Monoclinic TiNb2O7 (TNO) with the theoretical capacity of 387 mAh g−1 has been proposed as a high-capacity anode materials to replace Li4Ti5O12. In this work, homovalent doping strategy was used to enhance the electrochemical performance of TiNb2O7 (TNO) by employing Zr to partial substitute Ti through solvothermal method. The doping of Zr4+ ions can enlarge the lattice structure without changing the chemical valence of the original elements, refine and homogenize the grains, improve the electrical conductivity, and accelerate the ion diffusion kinetics, and finally enhance the cycle and rate performance. Specifically, Z0.05-TNO shows initial discharge capacity of as high as 312.2 mAh g−1 at 1 C and 244.8 mAh g−1 at 10 C, and still maintains a high specific capacity of 171.3 mAh g−1 after 800 cycles at 10 C. This study provides a new strategy for high-performance fast-charging energy storage electrodes.

The aim of this study is to enhance the carbonation resistance of fully recycled aggregate concrete through diverse measures in an effort to enhance solid waste disposal, reduce the consumption of natural aggregates, and broaden the utilization of recycled aggregate concrete. Six sets of fully recycled aggregate concrete specimens were prepared and subjected to rapid carbonation tests. Carbonation depth and compressive strength measurements were taken at different ages (3, 7, 14, and 28 days). Subsequent calculations and analyses were conducted on both parameters for each set of specimens. Results indicate that the incorporation of microspheres and high-toughness polypropylene fibers (HTPP) substantially improves the carbonation resistance of fully recycled aggregate concrete, leading to a 48% reduction in carbonation depth by the 28th day. Furthermore, a relative compressive strength model for fully recycled aggregate concrete post-carbonation was established based on the strength data of each specimen group. This model accurately depicts the growth pattern of compressive strength after carbonation. Additionally, a carbonation depth prediction model was developed through fitting analysis of carbonation depth data, effectively foreseeing the depth of carbonation in fully recycled aggregate concrete. Based on the carbonation depth, the carbonation life of fully recycled aggregate concrete was predicted. The carbonation life of recycled aggregate concrete with added microspheres and HTPP fibers can be increased by up to 278%. Finally, scanning electron microscopy (SEM) was employed to examine the microstructure of fully recycled aggregate concrete, revealing the mechanisms by which various methods enhance its carbonation resistance. The carbonation resistance improvement technology of fully recycled aggregate concrete is selected through this study characteristics such as simplicity, convenience, and cost-effectiveness, which are crucial for the widespread application of recycled aggregate concrete in building structures.

The synchronized development of mineralized bone and blood vessels is a fundamental requirement for successful bone tissue regeneration. Adequate energy production forms the cornerstone supporting new bone formation. ETS variant 2 (ETV2) has been identified as a transcription factor that promotes energy metabolism reprogramming and facilitates the coordination between osteogenesis and angiogenesis. In vitro molecular experiments have demonstrated that ETV2 enhances osteogenic differentiation of dental pulp stem cells (DPSCs) by regulating the ETV2- prolyl hydroxylase 2 (PHD2)- hypoxia-inducible factor-1α (HIF-1α)- vascular endothelial growth factor A (VEGFA) axis. Notably, ETV2 achieves the rapid reprogramming of energy metabolism by simultaneously accelerating mitochondrial aerobic respiration and glycolysis, thus fulfilling the energy requirements essential to expedite osteogenic differentiation. Furthermore, decreased α-ketoglutarate release from ETV2-modified DPSCs contributes to microcirculation reconstruction. Additionally, we engineered hydroxyapatite/chitosan microspheres (HA/CS MS) with biomimetic nanostructures to facilitate multiple ETV2-DPSC functions and further enhanced the osteogenic differentiation. Animal experiments have validated the synergistic effect of ETV2-modified DPSCs and HA/CS MS in promoting the critical-size bone defect regeneration. In summary, this study offers a novel treatment approach for vascularized bone tissue regeneration that relies on energy metabolism activation and the maintenance of a stable local hypoxia signaling state.

Abstract Hemangioma of infancy is the most common vascular tumor during infancy and childhood. Despite the proven efficacy of propranolol treatment, certain patients still encounter resistance or face recurrence. The need for frequent daily medication also poses challenges to patient adherence. Bleomycin (BLM) has demonstrated effectiveness against vascular anomalies, yet its use is limited by dose-related complications. Addressing this, this study proposes a novel approach for treating hemangiomas using BLM-loaded hyaluronic acid (HA)-based microneedle (MN) patches. BLM is encapsulated during the synthesis of polylactic acid (PLA) microspheres (MPs). The successful preparation of PLA MPs and MN patches is confirmed through scanning electron microscopy (SEM) images. The HA microneedles dissolve rapidly upon skin insertion, releasing BLM@PLA MPs. These MPs gradually degrade within 28 days, providing a sustained release of BLM. Comprehensive safety assessments, including cell viability, hemolysis ratio, and intradermal reactions in rabbits, validate the safety of MN patches. The BLM@PLA-MNs exhibit an effective inhibitory efficiency against hemangioma formation in a murine hemangioma model. Of significant importance, RNA-seq analysis reveals that BLM@PLA-MNs exert their inhibitory effect on hemangiomas by regulating the P53 pathway. In summary, BLM@PLA-MNs emerge as a promising clinical candidate for the effective treatment of hemangiomas. Graphical Abstract

Ulcerative colitis (UC) is a chronic intestinal disorder characterized by severe intestinal inflammation and superficial mucosal ulcers. Ramulus mori alkaloids (SZ-A) were approved by the National Medical Products Administration of China in 2020 for the treatment of type 2 diabetes mellitus. Later studies confirmed that SZ-A act on multiple inflammatory pathways to exert anti-inflammatory effects, suggesting that SZ-A has the potential to alleviate UC. A temperature-sensitive hydrogel embedded with sodium alginate (SA)-chitosan (CS) microspheres was constructed for colon-targeted delivery of SZ-A. The results showed that the microspheres prepared by exogenous emulsification had rounded and smooth surfaces with high drug-loading capacity. The optimum preparation conditions were as follows: 600 rpm stirring speed; a 1:4 ratio of water-to-oil phase; and a 5% Span80 emulsifier. The temperature-sensitive hydrogels embedded with SA-CS microspheres (TMH) had a moderate gelling temperature of 31.8 ± 0.74°C. The rheologic results showed that the internal structure of TMH was stable with viscoelasticity, and the in vitro release results indicated that the TMH exhibited slow-release performance. The findings suggest that TMH has suitable gelling temperature and viscoelasticity, and may be a promising targeted delivery vector for UC treatment.

The polymer/nano-inorganics composite microsphere possesses excellent application prospects, but it is difficult to resolve the problem of the aggregation of nano-inorganic particles in polymer and the affinity between inorganics and polymer matrix. In this study, the preparation and characterization of polystyrene (PS)/ethylene vinyl acetate copolymer (EVA)/CaCO3 microspheres fabricated via a novel phase inversion emulsion process are described. By this one-pot method, the PS/EVA/CaCO3 microspheres are obtained by firstly converting styrene monomer containing EVA and nano CaCO3 into droplets dispersed in water with help of emulsifiers and a following polymerization. Because the inorganic nanoparticles are ultrasonically dispersed in liquid monomer mixture before the polymerization, the aggregation of nano-inorganic particles could be prevented to a great extent. The EVA is designed to enhance toughness of polystyrene matrix and increase the affinity between polymer and inorganic particles. The morphological structure of PS/EVA/CaCO3 microspheres is that nano CaCO3 particles are embedded both in the interior and on the surface of the microspheres. The micro-sized PS/EVA/CaCO3 microspheres showed a significantly improved mechanical property and a better heat resistance. This technique also offers the possibility for fabricating many kinds of new and useful polymer/inorganic microspheres with tailored performance by using special monomers and inorganic particles. [ABSTRACT FROM AUTHOR]

The low energy density, unsatisfied cycling performance, potential safety issue and slow charging kinetics of the commercial lithium-ion batteries restrained their further application in the fields of fast charging and long-haul electric vehicles. Monoclinic TiNb2O7 (TNO) with the theoretical capacity of 387 mAh g-1 has been proposed as a high-capacity anode materials to replace Li4Ti5O12. In this work, homovalent doping strategy was used to enhance the electrochemical performance of TiNb2O7 (TNO) by employing Zr to partial substitute Ti through solvothermal method. The doping of Zr4+ ions can enlarge the lattice structure without changing the chemical valence of the original elements, refine and homogenize the grains, improve the electrical conductivity, and accelerate the ion diffusion kinetics, and finally enhance the cycle and rate performance. Specifically, Z0.05-TNO shows initial discharge capacity of as high as 312.2 mAh g-1 at 1 C and 244.8 mAh g-1 at 10 C, and still maintains a high specific capacity of 171.3 mAh g-1 after 800 cycles at 10 C. This study provides a new strategy for high-performance fastcharging energy storage electrodes. [ABSTRACT FROM AUTHOR]

The organic xerogel (OX) was synthesized through sol–gel polymerization of formaldehyde and resorcinol in inverse emulsion using Na2CO3 as a catalyst. Meanwhile, OX containing sepiolite (OX-Sep) and vermiculite (OX-Ver) were prepared similarly to OX but adding clays during synthesis. All materials were mesoporous and presented spherical morphology, and the surface of these materials exhibited an acidic character because the concentration of acidic sites was higher than those of basic sites. Cd(II) adsorption from aqueous solutions onto OX, OX-Sep, and OX-Ver was examined, and the OX-Sep showed the highest adsorption capacity towards Cd(II) of 189.7 mg/g, being 1.5, 2, and 36 times higher than that of OX-Ver, OX, and Sep. The OX-Sep capacity for adsorbing Cd(II) was significantly lessened by decreasing the pH from 7 to 4 and raising the ionic strength from 0.01 N to 0.1 N. This trend was ascribed to electrostatic attraction between the Cd+2 in water and the negatively charged surface of OX-Sep. Besides, desorption studies at pH 4 showed that the average desorption percentage of Cd(II) adsorbed on OX-Sep was 80%. The characterization results and the effect of the operating conditions on the adsorption capacity proved that electrostatic attraction and cation exchange play a crucial role in the adsorption mechanism. [ABSTRACT FROM AUTHOR]

Fly ash microspheres, also called cenospheres, have many valuable properties that allow them to be widely used. Some of its most important properties are its mechanical and thermal strength as well as its chemical stability. These features constitute an important commercial parameter. Refining processes aim to select the highest quality product from raw materials that meets the expectations of recipients. Generally, preparing a final product involves selecting the appropriate sequence and parameters of the grain separation process. However, the key to the optimal selection of these parameters is knowledge of the specificity of the processed raw material. Microspheres are materials that are created spontaneously, uncontrolled, and without the possibility of intentionally influencing their properties. Therefore, due to the potential directions of microsphere use, it is justified to study the relationship between density, grain size, and mechanical strength. Understanding these relationships in microspheres from various sources is particularly important at the stage of planning refining processes. This paper presents the results of research on microspheres from two different sources. The tested raw materials (microspheres) are subjected to densiometric and grain analysis. Also, mechanical strength was determined for the separated density fractions and grain classes. The test results did not show significant correlations between the tested features of the microspheres. In the case of both raw materials, the highest density was observed in the smallest grain classes, and the highest mechanical strength was determined for microspheres with grain sizes in the range of 75–100 µm. For this grain size range, the value of mechanical strength is 26 for raw Material 1 and 38 for raw Material 2. The shares of this grain fraction in the microsphere stream are 11.2% and 16%, respectively. An important difference that may significantly affect the efficiency of the refining process is the method of distribution of the primary falling parts, which affects the mechanical strength of the tested raw materials. [ABSTRACT FROM AUTHOR]

Cathode materials with conversion mechanisms for aqueous zinc-ion batteries (AZIBs) have shown a great potential as next-generation energy storage materials due to their high discharge capacity and high energy density. However, improving their cycling stability has been the biggest challenge plaguing researchers. In this study, CuO microspheres were prepared using a simple hydrothermal reaction, and the morphology and crystallinity of the samples were modulated by controlling the hydrothermal reaction time. The as-synthesized materials were used as cathode materials for AZIBs. The electrochemical experiments showed that the CuO-4h sample, undergoing a hydrothermal reaction for 4 h, had the longest lifecycle and the best rate of capability. A discharge capacity of 131.7 mAh g−1 was still available after 700 cycles at a current density of 500 mA g−1. At a high current density of 1.5 A g−1, the maintained capacity of the cell is 85.4 mA h g−1. The structural evolutions and valence changes in the CuO-4h cathode material were carefully explored by using ex situ XRD and ex situ XPS. CuO was reduced to Cu2O and Cu after the initial discharge, and Cu was oxidized to Cu2O instead of CuO during subsequent charging processes. We believe that these findings could introduce a novel approach to exploring high-performance cathode materials for AZIBs. [ABSTRACT FROM AUTHOR]

In the present study, at the first a blending of sodium alginate and soy protein isolate (SPI) as wall material were used to encapsulate chia seed (Salvia hispanica) oil as a source of omega-3 into the microspheres. The microspheres were formed at different ratios (5:1, 5:3, and 5:5) of sodium alginate/ (SPI) via the extrusion method, maintaining a constant core/wall ratio of 10%. Morphological structures and physicochemical properties of the microspheres were investigated. In the second step, the microspheres with a ratio 5:3 of alginate/SPI were added to dark chocolate formulation. The characteristics of the fortified dark chocolate were compared to the control sample through sensory evaluation, moisture content and water activity, differential scanning calorimetric (DSC), and texture analysis. The sensory evaluation revealed that the fortified dark chocolate achieved higher acceptance levels compared to the control sample, indicating its potential for commercial success. This research demonstrates a promising approach to enhance the nutritional profile of chocolate while maintaining its sensory appeal. Practical applications: • A blend of SPI/Alginate was successfully used to well entrap the chia seed oil. • Fortified dark chocolate with alginate/SPI microspheres showed higher acceptance level. • Alginate/SPI microspheres show a potential for enhancing nutritional profile of foods. [ABSTRACT FROM AUTHOR]

Hemangioma of infancy is the most common vascular tumor during infancy and childhood. Despite the proven efficacy of propranolol treatment, certain patients still encounter resistance or face recurrence. The need for frequent daily medication also poses challenges to patient adherence. Bleomycin (BLM) has demonstrated effectiveness against vascular anomalies, yet its use is limited by dose-related complications. Addressing this, this study proposes a novel approach for treating hemangiomas using BLM-loaded hyaluronic acid (HA)-based microneedle (MN) patches. BLM is encapsulated during the synthesis of polylactic acid (PLA) microspheres (MPs). The successful preparation of PLA MPs and MN patches is confirmed through scanning electron microscopy (SEM) images. The HA microneedles dissolve rapidly upon skin insertion, releasing BLM@PLA MPs. These MPs gradually degrade within 28 days, providing a sustained release of BLM. Comprehensive safety assessments, including cell viability, hemolysis ratio, and intradermal reactions in rabbits, validate the safety of MN patches. The BLM@PLA-MNs exhibit an effective inhibitory efficiency against hemangioma formation in a murine hemangioma model. Of significant importance, RNA-seq analysis reveals that BLM@PLA-MNs exert their inhibitory effect on hemangiomas by regulating the P53 pathway. In summary, BLM@PLA-MNs emerge as a promising clinical candidate for the effective treatment of hemangiomas. [ABSTRACT FROM AUTHOR]

Peripheral nerve block is performed for precise pain control and lesser side effects after surgery by reducing opioid consumption. Injectable hydrogel delivery systems with high biosafety and moisture content have good clinical application prospects for local anesthetic delivery. However, how to achieve high drug loading and long‐term controlled release of water‐soluble narcotic drugs remains a big challenge. In this study, heterogeneous microspheres and an injectable gel‐matrix composite drug delivery system are designed in two steps. First, heterogeneous hydrogel microspheres loaded with ropivacaine (HMS‐ROP) are prepared using a microfluidic chip and in situ alkalization. An injectable self‐healing hydrogel matrix (Gel) is then prepared from modified carboxymethylcellulose (CMC‐ADH) and oxidized hyaluronic acid (OHA). A local anesthetic delivery system, Gel/HMS‐ROP/dexmedetomidine (DEX), with long‐term retention and drug release in vivo is prepared by combining HMS‐ROP and Gel/DEX. The drug loading of HMS‐ROP reached 41.1%, with a drug release time of over 160 h in vitro, and sensory and motor blockade times in vivo of 48 and 36 h, respectively. In summary, the sequential release and synergistic analgesic effects of the two anesthetics are realized using core‐shell microspheres, DEX, and an injectable gel, providing a promising strategy for long‐acting postoperative pain management. [ABSTRACT FROM AUTHOR]

Whispering gallery mode resonator sensors are nondisruptive optical sensors that can detect and monitor perturbations in a gaseous environment. Through its resonant properties of peak wavelength, amplitude, and quality factor (Q factor), changes in concentration can be quantified within seconds and monitored over days with great stability. In addition, the small footprint, low cost, and high sensitivity are ideal properties for a disposable sensor that can be utilized in extreme environments. The large Q factor of the resonant cavity enables long interaction lengths and amplifies the effect of small changes in the background refractive index, which is detectable in picometer shifts of the resonance wavelength. However, this measurement is susceptible to changes in other environmental factors such as temperature, pressure, and humidity, which manifest on the picometer wavelength scale, reinforcing the need to decouple the variables. In this work, we compare the spectral response of different diameter resonators to carbon dioxide, nitrogen, and its mixtures, observing the spectral shifting and broadening of the cavity resonance near 1550 nm. In addition, the effect of environmental temperature on spectral shifting due to the thermo-optic effect is characterized and quantified. Lastly, the gas concentrations are changed in real time to showcase the tracking and recovery capabilities of the resonator sensor. [ABSTRACT FROM AUTHOR]

Controlled drug delivery system (CDDS) allows active pharmaceutical agent (API) to be released over extended periods of time, ranging from days to months, by using drug-encapsulating devices. Such systems have a number of merits over conventional drug delivery techniques, including the ability to customize drug release rates, safeguard delicate medications, and improve patient comfort and compliance. Microspheres are suitable carriers for numerous controlled delivery applications owing to CDDS's high bioavailability, prolonged drug release features, biocompatibility and ability to encapsulate a wide range of medicines. This review paper discusses fabrication techniques for microparticles, preparation and characterization processes used to prepare these microspheres, various types of microspheres such as on the basis of drug release pattern (matrix, coated, reservoir) and on the basis of drug delivery system (mucoadhesive, floating, bio-adhesive, radioactive, polymeric, and magnetic, etc.), and the key variables affecting drug release rates from encapsulated particles. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the characteristics of testosterone polylactic-co-glycolic (PLGA) microspheres prepared by a paddle mixer or microfluidics device. The comparison was conducted by not only in vitro evaluation but also in vivo evaluation which has not been reported up to date. We discovered that, among the steps in microsphere preparation, the solvent removal process strongly impacted drug content, particle size and surface morphology. Spectroscopic measurements suggested that molecular interactions and crystallinity of the drug incorporated in the microspheres differed. For the drug release profile, although both mixer- and microfluidics-prepared samples showed similar sustained release of the incorporated drug for approximately one month in vitro, they exhibited different plasma concentration profiles in vivo. Together, our findings show that the preparation process, especially the solvent removal process, may affect the physicochemical characteristics of testosterone PLGA microspheres, leading to different in vivo performance. [ABSTRACT FROM AUTHOR]

This study aimed to synthesize the chitosan-based gel microspheres and use them as a sorbent for Basic Blue 41 dye molecules (BB41) from aqueous solutions. For this aim, polymeric gel microspheres were produced from chitosan by a cross-linking method. The produced gel microspheres were characterized by appropriate instrumental methods such as FTIR and SEM. The effects of deacetylation degree and molecular weight of chitosan, type of cross-linking agent, cross-linking rate and time, etc. on sorption yield and sorption capacity of BB41 dye molecules on chitosan-based microsphere were investigated. It was concluded that epichlorohydrin was used as a cross-linking agent that promoted pore formation and significantly increased the sorption yield of BB41 molecules. It was seen that the concentration of the cross-linker solution and cross-linking time were critical parameters. On the other hand, the sorption yield of BB41 molecules was increased when the degree of deacetylation of chitosan is increased. However, while the molecular weight of chitosan is increased, the sorption efficiency and capacity of the microsphere were decreased. According to the experimental results, the optimum conditions of microsphere production were determined as deacetylation degree: 85%; cross-linker: epichlorohydrin; the concentration of the cross-linker solution: 0.75%; and cross-linking time: 5 min. The sorption yield and capacity of BB41 dye molecules on the microsphere were found to be approximately 99.5% and 10 mg/g under optimum conditions. In addition, the desorption yield of BB41 molecules from the chitosan microsphere was determined to be over 90%. It was discovered that the desorption process had no negative effect on the shape of the chitosan microsphere. [ABSTRACT FROM AUTHOR]

Porous CeO2 has been of great interest recently, due to its great catalytic efficiency in splitting CO2 into CO and O2. Porous CeO2 microspheres are the key to scaling up such reactions in the fluidized-bed solar thermochemical reactors. In this paper, we report the processing and CO2 splitting performance of porous ceria microspheres. To fabricate the porous ceria microspheres, homogenous cerium-based sol-gel precursors were synthesized from cerium acetate. The acrylamide (AM) was used as both solidification and pore-generation agent. The polymerization of acrylamide facilitated the conversion of liquid droplets to solid gel microspheres. The optimal AM content was around 20 wt%, ensuring both sufficient porosity and the integrity of the ceria microspheres after thermal decomposition. After heat treatment at 1500 °C for 1 h, porous CeO2 microspheres were obtained, with an average diameter of ~800 µm and surface area of 2.9 m2/g. These microspheres had high porosity and good sphericity. The CO2 splitting performances of these microspheres were characterized using thermogravimetric analysis (TGA). During the thermal cycles between 1000 and 1400 °C, the O2 yield of porous ceria microspheres was 49 µmol/g, and the CO yield was 88 µmol/g. Compared with porous ceria granules of particle size of ~800 µm, the porous ceria microspheres exhibited higher O2 and CO production yields. After thermochemical cycles, the microspheres were not sintered together, and the surface area was slightly reduced to 2.7 m2/g. [ABSTRACT FROM AUTHOR]

The in vitro expansion of stem cells is important for their application in different life science fields such as cellular tissue and organ repair. An objective of this paper was to achieve static cell culture in vitro through peptide hydrogel-supported microspheres (MSs). The peptides, with their gel-forming properties, microstructures, and mechanical strengths characterized, were found to have good support for the MSs and to be injectable. The internal structures of poly(L-lactic acid) microspheres (PLLA-MSs) and polystyrene microspheres (PS-MSs) made in the laboratory were observed and statistically analyzed in terms of particle size and pore size, following which the co-cultured MSs with cells were found to have good cell adhesion. In addition, three-dimensional (3D) culturing of cells was performed on the peptide and microcarrier composite scaffolds to measure cell viability and cell proliferation. The results showed that the peptides could be stimulated by the culture medium to self-assembly form a 3D fiber network structure. Under the peptide-MS composite scaffold-based cell culture system, further enhancement of the cell culture effect was measured. The peptide-MS composite scaffolds have great potential for the application in 3D cell culture and in vitro cell expansion. [ABSTRACT FROM AUTHOR]

In recent years, the treatment of chronic osteomyelitis mediated by biodegradable polymer platforms has received increasing attention. This paper reports an advanced drug delivery system, vancomycin (VA) and DGEA loaded microspheres embedded in injectable thermosensitive polypeptide hydrogels (i.e., hydrogel-microsphere (Gel-MP) construct), for continuous release of drugs with different mechanisms and more comprehensive treatment of chronic osteomyelitis. The Gel-MP construct exhibits continuous biodegradability and excellent biocompatibility. Microspheres (MP) are wrapped inside Gel. With the degradation of Gel, VA and MP are released from them, VA released with faster degradation speed, achieving a potent antibacterial effect and effectively controlling infection. Due to the slower degradation rate of MP compared to Gel, subsequently, DGEA is released from MP to induce bone formation and produce the effect of filling bone defects. Compared with other formulations, the in vivo combinational treatment of Gel/VA-MP/DGEA can simultaneously balance antibacterial and osteogenic effects. More importantly, local sustained-release drug delivery systems can significantly mitigate the systemic toxicity of drugs. Therefore, the injection local sequential drug delivery system has broad prospects in the clinical application of treating chronic osteomyelitis.

The optical diffraction effect imposes a radical obstacle preventing conventional optical microscopes from achieving an imaging resolution beyond the Abbe diffraction limit and thereby restricting their usage in a multitude of nanoscale applications. Over the past decade, the optical microsphere nano-imaging technique has been demonstrated to be a cost-effective solution for overcoming the diffraction limit and has achieved an imaging resolution of up to about λ6-λ8 in a real-time and label-free manner, making it highly competitive among numerous super-resolution imaging technologies. In this review, we summarize the underlying nano-imaging mechanisms of the microsphere nanoscope and key advancements aimed at imaging performance enhancement: first, to change the working environment or modify the peripheral hardware of a single microsphere nanoscope at the system level; second, to compose the microsphere compound lens; and third, to engineer the geometry or ingredients of microspheres. We also analyze challenges yet to be overcome in optical microsphere nano-imaging, followed by an outlook of this technique.

Light microscopes are the most widely used devices in life and material sciences that allow the study of the interaction of light with matter at a resolution better than that of the naked eye. Conventional microscopes translate the spatial differences in the intensity of the reflected or transmitted light from an object to pixel brightness differences in the digital image. However, a phase microscope converts the spatial differences in the phase of the light from or through an object to differences in pixel brightness. Interference microscopy, a phase-based approach, has found application in various disciplines. While interferometry has brought nanometric axial resolution, the lateral resolution in quantitative phase microscopy (QPM) has still remained limited by diffraction, similar to other traditional microscopy systems. Enhancing the resolution has been the subject of intense investigation since the invention of the microscope in the 17th century. During the past decade, microsphere-assisted microscopy (MAM) has emerged as a simple and effective approach to enhance the resolution in light microscopy. MAM can be integrated with QPM for 3D label-free imaging with enhanced resolution. Here, we review the integration of microspheres with coherence scanning interference and digital holographic microscopies, discussing the associated open questions, challenges, and opportunities.

Osteoarthritis (OA), a common degenerative disease, is characterized by high disability and imposes substantial economic impacts on individuals and society. Current clinical treatments remain inadequate for effectively managing OA. Organoids, miniature 3D tissue structures from directed differentiation of stem or progenitor cells, mimic native organ structures and functions. They are useful for drug testing and serve as active grafts for organ repair. However, organoid construction requires extracellular matrix-like 3D scaffolds for cellular growth. Hydrogel microspheres, with tunable physical and chemical properties, show promise in cartilage tissue engineering by replicating the natural microenvironment. Building on prior work on SF-DNA dual-network hydrogels for cartilage regeneration, we developed a novel RGD-SF-DNA hydrogel microsphere (RSD-MS) via a microfluidic system by integrating photopolymerization with self-assembly techniques and then modified with Pep-RGDfKA. The RSD-MSs exhibited uniform size, porous surface, and optimal swelling and degradation properties. In vitro studies demonstrated that RSD-MSs enhanced bone marrow mesenchymal stem cells (BMSCs) proliferation, adhesion, and chondrogenic differentiation. Transcriptomic analysis showed RSD-MSs induced chondrogenesis mainly through integrin-mediated adhesion pathways and glycosaminoglycan biosynthesis. Moreover, in vivo studies showed that seeding BMSCs onto RSD-MSs to create cartilage organoid precursors (COPs) significantly enhanced cartilage regeneration. In conclusion, RSD-MS was an ideal candidate for the construction and long-term cultivation of cartilage organoids, offering an innovative strategy and material choice for cartilage regeneration and tissue engineering.

Seroma formation and poor wound healing are common complications of many surgeries that create anatomical dead space (i.e., mastectomy), often causing tissue infection and even necrosis. Although negative pressure drainage and tissue adhesives are investigated to alleviate fluid accumulation post-surgery, however, their therapeutic efficacy remains unsatisfactory in most cases. Herein, the catechol-rich chemically crosslinked gelatin microspheres (ca-CGMSs) have been developed as biodegradable reconstructive implants for preventing seroma formation and concurrently promoting subcutaneous wound healing. Compared with the most representative hydrogel adhesive, i.e. commercial porcine fibrin sealant (PFS), the loosely packed ca-CGMSs with diameters range from 50 to 350 μm, provide numerous cell-adhesive interfaces and interconnected macro-pores for enhanced cell adhesion, proliferation and migration. Subcutaneous embedding trials show the in situ swelling aggregation and wet tissue adhesion of ca-CGMSs as well as their capacity in recruiting autologous cells in rat mastectomy models. The trials in rabbit mastectomy models demonstrate that, compared with PFS gluing, the implanted dried ca-CGMSs not only significantly inhibit seroma formation, but also achieve enhanced wound healing by inducing the formation of vascularized neo-tissue. The ca-CGMSs show a great potential to be the next-generation of restorative materials for both preventing seroma formation and healing subcutaneous wounds.

This study presents an unconventional flow processing technique that uses glass microspheres instead of abrasives. The fundamentals of flow machining with glass microspheres, including microsphere flow burnishing (MFB) and the conditions necessary for cutting or plastic deformation of a surface to occur during MFB, are determined. Details on such conditions are lacking, and therefore, this study attempts to define these conditions. To this end, MFB was experimentally confirmed to be a burnishing process, and the effects of MFB and abrasive flow machining (AFM) on 2017A aluminum alloy were compared. Both processes achieved a surface roughness (Sa) of < 0.5 μm, while MFB yielded higher values of surface microhardness and compressive stress. The effects of basic process parameters on the MFB and AFM results (workpiece weight loss and Sa) were compared experimentally, and the corresponding mathematical models were established. Utilizing these relationships, MFB parameters can be selected so as to obtain the most favorable surface layer for the expected operating conditions. [ABSTRACT FROM AUTHOR]

In 3D microsphere tracking, unlike in-plane motion that can be measured directly by a microscope, axial displacements are resolved by optical interference or a diffraction model. As a result, the axial results are affected by the environmental noise. The immunity to environmental noise increases with measurement accuracy and the signal-to-noise ratio (SNR). In compound digital holography microscopy (CDHM)-based measurements, precise identification of the tracking marker is critical to ensuring measurement precision. The reconstruction centering method (RCM) was proposed to suppress the drawbacks caused by installation errors and, at the same time, improve the correct identification of the tracking marker. The reconstructed center is considered to be the center of the microsphere, rather than the center of imaging in conventional digital holographic microscopy. This method was verified by simulation of rays tracing through microspheres and axial moving experiments. The axial displacements of silica microspheres with diameters of 5 μm and 10 μm were tested by CDHM in combination with the RCM. As a result, the SNR of the proposed method was improved by around 30%. In addition, the method was successfully applied to axial displacement measurements of overlapped microspheres with a resolution of 2 nm. [ABSTRACT FROM AUTHOR]

The nacre with brick‐and‐mortar structure enables multiple toughening and strengthening mechanisms, and bioinspired ceramics with brick‐and‐mortar structure have been attracting much attention from many researchers. However, the process of constructing precise and uniform microstructure is quite complicated. Herein, we propose a novel and facial method to fabricate composite ceramics with brick‐and‐mortar structure. Si3N4 microspheres prepared by particle‐stabilized foaming and centrifugal spray drying were directly hot pressed after being immersed in suspension and evenly wrapped with ZrO2. The mechanical properties of composite ceramics were optimized by adjusting the pressure during sintering and ZrO2 content. When ZrO2 content was 10 wt% and sintering pressure was 5 MPa, the fracture toughness of ZrO2/Si3N4 brick‐and‐mortar composite ceramics reached 9.02 MPa·m1/2, and the flexural strength was 784 MPa, which were increased by 46.9% and 26.5%, respectively, compared with the control group. While retaining excellent flexural strength, the strong interface also induces crack to deflect and branch along the two‐phase interface of the brick‐and‐mortar structure caused by the residual stress, which was derived from the mismatch of the thermal expansion coefficient of ZrO2 and Si3N4, consuming more fracture energy to achieve the toughening effect. [ABSTRACT FROM AUTHOR]

A short monodisperse poly(ethylene glycol) (PEG) and a neutral organic rotamer conjugate TEG‐BTA‐2 amphiphile was designed for the construction of a stimuli‐responsive switchable self‐assembled structure for drug encapsulation by noncovalent interaction and targeted controlled delivery. A short PEG, tetraethylene glycol (TEG) was covalently attached with a neutral organic rotamer benzothiazole dye (BTA‐2) affording the neutral TEG‐BTA‐2 (<500 D). The TEG‐BTA‐2 is self‐assembled into a microsphere in an aqueous medium, but remarkably undergoes morphology change switching to a rice‐like microcapsule for curcumin encapsulation. Curcumin‐loaded microcapsules were stable in an aqueous solution, however, were noticed disintegrating upon the addition of BSA protein. This is possibly due to an interaction with BSA protein leading to a protein affinity‐controlled curcumin release in a neutral PBS buffer. Moreover, cell internalization of the neutral amphiphile TEG‐BTA‐2 into A549 cells was observed by fluorescence microscopy, providing an opportunity for application as a molecular vehicle for targeted drug delivery and monitoring. [ABSTRACT FROM AUTHOR]

Whispering gallery mode (WGM) resonators doped with fluorescent materials find impressive applications in biological sensing. They do not require special conditions for the excitation of WGM inside that provide the basis for in vivo sensing. Currently, the problem of materials for in vivo WGM sensors are substantial since their fluorescence should have stable optical properties as well as they should be biocompatible. To address this we present WGM microresonators of 5–7 μ m, where the dopant is made of carbon quantum dots (CDs). CDs are biocompatible since they are produced from carbon and demonstrate bright optical emission, which shows different bands depending on the excitation wavelength. The WGM sensors developed here were tested as label-free biosensors by detecting bovine serum albumin molecules. The results showed WGM frequency shifting, with the limit of detection down to 10 − 16 M level. [ABSTRACT FROM AUTHOR]

A novel approach is reported that harnesses laser‐induced shockwave spallation technique to selectively remove clusters of polystyrene (PS) microspheres from close‐packed monolayers for the creation of 2D colloidal micropatterns. The strategic design of the layer structure by incorporating a thin layer of poly(vinyl alcohol) (PVA) on top of the PS monolayer enables the complete delamination of PS particle clusters. Its use is demonstrated for creating different sizes of circular microscale spallation patterns by regulating the tensile force of the shockwave with laser fluence adjustments. To further control the diameter of the spallation pattern, various shadow masks are utilized to tune the shockwave generation region. The finding reveals that both PVA thickness and spallation force play key roles in adjusting cluster spallation size with complete removal. The study highlights the potential of laser spallation techniques as a rapid and non‐contact method for 2D colloidal crystal patterning by leveraging spatially regulated shockwave spallation forces. [ABSTRACT FROM AUTHOR]

Rough structure microspheres developed using electrospinning show many superior properties, such as increased specific surface area and enhanced wettability, yielding numerous benefits to the applications in adsorption, separation, and others. In this study, biomimetic rough microspheres on string of polymethyl methacrylate nanofiber with hierarchical structure of micron-scale microsphere, and nanoscale Y-shape edges on the microsphere were innovatively and successfully developed by electrospinning. The resulting microsphere exhibited a steering-wheel-like Y shape, and the formation process was physically explained by the geometric potential theory. In the spinning process, irregular hexahedron-like droplet was firstly formed. Then, the hexahedron-like droplet changed to tetrahedron-like after the bottom contacted the collector. The tetrahedron-like droplet evolved into Y-shaped microsphere due to the geometric potential and the collapse of the center part owing to the solvent evaporation. Furthermore, similar to the natural lotus leaf, the hierarchical steering-wheel structure strengthened the nanofiber membrane roughness and endowed the membrane with superhydrophobicity, indicating the potential application in water treatment (oil-water separation, and dye and heavy metal ion adsorption), functional surface materials (self-cleaning fabrics), energy generation and other salient areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon-rich and low-ash hydrochars is prepared innovatively from sewage sludge. • Hydrochar produced from sludge alkaline hydrolysate showed nanoparticle structure. • Multilayer microsphere structure was formed from sludge alkali-thermal hydrolysate. • Hydrochar with carbon content over 70% and ash content less than 5% was realized. • Hydrolysis temperature is an important factor to influence the hydrochar formation. The production of carbon-rich and low-ash hydrochar from sewage sludge is attracting interest due to its great application prospect in high value-added carbon materials fields, but which is impossible through direct hydrothermal carbonization. In this study, alkali-thermal hydrolysis followed by acid-assisted hydrothermal carbonization was thus proposed. Thermal hydrolysis at strong alkaline environment was more effective than acid one to promote the dissolution of organic matters and restrain the release of inorganic matters from sludge, which created a favorable condition for hydrochar formation in a carbon-rich and low-ash way. Alkali-thermal hydrolysis began to show a positive effect on the dissolution of organics in sludge when temperature exceeded the threshold of 90 °C, and an increase of 9.77 % was found at 150 °C when compared to 30 °C. Acid-assisted hydrothermal carbonization of alkali-thermal hydrolysate (ATH) at pH 1.0 strongly promoted condensation polymerization of dissolved organics to form hydrochar and meanwhile inhibited introduction of dissolved inorganics. The nanosized microparticulate hydrochar derived from ATH-30 had a carbon and ash content of 50.98–61.31 % and 10.76–12.09 %, while the micro-sized microspheric hydrochar with multiple deposition layers formed from ATH-150 showed a better performance in carbon-rich and low-ash aspect where a carbon and ash content of 58.24–70.07 % and 0.40–3.24 % was realized, both of which were obviously superior to the direct hydrochar (carbon 34.86 % and ash 46.11 %). The condensation of dissolved organics during alkali-thermal hydrolysis stage is important to the carbonization degree of hydrochar. This study provides a new perspective in sludge disposal and production of advanced carbon materials. [ABSTRACT FROM AUTHOR]

Zeolite microspheres have been successfully applied in commercial-scale separators such as oxygen concentrators. However, further enhancement of their applications is hampered by the post-synthetic shaping process that formulates the zeolite powder into packing-sized spherical bodies with various binders leading to active site blockage and suboptimal performance. Herein, binderless zeolite microspheres with a tunable broad size range from 2 µm to 500 µm have been developed with high crystallinity, sphericity over 92%, monodispersity with a coefficient of variation (CV) less than 5%, and hierarchical pore architecture. Combining precursor impregnation and steam-assisted crystallization (SAC), mesoporous silica microspheres with a wide size range could be successfully transformed into zeolite. For preserved size and spherical morphology, a judicious selection of the synthesis conditions is crucial to ensure a pure phase, high crystallinity, and hierarchical architecture. For the sub-2-µm zeolite microsphere, low-temperature prolonged aging was important so as to suppress external zeolization that led to a large, single macroporous crystal. For the large 500 µm sphere, ultrasound pretreatment and vacuum impregnation were crucial and facilitated spatially uniform gel matrix dispersion and homogenous crystallization. The obtained zeolite 5A microspheres exhibited excellent air separation performance, while the 4A microspheres displayed ammonium removal capabilities. This work provides a general strategy to overcome the existing limitations in fabricating binder-free technical bodies of zeolites for various applications. [ABSTRACT FROM AUTHOR]

Single-particle inductively coupled plasma mass spectrometry (spICP-MS) has been used for particle size measurement of diverse types of individual nanoparticles and micrometer-sized carbon-based particles such as microplastics. However, its applicability to the measurement of micrometer-sized non-carbon-based particles such as silica (SiO2) particles is unclear. In this study, the applicability of spICP-MS to particle size measurement of non-porous/mesoporous SiO2 microspheres with a nominal diameter of 5.0 µm or smaller was investigated. Particle sizes of these microspheres were measured using both spICP-MS based on a conventional calibration approach using an ion standard solution and scanning electron microscopy as a reference technique, and the results were compared. The particle size distributions obtained using both techniques were in agreement within analytical uncertainty. The applicability of this technique to the detection of metal-containing protein-binding mesoporous SiO2 microspheres was also investigated. Bound iron (Fe)-containing proteins (i.e., lactoferrin and transferrin) of mesoporous SiO2 microspheres were detected using Fe as a presence marker for the proteins. Thus, spICP-MS is applicable to the particle size measurement of large-sized and non-porous/mesoporous SiO2 microspheres. It has considerable potential for element-based detection and qualification of bound proteins of mesoporous SiO2 microspheres in a variety of applications. [ABSTRACT FROM AUTHOR]