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Janus-microswimmers, as efficient self-propelled materials, have garnered considerable attention, particularly for their potential applications in nonagitated liquids, like natural aquatic systems. However, current microswimmers face challenges such as unconfined diffusion areas and small-scale production. Herein, we propose a scalable spray-drying-assisted strategy for the efficient production of Janus-microswimmers. The Janus structures are fabricated by the assembly of polystyrene microparticles and SiO2/polydopamine nanoparticles in the microdroplets, and the single-side propulsion microswimmers are subsequently obtained by loading MnO2. By catalyzing the decomposition of H2O2to produce oxygen, the speed of these microswimmers is much faster than those of other reported continuous-motion microswimmers. Interestingly, the microswimmers are self-propelled and gather in the proximity of water surface, and the extent of the confined area is controllable. This range-confined motion, distinct from the traditional irregular motion, offers a novel perspective on the behavioral patterns of Janus-microswimmers. Furthermore, by in situ loading of Fe3O4nanoparticles, the microswimmers can be sensitively induced and controlled in their movement direction by a magnetic field. As a proof-of-concept, by harnessing the hydrophobic components of the microswimmers, we successfully recover floating oil films in a simulated natural water body, offering a promising approach for the remediation of petroleum pollution in the environment.

Calcium fluoride (CaF2) is an ideal adsorbent for the dehydration of gaseous hydrogen fluoride (HF) containing water vapor. In this work, a novel CaF2absorbent, spherical CaF2nanoaggregates (NAs) with a closely packed structure, was proposed and efficiently fabricated by spray drying technology. As the building blocks of CaF2NAs, the CaF2nanoparticles (NPs) were prepared by the addition of excess calcium ions (Ca2+) or fluorine ions (F−) in the synthesis. The results indicated that the CaF2NPs synthesized by excess Ca2+and the corresponding NAs exhibited much better water vapor adsorption properties than their counterparts by excess F−, owing to higher zeta potentials. More importantly, whether excess Ca2+or F−, CaF2NAs had further enhanced water vapor adsorption capacity compared to primary CaF2NPs, possibly owing to their unique nano-micro secondary structures and higher surface areas. This work has great potential in the development of high-performance absorbents for separating moisture from corrosive gas HF.

The applications of nanoparticles suffer from their extremely small size and intrinsic trend of agglomeration. Rearranging nanoparticles to form micro-sized nanoaggregates (MNAs) with increased size, ordered structure, as well as controllable size, shape, and morphology is a crucial step in various fields of science and technology to maintain the unique characteristics of nanoparticles while obtaining greatly enhanced or new performance at the microscale. The structure of MNAs prominently affects their functionality, which is determined by the arrangement of nanoparticles and the interaction between primary particles. Several methods have been proposed to prepare the MNAs, in which spray-drying technology stands out considering the feasibility, scalability for industry, cost, and efficiency. Forced assembly of nanoparticles through spray-drying under tunable process parameters yields diverse physical properties and structural arrangements of nanoparticles of the MNAs, they therefore exhibit enormous potential in a wide range of application fields. This review presents the construction and applications of spray-dried MNAs. The factors that influence the size, morphology, and structure of the MNAs are discussed in detail. In addition, the outstanding application performance resulting from the tightly packed nanoparticles in regular-shaped MNAs obtained by the spray-drying process is illustrated.

Intelligent responsive colloidosomes have attracted increasing attention for their potential to enhance the efficacy and decrease the side effects of drugs in biomedical applications. However, a low encapsulation efficiency and complicated preparation method greatly limit their development. Herein, we report an efficient approach for the construction of pH-stimuli-responsive colloidosomes with high encapsulation efficiency by a high-gravity technology. The conditions under which latex particles with different methacrylic acid contents can successfully self-assemble into colloidosomes are explored. During the preparation process, emulsions emulsified for only 10 min at 2500 rpm in a unique high-gravity shearing surroundings are clarified owing to the greatly enhanced micromixing, while the emulsions emulsified for 30 min by a traditional high-speed shear machine at 4000 rpm are still yellow–white. More importantly, regular spherical colloidosomes encapsulating an anticancer drug doxorubicin not only achieve a small mean diameter of 2.82 μm but also realize a high encapsulation efficiency of 76.5%. The release performance of doxorubicin has an obvious pH-stimuli-responsive regularity and follows the first-order model of sustained release. The construction of intelligent responsive colloidosomes as drug carriers provides a route for controlled drug release and biomedical applications.

Colloidosomes have been extensively studied in recent years because of their potential applications in various fields, such as food, cosmetics, or pharmaceutical industries. Herein, we present a simple and highly efficient route for large-scale preparation of colloidosomes with controllable permeability using spray drying technology. By using the latex particles with different glass transition temperatures, the colloidosomes with uniform and controllable shell porosities can be easily constructed. The effects of latex particle concentrations, flow rates of compressed air, inlet temperatures, and feed rates on the morphologies of colloidosomes were explored in detail, and the possible formation mechanism was given. Both the feed rates and inlet temperatures can affect the evaporation rate of solvents. Only the preparation conditions falling on the suitable speed of the solvent evaporation “area” can result in complete colloidosomes. In addition, the Congo red dye was used as a model for encapsulation and controllable release. The release duration of colloidosomes prepared with different Tg latex particles ranged from 23 to 52 h as the permeability drops. The results demonstrate that this colloidosome fabrication method is feasible for continuous large-scale production and precisely controllable release for practical applications.

Colloidosomes as Pickering emulsion microcapsules are expected to serve various applications, including encapsulation of drugs and loading of functional materials. Normally, when using colloidosomes for drug encapsulation, the latex particles as shell materials need to be mixed with drugs before the assembly process. However, this procedure may cause aggregation of latex particles, thereby resulting in disordered assembled shells or a low loading efficiency. Herein, we propose a three-fluid nozzle spray drying process to efficiently assemble latex particles of P(styrene (St)-co-butyl acrylate (BA)) into colloidosomes. The three-fluid nozzle spray drying equipment allows for the preparation for drug encapsulation without advance mixing of drug and shell materials. This strategy enables the construction of colloidosomes with uniform and controllable pores and the loading of functional materials. The effects of the compressed air flow rate, inlet temperature, feed rate, and solid content were explored, revealing the formation mechanism of colloidosomes during the spray drying process. Doxycycline hydrochloride (DH) was encapsulated in colloidosomes for controllable release, and the sustained release time is up to 100 h. The release rate can be adjusted by varying the glass transition temperature (Tg) and size of latex particles. Furthermore, Fe3O4nanoparticle (NP)-loaded colloidosomes were constructed by this strategy. The magnetic response intensity of colloidosomes can be modulated by varying the amount of Fe3O4NPs. The anticancer drug encapsulation and loading of other functional particles were also explored to expand applications.

Colloidosomes are widely applied in drug delivery systems on account of their outstanding biocompatibility and stimuli response. Herein, a novel and environmentally friendly approach is presented for efficiently fabricating colloidosomes by high-gravity technology, which is not only favorable for controllable latex particle size and large-scale production but also makes it avoidable to use a great deal of organic solvents. First, the latex particles as shell materials with a range of 47–62 nm are controllably prepared using high-gravity-assisted pre-emulsification for emulsion polymerization. Because of this pre-emulsification, the polymerization time is greatly shortened from 4 to 1 h, and the mean particle diameter is reduced by about 29%. In addition, the self-assembly of latex particles forming into colloidosomes is achieved using high-gravity technology. Compared with the preparation process in a conventional high-speed shearing machine, the colloidosomes prepared with the high-gravity self-assembly process have a decreased size of 3.5 to 2 μm and a narrower size distribution. Furthermore, an anticancer drug of doxorubicin hydrochloride is in situ encapsulated into the colloidosomes, displaying excellent controllable release properties.

Background:Impaired polymorphonuclear neutrophil (PMN) functions were generally considered to be related to the onset of generalized aggressive periodontitis (GAgP). However, some research has indicated that the hyperreactivity of PMN seems to be involved in the inflammatory response of GAgP. The present study's main purpose was to provide more evidence about the role of PMN in the pathogenesis of GAgP by surveying PMN infiltration in gingiva and its relationship with the expression of their mediators including intercellular adhesion molecule‐1 (ICAM‐1), interleukin‐8 (IL‐8), interleukin‐1β (IL‐1β), and tumor necrosis factor‐α (TNF‐α). The inflammatory response in GAgP was also compared with that in adult periodontitis (AP) and periodontally healthy subjects. Since these PMN mediators were reported to be produced mainly by macrophages, the association between the expression of these PMN mediators and the distribution of macrophages was also investigated. Methods:A total of 25 gingival specimens were obtained from 10 GAgP patients, 10 AP patients, and 5 periodontally healthy subjects. Serial sections were obtained from each specimen, and the following techniques were adopted to investigate the distribution and interrelation of different cells and cytokines. Infiltration of PMN was observed by using hematoxylin and eosin staining. Distribution of the macrophages, identified as CD68+, was shown by using immunohistochemistry. Immunohistochemistry and in situhybridization were used to detect the expression of ICAM‐1, IL‐8, IL‐1β, and TNF‐α in gingival tissues. These techniques were performed in serial sections from each individual specimen. Results:Large numbers of infiltrating PMNs were observed in gingiva from GAgP. In gingiva from both GAgP and AP, the strongest protein and mRNA expression of IL‐8, ICAM‐1, IL‐1β, and TNF‐α were located in pocket epithelium and adjacent connective tissue with large numbers of infiltrating PMNs. In tissues without abundant PMN infiltration, the appearance of positive cells expressing IL‐8, ICAM‐1, IL‐1β, and TNF‐α was scattered. CD68+was distributed sparsely in connective tissue and was hardly seen in pocket epithelium with large numbers of PMN infiltration. The degree of leukocyte infiltration and connective tissue destruction in gingiva from GAgP patients was not distinctly different from that in gingiva from AP. The gingival specimens with heavy PMN infiltration from both GAgP and AP patients presented strong expressions of IL‐1β and TNF‐α; showed more extensive inflammatory cell infiltration; had severe connective tissue destruction; and presented severe elongation and ulceration of pocket epithelium. In gingiva from healthy subjects, inflammation was minor with visually no PMN, CD68+, or the positive cells of IL‐8, ICAM‐1, IL‐1β and TNF‐α expression. Conclusions:Enhanced accumulation of PMN, which is associated with the upregulation of IL‐8, ICAM‐1, IL‐1β, and TNF‐α expression, relates to the severity and activity of GAgP. In addition to macrophages, PMN and/or epithelial cells might also be important sources of IL‐8, IL‐1β, and TNF‐α production in gingiva. J Periodontol 2001;72:1545‐1553.