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Dissipative particle dynamics simulation is used to reveal the loading/release of small interfering RNA (siRNA) in pH‐sensitive polymers/gold nanoparticles (AuNPs) polyplex. The conformation dynamics of these polyplex at various Au/siRNA mass ratios, the original AuNPs sizes, polymer types, and pH values are simulated and compared to experimental results. At neutral conditions (pH = 7.4), spherical micelles with a multilayer structure are formed in siRNA/polyethyleneimine/cis‐aconitic anhydride functionalized poly(allylamine)/polyethyleneimine/11‐mercaptoundecanoic acid‐gold nanoparticle (siRNA/PEI/PAH‐Cit/PEI/MUA‐AuNP) polyplex. Large polyplex are obtained with high Au/siRNA mass ratio and/or small original AuNPs size. The release dynamics of siRNA from AuNPs‐polyplex systems were also simulated in the intracellular environment (pH = 5.0). A swelling‐demicellization‐releasing mechanism is followed while the release of siRNA is found much faster for polyplex involving charge‐reversal PAH‐Cit. These findings are qualitatively consistent with the experimental results and may provide valuable guidance in later design and optimization of delivery carriers for siRNA or other molecule probes. © 2017 American Institute of Chemical Engineers AIChE J, 64: 810–821, 2018 [ABSTRACT FROM AUTHOR]

A slice sample is cut and saturated with 10% concentration sodium chloride solution. The saturated slice sample and 10% concentration sodium chloride solution are then connected in a continuous ring mould as a secondary coil in a non-contact electrical resistivity apparatus. The chloride diffusion coefficient of hardened paste and concrete is calculated from the measured electrical resistivity of the slice sample based on the Nernst-Einstein equation. There is a bilinear relationship between the chloride diffusion coefficient and the reciprocal of time logarithm for different hydration periods of the samples. The slope is higher before 72 h than after 72 h. Parameter is obtained to describe connectivity for migration of ions. There is a good linear correlation of the chloride diffusion coefficient between concrete with an aggregate volume fraction 65% and paste with the same water-cement ratio, showing that the chloride diffusion coefficient of a concrete is a function of the chloride diffusion coefficient of a paste with the same water-cement ratio and the paste matrix volume fraction (1 − ) inside the concrete. [ABSTRACT FROM AUTHOR]

A novel amphoteric polycarboxylic (APC) acid-based superplasticizer was prepared by solution copolymerization from maleic anhydride, allyl polyethylene glycol, and methacryloxyethyltrimethyl ammonium chloride (DMC). The cationic monomer DMC was introduced for improving the performances of sulfoaluminate cement (SAC) with APC. The condition on preparation of APC was determined by the orthogonal experiment, and the performances of fresh and hardened superplasticized mortars were assessed. APC was characterized by FTIR spectra. Adsorption amount and dispersing effectiveness of APC were also investigated. Results indicated that APC could improve the fluidity and enhance the mechanical performances of SAC mortars. Adsorption amount of APC in SAC is large. Compared with an anionic PC superplasticizer and a commercial superplasticizer Visco Crete 3390, APC has the better performance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Lead halide perovskites have generated considerable interest in solar cell, sensor, and electronics applications. While great focus has been placed on (CH 3 NH 3 )PbI 3 , an organic-inorganic hybrid perovskite, comparatively little work has been done to understand some of its existing crystal phases and analogous materials after substituting with Sn and/or other halogens in the framework. Here, first-principles density functional theory calculations are performed to comprehensively evaluate the electronic and optical properties of (CH 3 NH 3 )BX 3 (B = Sn, Pb; X = F, Cl, Br, I) in a low-temperature orthorhombic phase. Bulk modulus, electronic structures, and several optical properties of these perovskite systems are further calculated. The obtained results are first confirmed by comparing with existing perovskite systems in literature. The shifting trends on those physical properties when extending to other barely studied systems of (CH 3 NH 3 )BX 3 is further revealed. The band gap of these perovskites is found to decrease when varying halogen anion in "X" sites from F to I, and/or substituting Pb cations with Sn in "B" sites. Notably, the less toxic Sn-containing perovskites, (CH 3 NH 3 )SnI 3 in particular, display higher absorption coefficients in the visible light range than their Pb-containing counterparts. An orthorhombic (CH 3 NH 3 )PbF 3 is predicted to exist at low temperature, and adsorb strongly UV energy. Our systematical examination efforts on the two groups of perovskites provide valuable physical insights in these materials, and the accompanied new findings warrant further investigation on such subjects., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Lead halide perovskites are excellent candidates for photoelectronic and photovoltaic applications, but the toxicity from lead is extremely concerning. Recently, Sn-based zero-dimensional lead-free perovskites synthesized using solid-state reaction techniques have become a new focus in the field. Here, we report a simple room temperature antisolvent method for the synthesis of all inorganic lead-free green emissive Cs 4 SnBr 6 (emission at 524 nm) and cyan emissive Cs 3 KSnBr 6 (emission at 500 nm) zero-dimensional perovskites. Their photoluminescence quantum yields reach 20% and 35%, respectively. In addition, they maintain their emission for 46 and 55 h in the air, respectively, compared to only 5 min of CsSnBr 3 . This method provides a convenient way to do the research and apply these highly emissive perovskites.

In this study, we reported a new micropillar array electroporation (MAE) platform to accomplish large-scale, size-specific DNA and RNA delivery to mammalian cells for nanomedicine. By introducing well-patterned micropillar array on the electrode surface, the number of micropillars each cell faces varies with the surface area of cell membrane or the size of cells. In this way, cell size-specific electroporation is conveniently done on a large population of cells in despite of their random locations between the two electrodes. The enhancement of this MAE system on the delivery of DNA and RNA probes without sacrifice of cell viability is demonstrated with an average increase of 2.5 to 3-fold on the transfection efficiency of DNA plasmids and additional knockdown of the targeted protein 10-55% more in siRNA delivery when compared to that using a commercial electroporation system. This MAE system works like many single cell electroporation are carried out in parallel, showing potential to bridge the gap between single cell electrophysiology study and in vitro electroporation to a large population of cells.

Colloidal lead halide perovskite nanocrystals (NCs) have high tunability in the visible light region and high photoluminescence quantum yields (PL QYs) for green and red emissions, but bright blue emission is still a challenge. Super small CsPbBr 3 perovskite NCs emit blue light around 460 nm with a narrow peak width, and they do not have the problem of phase separation like their Cl-Br counterparts. However, the blue emission from super small CsPbBr 3 NCs easily becomes green over time, and their PL QY is still low. The doping of Sb 3+ ions successfully reduced the surface energy, improved the lattice energy, passivated the defect states below the band gap, eventually boosted the PL QY of blue emission to 73.8%, and resulted in better spectral stability even at elevated temperatures in solution (40-100 °C). Its CIE coordinates were (0.14, 0.06), which are close to the primary blue color (0.155, 0.070) according to the NTSC TV color standard.

Electroporation serves as an attractive nonviral gene delivery approach for its effectiveness, operational simplicity, and no restrictions of probe or cell type. The commercial electroporation systems have been widely adopted in research and clinics with protocols usually compromising appropriate transfection efficiency and cell viability. By introducing gold nanoparticles (AuNPs), we demonstrated greatly enhanced performance of electroporation from two aspects: the highly conductive, naked AuNPs help reduce the potential drop consumed by the electroporation solution so that the majority of the applied voltage of an electric pulse is truly imposed on cells with enhanced field strength; AuNPs with targeting ligands (e.g., transferrin-AuNPs or Tf-AuNPs) are bound to the cell membrane, working as virtual microelectrodes to create pores on cells with limited opening area while from many different sites. The addition of AuNPs during electroporation therefore benefits not only quicker recovery and better survival of cells but also more efficient uptake of the subjected probes. Such enhancement was successfully confirmed on a chronic myeloid leukemia cell line (i.e., K562 cells) in both a commercial batch electroporation system and a homemade flow system with pWizGFP plasmid DNA probes. The efficiency was found to be dependent on the size, concentration, and mixing ratio of free AuNPs/Tf-AuNPs. An equivalent mixture of free AuNPs and Tf-AuNPs exhibited the best enhancement with the transfection efficiency increase of two to threefold at a minimum sacrifice of the cell viability.

Objective: To investigate the effect of Ca(2+) on lipopolysaccharide (LPS)-induced NF-kappa B activation in pancreatic acinar cells and the role of NF-kappa B in LPS-induced acinar cell injury., Methods: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to varying concentrations of LPS (from 1 to 20 mg/L) in the presence or absence of EGTA. At various time points (30 minutes, 1 hour, 2 hours, 4 hours and 10 hours) after treatment with the agents, cell viability was determined by MTT. Nuclear translocation of NF-kappa B's subunit p65 was visualized by immunofluorescence staining and nuclei protein was extracted to perform EMSA which was used to assay the activity of NF-kappa B binding to the DNA sequence containing the recognition site of NF-kappa B., Results: LPS induced cell damage in a time- and concentration-dependent manner while EGTA attenuated LPS-induced cell damage (P < 0.05). NF-kappa B p65 immunofluorescence staining had increased intensity in the cytoplasm and indicated that nuclear translocation occurred within 30 minutes and its zenith was reached at 1 hour after LPS (10 mg/L) treatment. Testing of NF-kappa B DNA binding activity showed the same alteration phase as p65 immunofluorescence staining. NF-kappa B activation preceded the pathological alteration of pancreatic acinar cells. The Ca(2+) chelator EGTA inhibited LPS-induced NF-kappa B activation., Conclusions: NF-kappa B activation is an important early event in LPS-induced injury to pancreatic acinar cells. Ca(2+) is an important mediator in the process of LPS-induced NF-kappa B activation.

Macrophages form a crucial bridge between the innate and adaptive immune response. One of their most important functions is to recognize infectious microorganisms. Toll-like receptors (TLRs) are key elements in pathogen recognition, and among them, TLR2 and TLR4 are most discussed. However, expression patterns of TLRs during myeloid cell differentiation to macrophage are unknown. In this study, we examined differentiation in the model human myeloid cell line, HL-60, treated with phorbol 12-myristate 13-acetate (PMA) or VitD(3). Expression of TLR2, TLR4, and CD14 were measured by reverse transcription-PCR, RNase protection assay, and fluorescence-activated cell sorter assays. After treatment by PMA (1, 10, and 100 nM) for 12, 24, and 48 h, expression of TLR2 and CD14 mRNA was increased in a time- and dose-dependent manner. However, VitD(3) only induced expression of CD14 but not TLR2 in HL-60 cells. TLR4 was expressed constitutively before differentiation and increased slightly after that. Thus, PMA-mediated differentiation of HL-60 cells to macrophages is associated largely with TLR2 expression and, to a much lesser extent, with TLR4. Furthermore, up-regulation of TLR2 and CD14 mRNA expression by PMA was abrogated by a protein kinase C inhibitor, Calphostine C, suggesting the up-regulation of TLR2 and CD14 mRNA is dependent on the activation of protein kinase C. Coexpression of CD14/TLR2 and/or CD14/TLR4 may be essential but not sufficient for the production of tumor necrosis factor-alpha in response to lipopolysaccharide in our system.