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Interaction of biologically relevant proteins with ZnO nanomaterials: A confounding factor for in vitro toxicity endpoints
摘要： The results of in vitro toxicological studies for manufactured nanomaterials (MNs) are often contradictory and not reproducible. Interference of the MNs with assays has been suggested. However, understanding for which materials and how these artefacts occur remains a major challenge. This study investigated interactions between two well-characterized ZnO MNs (NM-110 and NM-111) and lactate dehydrogenase (LDH), and two interleukins (IL-6 and IL-8). Particles (10 to 640 μg/mL) and proteins were incubated for 24 hours in routine in vitro assays test conditions. LDH activity (ODLDH), but not interleukins concentrations, decreased sharply in a dose-dependent manner within an hour after exposure (ODLDH < 60% of ODref for both MNs at 10 μg/mL). A Freundlich adsorption isotherm was successfully applied, indicating multilayer adsorption of LDH. ZnO MNs and LDH had neutral to slightly negative surface charges in dispersion, precluding electrostatic attachment. Particle sedimentation was not a limiting factor. Fast dissolution of ZnO MNs was shown and Zn2+ could play a role in the ODLDH drop. To summarize, ZnO MNs quickly reduced ODLDH due to concentration-dependent adsorption and LDH inhibition by interaction with dissolved Zn. The control of particle interference in toxicological in vitro assays should become mandatory to avoid misleading interpretation of results.
关键词： artefact,pH,interleukin,adsorption,lactate dehydrogenase,dissolution
更新于2025-09-23 15:23:52
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Low-density PMMA/MAM nanocellular polymers using low MAM contents: Production and characterization
摘要： Low-density nanocellular polymers are required to take advantage of the full potential of these materials as high efficient thermal insulators. However, their production is still a challenging task. One promising approach is the use of nanostructured polymer blends of poly(methyl methacrylate) (PMMA) and a block copolymer poly(methyl methacrylate)-poly(butyl acrylate)-poly(methyl methacrylate) (MAM), which are useful for promoting nucleation but seem to present a severe drawback, as apparently avoid low relative densities. In this work, new strategies to overcome this limitation and produce low-density nanocellular materials based on these blends are investigated. First, the effect of very low amounts of the MAM copolymer is analysed. It is detected that nanostructuration can be prevented using low copolymer contents, but nucleation is still enhanced as a result of the copolymer molecules with high CO2 affinity dispersed in the matrix, so nanocellular polymers are obtained using very low percentages of the copolymer. Second, the influence of the foaming temperature is studied. Results show that for systems in which there is not a clear nanostructuration, cells can grow more freely and smaller relative densities can be achieved. For these studies, blends of PMMA with MAM with copolymer contents from 10 wt% and as low as 0.1 wt% are used. For the first time, the production strategies proposed in this work have allowed obtaining low density (relative density 0.23) nanocellular polymers based on PMMA/MAM blends.
关键词： nanostructuration,gas dissolution foaming,PMMA,MAM,block copolymer,nanocellular polymer,nanocellular foam
更新于2025-09-23 15:23:52
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Analysis and correction of probe location errors in spherical near-field antenna measurement
摘要： Cellulose is the most abundant natural polymer on earth. With the increasing shortage of oil resources, people have been focusing more on producing natural cellulose. In this study, guaiacol was used as the model compound to investigate the degradation of lignin in luffa. A new cellulose material was extracted from natural luffa by a pretreatment based on the oxidation and acidity of glow discharge plasma in water. The produced luffa cellulose was dissolved in anhydrous phosphoric/polyphosphoric acid (aPPAC) solvent to prepare cellulose film. Results showed that the reactive species of OH·, HO2· and H3O+ were produced during the plasma discharge of water. The free radicals ·OH were useful in eliminating lignin by the destruction of aromatic structure, whereas H3O+ in eliminating hemicellulose in the luffa raw material. At the conditions of luffa powder concentration of 9.26 g/L, discharge time of 20 min, and plasma power of 100W, the cellulose component was increased to 81.2%. After 25 min, the luffa cellulose was completely dissolved in the aPPAC solvent at 0–5 ?C. Thus, a regenerated cellulose film of cellulose II was prepared. The aPPAC solvent was a good non-derivatizing solvent for the luffa cellulose. The regenerated film exhibited good mechanical properties, wettability and a compact structure. Therefore, plasma pretreatment was an environmentally friendly and high-efficiency method for luffa degumming. The luffa cellulose can be well used in dissolution and regeneration in films.
关键词： plasma treatment,film,dissolution,luffa cellulose
更新于2025-09-23 15:22:29
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Elucidating Spray Dried Dispersion Dissolution Mechanisms with Focused Beam Reflectance Measurement: Contribution of Polymer Chemistry and Particle Properties to Performance
摘要： Amorphous spray dried dispersions (SDDs) are a key enabling technology for oral solid dosage formulations, used to improve dissolution behaviour and clinical exposure of poorly-soluble active pharmaceutical ingredients (APIs). Appropriate assessment of amorphous dissolution mechanisms is an ongoing challenge. Here we outline the novel application using Focused Beam Reflectance Measurement (FBRM) to analyse particle populations orthogonal to USP 2 dissolution. The relative impact of polymer substitution and particle attributes on 25% BMS-708163/HPMC-AS SDD dissolution was assessed. Dissolution mechanisms for SDDs were categorized into erosion versus disintegration. Beyond an initial mixing period, FBRM particle counts diminish slowly and particles are detectable until the point where API dissolution is complete. There is correlation between FBRM particle count decay rate, representing loss of SDD particles in the dissolution media, and UV dissolution rate, measuring dissolved API. For the SDD formulation examined, the degree of succinoyl substitution for HPMC-AS, SDD particle size and surface area all had an impact on dissolution. These data indicate the SDD displayed an erosion mechanism and that FBRM is capturing a rate-limiting step. From this screening tool, the mechanistic understanding and measured impact of polymer chemistry and particle properties can inform a risk-assessment and control strategy for this compound.
关键词： HPMC-AS,FBRM,SDD,substitution,dissolution-mechanism,amorphous,surface area,erosion,dispersion,particle-size
更新于2025-09-23 15:22:29
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Development of Dissolution Inhibitor in Chemically Amplified Positive Tone Thick Film Resist
摘要： Thick film resist is applied to a template for microelectrode used in semiconductor device integration. Utilization of positive type resist in chemically amplified system for thick film is expected to improve production efficiency of semiconductor device integration, but improvement of resolution is required. In order to improve the resolution of chemically amplified positive tone thick film resist, chemical structure of the dissolution inhibitor (DI) was designed for the control of solubility in resist polymer. The increase of molecular size in DI improved the dissolution inhibiting ability for the resist polymer in the unexposed area and the high acidity of the deprotected DI having carboxyl group improved dissolution promoting ability for the resist polymer in the exposed area. The resist containing DI possessing a large molecular size and high acidity improved its sensitivity and resolution.
关键词： Positive tone resist,Chemically amplified system,Thick film resist,Dissolution inhibitor
更新于2025-09-23 15:21:21
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Application of a suitable particle engineering technique by pulsed laser ablation in liquid (PLAL) to modify the physicochemical properties of poorly soluble drugs
摘要： Several disintegration procedures are well known in the field of pharmaceutical technology to improve the solubility, dissolution rate and bioavailability. Only a few, organic materials were applied for micro/nanoparticle generation by pulsed laser ablation in liquid (PLAL), however in the last decade, several studies presented successful production from different active agents. PLAL could be a non-conventional approach by the preformulation of the drug, as a simple, clean (no additional chemicals are needed) and a rapid wet grinding method. It can be stated about the novelty of the work that a poorly water-soluble meloxicam was milled first time by pulsed laser ablation in liquid, where the effect of three different wavelengths, fluence values (energy density) and polymer type (PVP, PVA, Poloxamer) on the habit, structure, solubility and in vitro properties of the drug were investigated. Nearly spherical amorphous micro- and nanoparticles could be reached in a size range between 60-700 nm. Fourier-transform infrared spectroscopy (FT-IR) was applied to check the purity, secondary interaction and High performance liquid chromatography (HPLC) method was used for the determination of the presence of the meloxicam content and the final yield. The results suggest that laser ablation a useful approach to modify the physicochemical properties of the active agents, introduced a novel preparation method in drug preformulation with improved solubility (from 0.0203 mg/mL to 0.0797 mg/mL), dissolution rate (~85%) and also to produce a suitable intermediate product for traditional and alternative drug administration (e.g. pulmonary, nasal, transdermal).
关键词： physicochemical characterization,novel wet-milling,meloxicam,in vitro dissolution,nanosuspension,laser fragmentation
更新于2025-09-23 15:21:01
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High-quality Concentrated Precursor Solution in N,N-dimethylformamide for Thick Methylammonium Triiodoplumbate Layer in Solar Cells
摘要： High-quality precursor solution is essential for the fabrication of hybrid perovskite solar cells. This paper reports a simple and efficient method of preparing the high-quality concentrated solution of methylammonium triiodoplumbate (MAPbI3) in N,N-dimethyl formamide (DMF) by using MAPbI3 crystal instead of conventional lead iodine and methylammonium iodine blend. The MAPbI3 concentration of the precursor solution is easily and accurately adjusted from zero up to 1.64 M. The investigation on the dissolution process of the MAPbI3 crystal reveals that the concentrated solution of MAPbI3 in DMF is metastable, and transition from the concentrated solution to solvated intermediate MAPbI3?DMF determines the solubility of MAPbI3 in DMF. The high purity and precise stoichiometric ratio of the crystal eliminate the possible impurities that initialize the transition to MAPbI3?DMF, and consequently suppress the transition and increase the stability of the concentrated solution. MAPbI3 films with different thickness up to 800 nm are prepared with conventional film fabrication technique, and a highest power conversion efficiency of 20.7% is achieved on corresponding solar cells. The newly developed method to prepare the concentrated precursor solution can be easily combined with other fabrication techniques for the further development of industrial-scale manufacture of solar cells.
关键词： dissolution kinetics,methylammonium triiodoplumbate,solubility,crystal
更新于2025-09-23 15:21:01
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Asphaltenes dissolution mechanism study by <i>in-situ</i> Raman characterization of a packed-bed microreactor with HZSM-5 aluminosilicates
摘要： Asphaltenes, the most aromatic component of heavy oil, are responsible for the fouling and impairment in flow lines, wellbores, and other production facilities in the petroleum industry. Aromatic solvents such as xylenes are commonly used for the asphaltenes’ cleaning process. Understanding the mechanism of asphaltenes’ dissolution in aromatic solvents is significant for the development of a remediation strategy. The reduction of a reactor’s characteristic length scale leads to the decrease in experimental period while providing high throughput information. Microfluidic systems with in-situ spectroscopy is an excellent platform for time-effective studies of the molecular behavior of asphaltenes in simulated sandstone reservoirs. Here, we injected the HZSM-5 zeolite nanoparticles (707 nm ·aggregate-1 in isopropanol solution) with varying Al2O3/SiO2 ratios (from 0 to 1/26) into the quartz porous media to represent reservoirs with different characteristic acidity. In-line UV-Vis spectroscopy enabled the direct measurement of the dissolution percentage, while in-situ Raman spectroscopy revealed where the dissolution took place within the porous media. In addition to bed occupancy, sheet sizes of asphaltenes molecules can also be determined by in-situ Raman spectroscopy. Our results show that the average sheet size of deposited asphaltenes molecules decreased from 2.97 ± 0.25 nm to 2.74 ± 0.26 nm after cleaning the porous media with xylenes. This trend is confirmed with the fluorescence emission spectra of dissolved asphaltenes molecules, where a 10-30 nm red-shift is present when referenced to asphaltenes source samples. These results provide an explanation to why the dissolution percentage of asphaltenes in aromatic solvents increases from 20.15 wt% to 51.00 wt% as the Al2O3 content increases. We can speculate that this increase in weight percentage is attributed to the differences in deposited asphaltenes molecules’ sheet size. These results reveal the importance of π-π interactions during asphaltenes dissolution process in the aromatic solvent. Our results provide the fundamental understanding of asphaltenes dissolution, which otherwise would be challenging to observe using any other analytical methods.
关键词： in situ Raman spectroscopy,Asphaltenes dissolution,Porous media
更新于2025-09-23 15:21:01
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In Vivo Bioimaging of Silver Nanoparticle Dissolution in the Gut Environment of Zooplankton
摘要： Release of silver ions (Ag+) is often regarded as the major cause for silver nanoparticles (AgNPs) toxicity towards aquatic organisms. Nevertheless, differentiating AgNPs and Ag+ in complicated biological matrix and its dissolution remains a bottleneck in our understanding of AgNPs behavior in living organisms. Here, we directly visualized and quantified the time-dependent release of Ag+ from different sized AgNPs in an in vivo model zooplankton (Daphnia magna). A fluorogenic Ag+ sensor was used to selectively detect and localize the released Ag+ in daphnids. We demonstrated that the ingested AgNPs were dissoluted to Ag+, which was heterogeneously distributed in daphnids with much higher concentration in the anterior gut. At dissolution equilibrium, a total of 8.3-9.7% of ingested AgNPs was released as Ag+ for 20 nm and 60 nm AgNPs. By applying a pH sensor, we further showed that the dissolution of AgNPs was partially related to the heterogenous distribution of pH in different gut sections of daphnids. Further, Ag+ was found to across the gills and enter the daphnids, which may be a potential pathway leading to AgNPs toxicity. Our findings provided fundamental knowledge about the transformation of AgNPs and distribution of Ag+ in daphnids.
关键词： guts,Daphnia,AgNPs,AIE,bioimaging,dissolution
更新于2025-09-23 15:21:01
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Thermochromism from Ultrathin Colloidal Sb <sub/>2</sub> Se <sub/>3</sub> Nanowires Undergoing Reversible Growth and Dissolution in an Amine-Thiol Mixture
摘要： Thermochromism from Ultrathin Colloidal Sb2Se3 Nanowires Undergoing Reversible Growth and Dissolution in an Amine–Thiol Mixture. Liquid-based thermochromics can be incorporated into an arbitrarily shaped container and provide a visual map of the temperature changes within its volume. However, photochemical degradation, narrow temperature range of operation, and the need for stringent encapsulation processes are challenges that can limit their widespread use. Here, a unique solution-based thermochromic comprising ultrathin colloidal Sb2Se3 nanowires in an amine–thiol mixture is introduced. The nanowires undergo reversible growth and dissolution with repeated cycles of heating and cooling between 20 and 160 °C, exhibiting intense and contrasting color changes during these processes. Furthermore, the transition temperature in which a change in color first appears can be continuously tuned over a range larger than 100 °C by introducing controlled amounts of Sn2+. The colloidal nanowire dispersion in the amine–thiol mixture retains its thermochromic properties over hundreds of temperature cycles, continuous heating at 80 °C over months, and shelf life of up to 2 years in an open container under ambient conditions. To illustrate its utility as a robust liquid thermochromic, the nanowire solution is coated onto standard filter paper and its uses as a rewritable surface by thermal scribing, as well as an inexpensive means of visualizing the temperature distribution of an anisotropically heated block are demonstrated.
关键词： tin-doped antimony selenide,colloidal nanowires,thermochromic materials,liquid-based,reversible growth and dissolution
更新于2025-09-23 15:21:01