The relationship between the particle size and lung retention time of inhaled nanocarriers was unclear, and this uncertainty hampered the design of nanocarriers for pulmonary delivery. The debate ...resulted from a lack of knowledge regarding the integrity of the involved nanocarriers. A distinguishable bioimaging probe which could differentiate between integrated and disintegrated nanocarriers by emitting different signals was introduced to address this problem. The aza-BODIPY structured aggregation-caused quenching (ACQ) probes were promising candidates, because they showed intense fluorescence signals in intact nanocarriers while quenched after the decomposition of nanocarriers. This attribute was called an on-off switch. In this paper, ACQ probes were encapsulated into a solid lipid nanoparticle suspension (SLNS) with different particle sizes (120–480 nm), and the relationship between particle size and lung retention time after pulmonary delivery was investigated in BALB/c mice. The results showed that a larger particle size led to a longer lung retention time. By comparing with the results of a non-water-quenching probe, the SLNS systems were found to be mostly intact in the pulmonary region. These findings will serve as a firm basis for the design and development of nanocarriers for pulmonary delivery.
Display omitted
•In vivo fate of inhaled nanocarriers (NC) were investigated in BALB/c mice.•Aggregation-caused quenching fluorescence probe was used to label the intact NC.•In vivo fate was monitored by in-vivo and ex-vivo fluorescence bioimaging.•Positive correlation between particle size and lung retention time of NC was shown.
Colloidal suspensions of EuCl2, EuBr2, and EuSO4 nanoparticles (<50 nm) in dodecane and EuSO4 in 70% H2SO4 were synthesized. Moving single-bubble sonoluminescence (m-SBSL) spectra were obtained for a ...bubble performing radial oscillations in these suspensions and translational motions at the antinode of a standing ultrasonic wave with a frequency of about 27 kHz. In these spectra (at a spectral resolution of 10 nm), the sono-excited luminescence bands of the Eu2+ ion were detected for the first time, coinciding in the shape and position of the maxima (404, 413, and 377 nm for EuCl2, EuBr2, and EuSO4, respectively) with the bands of Eu2+ located in a crystalline environment in the photoluminescence spectra of nanoparticles of europium salts in suspensions. The detected sonoluminescence of Eu2+ arises due to the injection of nanoparticles into a bubble deformed during motion and excitation of a lanthanide ion at the periphery of the bubble volume during collisions of nanoparticles with charged particles, mainly electrons, coming from a hot nonequilibrium plasma, which periodically arises during bubble compression. Evidence for the excitation of the europium ion in the bubble is the absence of its luminescence bands in the SBSL spectra of the translationally immobile bubble, in which nanoparticles are unlikely to enter. The nanoparticles that enter the bubble also undergo decomposition in the plasma into fragments, in particular, with the formation of Eu, Eu+ in the excited state. The atomic lines of these fragments were recorded for the first time in the m-SBSL spectrum with a resolution of 1 nm for a suspension of EuSO4 nanoparticles in 70% H2SO4. The resulting m-SBSL spectra will add to the library of characteristic spectra of objects of sonoluminescent spectroscopic analysis and will make it possible to identify and determine the content of Eu or Eu2+ in these objects.
Graphical abstract
This is a visual representation of the abstract.
The volume and morphology of calcium hydroxide (CH) precipitating from supersaturated solutions is monitored as a function of the concentration of either of two types of nanoparticles dispersed in ...the solution. The CH precipitated in the presence of sulfonated graphene nanosheets (SGN) had well-developed hexagonal platelet shapes, while that forming in the presence of cationic polyurethane nanospheres (PUC) tended to aggregate around the PUC and developed as spherulitic masses. The terminal CH platelet size in SGN suspensions was 8 μm; with increasing SGN dosage, the mean size increased to 23 μm. Taking into consideration complementary experimental measurements of isothermal adsorption and zeta potential, we speculate that calcium from the solution adsorbs on the surfaces of both SGN and PUC prior to nucleation of CH. Furthermore, molecular-scale mechanism indicated the interaction of Ca-Ocoo from PUC is stronger than Ca-Oso3 from SGN. Simultaneously the number of adsorbed calcium by PUC is roughly 3 times greater than for SGN, which is perfectly matched with the measured adsorption isotherm. Hopefully, this work can provide scientific guidance for hydration mechanism of cementitious materials in the presence of nanoparticles suspensions.
The mapping method represents a crucial factor affecting the rate of sentinel lymph node detection in breast cancer. We carried out this meta-analysis to assess the clinical utility of carbon ...nanoparticle suspensions (CNSs) in guiding sentinel lymph node biopsy (SLNB) for breast cancer patients.
Electronic databases, which comprised the China National Knowledge Infrastructure, the Wanfang electronic database, the Cochrane Library, EMBASE, and PubMed, were explored to identify relevant studies from database inception to July 2021 that studied the detection rate of CNSs-guided SLNB. A meta-analysis was performed to generate pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), a summary receiver operator characteristic curve (SROC), and a diagnostic odds ratio (DOR).
A total of 33 publications that enrolled 2,171 patients were analyzed. The pooled sensitivity, specificity, PLR, and NLR were 0.93 (95% CI: 0.91-0.95,
= 0.0%), 0.99 (95% CI: 0.98-0.99,
= 56.5%), 42.85 (95% CI: 29.73-61.77,
= 47.0%), and 0.09 (95% CI: 0.07-0.11,
= 0.0%), respectively. The area under the curve (AUC) of the SROC curve was 0.98. There were no significant differences when analyzed based on the dose and site of CNS injection. There was significant publication bias among the included publications based on Deeks' funnel plot Slope (Bias) = -7.35,
= 0.00. Nonetheless, the sensitivity analysis identified the results to be reliable and stable.
This meta-analysis highlights the accuracy and feasibility of using CNSs for SLNB in patients with breast cancer. Clinically, the identification and predictive values of CNSs as an optimal tracer for SLNB remains undisputed.
The potential eco-toxicity of nanosized titanium dioxide (TiO(2)), silicon dioxide (SiO(2)), and zinc oxide (ZnO) water suspensions was investigated using Gram-positive Bacillus subtilis and ...Gram-negative Escherichia coli as test organisms. These three photosensitive nanomaterials were harmful to varying degrees, with antibacterial activity increasing with particle concentration. Antibacterial activity generally increased from SiO(2) to TiO(2) to ZnO, and B. subtilis was most susceptible to their effects. Advertised nanoparticle size did not correspond to true particle size. Apparently, aggregation produced similarly sized particles that had similar antibacterial activity at a given concentration. The presence of light was a significant factor under most conditions tested, presumably due to its role in promoting generation of reactive oxygen species (ROS). However, bacterial growth inhibition was also observed under dark conditions, indicating that undetermined mechanisms additional to photocatalytic ROS production were responsible for toxicity. These results highlight the need for caution during the use and disposal of such manufactured nanomaterials to prevent unintended environmental impacts, as well as the importance of further research on the mechanisms and factors that increase toxicity to enhance risk management.
•Effect of pH on particle agglomeration and optical properties NPSs are investigated experimentally and theoretically.•The dependent/independent scattering and their boundaries are investigated and ...demarcated for different conditions.•Effect of particle size distribution on the scattering coefficient is studied to account the impact of compact particle agglomerates.•In comparison to the other parameters, pH was found to be a dominant effect on the dependent/independent scattering in NPSs.
Nanoparticle suspensions (NPSs) are used extensively to improve the thermal efficiency of different engineering systems because of their unique thermo-optical properties. NPSs have also been uses in coatings as they improve or alter the appearance of objects, where radiative and optical properties play a significant role. In all these applications, pH of a suspension has a significant impact on the particle agglomeration behaviour, and consequently on optical properties and then on radiative heat transfer. In the present study, the effect of pH on the agglomeration of TiO2 NPSs is investigated. For this purpose, both the experimental and theoretical studies were carried out. In the experiments, the particle size distribution and the average (effective) particle size for the NPSs in different conditions (the pH and particle volume fraction) were measured using the dynamic light scattering (DLS) technique. The effects of different particle agglomerates under different pH values on the dependent/independent scattering are explored and the corresponding regimes are demarked for different conditions. The effects of particle agglomeration, particle size distribution and their contributions to the scattering coefficients are obtained using the UV–Vis-NIR spectroscopy technique.
The results show that pH may have significant effect on the optical properties involving NPSs. Adjusting the pH value based on the isoelectric point of the nanoparticle is an efficient method when specific radiative properties are required for specific applications. Different regimes of the dependent/independent scattering can be obtained by changing the pH of a particular nanoparticle suspension.
Intensity of the bands of upconversion luminescence of β-NaYF
4
:Yb
3+
/Tm
3+
nanopowders in DMSO suspensions vs intensity of exciting radiation were analyzed. Ranges of changes in the intensity of ...excitation have been established, in which either the processes of energy transfer from the sensitizer ion to the activator ion or the decay of intermediate levels of activator ions dominate.
We study rheological and rheo-optical properties of suspensions of anisometric pigment particles in a non-polar fluid. Different rheological regimes from the dilute regime to an orientationally ...arrested gel state were characterized and compared with existing theoretical models. We demonstrate the intricate flow behaviour in a wide range of volume fractions. A unique combination of the optical properties of the particles results in a giant rheo-optical effect: an unprecedentedly large shear stress-induced birefringence was found in the isotropic range, exhibiting a sharp pre-transitional behaviour.
Display omitted
•Suspensions of anisometric pigment nanoparticles show complex rheology.•Our studies span from dilute to concentrated suspensions.•A giant effective stress-optical coefficient is found even at low concentrations.•Concentrated suspensions exhibit an orientationally arrested nematic-like gel state.
An experimental investigation of nanoparticle suspensions utilized as nano-enhanced phase change materials (NePCM) was conducted. Cyclohexane-based NePCM samples were prepared with copper oxide ...nanoparticles with various mass concentrations. Thermal conductivity of the samples was measured using the transient plane source technique for both liquid and solid phases at multiple temperatures. Unidirectional freezing of the samples was investigated and the experimental results were compared with the numerical predictions of a one-dimensional Stefan model proposed earlier by the authors. It was shown that the measured thermal conductivity for samples in their liquid phase is enhanced with increasing concentration of nanoparticles, whereas the data in the solid phase exhibit a non-monotonic enhancement when the concentration is greater than 2%. Unidirectional freezing was found to be expedited by up to 5.2%.
► Cyclohexane enhanced by copper oxide nanoparticles as novel phase change materials. ► Enhanced thermal conductivity measured in both liquid and solid phases. ► Non-monotonic enhancement of thermal conductivity observed in the solid phase. ► Unidirectional freezing observed to be expedited by up to 5.2%. ► Non-monotonic expediting of freezing observed and verified by the Stefan model.
In this article, a practical procedure for absolute intensity calibration for small‐angle scattering (SAXS) studies on liquid microjets is established. A gold nanoparticle suspension is used as ...standard so that the intercept at Q = 0 of the SAXS scattering curve provides a scaling reference. In order to obtain the most precise extrapolation at Q = 0, an extension of the Guinier approximation has been used, with a second‐order term in the fit that adapts to a larger Q range.
A gold nanoparticle suspension is established as an absolute intensity standard for small‐angle X‐ray scattering experiments on dilute liquid suspensions. An extension of the Guinier method was used to achieve maximum precision on the extrapolated intercept at Q = 0.
PDF
