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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 ( T g ) and size of latex particles. Furthermore, Fe 3 O 4 nanoparticle (NP)-loaded colloidosomes were constructed by this strategy. The magnetic response intensity of colloidosomes can be modulated by varying the amount of Fe 3 O 4 NPs. The anticancer drug encapsulation and loading of other functional particles were also explored to expand applications.

The intrinsic properties and structure of carrier materials, as well as the drug-loading method, are crucial to the fabrication of high-performance controlled drug release systems. Metal-organic frameworks (MOFs) have attracted great attention in drug delivery due to their rich variety and very precisely designable structures, but their inherent small pores limit their application towards large-size drug molecules. Herein, we report a facile and efficient approach for the construction of hierarchically porous ZIF-8 (HP-ZIF-8) by spray drying. The homogeneously distributed mesopores, which result from the interspaces in the closely arranged nanosized ZIF-8 (N-ZIF-8), can be tuned by adjusting the primary particle size. More importantly, a drug (doxorubicin (DOX), for example) can be simultaneously encapsulated during the fabrication process of HP-ZIF-8, achieving a high loading rate of 79% and an encapsulation efficiency of 79%. Furthermore, we demonstrate that the obtained DOX@HP-ZIF-8 is a pH-responsive system and the release can also be controlled by the mesopore size. Although HP-ZIF-8 shows obvious advantages in drug loading and release performance compared with N-ZIF-8 loaded with DOX by the same solvent adsorption approach, DOX@HP-ZIF-8 displays significantly increased loading capacity (more than 3 times) and the slowest release rate due to its drug-loading method. Their therapeutic efficacy on HeLa cells has also been proved. These findings have important implications for the construction of HP-MOFs as drug carriers and will also present a new platform for controlled drug release and biomedical applications.

The colloidosome, as a kind of Pickering microcapsule, offers a highly functionalizable approach for encapsulation, but current studies mainly focus on shells that lack real‐time modulated permeability. Herein, a scalable spray drying method was employed to fabricate temperature/near‐infrared (NIR)/magnetic multi‐stimuli responsive colloidosomes with adjustable permeability, facilitating intelligent transmembrane transport of molecules. The colloidosomes assembled with SiO2/polydopamine/poly (N‐isopropyl acrylamide) nanoparticles can be heated from 25°C to 50°C within 5 min upon NIR exposure. The permeability of shells regulated by temperature and NIR allows for real‐time remote control. Yeast cells, as an example, are encapsulated within colloidosomes. The decomposition rate of H2O2 varies with temperature (25–45°C) and NIR intensity (0.5–1 W cm−2), which can attain a more than sixfold increase in the rate constant of pseudo‐first‐order kinetic model. Furthermore, the strategy was expanded by encapsulating doxorubicin/UiO‐66 particles, highlighting its great potential in realms of multi‐stimuli responsive colloidosomes applications. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET), as the most widely utilized polyester, causes global environmental problems due to its massive and durable accumulation in natural environments. The glycolysis of PET is an attractive alternative to mechanical recycling, but there remains a strong demand for efficient, convenient, and inexpensive catalysts. Herein, we present a spray-drying-assisted way to construct magnetic hollow micro-sized nanoaggregates (HMNAs) by assembling composite metal oxide nanoparticles to depolymerize PET synergistically. The as-prepared ZnO–Fe3O4 HMNAs completely depolymerized PET with a high monomer yield of 92.3% in a short period of 30 min at 190 °C, far above individual ZnO and Fe3O4 nanoparticles (NPs). The composite HMNAs can be magnetically separated in a few minutes and maintain a high activity for 5 cycles. DFT study reveals that the HMNAs effectively facilitated glycolysis by the high content of Lewis acid sites as well as the stronger adsorption between PET and the catalyst owing to the structural synergy effect of ZnO–Fe3O4 HMNAs. Furthermore, this spray drying strategy as a versatile and scalable methodology is extended to fabricate other HMNAs, exhibiting a similarly enhanced efficiency of glycolysis. The HMNAs are expected to open up avenues for the design of catalysts for upcycling of discarded plastics. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have attracted much attention owing to their tailored pore environment and surface functionality. However, most of the currently reported MOFs are confined to small pore sizes (<5 nm), limiting their practical applications. Here, a facile and versatile strategy for rapid construction of hierarchically porous MOFs (HP‐MOFs) by spray‐drying is reported, in which presynthesized nanosized MOFs (N‐MOFs) can be assembled to form MOF microspheres with meso/macropores resulting from the interspace among closely arranged N‐MOFs. This strategy enables the construction of multicomponent HP‐MOFs with various functions. As a proof of concept, we show that the adsorption for tannic acid (TA) can be significantly enhanced using HP‐MIL‐101(Cr). Particularly, HP‐MIL‐101‐30 (30 represents the primary nanoparticle size) exhibits a record‐high adsorption capacity (1175 mg g−1), and the adsorption rate of HP‐MIL‐101‐30 is increased by 50% compared to that of N‐MIL‐101‐30. These findings have important implications for the rapid construction of HP‐MOFs, which is beneficial for the adsorption of large molecules. [ABSTRACT FROM AUTHOR]

Disperse dyes are poorly water‐soluble and difficult to stably disperse in an aqueous medium, which greatly limits their application in dyeing synthetic fibers. Micronization can solve this problem. Herein, a facile way to prepare stable aqueous nanodispersions of disperse dye (C.I. disperse yellow 54) is presented by combining high‐gravity antisolvent precipitation in a rotating packed bed (RPB) with spray drying. The as‐prepared product had an average particle size of 120 nm, which could be readily redispersed in water. Compared with raw dye, the wettability and dispersibility of disperse dye nanoparticles were remarkably improved. Furthermore, the dyeing properties of the nanodispersions were obviously better than those of the commercial dye, which was micronized by ball milling. [ABSTRACT FROM AUTHOR]

Dental resin-based composites have been used for more than 50 years. The size and the structure of inorganic filler have a great effect on the mechanical properties of the composite resin. In this study, novel micro-sized clusters of hydroxyapatite nanorods (MCHN) were designed and conveniently fabricated by spray drying combined with heat treatment. The effects of the aspect ratio of primary hydroxyapatite nanorods (HN), suspension concentration for spray drying and heat treatment temperature were explored. The results indicated that HN with a lower aspect ratio of 2 (HN-2) and a heat treatment temperature of 500 °C were beneficial to the construction of high-performance MCHN (MCHN-2). As compared to HN-2, MCHN-2 had a further increased filling amount by 10%. More importantly, the flexural strength, flexural modulus and compressive strength of the composite resin were greatly improved by 36.3%, 11.4% and 56.6%, respectively. Therefore, it could be envisioned that MCHN could have a great potential in dental restorative application. [ABSTRACT FROM AUTHOR]

Abstract: Amorphous atorvastatin calcium (AC) ultrafine powder has been successfully prepared by antisolvent precipitation and spray drying process, in which hydroxypropyl methylcellulose (HPMC) was employed to control the particle size and morphology. The effects of experimental parameters, such as stirring time, drug concentration and drying methods, on particle size and morphology were investigated. The average particle size of AC obviously increased from 410nm to 1200nm as the stirring time changed from 30s to 60min. The enhancement of drug concentration favored to decrease the particle size from 410nm to 240nm. After spray drying process, ultrafine AC powder was obtained, which had good dispersibility and narrow particle size distribution of 1–3μm. The as-prepared ultrafine AC was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TG), differential scanning calorimetry (DSC), specific surface area and dissolution test. The XRD analyses indicated that the ultrafine AC was amorphous. In the dissolution tests, the amorphous AC ultrafine powder exhibited enhanced dissolution property when compared to the raw material. [Copyright &y& Elsevier]

Abstract: Resveratrol is a highly polyphenolic substance which possesses extensive physiological activities. However, its application is limited by light instability and poor aqueous solubility. In this paper, resveratrol nanodispersion with high light stability and water dissolution rate was prepared by a combination of antisolvent precipitation in the presence of nontoxic polymer and spray-drying. The active ingredients of the unprocessed raw resveratrol decreased 80 wt% when exposed to sun light directly, while that of the resveratrol nanodispersion only reduced 14 wt% at the same condition. The resveratrol nanodispersion dissolved completely in less than 45 min, while raw resveratrol didn''t dissolve completely after 120 min. Meanwhile, resveratrol nanodispersion exhibited better antioxidant activity compared to that of raw resveratrol when added in artificial intestinal juice. This study is helpful to promote the application of resveratrol and provides a routine for enhancing stability and water solubility of photosensitive lipophilic materials. [Copyright &y& Elsevier]

Highlights: [•] High-performance ultrafine budesonide particles were prepared for dry powder inhalation. [•] High pressure homogenization combined with spray drying was adopted. [•] The low-density porous spherical drug agglomerates with a VMD of 2.9μm could be generated. [•] An excellent aerosol performance with a FPFemitted value of 81±3% could be achieved. [•] The pressure, cycle time, initial particle size and concentration had obvious effects. [ABSTRACT FROM AUTHOR]

Abstract: Beclomethasone dipropionate (BDP), which is a member in the inhaled glucocorticosteroid class, is commonly used in the treatment of asthma by pulmonary delivery. The purpose of this study is to prepare ultrafine BDP particles for dry powder inhalation (DPI) administration by combining microfluidic antisolvent precipitation without surfactant, high-pressure homogenization (HPH) and spray drying. T-junction microchannel was adopted for the preparation of needle-like BDP particles. The needle-like particles could be easily broken down into smaller particles during HPH, which were assembled into uniform low-density spherical BDP aggregates by spray drying. The effects of the operation parameters, such as the flow rates of BDP methanol solution and antisolvent, the overall flow rate, the BDP concentration, and the change of the injection phase on BDP particle size were explored. The results indicated that the BDP particle size greatly decreased with the reduction of BDP solution flow rate and the increase of antisolvent flow rate. However, the BDP particle size firstly decreased and then increased with the increase of the overall flow rate and the increase of BDP concentration. Also, BDP solution as the injection phase could form the smaller BDP particles. 10 HPH cycles are enough to forming short rod-like particles. After spray drying, the BDP spherical aggregates with a 2–3μm size could be achieved. They have an excellent aerosol performance, 2.8 and 1.4 times as many as raw BDP and vacuum-dried BDP particles, respectively. [Copyright &y& Elsevier]

• Highly stable monodispersed sulfur nanoparticles with a size of 15–50 nm. • Controllable preparation using a microfluidic anti-solvent precipitation method. • Efficient and continuous synthesis in both Y-type and T-type microchannels. • CFD simulation to verify the mixing process. • Modified sulfur nanoparticles with good antibacterial properties. Sulfur nanoparticles (SNPs) have been frequently used for sterilization due to their high biocompatibility and environmental friendliness. Compared with traditional sublimed sulfur, SNPs have some superior properties, such as the smaller particle size, better dispersibility in water and even higher antibacterial performance. Therefore, the objective of this study is to prepare SNPs with a controllable particle size and uniform morphology using a microfluidic anti-solvent precipitation method, whose process is continuous and ideal for large-scale production. The SNPs with a range of 15–50 nm can be prepared in both a Y-type microchannel (YMC) and T-type microchannel (TMC). Interestingly, for the SNP preparation process, the YMC shows a better mixing effect than TMC, which has been verified by the CFD simulation. Compared with a traditional batch stirred tank (ST), these two microchannels can not only guarantee a relatively small and uniform particle size, but also reduce the solvent consumption by at least 50%. More importantly, the SNPs show a better continuous bactericidal ability for Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), compared with traditional micro-sized sublimed sulfur. The SNPs together with surfactant CTAB have a synergistic effect, which can enhance their antibacterial activities. Especially, among all the control groups, the as-prepared 15 nm SNPs have a better bactericidal performance, which can reduce the S. aureus colony number from ∼ 8 log CFU/mL to below the detection limit in 15 h, and reduce the colony number of E. coli from ∼ 8 to 1.8 log CFU/mL. [ABSTRACT FROM AUTHOR]