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Microcapsules have attracted significant attention in academia and industry due to their unique properties for protecting and controlling the release of active substances. However, based on water-insoluble biopolymers, developing a straightforward approach to prepare microcapsules with improved biocompatibility and functional shells remains a great challenge. In this study, zein, a water-insoluble protein, is employed to prepare robust microcapsules facilely using oil-in-aqueous ethanol Pickering emulsions as templates. First, the emulsion template is stabilized by hydrophobic silica nanoparticles with in situ surface modification of tannic acid. The zein is then precipitated at the interface in a controlled manner using antisolvent approach to obtain silica/tannic acid/zein (STZ) microcapsules. It is found that the concentration of zein and the presence of tannic acid played a significant role in the formation of STZ microcapsules with well-defined morphology and a robust shell. The uniform deposition of zein on the surface of template droplets is facilitated by the interactions between tannic acid and zein via hydrogen bond and electrostatic force. Finally, the resulting STZ microcapsules showed super resistance to ultraviolet (UV) radiation and high temperature for the unstable, lipophilic, and active substance of ß-carotene.
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Pickering double emulsions exhibit higher stability and biocompatibility compared with surfactant-stabilized double emulsions. However, tailored synthesis of particle stabilizers with appropriate wettability is time consuming and complicated and usually limits their large-scale adoption. Using binary stabilizers may be a simple and scalable strategy for Pickering double emulsion formation. Herein, commercially available hydrophobic silica nanoparticles (SNPs) and sodium alginate (SA) as binary stabilizers are used to prepare O/W/O Pickering double emulsions in one-step emulsification. The influence of system composition on double emulsion preparation is identified by optical microscopy, confocal laser scanning microscopy, and interfacial tension and water contact angle analyses. The formation of the O/W/O Pickering double emulsion depends critically on the aqueous phase viscosity and occurrence of emulsion inversion. Both hydrophobic SNPs and SA adsorb at the droplet surface to provide a steric barrier, while SA also reduces interfacial tension and increases aqueous phase viscosity, giving double emulsion long-term stability. Their microstructure and stability are controlled by adjusting the SA concentration, water-oil volume ratio, concentration and wettability of the particle stabilizer, and oil type. As a demonstration, the middle layer of the as-prepared O/W/O Pickering double emulsions can be cross-linked in situ with calcium ions to produce calcium alginate porous microspheres. We believe that our strategy for double emulsion formation holds great potential for practical applications in food, cosmetics, or pharmaceuticals.
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Herein, the starch nanocrystal/tannic acid (ST) complex particles, which were prepared based on the hydrogen bond between starch nanocrystal (SNC) and tannic acid (TA), were successfully used to stabilize the HIPPE gels. The optimal TA concentration of the ST complex particles resulted in better water dispersibility, surface wettability, and interfacial activity as compared to SNC. The hydrogen bond responsible for the formation of ST complex particles and subsequent stable emulsions was demonstrated by varying the pH and ionic strength of the aqueous phase. Notably, the HIPPE gels stabilized via the ST complex particles can maintain long-term stability for up to three months. The HIPPEs stabilized via the ST complex particles all displayed gel-like features and had smaller droplets and denser droplet networks than the SNC-stabilized HIPPEs. The rheological behavior of HIPPE gels stabilized via the ST complex particles can be readily changed by tuning the mass ratio of SNC and TA as well as pH. Finally, the prepared HIPPE gels used to effectively protect encapsulated ß-carotene against high temperatures and ultraviolet radiation and its controllable release at room temperature were demonstrated. It is anticipated that the aforementioned findings will provide new perspectives on the preparation of Pickering emulsion for delivery systems.
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Correction for 'Pickering emulsion templated proteinaceous microparticles as glutathione-responsive carriers for endocytosis in tumor cells' by Weijie Jiang et al., Nanoscale Horiz., 2024, 9, 536-543, https://doi.org/10.1039/D3NH00551H.
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In this study, we established a versatile and simple magnetic-assisted microfluidic method for fast bacterial detection. Quantum dots (QDs) were loaded onto magnetic beads (MBs) to construct performance enhanced on-chip capture of bacteria. Escherichia coli (E. coli), as a model bacterium was studied. CdSe QDs were deposited onto the surface of Fe3O4 MBs through layer-by-layer self-assembly to enhance the loading of antibodies (Abs). MBs functionalized with anti-E. coli antibody molecules in a micropillar-based microfluidic chip were utilized to capture E. coli, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for characterization of captured bacteria. This method was found capable of specifically isolating E. coli within the range of 1.0 to 1.0 × 109 CFU/mL, having a detection limit (LOD) of 10 CFU/mL. The average similarity score among mass spectra for the bacterial capture obtained in independent experiments is calculated as 0.97 ± 0.01 (n = 3), which shows this work's excellent reproducibility for bacterial capture. Bacterial growth on ready-to-eat (RTE) foods during its time of storage was successfully monitored. The present protocol has promising potential for microbial control and pathogen detection in the food industry.
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Escherichia coli , Pontos Quânticos , Reprodutibilidade dos Testes , Bactérias , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Fenômenos MagnéticosRESUMO
Microalgae are highly regarded as ideal materials for the creation of liquid biofuels and have substantial potential for growth and utilization. However, traditional storage and culture methods for microalgae are plagued by challenges such as uncontrolled growth, bacterial contamination, and self-shading among algae. These issues severely impede the photosynthetic process and the efficient extraction of biomass energy. This study tackles these problems by utilizing magnetic hydrophobic protein particles to stabilize water-in-oil Pickering emulsions. This allows for the micro-compartment storage and magnetic transfer of algae. Additionally, the successful encapsulation of Chlorella cells in high-internal-phase water-in-oil Pickering emulsions effectively mitigates the settling problem of Chlorella cells in the liquid phase, thereby enabling the potential use of Pickering emulsions for the confined cultivation of microalgae.
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The use of glucose oxidase (GOx) to disrupt glucose supply has been identified as a promising strategy in cancer starvation therapy. However, independent delivery of GOx is prone to degradation upon exposure to biological conditions and may cause damage to blood vessels and normal organs during transportation. Although some carriers can protect GOx from the surrounding environment, the harsh preparation conditions may compromise its activity. Moreover, the commonly used materials often exhibit poor biocompatibility and possess certain cytotoxicity. To address this issue, we developed a gentle and efficient method based on Pickering emulsion templates to synthesize protein-based microparticles using zein as the matrix material. These microparticles have high stability and can be tailored to efficiently encapsulate biomolecules while preserving their activity. Moreover, the zein-based microparticles can be triggered to release biomolecules in tumor cells under high glutathione levels, demonstrating excellent responsiveness, biocompatibility, and low cytotoxicity. Additionally, when loaded with GOx, these protein-based microparticles effectively deprive tumor cells of nutrients and induce apoptosis by generating high levels of H2O2, thereby exhibiting enhanced anticancer properties.
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Zeína , Emulsões , Peróxido de Hidrogênio , Endocitose , Glutationa , Glucose OxidaseRESUMO
The intelligent regulation of microgel-stabilized Pickering emulsions with multi-responsiveness is presently constrained to the processes of emulsification and destabilization. However, the expansion of multi-control over Pickering emulsions to involve phase inversion and the investigation of the accompanying processes and mechanisms present a great challenge. In this study, a microgel with dual responsiveness to both pH and temperature was synthesized using an emulsion template. The resulting microgel exhibited a robust colloidosome-like structure, distinguished by the presence of monolayer-adsorbed silica nanoparticles. The regulation of the packing of surface-covered silica nanoparticles was easily achieved through the swelling of the microgel matrix. Furthermore, the wettability of the microgel can be adjusted between hydrophilic and hydrophobic intervals, allowing for the effective and dual-responsive phase inversion of Pickering emulsions. Moreover, it has been observed that colloidosome-like microgels can lead to unique interfacial structures during the emulsification process, thereby elucidating the fundamental mechanism governing emulsion phase inversion.
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Microgels are excellent emulsifiers that can self-assemble to reduce interfacial tension and form a steric barrier at an oil-water interface. Herein, we report a two-step emulsification approach to prepare oil-in-water-in-oil (O/W/O) Pickering double emulsions through the dispersion of microgels in two immiscible phases. The stabilization mechanism depends on the uneven distribution and adsorption of hydrophilic water-swollen microgels and hydrophobic octanol-swollen microgels on either outer water droplets or inner oil droplets. Our results reveal that binary microgels outperformed single microgels in terms of interfacial tension reduction and emulsion stabilization. Notably, the binary microgel-stabilized Pickering double emulsions show excellent temperature responsiveness owing to the intrinsic thermal sensitivity of microgels. Consequently, the selective and rapid release of encapsulated substances in different phases can be achieved through the adjustment of the ambient temperature.
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BACKGROUND: Proteoglycans (PGs) accumulation and inflammation are two interactional pathological processes of atherosclerosis (AS). Up to now, there is no ideal drug for decreasing these pathological changes. Gua Lou Er Chen decoction (GED) has been used to treat AS for several years. However, if GED could treat AS through reducing PGs accumulation and inflammation remains unknown. PURPOSE: This study was designed to illustrate whether GED could attenuate AS by reducing chondroitin sulphate proteoglycan (CSPG) expressions and alleviating inflammation. METHODS: In vivo study, apolipoprotein E-deficient mice were fed a high-fat diet to induce AS. In vitro study, oxidised low-density lipoprotein (ox-LDL) and tumour necrosis factor (TNF)-α were used to induce proteoglycans accumulation and inflammation changes of vascular smooth muscle cells (VSMCs) and RAW264.7 macrophages. Oil Red O was used to stain mouse aortic lipid plaque. Haematoxylin eosin staining was used to assess the pathological changes of aortic valve and thoracic aorta. Specialised kits were used to identify blood lipids and sGAGs. Immunofluorescence and immunohistochemistry was used to identify aortic valve CSPG and versican. Western blotting, enzyme-linked immunosorbent assay and quantitative reverse transcription-polymerase chain reaction were used to measure versican, interleukin (IL)-6, TNF-α, and chondroitin sulphate (CS) synthetase expressions. CCK-8 was used to measure the cells proliferation. RESULTS: In vivo experiments revealed that GED significantly improved hyperlipidemia, lowered lipid plaque deposition in the aorta, and increased plaque stability of AS mice. In addition, further studies revealed that GED lowered the sGAGs, CSPG, and versican levels and down-regulated CS synthetase and inflammatory factor expressions. In vitro experiments revealed that GED decreased TNF-α expression in the RAW264.7 macrophage supernatant stimulated by ox-LDL; decreased versican, CS-related synthetase, and IL-6 expressions; reduced VSMC proliferation stimulated by ox-LDL; down-regulated sGAG and versican expressions of VSMCs stimulated by TNF-α. CONCLUSION: Our results demonstrated that GED could attenuate AS by reducing hyperlipidemia, hyper-expression of CSPG, and inflammation. This study might provide a novel insight into the development of innovative drug for AS.
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Aterosclerose , Hiperlipidemias , Placa Aterosclerótica , Camundongos , Animais , Fator de Necrose Tumoral alfa/metabolismo , Versicanas , Aterosclerose/tratamento farmacológico , Aterosclerose/metabolismo , Placa Aterosclerótica/tratamento farmacológico , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Lipoproteínas LDL , Interleucina-6 , Lipídeos , Hiperlipidemias/tratamento farmacológicoRESUMO
Human embryonic stem cells (hESCs) have become an ideal cell source for the ex vivo generation of megakaryocyte (MK) and platelet products for clinical applications. However, an ongoing challenge is to establish scalable culture systems to maximize the yield of stem cell-derived MKs that release platelets. We defined a specific dynamic 3D manufacturing system in a baffled-flow manner that could remarkably facilitate megakaryopoiesis and increase the yield of platelet-producing MKs from hESCs within a 12-day induction period. Additionally, an increased number of >16N ploidy MKs, proplatelets, and platelets were generated from induced cells harvested on Day 12 using the specific dynamic culture method. The specific dynamic culture method significantly enhanced endothelium-to-haematopoietic transition and early haematopoiesis. More importantly, MK fate was significantly facilitated in a specific dynamic manner during early haematopoiesis. Mechanistically, this dynamic culture significantly enhanced mitochondrial function via the oxidative phosphorylation pathway and caused differentiation skewing of hESCs toward megakaryopoiesis. This study can aid in the automatic and scalable production of MKs from stem cells using baffled-flow bioreactors and assist in the manufacturing of hESC-derived MK and platelet products.
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Células-Tronco Embrionárias Humanas , Megacariócitos , Humanos , Células-Tronco Embrionárias Humanas/metabolismo , Plaquetas/metabolismo , Diferenciação Celular , MitocôndriasRESUMO
Emulsion gels with the mixtures of low-molecular-weight emulsifier (LME) and polymer have attracted much attention in food; however, the LME-polymer interactions in emulsion system are complex and unclear. Here, the interactions between SSL and xanthan in emulsions and the mechanisms of stabilizing emulsions were investigated by using tensiometry, zeta potential, Fourier transform infrared spectroscopy (FTIR), confocal laser scanning microscopy (CLSM), cryo-scanning electron microscopy (cryo-SEM) and rheology. SSL was more efficiently adsorbed on the oil-water interface than xanthan. Interestingly, the honeycomb structure was formed in emulsion gels, which firmly immobilized oil droplets. Furthermore, electrostatic repulsion and hydrophobic interactions between xanthan and SSL facilitated the efficient bonding at interface and in bulk. Both linear and nonlinear rheology strongly supported the fact that the interactions between xanthan and SSL enhanced gel-like viscoelastic structure of emulsion gels. This structure endows excellent stability of emulsion gels under high temperature storage, sealed conditions and pH change.
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Polímeros , Água , Emulsões/química , Géis/química , Polissacarídeos Bacterianos , Reologia , Sódio , Água/químicaRESUMO
There is an urgent medical need to develop effective therapies that can ameliorate damage to the radiation-exposed hematopoietic system. Nanozymes with robust antioxidant properties have a therapeutic potential for mitigating radiation-induced hematopoietic injury. However, enhancing nanozyme recruitment to injured tissues in vivo while maintaining their catalytic activity remains a great challenge. Herein, we present the design and preparation of a biomimetic nanoparticle, a mesenchymal stem cell membrane camouflaged Prussian blue nanozyme (PB@MSCM), which exhibits biocompatible surface properties and demonstrates enhanced injury site-targeting towards the irradiated murine bone marrow niche. Notably, the constructed PB@MSCM possessed redox enzyme-mimic catalytic activity and could scavenge overproduced reactive oxygen species in the irradiated bone marrow cells, both in vitro and ex vivo. More importantly, the administration of PB@MSCM significantly mitigated hematopoietic cell apoptosis and accelerated the regeneration of hematopoietic stem and progenitor cells. Our findings provide a new targeted strategy to improve nanozyme therapy in vivo and mitigate radiation-induced hematopoietic injury.
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Biomimética , Medula Óssea , Camundongos , Animais , Ferrocianetos , Células da Medula ÓsseaRESUMO
Targeted protein degradation (TPD) is a promising approach in drug discovery for degrading proteins implicated in diseases. A key step in this process is the formation of a ternary complex where a heterobifunctional molecule induces proximity of an E3 ligase to a protein of interest (POI), thus facilitating ubiquitin transfer to the POI. In this work, we characterize 3 steps in the TPD process. (1) We simulate the ternary complex formation of SMARCA2 bromodomain and VHL E3 ligase by combining hydrogen-deuterium exchange mass spectrometry with weighted ensemble molecular dynamics (MD). (2) We characterize the conformational heterogeneity of the ternary complex using Hamiltonian replica exchange simulations and small-angle X-ray scattering. (3) We assess the ubiquitination of the POI in the context of the full Cullin-RING Ligase, confirming experimental ubiquitinomics results. Differences in degradation efficiency can be explained by the proximity of lysine residues on the POI relative to ubiquitin.
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Proteínas Culina , Simulação de Dinâmica Molecular , Proteínas Culina/metabolismo , Deutério , Lisina/metabolismo , Espectrometria de Massas , Proteólise , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , UbiquitinaçãoRESUMO
Water-in-oil (w/o) Pickering emulsions have gained considerable attention in colloid science and daily applications. However, for the formation of w/o emulsions, especially those with high internal water content, the particulate stabilizers are required to be sufficiently hydrophobic, and synthetic or chemically modified particles have been mostly reported until now, which are not biocompatible and sustainable. We present a zein protein-based microsphere derived from the Pickering emulsion template, in which protein microspheres are feasibly in situ hydrophobized by silica nanoparticles, enabling the stabilization of w/o Pickering emulsions. The effects of microsphere concentration, water/oil volume ratio, oil types, and pH on the stabilization of prepared w/o emulsions are systematically studied, revealing prominent characteristics of the controllable size, high water fraction, universal adaptation of oils, as well as broad pH stability. As a demonstration, the Pickering emulsion effectively encapsulates vitamin C and shows high stability for long storage duration against ultraviolet radiation/heat. Therefore, this novel proteinaceous particle-stabilized w/o Pickering emulsion has great potential in the delivery and protection of water-soluble bioactive substrates.
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Nanopartículas , Zeína , Ácido Ascórbico , Emulsões/química , Microesferas , Nanopartículas/química , Óleos/química , Tamanho da Partícula , Dióxido de Silício/química , Raios Ultravioleta , Água/químicaRESUMO
This study investigated new avenues for understanding the association between parental autonomy support and academic engagement among Chinese secondary vocational students based on Self-Determination Theory and Career Construction Theory. We highlighted the mediator role of career adaptability and career decision-making self-efficacy in the relationship between parental autonomy support and academic engagement. Using self-reported data from 1,930 secondary vocational students in a city in Central China, we performed correlation analysis and mediation analysis by using SPSS and Mplus. The results revealed that parental autonomy support was positively associated with students' academic engagement. Moreover, as an adaptability resource and adapting response, career adaptability and career decision-making self-efficacy played mediating roles between parental autonomy support and academic engagement. These findings offered crucial empirical evidence for understanding the association between parental support and academic engagement among Chinese secondary vocational students. Meanwhile, it also validated the application of Career Construction Theory in a sample of secondary vocational students in China and provided constructive insights for implementing diverse support measures to boost their academic and career development.
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Microgels are regarded as soft colloids with environmental responsiveness. However, the majority of reported microgels are inherently hydrophilic, resulting in aqueous dispersions, and only used in water-based applications. Herein, we reported an efficient method for hybridization of poly(N-isopropylacrylamide) microgel by coating hydrophobic silica nanoparticles on their surface. The resultant hybrid microgel had switchable surface wettability and could be dispersed in both aqueous and oil phases. Meanwhile, the coated hydrophobic silica nanoparticles solved the difficulty in redispersing microgels caused by particle aggregation and film formation during the drying process, providing a significant advantage in dried storage. Furthermore, the introduction of hydrophobic silica nanoparticles endowed the hybrid microgel with a variety of applications, including cargo encapsulation, active release induced by emulsion reversion, and trace water absorption.
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Reducing the formation of oral bacterial biofilms is critical to prevent common dental diseases. Though many strategies for restricting bacterial adhesion on tooth surfaces have been reported, a simple method for efficient oral bacteriostasis is still highly expected. Herein, we have proved a soft gel made of an alginate-catechol conjugate (SA-DA) and the ferrous cation (Fe2+) as an effective antibacterial coating on hydroxyapatite (HAP, a tooth model). As suggested by quartz crystal microbalance (QCM) measurements, SA-DA/Fe2+ coating possessed a high binding affinity to HAP without destruction by either immersion in artificial saliva or simulated tooth brushing. Significantly less protein (bovine serum albumin) and Streptococcus mutans (S. mutans, an oral bacterial model) could be found on HAP after coating with SA-DA/Fe2+, indicating that the prepared gel could resist well the adhesion of biofouling and microbes due to its hydrophilicity. Notably, such an antibacterial effect (around 70% S. mutans was inhibited) could be maintained for 3 d, which resulted from the extremely good stability of SA-DA/Fe2+ coating, as confirmed by QCM analysis. Our results may offer possibilities for developing applications in order to further improve oral hygiene.
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Alginatos , Durapatita , Alginatos/farmacologia , Antibacterianos/farmacologia , Catecóis/farmacologia , Durapatita/farmacologia , Streptococcus mutansRESUMO
HYPOTHESIS: Synergistic stabilization of high internal phase Pickering emulsions (HIPPEs) by food-grade colloidal particles are necessary for food, pharmaceuticals or cosmetics owing to their biocompatibility and multi-functionality. By tuning the interfacial structure of adsorbed binary particles, the HIPPE may exhibit extraordinary characteristics compared to conventional all-natural HIPPEs solely stabilized by single-component particle or composite particle, which should have potential applications in varies fields. EXPERIMENTS: HIPPEs were prepared by using zein protein nanoparticles (ZNPs) and starch nanocrystals (SNCs) as stabilizers. We systematically investigated the effect of particle concentration and internal phase fraction on HIPPEs morphology, stability and rheological behaviors. Further, the stabilization mechanism as well as potential applications were demonstrated. FINDINGS: HIPPEs were prepared with excellent stability against centrifugation and high temperature (50 °C). Our result indicates the successful construction of unique bilayer interfacial structures consisting of inner ZNPs layer and outer SNCs layer. Since SNCs could gelatinize at 50 °C, dense shells can form around droplets afterwards. Such thermally responsive interfacial structures can be used to protect hydrophobic bioactive substances at higher temperatures while still allowing controlled release at certain conditions. Furthermore, with high internal phase fraction, HIPPEs can possibly replace mayonnaise and salad dressing on the market due to comparable appearance and properties. Following the removal of inner oil, porous materials can be further fabricated, which have potential applications in environmental protection or tissue engineering.
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Nanopartículas , Zeína , Emulsões , Tamanho da Partícula , ÁguaRESUMO
Serine hydroxymethyltransferase 2 (SHMT2), a catalytic enzyme playing an important role in aerobic cellular respiration and mitochondrial metabolism, might be pivotal in self-renewal and differentiation of human pluripotent stem cells. Herein, we used the CRISPR/Cas9 editing system to construct a homozygous SHMT2 knockout (SHMT2-KO) human embryonic stem cell (hESC) line, exhibiting a normal karyotype, colony morphology, and high expression levels of pluripotent proteins. Furthermore, SHMT2 knockout did not impact the self-renewal ability or differentiation potential into three germ layers of hESCs. Accordingly, this cell line provides a valuable model for further assessing SHMT2 functions in human embryonic development.