Formation Of Microspheres Research Articles

Development of chitosan microparticles via interfacial polymeric crosslinking method utilizing sodium trimetaphosphate

Chitosan derived from the alkaline deacetylation of chitin found in crustacean exoskeletons, is a natural biopolymer. It has been employed as a matrix for microparticles and crosslinked systems, facilitating the immobilization and controlled release of drugs, ensuring stability, safety, and efficacy. Microencapsulation, a technique involving the coating of active products in polymeric layers, allows for their release under specific conditions and controlled rates, achieved through the formation of microspheres or microcapsules. The distinctive features of chitosan, such as its non-toxicity, biodegradability, and cost-effectiveness, make it advantageous over other polysaccharides. This study aimed to produce chitosan microparticles through the interfacial polymeric crosslinking method, utilizing sodium trimetaphosphate as the crosslinking agent. A pre-formulation study, involving varying concentrations of polymer, crosslinking agent, and two stirring speeds, was conducted to assess their direct correlation with microparticle size. The interfacial polymeric crosslinking method successfully yielded spherical microparticles, maintaining a wrinkled surface aspect, with size variations according to the formulation. Parameters such as crosslinking agent concentration and stirring speed were identified as influencing factors on microparticle size. In conclusion, interfacial polymeric crosslinking using sodium trimetaphosphate proves effective in obtaining chitosan microparticles.

Cellulose esters: Synthesis for further formation of films with magnetite nanoparticles incorporated

This study investigated the homogeneous synthesis of cellulose acetate (CA) and propionate (CP) with varying degrees of substitution (DS) from sisal cellulose in a N, N-dimethylacetamide/lithium chloride (DMAc/LiCl) solvent system. These esters were used to prepare neat (CADSF/CPDSF) and nanocomposite films (CADSFFe/CPDSFFe) from prior synthesized magnetite nanoparticles (NPs, Fe3O4, 5.1 ± 0.5 nm). Among the CA and CP series, the composite CA0.7FFe and the neat CP0.7F films exhibited the highest modulus of elasticity, 2105 MPa and 2768 MPa, respectively, probably a consequence of the continuous fibrous structures present on the surface of these films. Microsphere formation on the film's surface was observed in scanning electron microscopy micrographs. This points to applications in the controlled release of targeted substances. The VSM analysis showed that the cellulosic matrices preserved the superparamagnetic characteristics of the NPs. This study suggested a reduced coupling effect between nanoparticles inside polymeric films due to magnetic saturation at low fields. CA0.7FFe and CA1.3FFe composite films reached a saturation magnetization (MSAT) of 46 emu/g around 7 kOe field. Hosting magnetite nanoparticles in cellulose ester matrices may be an interesting way to develop new functional cellulose-based materials, which have the potential for diverse applications, including microelectromechanical systems and microsensors.

Scalable spray-dried high-capacity MoC1-x/NC-Li2C2O4 prelithiation composite for lithium-ion batteries

Li2C2O4 is recognized as a promising prelithiation reagent for compensating active lithium owing to its residue-free, high-capacity, air-stable and cost-effective advantages. However, the inherent challenges of low conductivity and high reaction energy barriers necessitate the incorporation of a catalyst to expedite charge conduction and enhance electrochemical activity. It is essential to achieve an efficient composite Li2C2O4 with the catalyst while maintaining substantial prelithiation capacity. Herein, a scalable spray-dried strategy is developed to fabricate MoC1-x/NC-Li2C2O4 composites. The defect-rich nano-MoC1-x/NC catalysis facilitates intimate contact with Li2C2O4, leading to the formation of homogeneous microspheres that promote efficient solid-solid catalysis. Remarkably, the specific capacity of MoC1-x/NC-Li2C2O4 can reach up to 1117 mAh g−1 (calculation based on the complete release of CO2) with a low ratio of catalysts, demonstrating significant application potential. Furthermore, the activation potential of homogeneous MoC1-x/NC-Li2C2O4 composite can be reduced to 4.12 V at 50 °C, while maintaining favorable electrode integrity and wettability. Upon implementation in Gr||NCM622 and SiC||NCM622 full cell, the initial discharge specific capacity is improved by 10.5 % and 11.6 %, respectively. Notably, sufficient active lithium post-prelithiation preserves the cathode and SEI structural stability, ensuring a stable cycling performance. This work presents a scalable prelithiation material with great promise for advanced lithium-ion battery applications.

Taraxasterol enhanced bladder cancer cells radiosensitivity via inhibiting the COX-2/PGE2/JAK2/STAT3/MMP pathway

Purpose Radiotherapy with bladder preservation is highly acceptable among patients bearing bladder cancer (BCa), but the occurrence of secondary tolerance (ARR) during treatment is one of the important reasons for the failure of clinical radiotherapy. COX-2 has been frequently reported to be highly expressed and associated with radio-resistance in various cancers. In this study, the feasibility of Taraxasterol (Tara) as a radiosensitizer was investigated, and the target effect of Tara on COX-2 and its underlying mechanism were explored. Methods and materials The toxicity of Tara toward BCa cells was detected with the MTT method and cells in response to IR or Tara + IR were compared by clone formation assay. Next, a small RNA interference system (siRNA) was employed to decrease endogenous COX-2 expression in BCa cells, and the stem cell-like features and motion abilities of BCa cells under different treatments were investigated using microsphere formation and transwell chamber assay, respectively. Meanwhile, the expression of a series of inflammation-related molecules and stem cell characteristic molecules was determined by qRT-PCR, western blot and ELISA method. In vivo studies, BCa cells were subcutaneously injected into the right flank of each male mouse. Those mice were then grouped and exposed to different treatment: Tara, IR, IR + Tara and untreated control. The volumes of each tumor were measured every two days and target proteins were detected with immunohistochemical (IHC) staining. Results The results show that COX-2 decline, due to COX-2 knocking-down or Tara treatment, could greatly enhance BCa cells’ radiosensitivity and significantly decrease their migration, invasion and microsphere formation abilities, companied with the reduce of JAK2, phos-STAT3, MMP2 and MMP9 expression. However, Tara could not further reduce the expression of an above molecule of cells in COX-2-deficient BCa cells. Correspondingly, Tara treatment could not further enhance those siCOX-2 BCa cells response to IR. Conclusions Our data support that Tara can improve the radiosensitivity of BCa cells by targeting COX-2/PGE2. The mechanism may involve regulating STAT3 phosphorylation, DNA damage response protein activation, and expression of MMP2/MMP9.

Intestinal organoid modeling: bridging the gap from experimental model to clinical translation.

The 3D culture of intestinal organoids entails embedding isolated intestinal crypts and bone marrow mesenchymal stem cells within a growth factor-enriched matrix gel. This process leads to the formation of hollow microspheres with structures resembling intestinal epithelial cells, which are referred to as intestinal organoids. These structures encompass various functional epithelial cell types found in the small intestine and closely mimic the organizational patterns of the small intestine, earning them the name "mini-intestines". Intestinal tumors are prevalent within the digestive system and represent a significant menace to human health. Through the application of 3D culture technology, miniature colorectal organs can be cultivated to retain the genetic characteristics of the primary tumor. This innovation offers novel prospects for individualized treatments among patients with intestinal tumors. Presently established libraries of patient-derived organoids serve as potent tools for conducting comprehensive investigations into tissue functionality, developmental processes, tumorigenesis, and the pathobiology of cancer. This review explores the origins of intestinal organoids, their culturing environments, and their advancements in the realm of precision medicine. It also addresses the current challenges and outlines future prospects for development.

Functional Nanostructures from Sol-Gel Synthesis Using Keggin Polyoxometallate Phosphotungstic Acid as a Precursor.

Subjecting phosphotungstic acid solutions to low pH in combination with introduction of polyvalent cations led to the formation of nanostructured microspheres of approximately 2 μm in size, as shown by scanning electron microscopy, which were almost insoluble and resistant to degradation at neutral and high pH. These microspheres were composed of secondary nanospheres with diameters around 20 nm as revealed by transmission electron microscopy and atomic force microscopy. Investigations of the crystal structure of a potential intermediate of this process, namely, acidic lanthanum phosphotungstate, [La(H2O)9](H3O)3[PW12O40]2(H2O)19, showed a tight network of hydrogen bonding, permitting closer packing of phosphotungstic acid anions, thereby confirming the mechanism of the observed self-assembly process. The new material demonstrated promising electrochemical properties in oxygen evolution reactions with the high stability of the obtained electrode material.

Microstructure Formation and Characterization of Long-Acting Injectable Microspheres: The Gateway to Fully Controlled Drug Release Pattern.

Long-acting injectable microspheres have been on the market for more than three decades, but if calculated on the brand name, only 12 products have been approved by the FDA due to numerous challenges in achieving a fully controllable drug release pattern. Recently, more and more researches on the critical factors that determine the release kinetics of microspheres shifted from evaluating the typical physicochemical properties to exploring the microstructure. The microstructure of microspheres mainly includes the spatial distribution and the dispersed state of drug, PLGA and pores, which has been considered as one of the most important characteristics of microspheres, especially when comparative characterization of the microstructure (Q3) has been recommended by the FDA for the bioequivalence assessment. This review extracted the main variables affecting the microstructure formation from microsphere formulation compositions and preparation processes and highlighted the latest advances in microstructure characterization techniques. The further understanding of the microsphere microstructure has significant reference value for the development of long-acting injectable microspheres, particularly for the development of the generic microspheres.

Hierarchical Mo-doped Ni[sbnd]Co hydroxides cauliflower-like microspheres via a rapid microwave hydrothermal synthesis for supercapacitors

Transition metal double hydroxide (TMDH) materials have the advantages of low cost, simple preparation, wide variety, and tunable physical and chemical properties, which have broad research prospects in developing and applying high-performance electrode materials. Herein, molybdenum-doped nickel-cobalt double hydroxides (NiCoDH-Mo) were prepared by a rapid one-step microwave hydrothermal method in tens of minutes. Extensive investigations have been conducted on the morphology, crystal structure, and electrochemical properties of nickel‑cobalt double hydroxides with varying concentrations of Mo doping. The incorporation of Mo dopants into NiCoDH-Mo0.50 has yielded the formation of hierarchical cauliflower-like microspheres, which exhibit a significantly enhanced specific surface area of 91.7 m2 g−1 along with an improved electrical conductivity of 0.0233 μS cm−1. Thus, the optimized NiCoDH-Mo0.50 electrode has a high specific capacity of 160.5 mAh g−1 at a current density of 1 A g−1 and can maintain a high specific capacity of 115.3 mAh g−1 when the current density increases by 20 times. Finally, the NiCoDH-Mo cathode and mango seed-derived activated carbon anode were assembled into a hybrid supercapacitor with an energy density of 41.3 Wh kg−1 at a power density of 850 W kg−1, which also exhibits a capacity retention of 84 % after 8000 cycles. Therefore, we provide a facile and efficient strategy to prepare TMDH electrode materials with excellent performance for energy storage systems.

Hydrazine hydrate free one pot rapid hydrothermal synthesis of crystalline Zn1−xNdxSe nanostructures for wastewater treatment

Non-hydrazine based hydrothermal synthesis of ZnSe nanostructures is reported. Zinc dust and elemental selenium were the starting materials for the synthesis. 4 h were consumed for the synthesis wherein merceptoacetic acid and methylamine were used for the dissolution of elemental precursors. Influence of Nd doping on growth and properties of the nanostructures is studied. Structural properties (X-ray diffraction) revealed that the nanoparticles grow in cubic crystal phase. Morphology of the nanostructures showed formation of microspheres that are formed by the agglomeration of smaller spherical nanoparticles. Optical properties demonstrated that the nanoparticles show red shift in the transmittance band upon doping making ultraviolet active ZnSe suitable for visible light photocatalysis. The photocatalytic activity of the nanostructures was demonstrated in the presence of ultraviolet and visible light photons separately. The doped samples show prominent activity than ZnSe nanoparticles in the visible light and the reason for this is optimum band gap and the electron scavenging property of Nd3+ ions that reduces electron hole recombination rate. The doped nanoparticles degraded more than 80 % of rhodamine B (RhB) in just two hours of visible light irradiation. The nanoparticles retained their properties after photocatalytic experiments were done, revealing their high stability. Photocatalytic degradation of the dye molecules resulted because of formation of highly oxidative species (free radicals) upon light illumination that was determined by the scavenger experiments.

Microwave–assisted hydrothermal conversion of crop straw into value–added products via magnesium acetate

Rational utilization of crop straw is conducive to sustainable development of society. This study focused on the mechanism for the effect of magnesium acetate on the microwave–assisted hydrothermal conversion (MHTC) products of crop straw for more efficient use of resources. The results showed that magnesium acetate improves the hydrothermal liquid yield and quality of hydrochar from crop straw under MHTC. With increasing amount of magnesium acetate, there were obvious increases in TOC concentration and organic acid concentration, while notable decreases in total sugar concentration of hydrothermal liquid. Magnesium acetate promoted the conversion of nitrogen and phosphorus elements to inorganic forms and the release of potassium, calcium, and magnesium ions, leading to increases in both conductivity and pH value of the hydrothermal liquid. Furthermore, magnesium acetate promoted the hydrolysis of crop straw, facilitated the formation of carbon microspheres, and greatly increased the surface area, mesopore volume, and average diameter of hydrochar. With increasing addition amount of magnesium acetate, there was an increase in oxygen–containing groups in the hydrochar. The equilibrium moisture content of the hydrochar remained at high levels (54.09–61.30 wt%), with the maximum values ranging from 60.71 wt% to 61.30 wt%. Finally, the concentrations of acetate and magnesium ions were found to be two parameters with the highest correlation and contribution with the organic matter concentration in hydrothermal liquid and also the greatest influence on the physicochemical properties of hydrochar by affecting the hydrolysis process of crop straw.

A novel approach for transforming breast cancer stem cells into endothelial cells.

Tumor vascular endothelial cells play a pivotal in the tumor microenvironment, influencing the proliferation, invasion, and metastasis of tumor progression. The present study investigated a novel method for inducing the transformation of breast cancer stem cells into endothelial cells, providing a cellular model investigating anti-angiogenic mechanisms in vitro. The breast cancer cell line MCF-7 was used, and the expression of CD133 was initially detected using flow cytometry. CD133+ breast cancer cells were purified using immunomagnetic bead sorting technology, yielding an MCF-7CD133+ subpopulation. The proliferation ability of these cells was assessed using an MTT assay, while their microsphere formation ability was evaluated using a microsphere formation assay. Post-transformation in an optimized endothelial cell culture medium, expression of endothelial cell markers CD31 and CD105 were detected using flow cytometry. Endothelial cell tube formation assays and DiI-labeled acetylated low-density lipoprotein (DiI-Ac-LDL) assays were employed to analyze the endothelial cell function of the MCF-7CD133+ cells. MDM2/CEN12 gene amplification was detected through fluorescence in situ hybridization (FISH). The MCF-7 breast cancer cell line exhibited 1.7±0.3% trace cells expressing the stem cell surface marker CD133. After anti-CD133 immunomagnetic bead sorting, MCF-7CD133+ and MCF-7CD133- subpopulation cells were obtained, with CD133 expression rates of 85.6±2.8 and 0.18±0.08%, respectively. MTT assay results demonstrated that, after 7 days, the proliferation rate of MCF-7CD133+ cells was significantly higher compared with MCF-7CD133- cells. MCF-7CD133+ subpopulation cells displayed strong stem cell characteristics, growing in suspension in serum-free media and forming tumor cell spheres. In contrast, MCF-7CD133- cells failed to form microspheres. After culturing cells in endothelial cell differentiation and maintenance media, the percentage of MCF-7CD133+ cells before and after endothelial cell culture was 0.3±0.16 and 81.4±8.37% for CD31+ cells and 0.2±0.08 and 83.8±7.24% for CD105+ cells, respectively. Vascular-like structure formation and Ac-LDL phagocytosis with red fluorescence in the tube formation assays confirmed endothelial cell function in the MCF-7CD133+ cells. FISH was used to verify MDM2/CEN12 gene amplification in the induced MCF-7CD133+ cells, indicating tumor cell characteristics. The modified endothelial cell transformation medium effectively induced differentiated tumor stem cells to express vascular endothelial cell markers and exhibit endothelial functions, ideal for in vitro anti-angiogenesis research.

Cyclic voltammetric formation of hollow porous γ-MnO2 microspheres as stable electrodes for high-performance supercapacitors

Cyclic voltammetry enables the fast formation of a binder-free γ-MnO2 electrode at room temperature, which features hollow porous microspheres with electrically connected networks. This process leads to a significantly improved supercapacitive performance compared to conventional binder-based MnO2, which requires chemical conversion at high temperature. Compared to amorphous MnO2, the hollow γ-MnO2 microsphere has a higher content of Mn3+, which facilitates the adsorption/desorption of electrolyte ions and redox reactions at the electrode-electrolyte interface. The hollow porous γ-MnO2 exhibits a high specific capacitance of 405 F g−1 at 1 A g−1 and demonstrates excellent rate capability, with a specific capacitance of 250 F g−1 at 50 A g−1. Remarkably, the specific capacitance remains almost unchanged after 3000 charge/discharge cycles at 10 A g−1. The electrochemical impedance spectroscopy confirms that the γ-MnO2 electrode with hollow porous microspheres outperforms its counterpart, due to its shorter dielectric relaxation time (1.4 s), lower contact resistance, and smaller charge and mass transfer resistances. The novel binder-free γ-MnO2 electrode with hollow porous microspheres provides electrically connected networks, large active sites, and rapid ion transport within the pores and crystal tunnels. This enables faster and more efficient charge storage.

Hollow carbon spheres derived from self-assembled chitosan/poly(γ-glutamic acid) nanoparticles for oil-in-water emulsion separation

With the rapid science and technology advancement, the oil-water separation in oily wastewater has become an urgent problem, especially the emulsified oil-water mixtures. Hollow carbon spheres (HCSs) have tremendous potential in separating oil-water emulsions due to their rich porous channels and high surface-to-volume ratio. In this work, as-prepared chitosan/poly(γ-glutamic acid) nanoparticles crosslinked by Ni2+ (Ni2+/CS/γ-PGA NPs) were used as carbon precursor to fabricate HCSs. This strategy separated the formation process of the biomolecular microspheres and the carbonization process. Especially, the Ni2+/CS/γ-PGA NPs were fabricated from the self-assembly of chitosan and γ-PGA in aqueous solution and the crosslinking of Ni2+ via the electrostatic interactions, facilitating the formation of biomolecular microspheres and making the usable of biomolecule-based carbon precursors diversity. After lyophilization, Ni2+/CS/γ-PGA NPs powder was obtained, which was then carbonized in a tube furnace under N2 atmosphere. During the carbonization process, the nickel species aggregated together to form the core of nickel@carbon nanoparticles, and carbon formed the shell. At last, nickel nanoparticles were removed from the carbon framework by hydrochloric acid, obtaining HCSs with super-hydrophobicity and lipophilicity. The as-prepared HCSs exhibited excellent separation performance in oil-in-water emulsions.

Preparation of cassava starch-gelatin yolk-shell microspheres by water-in-water emulsion method

This paper reports the preparation and characterization of gelatin-cassava starch microspheres using the water-in-water emulsion technique. The effects of different weight ratios (10: 0, 9: 1, 8: 2, 7: 3, 6: 4, 5: 5) of starch to gelatin on the morphology, structure, thermal properties, and stability of microspheres were investigated. The morphology results showed that most microspheres had spherical shapes and smooth surfaces. When the weight ratio of starch to gelatin was 5: 5, the prepared microspheres formed a stable yolk-shell structure. The swelling capacity of the microspheres increased with the proportion of gelatin, up to 682.3 %. The gelatin and starch in the microspheres were compatible but not miscible. Compared with the native starch, the crystalline structure of microspheres changed from A-type to a mixture of B-type and V-type, and the relative crystallinity decreased. Differential scanning calorimetry results showed that the melting of microspheres involved both gelatin dissolution and starch gelatinization. Due to the formation of composite microspheres, the starch content decreased, and the release of reducing sugars from the microspheres upon hydrolysis was reduced. The gelatin-cassava starch microspheres are simple to prepare, biocompatible, and can be used as a potential material for microencapsulation.

Role of interfacial layer on exchange-coupled magnetic properties of bi-magnetic nanostructures: An experimental and theoretical approach

Bi-magnetic hetero-nanostructures exhibiting significant exchange bias effects are highly desirable for technological advancement in spin valves, memory devices, data storage, biomedicine, and hyperthermia-based cancer treatment. As the interfacial spin interaction and the resulting anisotropy play a central role in these phenomena, investigating the tailored physical properties of hetero-structures of magnetically contrasting nanoparticles in different architectures is extremely useful. In this work, we report the formation of microspheres containing nano-aggregates of ferrimagnetic Fe3O4 and antiferromagnetic NiO phases. We demonstrate that this kind of bi-magnetic hetero-structures provide a conducive atmosphere for strong interfacial coupling giving rise to an extensive exchange bias effect (∼1.6 kOe). In addition, we also observe a substantial enhancement of the coercive field, indicating the onset of an additional unidirectional anisotropy under the field-cooled condition. Our first-principle density functional theory calculations reveal the role of cation intermixing at the interface of the two phases, being the source of an additional higher magneto-crystalline anisotropy than the original phases. This cation intermixing at the interface also causes a narrowed energy band, which was demonstrated by UV–Vis spectroscopy and first principle calculations. Having these technologically essential features with a tunable band gap, the embedded hetero-nanostructures are envisioned to cater to the requirement of high-density data storage and memory devices.

Extraction, characterization and controlled release application of pectin-like/chitosan hydrogels system loaded Ciprofloxacin.

In recent decades, drug delivery applications have extensively utilized hydrogel systems based on natural polymers. Among the numerous biopolymer-based hydrogel drug delivery systems reported, a novel pectin-like substance was extracted from fig leaves and copolymerized with chitosan. The hydrogel was reformed into microspheres using glutaraldehyde (chemical cross-linker) and sodium hexametaphosphate (physical cross-linker). The extracted polysaccharide and the prepared hydrogels were characterized by FTIR, GC/MS, SEC/MALS/DRI as well as XRD, SEM, BET, and thermal analysis. SEM images revealed the formation of porous microspheres with an average size of 50 μm in diameter. Degrees of swelling in pH7 at 35°C have shown the hydrogels reached two to three times their weights. This has been reflected in their ability to load drugs or any other chemicals. The loading formula shows that hydrogels have maximum loading efficiency more than one-third of the weight of hydrogel. The antimicrobial ciprofloxacin was used as a model for loading on prepared hydrogels. The loaded hydrogels were tested for their biological activities against staphylococcus aureus (S. aureus) bacteria. The antimicrobial growth inhibition zone of the cultured (S. aureus) by ciprofloxacin-loaded hydrogel was followed, which shows controlled growth in inhibition zone sizes and for long time intervals. Results showed that the pectin-chitosan hydrogels exhibited significant antibacterial activity against gram - positive bacteria (S. aureus), with an inhibition zone of 45 mm for (CH-co-FLP)/GLU hydrogel. In vitro, the ciprofloxacin-loaded hydrogels were studied and the cumulative release of ciprofloxacin under suitable conditions was found in a controlled manner and kept release for a long time interval. Data exhibited that the cumulative release profile of ciprofloxacin from the hydrogel demonstrated sustained release over 48 hours, with a value of 6.9% released within the first 24 hours and 7.0 and 6.9% % released at the end of the study for the (CH-co-FLP)/GLU and (CH-co-FLP)/SMP hydrogels, respectively. The novel pectin-chitosan hydrogels hold the potential to enhance the quality of life for numerous patients by minimizing the need for frequent intake of chronic medications.

Mechanistic Study of the Formation of Multicomponent Oxide Porous Microspheres (MICROSCAFS®) by Cryo-Scanning Electron Microscopy.

Multicomponent oxide microspheres with interconnected macroporosity (MICROSCAFS®) are new materials with great potential as support materials for photocatalysis, optimized for real life applications and for other uses that are still being explored. They are obtained from an adapted sol-gel process combined with phase separation phenomena that occur within the water droplets of an emulsion. We present here a methodology based on cryogenic scanning electron microscopy (cryo-SEM) that allows, with minimal specimen preparation, the direct and in situ visualization of 'wet' alkoxide-derived microstructures, for the mechanistic study of the complex process of MICROSCAFS® generation. It is simultaneously combined with energy dispersive X-ray spectroscopy (EDS) to visualize phase separation phenomena and study the chemical elemental composition at specific regions of the sample and reaction times.

Farklı Kalınlıklarda Üretilen TiO2 İnce Filmlerinin Boya Duyarlı Güneş Pili Performansına Etkisi

Dye-sensitized solar cells (DSSC) are known as 3rd generation solar cells. One of the most important parameters affecting the performance of DSSCs is the thin film thickness that forms the photoanode layer. In this study, we examined how 38, 60 and 76 µm thick TiO2 thin films change dye-sensitized solar cell performance. The highest efficiency (4.73%) was seen in the solar cell with 38 µm thin film thickness. In addition, the mineralogical and morphological analyses of the produced TiO2 nanopowders were performed with X-ray diffraction (XRD) and Scanning electron microscopy (SEM). XRD analyses showed that TiO2 was in the anatase crystal phase. SEM photographs confirmed the formation of microspheres in close contact with each other.

Four-Arm Polymer-Guided Formation of Curcumin-Loaded Flower-Like Porous Microspheres as Injectable Cell Carriers for Diabetic Wound Healing.

Stem cell injection is an effective approach for treating diabetic wounds; however, shear stress during injections can negatively affect their stemness and cell growth. Cell-laden porous microspheres canprovide shelter for bone mesenchymal stem cells (BMSC). Herein, curcumin-loaded flower-like porous microspheres (CFPM) are designed by combining phase inversion emulsification with thermally induced phase separation-guided four-arm poly (l-lactic acid) (B-PLLA). Notably, the CFPM shows a well-defined surface topography and inner structure, ensuring a high surface area to enable the incorporation and delivery of a large amount of -BMSC and curcumin. The BMSC-carrying CFPM (BMSC@CFPM) maintains the proliferation, retention, and stemness of -BMSCs, which, in combination with their sustainable curcumin release, facilitates the endogenous production of growth/proangiogenic factors and offers a local anti-inflammatory function. An in vivobioluminescence assay demonstrates that BMSC@CFPM cansignificantly increase the retention and survival of BMSC in wound sites. Accordingly, BMSC@CFPM, with no significant systemic toxicity, couldsignificantly accelerate diabetic wound healing by promoting angiogenesis, collagen reconstruction, and M2 macrophage polarization. RNA sequencing further unveils the mechanisms by which BMSC@CFPM promotes diabetic wound healing by increasing -growth factors and enhancing angiogenesis through the JAK/STAT pathway. Overall, BMSC@CFPM represents a potential therapeutic tool for diabetic wound healing.

Atomization of Borosilicate Glass Melts for the Fabrication of Hollow Glass Microspheres

Direct atomization of a free-flowing glass melt was carried out using a high-speed flame with the aim of producing tiny, self-expanding glass melt droplets to form hollow glass microspheres. Atomization experiments were carried out using a specially adapted free-fall atomizer in combination with a high-power gas burner to achieve sufficient temperatures to atomize the melt droplets and to directly expand them into hollow glass spheres. In addition, numerical simulations were carried out to investigate non-measurable parameters such as hot gas velocities and temperatures in the flame region by the finite volume-based software Star CCM+® (v. 2022.1.1), using the Reynolds-Averaged Navier–Stokes (RANS) turbulence and the segregated flow model. To calculate the combustion process, the laminar flamelet method was used. The experiments and simulations indicated that a maximum gas velocity of about 170 m/s was achieved at the point of atomization in the flame. The particle size distribution of the atomized glass droplets, either solid or hollow, ranged from 2 µm to 4 mm. Mean particle sizes in the range of 370 µm to 650 µm were highly dependent on process parameters such as gas velocity. They were in good agreement with theoretically calculated median diameters. The formation of hollow glass microspheres with the proposed concept could be demonstrated. However, only a small fraction of hollow glass spheres was found to be formed. These hollow spheres had diameters up to 50 µm and, as expected, a thin wall thickness.