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Particle size is a key parameter to determine the capacity of nanoparticles to overcome the skin barrier; however, such effect and the possible mechanism remain only partially understood for nanosuspensions. In this work, we examined the skin delivery performance of andrographolide nanosuspensions (AG-NS) ranging in diameter from 250 nm to 1000 nm and analyzed the role of particle size in influencing their ability of skin penetration. The AG-NS with particle sizes of about 250 nm (AG-NS250), 450 nm (AG-NS450), and 1000 nm (AG-NS1000) were successfully prepared by ultrasonic dispersion method and characterized by transmission electron microscopy. The drug release and penetration via the intact and barrier-removed skin were compared by the Franz cell method, and the related mechanisms were probed using laser scanning confocal microscopy (LSCM) via visualization of penetration routes and histopathological study via observation of structural change of the skin. Our finding revealed that drug retention in the skin or its sub-layers was increased with the reduction of particle size, and the drug permeability through the skin also exhibited an obvious dependence on the particle size from 250 nm to 1000 nm. The linear relationship between the in vitro drug release and ex vivo permeation through the intact skin was well established among different preparations and in each preparation, indicating the skin permeation of the drug was mainly determined by the release process. The LSCM indicated that all these nanosuspensions could deliver the drug into the intercellular lipid space, as well as block the hair follicle in the skin, where a similar size dependence was also observed. The histopathological investigation showed that the formulations could make the stratum corneum of the skin loose and swelling without severe irritation. In conclusion, the reduction of particle size of nanosuspension would facilitate topical drug retention mainly via the modulation of drug release., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The use of polydopamine-based bioinspired nanomaterials has shed new light on advanced drug delivery arising from their efficient surface functionalization. More recently, the polydopamine self-assemblies formed in two different modalities, i.e., nonporous and mesoporous nanoparticles, have begun to attract attention due to their expedient and versatile properties. However, their possibility for use in dermal drug delivery for local therapy, as well as their interaction with the skin, has not yet been demonstrated. Our study aimed to compare and explore the feasibility of the self-assembled nonporous polydopamine nanoparticles (PDA) and mesoporous polydopamine nanoparticles (mPDA) for local skin drug delivery. The formation of the PDA and mPDA structures was confirmed by the UV-vis-NIR absorption spectrum, the Fourier transform infrared spectroscopy, and the nitrogen adsorption/desorption isotherms. Using retinoic acid (RA) as the model drug, their effects on drug loading, release, photostability, skin penetration, and radical scavenging were investigated. Laser scanning confocal microscopy (LSCM) and hematoxylin and eosin (H&E) were introduced to probe their delivery routes and possible interaction with the skin. The results indicated that both PDA and mPDA could reduce the photodegradation of RA, and mPDA showed significantly better radical scavenging activity and drug loading capacity. The ex vivo permeation study revealed that both PDA and mPDA significantly enhanced the delivery of RA into the deep skin layers by comparison with the RA solution, in which follicular and intercellular pathways existed, and alteration in the structure of stratum corneum was observed. In light of drug loading capacity, size controllability, physical stability, as well as radical scavenging activity, mPDA was more preferable due to the improvement of these factors. This work demonstrated the feasibility and promising application of PDA and mPDA nanoparticles for dermal drug delivery, and the comparative concept of these two types of biomaterials can provide implications for their use in other fields.

The study aimed to explore the size effect on the in vitro-in vivo correlation (IVIVC) in the oral absorption of andrographolide nanosuspensions (Ag-NS). Ag-NS with controllable particle sizes were prepared by ultrasonic dispersion method, and the formulation and process parameters were optimized through single factor experiments using mean particle size, polydispersity index, and stability as evaluation indicators. The morphology of Ag-NS was observed by scanning electron microscopy (SEM), and the crystalline state of the nanosuspensions was characterized by X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC). The dissolution tests were carried out with the paddle method in two different mediums simulating the pH conditions in intestinal fluid (pH 6.8) and gastric fluid (pH 1.2), respectively. The pharmacokinetic behaviors were investigated in rats after oral administration, and a deconvolution approach was introduced to determine the correlation between in vitro dissolution and in vivo absorption (IVIVC). The formulation with the use of lecithin and PEG-800 as stabilizers showed its potential in the size-controllable preparation of Ag-NS. Via altering the ultrasonication amplitude and time, three Ag-NS suspensions with three particle sizes, i.e., Ag-NS 250 (249.8 ± 1.3 nm), Ag-NS 450 (485.2 ± 3.7 nm), Ag-NS 1000 (1015 ± 36.1 nm) were prepared. Their morphological and crystal characteristics were not changed during the size reduction process, but both of their in vitro dissolution and in vivo absorption were improved. Relatively better IVIVC performance was observed with the in vitro dissolution data at pH 6.8 (r > 0.9). With the reduction of particle size, the in vivo absorption fraction was more closed to the level of the in vitro dissolution. In conclusion, the decrease in particle size would improve the dissolution and absorption of Ag-NS, and also affect their IVIVC performance. The study would facilitate the design and quality control of Ag-NS in terms of particle size and dissolution specifications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Radiotherapy is one of the conventional tumor treatments, while its abscopal therapeutic efficacy is severely hampered by the immunosuppressive tumor microenvironment. To address this challenge, we herein report on the morphology-adaptable peptide-based therapeutics for efficiently reversing the immunosuppression in the combinatorial radio-immunotherapy through simultaneous checkpoint blocking and induction of immunogenic cell death. The peptide-based therapeutics were created via co-assembling a pentapeptide containing a 4-amino proline residue with its derivatives containing IDO-1 inhibitor NLG919. The resulting therapeutics underwent pH-adaptable morphological transformation between nanofibrils and nanoparticles and released NLG919 upon GSH cleavage. In vivo studies confirmed that the pH-adaptable morphologies of the therapeutics facilitated their tumor accumulation and retention at tumor sites compared to morphology-persistent counterparts, thus resulting in efficient delivery of IDO-1 inhibitors. Simultaneously treating the tumor-bearing mice with the therapeutics and external γ-ray radiation boosted the tumor immunogenicity via inducing ICD cascade of the tumor cells and reverse the immunosuppressive tumor microenvironment due to the inhibition of IDO-1 for depletion of tryptophan. Our findings strongly demonstrate that the morphology-adaptable peptide-based therapeutics exhibit the capability to reverse the immunosuppressive tumor microenvironment during irradiation, thus providing a new strategy for the combinatorial radio-immunotherapy., (Copyright © 2021. Published by Elsevier B.V.)

Background: Mesoporous calcium-silicate nanoparticles (MCSNs) have good prospects in the medical field due to their great physicochemical characteristics, antibacterial activity and drug delivery capacity. This study was to analyze the antibiofilm activity and mechanisms of silver (Ag) and zinc (Zn) incorporated MCSNs (Ag/Zn-MCSNs) with different percentages of Ag and Zn., Methods: Ag/Zn(1:9, molar ratio)-MCSNs and Ag/Zn(9:1, molar ratio)-MCSNs were prepared and characterized. Endocytosis of nanoparticles by Enterococcus faecalis ( E. faecalis ) treated with Ag/Zn-MCSNs was observed using TEM to explore the antibacterial mechanisms. The antibiofilm activity of Ag/Zn-MCSNs with different ratios of Ag and Zn was tested by E. faecalis biofilm model in human roots. The human roots pretreated by different Ag/Zn-MCSNs were cultured with E. faecalis . Then, SEM and CLSM were used to observe the survival of E. faecalis on the root canal wall. Cytotoxicity of the nanoparticles was tested by CCK8 kits., Results: The Ag/Zn-MCSNs release Ag + and destroy the cell membranes to kill bacteria. The MCSNs containing Ag showed antibacterial activity against E. faecalis biofilms in different degrees, and they can adhere to dentin surfaces to get a continuous antibacterial effect. However, MTA, MCSNs and Zn-MCSNs could not disrupt the bacterial biofilms obviously. MCSNs, Ag/Zn(1:1, molar ratio)-MCSNs and Ag/Zn(1:9)-MCSNs showed no obvious cytotoxicity, while Ag-MCSNs and Ag/Zn(9:1)-MCSNs showed cytotoxicity. Zn-MCSNs can slightly promote cell proliferation., Conclusion: Ag/Zn-MCSNs have good antibiofilm activity. They might achieve an appropriate balance between the antibacterial activity and cytotoxicity by adjusting the ratio of Ag and Zn. Ag/Zn-MCSNs are expected to be a new type of root canal disinfectant or sealer for root canal treatment., Competing Interests: The authors report no conflicts of interest in this study., (© 2020 Leng et al.)

Carbon support in commercial Pt/C suffers severe corrosion in harsh electro-oxidation environments caused by anode potentials. Alternative support should be developed to improve the quality, activity, and durability of platinum by studying the relationship between platinum and support. Here, we prepare fluorine-free Ti3C2TX (T = –OH, –O) powder via a sodium hydroxide etching process to fix Pt nanoparticles. The resulting fluorine-free Ti3C2TX/Pt composite features stable layered structure and metallic properties. As an electrocatalyst for hydrogen evolution reaction (HER), the overpotential of fluorine-free Ti3C2TX/Pt in a 0.5 M H2SO4 water solution at − 10 mA/cm−2 is only 180 mV and 25% lower than that of fluorine-containing Ti3C2TX/Pt. The HER performance remains stable after 80 h of reaction. The improvement in HER activity of the fluorine-free Ti3C2TX/Pt can be attributed to the excellent electrical conductivity, more active sites, less inert surface groups, and electronic effects between the Pt and surface functional groups of alkali-etched Ti3C2TX. This work broadens the application of fluorine-free Ti3C2TX in the field of hydrogen evolution reactions. [ABSTRACT FROM AUTHOR]

Due to its unique structure and excellent properties, (β-cyclodextrin, as a green environmental material, is widely used in the fields ff the drug, medicine and environment and so on, and plays an increasingly important role. The excellent properties of (β-cyclodextrin and its derivatives were introduced. Several modification principles and methods of (β-cyclodextrin were briefly introduced. The preparation methods of (β-cyclodextrin nanoparticles and the results of their application researches in the fields of medicine and environment in recent years were mainly reviewed. Finally, the further works on the anti-tumor effect of modified β-cyclodextrin microparticles were suggested, and the modified methods to expand its application were forecasted. [ABSTRACT FROM AUTHOR]

A simple and feasible catalytic route has been successfully developed through the exsolution of Ni nanoparticles to enhance the proton conductivity of a high temperature proton conducting electrolyte La 0.95 Ca 0.05 NbO 4 (LCN). A series of compounds La 0.95 Ca 0.05 Ni x Nb 1-x O 4 (LCNNi, x = 0.01, 0.03, 0.05, 0.1, 0.2, 0.3) are prepared by solid state reaction. Nickel is added into the solid solution of La 0.95 Ca 0.05 NbO 4 in their oxidation phase, and precipitates as Ni nanoparticles upon being exposed to reducing atmosphere. Transmission electron microscopy and X-ray photoelectron spectroscopy confirmed the partial exsolution of Ni nanoparticles after exposure to 5% H 2 /Ar at 800 °C. The proton conductivity of LCNNi was investigated by electrochemical impedance spectroscopy in humidified Ar and 5% H 2 /Ar. In all cases, the total conductivities of Ni doped compositions are higher than that of the undoped one and proton conductivity is the dominant conductivity. At Ni0.05, it exhibits the maximum total conductivity (3.53 × 10 −4  S cm −1 ), that is twice more than twice as the value of LCN (1.73 × 10 −4  S cm −1 ) in humidified 5% H 2 /Ar at 800 °C. Both of the grain boundary and bulk conductivities are significantly improved in humidified 5% H 2 /Ar. The preliminary results demonstrate that this catalytic approach with precipitated Ni nanoparticles is viable and effective to optimize the conductivity of LCN electrolyte. [ABSTRACT FROM AUTHOR]

Transient electronic is an emerging field that designed electronic devices can be fleetly and partially (or completely) degraded when transiency is triggered. Here, a class of PVA-based degradable composite film was synthesized, whose physical properties allow it to be used as substrate material for transient electronic devices. We found the dielectric properties and dissolution rate of the composite film can be tuned by controlling the TiO nanoparticle addition. Based on the as-synthesized PVA/TiO composite film, patch antennas were further designed and fabricated. The antennas were found to possess excellent radiation performances at a frequency of 2.5 GHz. Most importantly, the antennas could be physically degraded within 1 h when immersed in pure water. This study shows that the PVA-based film is a good candidate substrate or supporting material for transient electronics. In addition, the design and manufacture methods reported here provide a reference for other transient devices with complex structure and function. [ABSTRACT FROM AUTHOR]

Nanoparticles may have suffered from low modification efficiency in hybrid membranes due to embedding and aggregating in polymer matrix. In order to analyze the modification mechanisms of nanoparticle migration and dispersion on the properties of hybrid membranes, we designed different F/ O ratios ( R ) of fluorinated graphene oxide (FGO, diameter = 1.5 ~ 17.5 μm) by carbon tetrafluoride (CF) plasma treatment GO for 3, 5, 10, 15, and 20 min and successfully prepared novel PVDF hybrid membranes containing FGO via the phase inversion method. After a prolonged plasma treatment, the R of FGO was enhanced sharply, indicating an increasing compatibility of FGO with the matrix, especially FGO-20 (GO treated for 20 min). FGO contents in the top layer, sublayer, and the whole of membranes were probed by X-ray photoelectron spectroscopy, energy-dispersive spectrometer, and indirect computation, respectively. In the top layer of membranes, FGO contents declined from 13.14 wt% (PVDF/GO) to 4.00 wt% (PVDF/FGO-10) and 1.96 wt% (PVDF/FGO-20) due to the reduced migration ability of FGO. It is worth mentioning that PVDF/FGO-10 membranes exhibited an excellent water flux and flux recovery rate (up to 406.90 L m h and 88.9%), which were improved by 67.3% and 14.6% and 52.5% and 24.0% compared with those of PVDF/GO and PVDF/FGO-20 membranes, respectively, although the dispersion and migration ability of FGO-10 was maintained at a moderate level. It indicated that the migration and dispersion of FGO in membranes could result in dynamic equilibrium, which played a key role in making the best use of nanomaterials to optimize membrane performance. [ABSTRACT FROM AUTHOR]

In this work, 〈1 0 0〉 textured Co 70 Fe 30 alloy was successfully prepared by directional solidification technique. The effect of heat treatment on magnetostriction and microstructure of Co 70 Fe 30 alloy has been investigated. The Co 70 Fe 30 alloy was annealed in argon atmosphere at 700 °C–900 °C for 9 days and then cooled to room temperature by slow cooling or quenching. The magnetostriction as large as 180 ppm has been achieved for the quenched samples when the annealing temperature is ranging from 820 °C to 860 °C. Structural analyses indicate that the large magnetostriction originates from precipitation of a nanoscale face-centered tetragonal (fct) phase embedded in a body-centered cubic (bcc) phase matrix. [ABSTRACT FROM AUTHOR]

To promote the oxygen permeability of Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) membranes, Co 3 O 4 nanoparticle catalysts were loaded onto the surfaces of BSCF membranes by a dip-coating process. X-ray diffraction (XRD) results reveal that Co 3 O 4 nanoparticles crystalize in spinel phase. Scanning electron microscope (SEM) observation indicates that the mean particle size of the Co 3 O 4 nanoparticles is about 100 nm in diameter and 20 μm in thickness after annealing at 500 °C for 5 h. Energy dispersive spectrometer (EDS) results testify that the percentage of the elements in the modified layer are in accordance with the stoichiometric ratio of Co 3 O 4 . Oxygen permeation tests were made in a laboratory self-made device, and the results show that loading Co 3 O 4 nanoparticle catalysts onto the surfaces of BSCF membranes can significantly increase the oxygen permeability of the BSCF membranes. The unmodified BSCF membranes have an oxygen permeation flux of 0.1080 ml cm −2 min −1 at 600 °C. This increases to 0.4302 ml cm −2 min −1 , for the modified membranes, which is four times higher than that of the unmodified BSCF membranes. The oxygen permeation activation energy decreases from 91.42 to 50.71 kJ mol −1 at 600–800 °C by loading Co 3 O 4 nanoparticle catalysts on the surface of BSCF membranes. [ABSTRACT FROM AUTHOR]

Abstract: Co1−x Ni x alloy nanoparticles (x =0.2, 0.5, 0.6, and 0.8) with the diameter 15–28nm attached on the surface of multi-walled carbon nanotubes (MWCNTs) were prepared to form Co1−x Ni x /MWCNT nanocomposites by microwave irradiation. Experimental results demonstrated that Co1−x Ni x alloy nanoparticles with quasi-spherical and face-centered cubic structure had been attached on the MWCNTs, the composition and size of Co1−x Ni x alloy nanoparticles could be controlled through adjusting the atomic ratios of metal Co to Ni in the mixed acetate solution, the microwave power and microwave irradiation time, respectively. Both the coercivity and the saturation magnetization of Co1−x Ni x alloy nanoparticles increased with increasing Co concentration from x =0.8 to 0.5, and decreased when Co concentration was increased from x =0.5 to 0.2. These confirm that microwave synthesis is promising for fabricating alloy nanoparticles attached on MWCNTs for magnetic storage and ultra high-density magnetic recording applications. [Copyright &y& Elsevier]