Search

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]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

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]

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 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 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]

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]

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]

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]

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]

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]

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]

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]

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 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]

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]

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]

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]

Micro-nanostructured electrode materials are characterized by excellent performance in various secondary batteries. In this study, a facile and green hydrothermal method was developed to prepare amorphous vanadium-based microspheres on a large scale. Hollow V2O5 microspheres were achieved, with controllable size, after the calcination of amorphous vanadium-based microspheres and were used as cathode materials for lithium-ion batteries. As the quantity of V2O5 microspheres increased, the electrode performance improved, which was ascribed to the smaller charge transfer impedance. The discharge capacity of hollow V2O5 microspheres could be up to 196.4 mAhg−1 at a current density of 50 mAg−1 between 2.0 and 3.5 V voltage limits. This sheds light on the synthesis and application of spherical electrode materials for energy storage. [ABSTRACT FROM AUTHOR]

Rapid and effective healing of irregular wounds caused by burns, lacerations, and blast injuries remains a persistent challenge in wound care. Hydrogel microsphere dressings that can adaptively fill and adhere to the wounds without external force are desired to treat irregular wounds, providing an external barrier and accelerating healing. Herein, we created multifunctional cellulose‐based surface‐wrinkled microspheres with antioxidant, antibacterial, hygroscopicity, wet‐adhesion and shape‐adaptive capabilities to relieve inflammation, bacteria and excess exudate situations in healing irregular wounds. This dressing rapidly adsorbs exudate and reversibly adheres wetly to the wounds upon being filled, effectively inhibiting bacterial infection and reducing the flooded exudate to accelerate wound healing. Polydopamine (PDA) provides catechol‐based tissue bioadhesion to microspheres through π–π stacking or hydrogen bond interaction, and also establishes a bond bridge with an antimicrobial component (thymol), which not only enables the microspheres to stably adhere to the wound to maintain hygroscopicity, but also improves the release of the introduced antimicrobial component (thymol). In vivo assays, as well as histopathological and immunofluorescence studies have shown that multifunctional cellulose‐based microspheres have excellent pro‐healing abilities and are promising candidates for dehumidification and healing of irregular wound in clinical applications. [ABSTRACT FROM AUTHOR]

Poly(D,L-lactide-co-glycolide is a biodegradable copolymer that can release pharmaceuticals. These pharmaceuticals can provide local therapy and also avert the clinical issues that occur when a drug must be given continuously and/or automatically. However, the drawbacks of using poly(D,L-lactide-co-glycolide include the kinetics and duration of time of poly(D,L-lactide-co-glycolide drug release, the denaturing of the drug loaded drug, and the potential clinical side effects. These drawbacks are mainly caused by the volatile organic solvents needed to prepare poly(D,L-lactide-co-glycolide spheres. Using the non-toxic solvent glycofurol solvent instead of volatile organic solvents to construct poly(D,L-lactide-co-glycolide microspheres may deter the issues of using volatile organic solvents. Up to now, preparation of such glycofurol spheres has previously met with limited success. We constructed dexamethasone laden poly(D,L-lactide-co-glycolide microspheres utilizing glycofurol as the solvent within a modified phase inversion methodology. These prepared microspheres have a higher drug load and a lower rate of water diffusion. This prolongs drug release compared to dichloromethane constructed spheres. The glycofurol-generated spheres are also not toxic to target cells as is the case for dichloromethane-constructed spheres. Further, glycofurol-constructed spheres do not denature the dexamethasone molecule and have kinetics of drug release that are more clinically advantageous, including a lower drug burst and a prolonged drug release. [ABSTRACT FROM AUTHOR]

This article discusses the development of a composite material for lithium-ion batteries that is made up of tin-based oxide microspheres reinforced by Al2O3 and CNTs. The researchers used a microwave-assisted method to create the composite, which showed better lithium storage performance compared to other electrode materials. The composite had a higher capacity, improved cycling stability, and better rate performance. The researchers attribute these improvements to the combination of SnO2, Al2O3, CNTs, and the unique structure of the composite. This research offers a potential solution for high-capacity and long-lasting lithium-ion batteries by addressing the challenges of low initial efficiency and capacity loss in SnO2-based electrodes. [Extracted from the article]

Arthritis is a widespread joint disorder globally, the patient completely dependent on NSAIDs which are administered after a fixed interval to subside the pain. This work aims to establish a preprogrammed drug delivery system of aceclofenac with a predetermined lag time for the treatment of arthritis. This new preprogrammed formulation microsphere reduces the time-dependent dose administration as it steadily releases the drug in the blood circulation reducing side effects and increasing patient compliance. Aceclofenac (ACF) loaded polymer microspheres were prepared by a new emulsification and crosslinking method using glutaraldehyde as crosslinking agent. Microspheres were prepared in 6 batches using different polymers like sodium alginate, guar gum and chitosan, alone, as well as in combinations. The type and quantity of polymers were changed in every batch while the amount of aceclofenac was unvarying. The microspheres were then evaluated for the particle size, drug content, percentage yield, percentage entrapment efficiency and percentage drug release followed by noting the lag time. The microsphere loaded with aceclofenac were formulated and evaluated, the result showed that all the preparations showed a good lag time (2–3 h), but chitosan (alone) gave the highest lag time, which fulfills the aim of pre-programmed drug delivery system. Preprogrammed drug release has been achieved from the microspheres over a period of 0–7 h, consistent with the demand for chronotherapeutic drug delivery for the treatment of arthritis. The major signification of the preparation technique includes short processing time and the lack of exposure of the ingredients to high temperatures. Aceclofenac-loaded microspheres offer a promising avenue for arthritis treatment, ensuring sustained drug release. Their potential clinical implications include enhanced therapeutic efficacy, reduced side effects, and improved patient compliance. Future directions may involve personalized formulations, targeted delivery systems, and exploring applications beyond arthritis, expanding the scope of this innovative drug delivery approach. [ABSTRACT FROM AUTHOR]

In the food industry, the microencapsulation process is important to control the release of active encapsulated ingredients, mask unwanted flavors, colors, and unpleasant smells, increase shelf life, and protect encapsulated components from light, moisture, and nutritional loss. In this process, microspheres are formed using cross-linked polymer, which can incorporate aqueous or oily ingredients, using simple physicochemical methods of phase separation by coacervation, without the need for organic solvents. In this context, this study aimed to develop bioactive, functional frozen yogurt through the incorporation of microspheres loaded with ascorbic acid or omega 3. The process used resulted in small microspheres (15–80 μm), imperceptible to the palate, and capable of swelling about 14 times, being suitable for incorporating omega 3, without altering the swelling, and extending the shelf life of the ascorbic acid for 6 weeks, even in an acid medium. Also, the matrix does not affect the properties of frozen yogurt and acts as a stabilizer, contributing to reduce the melting rate. The sensory analysis proved that encapsulation was promising to mask the taste and odor of omega 3 and to protect the ascorbic acid, without altering the properties and quality of the frozen product. [ABSTRACT FROM AUTHOR]

We report the evaluation of chiral nematic liquid crystal (CNLC) in blocking ultraviolet (UV). The CNLC was coated on a calcium fluoride substrate to measure the spectral transmittance, which was measured to detect the UV‐blocking effect of CNLC. The results show that CNLC could reduce UVB (290–320 nm) by 99.9% and UVA (320–400 nm) by 95.6%. The barrier effect of cake‐shaped semi‐solidified CNLC microspheres was further investigated, and it was found that cake‐shaped semi‐solidified CNLC microspheres could reduce UVB by 58.2% and UVA by 34.1%. This is due to the chemical absorption property of CNLC, which has UV‐absorbing functional groups such as the benzene rings. And the physical reflection properties of CNLC could periodically reflect a certain wavelength of light. Liquid crystal (LC) is a rich set of soft materials with rod‐like structures widely existing in nature, which is harmless to the human body and environment. Therefore, using CNLC's function of blocking UV, a new sunscreen can be developed. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to construct crosslinked polylysine‐hyaluronic acid microspheres (pl‐HAM) ladened with gingival mesenchymal stem cells (GMSCs) and explore its biologic behavior in soft tissue regeneration. Methods: The effects of the crosslinked pl‐HAM on the biocompatibility and the recruitment of L‐929 cells and GMSCs were detected in vitro. Moreover, the regeneration of subcutaneous collagen tissue, angiogenesis and the endogenous stem cells recruitment were investigated in vivo. We also detected the cell developing capability of pl‐HAMs. Results: The crosslinked pl‐HAMs appeared to be completely spherical‐shaped particles and had good biocompatibility. L‐929 cells and GMSCs grew around the pl‐HAMs and increased gradually. Cell migration experiments showed that pl‐HAMs combined with GMSCs could promote the migration of vascular endothelial cells significantly. Meanwhile, the green fluorescent protein‐GMSCs in the pl‐HAM group still remain in the soft tissue regeneration area 2 weeks after surgery. The results of in vivo studies showed that denser collagen deposition and more angiogenesis‐related indicator CD31 expression in the pl‐HAMs+ GMSCs + GeL group compared with the pl‐HAMs + GeL group. Immunofluorescence showed that CD44, CD90, CD73 co‐staining positive cells surrounded the microspheres in both pl‐HAMs + GeL group and pl‐HAM + GMSCs + GeL group. Conclusions: The crosslinked pl‐HAM ladened with GMSCs system could provide a suitable microenvironment for collagen tissue regeneration, angiogenesis and endogenous stem cells recruitment, which may be an alternative to autogenous soft tissue grafts for minimally invasive treatments for periodontal soft tissue defects in the future. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Test & Measurement Technology is the property of Publishing Center of North University of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The objective of the present investigation was to establish a molecular association of different proteases as cancer targets with the indinavir and how the physicochemical characteristics of the indinavir sulfate microsphere vary with different process variables was systemically established. Methods: Molecular interactions with indinavir were identified and established by molecular simulation docking studies. Indinavir sulfate-loaded microspheres were prepared by the oil-in-oil emulsion solvent evaporation technique. Results: Results indicated that indinavir could interact with all four proteases at the active binding site of receptors. Indinavir was found to show significantly higher interaction with Matrix Metalloproteases, Aspartate Proteases, and Cysteine Proteases with a binding energy of -8.80, -8.19, and -6.87, respectively, as compared to their native ligand. However, serine proteases exhibit less but significant interaction with a binding energy of -5.92 than the native ligand. The microspheres exhibited 72%-93% of entrapment and prolonged drug release (DR), up to 9 h. The drug-loaded microspheres showed invariable character by the Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermographs and revealed no drug-polymer interactions. The decrease in the drug's crystallinity was observed in X-ray diffraction (XRD). The scanning electron microscope (SEM) study revealed the spherical and porous nature of microspheres. Conclusion: Indinavir could act as a potential inhibitor of different proteases associated with tumor growth initiation, progression, and metastasis, and microspheres with sustained DR could be utilized to deliver an anticancer drug in a more targeted way as an emerging cancer microsphere technology. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shenyang Pharmaceutical University is the property of Shenyang Pharmaceutical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Functional Polymers is the property of Journal of Functional Polymers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We present a microsphere-based microsensor that can measure the vibrations of the miniature motor shaft (MMS) in a small space. The microsensor is composed of a stretched fiber and a microsphere with a diameter of 5 μm. When a light source is incident on the microsphere surface, the microsphere induces the phenomenon of photonic nanojet (PNJ), which causes light to pass through the front. The PNJ's full width at half maximum is narrow, surpassing the diffraction limit, enables precise focusing on the MMS surface, and enhances the scattered or reflected light emitted from the MMS surface. With two of the proposed microsensors, the axial and radial vibration of the MMS are measured simultaneously. The performance of the microsensor has been calibrated with a standard vibration source, demonstrating measurement errors of less than 1.5%. The microsensor is expected to be used in a confined space for the vibration measurement of miniature motors in industry. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Osteoarthritis (OA) is the most common form of joint disease affecting articular cartilage and peri-articular tissues. Traditional treatments are insufficient, as they are aimed at mitigating symptoms. Multipotent Stromal Cell (MSC) therapy has been proposed as a treatment capable of both preventing cartilage destruction and treating symptoms. While many studies have investigated MSCs for treating OA, therapeutic success is often inconsistent due to low MSC viability and retention in the joint. To address this, biomaterial-assisted delivery is of interest, particularly hydrogel microspheres, which can be easily injected into the joint. Microspheres composed of hyaluronic acid (HA) were created as MSC delivery vehicles. Microrheology measurements indicated that the microspheres had structural integrity alongside sufficient permeability. Additionally, encapsulated MSC viability was found to be above 70% over one week in culture. Gene expression analysis of MSC-identifying markers showed no change in CD29 levels, increased expression of CD44, and decreased expression of CD90 after one week of encapsulation. Analysis of chondrogenic markers showed increased expressions of aggrecan (ACAN) and SRY-box transcription factor 9 (SOX9), and decreased expression of osteogenic markers, runt-related transcription factor 2 (RUNX2), and alkaline phosphatase (ALPL). In vivo analysis revealed that HA microspheres remained in the joint for up to 6 weeks. Rats that had undergone destabilization of the medial meniscus and had overt OA were treated with empty HA microspheres, MSC-laden microspheres, MSCs alone, or a control vehicle. Pain measurements taken before and after the treatment illustrated temporarily decreased pain in groups treated with encapsulated cells. Finally, the histopathological scoring of each group illustrated significantly less OA damage in those treated with encapsulated cells compared to controls. Overall, these studies demonstrate the potential of using HA-based hydrogel microspheres to enhance the therapeutic efficacy of MSCs in treating OA. [ABSTRACT FROM AUTHOR]

Purpose: To examine the characteristics of drug-loaded superabsorbent polymer microspheres (SAP-MS) such as drug absorption, drug release, diameter, and visibility. Materials and Methods: SAP-MS (HepaSphere150–200 µm; Merit Medical, South Jordan, UT, USA) were suspended in drug solutions: (a) cefazolin, (b) lidocaine, (c) iopamidol and cefazolin, (d) iopamidol and lidocaine, and (e) iopamidol, cefazolin, and lidocaine. The concentrations of drugs were measured, and the amount of each drug absorbed was calculated. Filtered drug-loaded SAP-MS were mixed with saline, and the drug release rates were calculated. The diameter changes of SAP-MS during absorption were observed. Radiography of drug-loaded SAP-MS was evaluated as radiopacity by contrast-to-noise ratio (CNR). Results: The drug concentration did not change during absorption. The release rates increased for 10 min and then came to an equilibrium. The mean amounts of drug absorbed at 180 min and mean release rates at 24 h were (a) cefazolin: 265.4 mg, 64.2%; (b) lidocaine: 19.6 mg, 75.6%; (c) iopamidol: 830.2 mg, 22.5%; cefazolin: 137.6 mg, 21.2%; (d) iopamidol: 1620.6 mg, 78.5%; lidocaine: 13.5 mg, 81.4%; and (e) iopamidol: 643.7 mg, 52.9%; cefazolin: 194.0 mg, 51.6%; lidocaine: 5.3 mg, 58.4%. The diameter of SAP-MS increased for approximately 15 min. Finally, the diameters of SAP-MS were (a) 3.9 times, (b) 5.0 times, (c) 2.2 times, (d) 5.5 times, and (e) 3.6 times larger than the original size. Drug-loaded SAP-MS containing iopamidol were visible under X-ray imaging, with CNRs of (c) 3.0, (d) 9.0, and (e) 4.5. Conclusion: SAP-MS can absorb and release iopamidol, cefazolin, and lidocaine. [ABSTRACT FROM AUTHOR]

BACKGROUND: Advances in bone tissue engineering offer novel options for the regeneration of bone tissue. In the current clinical treatment, the method of accelerating bone tissue regeneration rate by promoting early angiogenesis has been widely accepted. OBJECTIVE: This study aimed to develop a long-acting slow-release system using the pro-angiogenic drug tetramethylpyrazine (TMPZ) and pro-osteogenic drug icariin (ICA), which can be administered locally to achieve the sequential release of TMPZ and ICA for better clinically efficiency in the treatment of bone defects. METHODS: This study aimed to prepare microspheres with a core-shell structure using two polymers, poly lactic-co-glycolic acid and silk fibroin, by coaxial electrostatic spraying. Based on the therapeutic model for bone defects, the pro-angiogenic drug TMPZ and pro-osteogenic drug ICA were encapsulated in the shell and core layers of the microspheres, respectively. Subsequently, TMPZ and ICA were released sequentially to promote early angiogenesis and late osteogenesis, respectively, at the site of the bone defect. The optimal preparation parameters for preparing the drug-loaded microspheres were identified using the univariate controlled variable method. Additionally, microsphere morphology and core-shell structure, such as physical properties, drug-loading properties, in vitro degradation and drug release patterns, were characterised using scanning electron microscope and laser scanning confocal microscopy. RESULTS: The microspheres prepared in this study were well-defined and had a core-shell structure. The hydrophilicity of the drug-loaded microspheres changed compared to the no-load microspheres. Furthermore, in vitro results indicated that the drug-loaded microspheres with high encapsulation and loading efficiencies exhibited good biodegradability and cytocompatibility, slowly releasing the drug for up to three months. CONCLUSION: The development of the drug delivery system with a dual-step release mechanism has potential clinical applications and implications in the treatment of bone defects. [ABSTRACT FROM AUTHOR]

The microsphere profile of probe tips has to be measured and compensated to improve the measurement accuracy of micro-coordinate measuring machines (micro-CMMs) to less than several hundred nanometers. A high-precision radius and sphericity measurement method for the microsphere of the CMM probe tip is proposed in this article. Different circumferences of the tested microsphere are measured, and the true radius of any measuring point on the surface can be obtained after separating the runout errors. Then the sphericity of the tested microsphere can be evaluated by the minimum zone sphere method. A corresponding measuring system is developed based on the analysis of the primary error model and mechanical model, and verification experiments are conducted using a ruby microsphere (A-5000-7801, Renishaw Corporation) as the reference, whose claimed diameter and sphericity are 700 µm and 130 nm, respectively. Six groups of repeated experiments are performed, and 18 000 measurement points on 15 circumferences are recorded in each group of experiments. Results show that the average radius of the tested microsphere is 350.003 µm, and the average sphericity error is 208 nm with a standard deviation of 5.3 nm. Finally, the expanded uncertainty of the measurement results of the developed system is calculated as 209 nm (k = 1.96, normal distribution). The proposed method and system can be used in the precision measurements and compensations for probe tips of micro-CMMs and other parts, such as microspheres used in micro-bearings and micro-manufacturing machines. [ABSTRACT FROM AUTHOR]

Copyright of Applied Chemical Industry is the property of Shaanxi Research Design Insitute of Petroleum & Chemical Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)