Polyhedral Shape Research Articles

3D RNA-scaffolded wireframe origami

Hybrid RNA:DNA origami, in which a long RNA scaffold strand folds into a target nanostructure via thermal annealing with complementary DNA oligos, has only been explored to a limited extent despite its unique potential for biomedical delivery of mRNA, tertiary structure characterization of long RNAs, and fabrication of artificial ribozymes. Here, we investigate design principles of three-dimensional wireframe RNA-scaffolded origami rendered as polyhedra composed of dual-duplex edges. We computationally design, fabricate, and characterize tetrahedra folded from an EGFP-encoding messenger RNA and de Bruijn sequences, an octahedron folded with M13 transcript RNA, and an octahedron and pentagonal bipyramids folded with 23S ribosomal RNA, demonstrating the ability to make diverse polyhedral shapes with distinct structural and functional RNA scaffolds. We characterize secondary and tertiary structures using dimethyl sulfate mutational profiling and cryo-electron microscopy, revealing insight into both global and local, base-level structures of origami. Our top-down sequence design strategy enables the use of long RNAs as functional scaffolds for complex wireframe origami.

Synthesis and characterization of the new carbacylamidophosphate based rare earth tetrakis-complexes NEt4[LnL4]. Effect of the ligand nitro group on luminescence of Eu3+ and Tb3+.

O,O′-dimethyl-N-(3-nitrobenzoyl)amidophosphate (HL) was synthesized, structurally characterized, tested as ligand to obtain lanthanide complexes NEt4[LnL4] (Ln = La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Er3+, Y3+) and as a sensitizer of Eu3+ and Tb3+ luminescence. It was shown that besides of typical for carbacylamidophosphates intermolecular contacts, the electrostatic interactions N∙∙∙O of the length 2.936 Å exist in the crystal of NEt4[EuL4] and influence on both the crystal packing and the lanthanide polyhedron shape. In the structure of the complex anion, two pairs of symmetry-related ligands differ in configuration (syn- or anti-) of nitro groups with respect to the carbonyl groups. The obtained complexes were found to be thermally stable to near 200 °C. Luminescent studies have shown that excitation energy is dissipated, which prevents ligands from efficient luminescence sensitization of europium and terbium.

Effect of temperature and presence of minor amount of metal on porous carbon materials derived from ZIF8 pyrolysis for electrocatalysis

ZIF8 without and with adsorption of minor amounts of Co precursor have been pyrolized at different temperatures studying systematically the effect of carbonization temperature on the texture, composition and ORR performance both in acidic and basic media. The increase of pyrolysis temperature diminished the N content but increased the graphitic character. The trade-off between these two parameters in metal-free electrocatalysts resulted in an improvement of ORR performance, which is met for the highest pyrolysis temperature of 1000 ºC. Moreover, the adsorption of minor amount of Co precursor enhanced further the ORR performance, increased the graphitic character and the porosity of the resulting carbon material. Morphologically, these carbon materials kept the polyhedral shape of ZIF8 and were covered by graphitic nanostructures devoid of metal nanoparticles. Co metal catalysed the growth of these graphitic nanostructures and concomitantly is stabilized as monoatomic Co-Nx-C species preventing the agglomeration as metal nanoparticles. Therefore, the need of an acid washing step is avoided, which is usually necessary in the carbonization of other metal containing MOFs.

Preparation of N and Ce Co-doped MIL-101(Fe) Heterogeneous Catalysts for Efficient Electro-Fenton Oxidation

Design and synthesis of high-efficiency and stable heterogeneous catalysts for the electro-Fenton process remain challenging. In this study, a co-doped Ce and N metal–organic framework MIL-101(Fe) heterogeneous catalyst (Ce/N-MIL-101(Fe) was synthesized by a facile one-step solvothermal method. Polyvinyl pyrrolidone played dual roles during the fabrication process, which not only acted as a nitrogen source for doping but also prevented MIL-101(Fe) molecules from aggregating and reinforcing the formation crystal with a complete polyhedral crystal shape. The introduction of Ce significantly enhanced the density of active sites and promoted the Fe3+/Fe2+ cycle of the reaction system. Owing to the specific structure and properties, the rate of electron transfer in the catalytic process was significantly promoted. The synthesized Ce/N-MIL-101(Fe) catalyst exhibited a high degradation rate for dyes (>98%) with competitive stability and reusability. Moreover, compared with common electro-Fenton catalysts usually operated in a limited pH range of 3.0–6.0, the working pH range of Ce/N-MIL-101(Fe) was widened up to 10.0. The design concept for producing abundant active sites with co-doping into frameworks can be extended to more heterogeneous electro-Fenton catalysts constituted by other porous materials.

Preferential binding effect of cocoa powder on fried donuts through the electrostatic coating method

SummaryDonuts are the snack food which are coated with powdered seasonings to increase flavour and shelf life. In this regard, electrostatic coating is being developed for efficient coating method and to overcome uneven coating and dust production. During electrostatic coating, charged powder particles produce even coating on target surface. Electrostatic coating of cocoa powder was carried out at high voltage (0–20 kV) and the results were compared to manually coated fried donuts. Cocoa powder particles had irregular polygonal and polyhedral shapes with an average particle diameter (18.12 ± 0.91 μm). The values of adhesion, dust reduction and transfer efficiency were higher at 15 kV and lower values at 0 kV. Coated sample at 15 kV showed the lowest change in weight loss (05.99%) during the storage. Due to an even coating of cocoa powder at 15 kV, donuts exhibited pleasant taste, uniform and dark brown colour. While, shelf life of coated donuts at 15 kV lasts up to 29 days as compared to other samples. It can be concluded from the results that the electrostatic coating of donuts with cocoa powder was best at 15 kV with higher transfer efficiency, adhesion and consumer acceptability.

Crystallographic-Morphological Connections in Star Shaped Metal-Organic Frameworks.

The symmetry of a crystal's morphology usually reflects the symmetry of the crystallographic packing. For single crystals, the space and point groups allow only a limited number of mathematical descriptions of the morphology (forms), all of which are convex polyhedrons. In contrast, concave polyhedrons are a hallmark of twinning and polycrystallinity and are typically inconsistent with single crystallinity. Here we report a new type of structure: a concave polyhedron shape single crystal having a multidomain appearance and a rare space group (P622). Despite these unusual structural features, the hexagonal symmetry is revealed at the morphological levels.

Buckling performance of the encased functionally graded porous composite liner with polyhedral shapes reinforced by graphene platelets under external pressure

This paper aims to rehabilitate the deteriorated pipeline by using a novel thin-walled polyhedral liner with functionally graded porous (FGP) metal and graphene platelets (GPLs). The liner may buckle since the underground water flows into the damaged pipeline and hydrostatic pressure develops at the outer surface of the liner. Symmetrical distributions are applied to both the pores and the GPLs on the cross-section of the liner. A polyhedral profile is developed to improve flexural rigidity. By introducing radial displacement formulae and thin-walled shell theory, the expression of the potential energy is accomplished, by differentiating which, two equilibrium equations are expressed explicitly. Solving these two equations yields the critical buckling pressure. Subsequently, comparison studies are achieved when the polyhedral liner reduces to a conventional circular liner. The result indicates the present derivation is highly consistent with the other closed-form solutions for a circular liner. In addition, the buckling pressure may depend highly on some key parameters, such as the content of the pores, the GPLs, the polyhedral shapes, etc. These parameters are analyzed by parametric evaluations. Finally, an improvement factor is introduced to explore the effect of the polyhedral shapes on the buckling pressure of the encased thin-walled polyhedral FGP-GPLs liner.

Segregation Modeling in Stockpile Using Discrete Element Method

During stockpile feeding, the small particles migrate to the center of the stock while large particles end up around the edges. This phenomenon influences how the mineral is fragmented in the subsequent stages of size reduction. In this study, the primary variables involved in this phenomenon were studied using the discrete element to simulate particle segregation. Results show that the ratio between coarse and fine particles strongly affects particle segregation. The segregation phenomenon was not observed when there were fewer coarse particles in the mix. The feeding height was also found to influence segregation and to affect the angles of repose and dumping. Finally, the rounded polyhedral shape of particles generated the simulation performance most similar to actual particle segregation based on a case study analyzed.

Characterization of precipitation, evolution, and growth of MnS inclusions in medium/high manganese steel during solidification process

MnS as a main manganese-containing inclusion in medium/high manganese steel, which can be determined to the mechanical properties of steel. However, the precipitation and evolution mechanism of MnS in medium/high manganese steel is still unclear due to the special solidification properties and element segregation behavior. Hence, the effects of sulfur content, manganese content and cooling rate on the precipitation, evolution, and growth behavior of MnS inclusions in medium/high manganese are various experimentally characterized and thermodynamically elucidated in the present work. The results of 2D and 3D observation indicated that the morphology of MnS in medium manganese steel were transformed from globular and spindle-like (type I MnS) into large-sized rods (type II MnS) and dendritic (type D MnS), when sulfur content was increased from 78 ppm to 1578 ppm. Particularly, the spatial distribution and structure of MnS inclusions are elaborated in detail through X-ray micro-CT observations, which are discussed by defining the quantitative topography parameters and statistical analysis. Based on in situ CSLM observations, MnS precipitation path in high sulfur medium manganese steel was monitored as L → (L + δ + MnS) → (δ + MnS) → (δ + γ + MnS) → (γ + MnS) → (α + γ + MnS) → (α+MnS). Simultaneously, the Scheil-solidification calculations demonstrated that MnS is precipitated at the interdendritic region where the solid-liquid states are coexisted, which is caused by the segregation of sulfur and manganese. Moreover, increasing sulfur content generates the earlier precipitation, and leads to the significant increase in the number and size of MnS inclusions. Besides, the increase of manganese content promotes the transition of MnS from globular to polyhedral shape, which is attributed to the dissociative eutectic reaction of MnS formation preferentially takes place earlier in case of high manganese steel. It is also found that the decreasing of cooling rate and increasing the manganese content tends to increase the number and size of MnS inclusions, which is resulted from the long growth times of high manganese steel induced by large solid-liquid temperature differences. This work provides a systematic understanding of the precipitation and evolution of MnS inclusions in medium/high manganese steel.

Facile synthesis and characterization of β-cobalt hydroxide/hydrohausmannite/ramsdellitee/spertiniite and tenorite/cobalt manganese oxide/manganese oxide as novel nanocomposites for efficient photocatalytic degradation of methylene blue dye

In this paper, our research team has synthesized new nanocomposites by simple precipitation/ignition method and using low-cost chemicals. Hence, β-cobalt hydroxide/hydrohausmannite/ramsdellitee/spertiniite and tenorite/cobalt manganese oxide/manganese oxide new nanocomposites were synthesized by precipitation of Mn(II)/Co(II)/Cu(II) solution using sodium hydroxide and ignition of precipitate at 700 °C for 3 hrs, respectively. The synthesized nanocomposites were characterized using different instruments such as energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), nitrogen gas sorption analyzer, and UV–vis spectrophotometer. Energy dispersive X-ray analysis revealed that the nanocomposite formed as a result of precipitation consists of copper, cobalt, manganese, and oxygen where the weight percentages are equal to 31.73, 27.01, 17.26, and 24 %, respectively. Also, the nanocomposite formed as a result of ignition consists of copper, cobalt, manganese, and oxygen where the weight percentages are equal to 31.26, 23.87, 14.56, and 30.31 %, respectively. Transmission electron microscope revealed that the nanocomposites formed as a result of precipitation and ignition consist of polyhedral and spherical shapes with an average diameter of 34.50 and 28.56 nm, respectively. The synthesized nanocomposites were used as new photocatalysts for the efficient degradation of methylene blue dye. 0.05 g of the synthesized nanocomposites degrade 100 % of 50 mL of 15 mg/L of methylene blue dye solution within 25 min in the presence of H2O2 under UV light.

Phase Control of Colloid-like Block Copolymer Micelles by Tuning Size Distribution via Thermal Processing

The formation of a Frank–Kasper (FK) phase in a one-component block copolymer (bcp) has been attributed to the sufficiently large conformational asymmetry parameter that leads to the deformation of the micellar core into the polyhedral shape templated by the Voronoi cells for relieving the packing frustration of the coronal blocks. Here we present the insight into the evolution of body-centered cubic (BCC) and Laves C14 phases from the corresponding metastable liquidlike packing (LLP) phases in a conformationally symmetric poly(2-vinylpyridine)-block-poly(dimethylsiloxane) (P2VP-b-PDMS) forming the colloid-like micelle with a hard P2VP core and a soft PDMS corona at the temperature of micelle ordering (Tgcorona < Ta < Tgcore). Different thermal processing conditions were applied to produce four distinct types LLP phase characterized by different average micelle size and size dispersity. The LLP phase was found to transform to BCC, C14 and a reorganized LLP phase with increasing polydispersity of particle size, showing the existence of a proper range of size dispersity for the formation of the Laves phase. The real-space analysis of the local environments of the particles revealed that the C14 phase can accommodate the particles with a broader range of interparticle distance and a less uniform local environment, such that the PDMS coronal blocks of the micelles with greater size dispersity suffered a lower degree of packing frustration when they organized into a C14 lattice. In view of the colloid-like nature of the micelle, a size fractionation process found in the crystallization of polydisperse colloidal particles was proposed as the mechanism for directing the effective development of C14 phase from the LLP phase. Due to the metastable nature of the ordered phases, their order–disorder transition temperatures were found to depend strongly on the structures of the LLP phases from which they developed and a strong memory effect underlying the phase transitions was identified.

Simple preparation and efficient fluoride removal of La anchored Zr-based metal–organic framework adsorbent

Excess fluoride in drinking water from groundwater can cause dental and skeletal fluorosis affecting millions of people worldwide. Adsorption is an appealing strategy for defluoridation due to its simple operation and environmental friendliness. However, conventional adsorbents exhibit low adsorption capacity because few exposed active sites. In this work, La anchored Zr-based metal-organic framework (La-UiO-66-(COOH)2) adsorbent with dual-metal sites was designed and synthesized to remove fluoride effectively. The doping of La(III) using uncoordinated carboxyl group of UiO-66-(COOH)2 increased the adsorption capacity. The morphology, composition, structure, surface area, and thermal stability of adsorbent were carefully characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrometer (EDX), fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) techniques. The adsorbent is a polyhedral shape with aggregated and smaller crystalline particles and La is uniformly distributed over the adsorbent, favoring the effective adsorption of fluoride. La-UiO-66-(COOH)2 showed excellent adsorption performance in a wide pH range of 3–9, and the maximum adsorption capacity was 57.23 mg g−1. The fluoride removal rate of as-prepared adsorbent reached as high as 87 % within 5 min. The adsorption process conformed to the pseudo-second-order equation model and the Freundlich isotherm model. Thermodynamic research indicated that the adsorption process was spontaneous and endothermic. After four adsorption-desorption cycles, the fluoride removal rate of the adsorbent was still retained at 79.7%. The design of dual-metal site adsorbents provides a potential strategy for highly efficient removal of fluoride.

Influence of structure and magnetic properties of surface modified nanoparticles for hyperthermia application

We report the study of CoFe2O4 with biopolymers (chitosan and dextran), synthesized via a solvothermal method. The formation of the CoFe2O4 spinel phase has been validated using XRD and Rietveld analyses. The pattern of polyhedral and spherical shapes was observed for uncoated and coated samples using TEM. Mössbauer's study revealed the mixed spinel nature of the nanoparticles, in which Fe3+ and Co2+ ions are distributed in both tetrahedral and octahedral sites. The M − H curves obtained at ambient temperature show the typical ferromagnetic behavior for all the magnetic nanoparticles. The surface modification influences the specific loss power (SLP) value of the magnetic nanoparticles. Furthermore, our study revealed that dipole-dipole interactions are responsible for the self-heating behavior. SLP values demonstrated non-monotonic behavior for all the nanoparticle samples, implying that both Néel and Brownian relaxation is the responsible for heat generation in a high viscosity medium.

Atomistic Simulations of the Elastic Compression of Platinum Nanoparticles

The elastic behavior of nanoparticles depends strongly on particle shape, size, and crystallographic orientation. Many prior investigations have characterized the elastic modulus of nanoscale particles using experiments or simulations; however their reported values vary widely depending on the methods for measurement and calculation. To understand these discrepancies, we used classical molecular dynamics simulation to model the compression of platinum nanoparticles with two different polyhedral shapes and a range of sizes from 4 to 20 nm, loaded in two different crystal orientations. Multiple standard methods were used to calculate the elastic modulus from stress-vs-strain data for each nanoparticle. The magnitudes and particle-size dependence of the resulting moduli varied with calculation method and, even for larger nanoparticles where bulk-like behavior may be expected, the effective elastic modulus depended strongly on shape and orientation. Analysis of per-atom stress distributions indicated that the shape- and orientation-dependence arise due to stress triaxiality and inhomogeneity across the particle. When the effective elastic modulus was recalculated using a representative volume element in the center of a large nanoparticle, the elastic modulus had the expected value for each orientation and was shape independent. It is only for single-digit nanoparticles that meaningful differences emerged, where even the very center of the particle had a lower modulus due to the effect of the surface. These findings provide better understanding of the elastic properties of nanoparticles and disentangle geometric contributions (such as stress triaxiality and spatial inhomogeneity) from true changes in elastic properties of the nanoscale material.

Facile synthesis and characterization of copper oxalate/cobalt oxalate/manganese oxalate and copper oxide/cobalt manganese oxide/manganese oxide as new nanocomposites for efficient photocatalytic degradation of malachite green dye

Scientists seek to synthesize new catalysts with simple methods to treat water pollution from organic dyes using photocatalytic degradation technology. In this technology, when light falls on the catalyst, the produced hydroxyl free radicals convert the dye into non-toxic gases such as CO2 and H2O.So, in this work, copper oxalate/cobalt oxalate/manganese oxalate (Abbreviated as P1) and copper oxide/cobalt manganese oxide/manganese oxide (Abbreviated as P2) new nanocomposites were fabricated via precipitation of Cu2+/Co2+/Mn2+ solution using oxalic acid and ignition of precipitate at 550 °C for 4 hrs, respectively. Some tools, involving X-ray diffraction (XRD), UV–vis spectrophotometer, energy dispersive X-ray spectroscopy (EDX), nitrogen gas sorption analyzer, transmission electron microscope (TEM), and field emission scanning electron microscope (FE-SEM), were used for characterizing the fabricated nanocomposites. The EDX spectra confirmed that the P1 composite consist of C (26.28 %), oxygen (46.66 %), manganese (7.27 %), cobalt (7.59 %), and copper (12.20 %). Also, the P2 composite consist of oxygen (8.23 %), manganese (31.34 %), cobalt (27.19 %), and copper (33.24 %). A transmission electron microscope shows that the P1 and P2 composites consist of polyhedral and spherical shapes with an average diameter of 28.13 and 14.37 nm, respectively. The BET surface area, average pore size, and total pore volume of the P1 composite are 29.0725 m2/g, 2.0749 nm, and 0.0302 cc/g, respectively. Besides, the BET surface area, average pore size, and total pore volume of the P2 composite are 58.1088 m2/g, 1.6087 nm, 0.0467 cc/g, respectively. 60 mg of the synthesized nanocomposites completely decompose 60 mL of 15 mg/L of malachite green dye solution within 20 min in the presence of hydrogen peroxide and UV light. The synthesized catalysts outperformed many other catalysts published in previous studies.

Magnetic Anomalies Caused by 3D Polyhedral Structures With Arbitrary Polynomial Magnetization

AbstractMagnetization is a natural property of magnetic materials which is widely used to analyze paramagnetic data, locate unexploded ordnance, explore mineral deposits and gas resources, and image anomalous magnetic structures in the Earth's crust. An essential and challenging task is to compute accurate magnetic anomalies caused by realistic magnetic 3D structures. In this study, for the first time, we derive the analytical expressions of magnetic potential, magnetic field and magnetic gradient tensor for magnetic materials with 3D polyhedral shapes and magnetization vectors that may vary in the space following polynomial trends. The order of polynomials can vary from one to high positive integers in both horizontal and vertical directions. Synthetic and realistic deposit models are used to validate our analytical solutions. We release the open‐source code in C++.

Facile synthesis of copper carbonate/cobalt carbonate/manganese carbonate and copper oxide/cobalt manganese oxide/manganese oxide as novel nanocomposites for efficient photocatalytic degradation of crystal violet dye

ABSTRACT In this work, copper carbonate/cobalt carbonate/manganese carbonate and copper oxide/cobalt manganese oxide/manganese oxide new nanocomposites were fabricated via precipitation of Cu(II)/Co(II)/Mn(II) solution using sodium carbonate and ignition of precipitate at 600°C for 3 h, respectively. Several instruments, including UV–Vis spectrophotometer, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), nitrogen gas sorption analyser, and field emission scanning electron microscope (FE-SEM), were used to characterise the fabricated nanocomposites. Energy dispersive X-ray investigation confirmed that the composite produced owing to precipitation by sodium carbonate comprises carbon, oxygen, manganese, cobalt, and copper where the weight percentages are equal to 27.15, 52.49, 5.59, 5.75, and 9.02%, respectively. In addition, the composite produced owing to ignition at 600°C for 3 h comprises oxygen, manganese, cobalt, and copper where the weight percentages are equal to 8.62, 31.50, 38.58, and 21.30%, respectively. Transmission electron microscope examination confirmed that the composites produced owing to precipitation by sodium carbonate and ignition at 600°C for 3 h comprise polyhedral and spherical shapes with an average diameter of 36.85 and 22.34 nm, respectively. The BET surface area, average pore size, and total pore volume of the composite produced owing to precipitation by sodium carbonate are 29.8662 m2/g, 2.1634 nm, and 0.0323 cc/g, respectively. In addition, the BET surface area, average pore size, and total pore volume of the composite produced owing to ignition at 600°C for 3 h are 33.3714 m2/g, 5.2308 nm, and 0.0873 cc/g, respectively. 0.06 g of the fabricated nanocomposites degrade 100% of 60 mL of 15 mg/L of crystal violet dye solution within 20 min in the presence of hydrogen peroxide under UV irradiation.

Exploring the impact of nickel doping on the structure and low-temperature magnetic features of cobalt nano-spinel ferrite

Tailoring the magnetic features of cobalt ferrite nanoparticles (NPs) has been achieved via varying the doping percent of nickel. The nickel-substituted cobalt ferrite NPs NixCo1-xFe2O4 (0 ≤ x ≤ 1.0) are constructed by the eco-friendly coprecipitation method. The formation of a nearly cubic single-phase spinel frame is assured by the analysis of XRD data. Moreover, the Rietveld analysis based on structure refinement is implemented in this study to precisely determine the microstructural parameters and estimate the cation distribution. A linear drop-in lattice constant with boosting the Ni2+ ion percent is acclaimed, in regard to Vegard's law. The creation of nanoparticles that are nearly spherical along with polyhedron shape and have a diameter of (about 39–45 nm) has been affirmed by utilizing high-resolution transmission electron microscopy (HRTEM). Also, the crystalline essence of the formed nanoparticles has been declared by selective area electron diffraction (SAED). The magnetic properties have been collected from the hysteresis loops and FC–ZFC curves. These curves have been tweaked as a function of low-temperature from 5 K up to 300 K and in the existence of an external magnetic field (± 70KOe). The magnetization curves revealed that CoFe2O4 (NPs) correspond to the hard ferrimagnetic material, whereas NiFe2O4 (NPs) matched well with identical soft ferrimagnetic material. Also, the divergence betwixt the theoretical and experimental values of the magnetic moment is well explained by the model of "Random Canting of Spins, (RCS)". In addition, a remarkable reduction is found in the recorded values of magnetic parameters by increasing Ni2+ content and decreasing the temperature towards 5 K. These findings imply the potential of Ni2+ ions doping in enhancing the magnetic properties of cobalt ferrite for vast magnetic applications.

Engineering Lipid Nanoparticles for Enhanced Intracellular Delivery of mRNA through Inhalation.

Despite lipid nanoparticles' (LNPs) success in the effective and safe delivery of mRNA vaccines, an inhalation-based mRNA therapy for lung diseases remains challenging. LNPs tend to disintegrate due to shear stress during aerosolization, leading to ineffective delivery. Therefore, LNPs need to remain stable through the process of nebulization and mucus penetration, yet labile enough for endosomal escape. To meet these opposing needs, we utilized PEG lipid to enhance the surficial stability of LNPs with the inclusion of a cholesterol analog, β-sitosterol, to improve endosomal escape. Increased PEG concentrations in LNPs enhanced the shear resistance and mucus penetration, while β-sitosterol provided LNPs with a polyhedral shape, facilitating endosomal escape. The optimized LNPs exhibited a uniform particle distribution, a polyhedral morphology, and a rapid mucosal diffusion with enhanced gene transfection. Inhaled LNPs led to localized protein production in the mouse lung without pulmonary or systemic toxicity. Repeated administration of these LNPs led to sustained protein production in the lungs. Lastly, mRNA encoding the cystic fibrosis transmembrane conductance regulator (CFTR) was delivered after nebulization to a CFTR-deficient animal model, resulting in the pulmonary expression of this therapeutic protein. This study demonstrated the rational design approach for clinical translation of inhalable LNP-based mRNA therapies.

Liquid–vapor coexistence of vibrating polygonal and polyhedral molecules composed of hard spheres interacting with square well potentials

Liquid–vapor coexistence is calculated via molecular dynamics for a variety of polygonal shaped molecules and for the platonic polyhedra. Tangential hard spheres interacting with an attractive square-well potential form the molecules. Spheres within the molecules are bonded together with in a small size infinitely high square-wells to keep them vibrating at the appropriate intra molecular distance. The total density of the system is near to its critical value. Liquid–vapor coexistence is obtained with the process of spinodal decomposition. Orthobaric densities, surface tensions, vapor pressures and Interfacial widths are calculated along with critical temperatures and densities. These polygonal and polyhedral shapes can be used in the development of a theoretical equation of state.