35 research outputs found
Galactosylated poly(ethylene glycol)-b-poly (l-lactide-co-β-malic acid) block copolymer micelles for targeted drug delivery: preparation and in vitro characterization
Biodegradable galactosylated methoxy poly(ethylene glycol)/poly(l-lactide-co-β-malic acid) (Gal-PEG-b-PLMA) block copolymer micelles were successfully prepared by a solvent diffusion method, and could efficiently encapsulate doxorubicin. The Gal-PEG-b-PLMA micelles before and after doxorubicin loading were characterized by size, morphology, in vitro drug release, and in vitro cytotoxicity in HepG2 cells. Transmission electron microscopy and dynamic light scattering results showed that the empty and doxorubicin-loaded micelles were approximately spherical in shape and had mean sizes of about 72 nm and 85 nm, respectively. In vitro release behavior of doxorubicin from the micelles was pH-dependent, with obviously faster release rates at mildly acidic pH 4.5 and 5.5 compared with physiologic pH 7.4. Methylthiazoletetrazolium assay and flow cytometric analysis indicated that the doxorubicin-loaded galactosylated micelles exhibited a greater growth-inhibitory effect on HepG2 cells than the nongalactosylated doxorubicin-loaded micelles, and induced S phase cell cycle arrest. Confocal laser scanning microscope observations revealed that the galactosylated micelles could be efficiently internalized by HepG2 cells through receptor-mediated endocytosis. The results suggest that Gal-PEG-b-PLMA copolymer micelles are a promising carrier system for targeted drug delivery in cancer therapy
Determining the Degree of [001] Preferred Growth of Ni(OH)\u3csub\u3e2\u3c/sub\u3e Nanoplates
Determining the degree of preferred growth of low-dimensional materials is of practical importance for the improvement of the synthesis methods and applications of low-dimensional materials. In this work, three different methods are used to analyze the degree of preferred growth of the Ni(OH)2 nanoplates synthesized without the use of a complex anion. The results suggest that the preferred growth degree of the Ni(OH)2 nanoplates calculated by the March parameter and the expression given by Zolotoyabko, which are based on the analysis and texture refinement of the X-ray diffraction pattern, are in good accordance with the results measured by SEM and TEM imaging. The method using the shape function of crystallites is not suitable for the determination of the preferred growth degree of the Ni(OH)2 nanoplates. The method using the March parameter and the expression given by Zolotoyabko can be extended to the analysis of block materials
Fast Diffusion of Silver in TiO\u3csub\u3e2\u3c/sub\u3e Nanotube Arrays
Using magnetron sputtering and heat treatment, Ag@TiO2 nanotubes are prepared. The effects of heat-treatment temperature and heating time on the evolution of Ag nanofilms on the surface of TiO2 nanotubes and microstructure of Ag nanofilms are investigated by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Ag atoms migrate mainly on the outmost surface of the TiO2 nanotubes, and fast diffusion of Ag atoms is observed. The diffusivity for the diffusion of Ag atoms on the outmost surface of the TiO2 nanotubes at 400 °C is 6.87 × 10−18 m2/s, which is three orders of magnitude larger than the diffusivities for the diffusion of Ag through amorphous TiO2 films. The activation energy for the diffusion of Ag atoms on the outmost surface of the TiO2 nanotubes in the temperature range of 300 to 500 °C is 157 kJ/mol, which is less than that for the lattice diffusion of Ag and larger than that for the grain boundary diffusion. The diffusion of Ag atoms leads to the formation of Ag nanocrystals on the outmost surface of TiO2 nanotubes. Probably there are hardly any Ag nanocrystals formed inside the TiO2 nanotubes through the migration of Ag
Clinical research on RSV prevention in children and pregnant women: progress and perspectives
Respiratory syncytial virus (RSV) is a significant causative agent of bronchitis and pneumonia in infants and children. The identification and structural analysis of the surface fusion glycoprotein of RSV represents a pivotal advancement in the development of RSV prevention. This review provides a comprehensive summary of RSV monoclonal antibody (mAb) and vaccine clinical trials registered on ClinicalTrials.gov, emphasizing on the classification, name, target, phase, clinical outcomes, and safety data of RSV vaccination in newborns, infants and children. We also discuss the characteristics of the types of RSV vaccines for maternal immunity and summarize the current clinical research progress of RSV vaccination in pregnant women and their protective efficacy in infants. This review will provide new ideas for the development of RSV prevention for children in the future
Bioinformatic prediction and functional characterization of human KIAA0100 gene
Our previous study demonstrated that human KIAA0100 gene was a novel acute monocytic leukemia-associated antigen (MLAA) gene. But the functional characterization of human KIAA0100 gene has remained unknown to date. Here, firstly, bioinformatic prediction of human KIAA0100 gene was carried out using online softwares; Secondly, Human KIAA0100 gene expression was downregulated by the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system in U937 cells. Cell proliferation and apoptosis were next evaluated in KIAA0100-knockdown U937 cells. The bioinformatic prediction showed that human KIAA0100 gene was located on 17q11.2, and human KIAA0100 protein was located in the secretory pathway. Besides, human KIAA0100 protein contained a signalpeptide, a transmembrane region, three types of secondary structures (alpha helix, extended strand, and random coil) , and four domains from mitochondrial protein 27 (FMP27). The observation on functional characterization of human KIAA0100 gene revealed that its downregulation inhibited cell proliferation, and promoted cell apoptosis in U937 cells. To summarize, these results suggest human KIAA0100 gene possibly comes within mitochondrial genome; moreover, it is a novel anti-apoptotic factor related to carcinogenesis or progression in acute monocytic leukemia, and may be a potential target for immunotherapy against acute monocytic leukemia
Determining the Preferred Orientation of Silver-Plating via X-ray Diffraction Profile
Determining the preferred orientation of plating film is of practical importance. In this work, the Rietveld method and quantitative texture analysis (RM+QTA) are used to analyze the preferred orientation of plating silver film with XRD profile, whose <311> axial texture can be completely described by a set of exponential harmonics index, extracted from a single XRD profile, C41,1(0.609), C61,1(0.278), C81,1(−0.970). The constructed pole figures with the index of the exponential harmonic are following those measured by the multi-axis diffractometer. The method using exponential harmonic index can be extended to characterize the plating by electroplating in a quantitative harmonic description. In addition, a new dimension involving crystallite shape and size is considered in characterizing the preferred orientation
Preparation of monoclonal antibody against human KIAA0100 protein and Northern blot analysis of human KIAA0100 gene
Monoclonal antibodies (MAbs) are important tools for the study of proteins′ function and structure. But there has been no report on the preparation of MAbs against human KIAA0100 protein up to date. Here, first, we generated the mouse MAb against human KIAA0100 protein using purified recombinant 6×Histidinc (6×His)-tagged human KIAA0100 protein segment (1557–2234) as an antigen; then, the mRNA expression of human KIAA0100 gene was detected in U937 cells using Northern blot analysis. The results showed that the mouse MAb against human KIAA0100 protein could sensitively recognize the human KIAA0100 protein using Western blot analysis and immunocytochemistry analysis. Besides, Western blot analysis revealed that human KIAA0100 gene possibly encoded two different protein products (254 kDa and <250 kDa) in U937 cells. Moreover, Northern blot analysis confirmed that human KIAA0100 gene might produced two different mRNA products (6000–10000 bp and 5000–6000 bp) in U937 cells. The results provide a basis for large-scale production of the MAb against human KIAA0100 protein, which will be useful for the study of human KIAA0100 protein′s function/structure and MAb-targeted drugs in the future