Latest ArticlesIn this study, we developed a rapid and sensitive ultra high-performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS) method to detect a sulfide bond doxorubicin conjugation prodrug (DOX-S-DOX) in human breast cancer tumor cells (MCF-7). The samples were prepared by acetonitrile precipitation using daunorubicin as internal standard (IS). A reversed phase C18 analytical column (Agilent Eclipse plus C18 RRHD 1.8 μm, 2.1 mm×50 mm) was utilized to separate the samples under gradient elution conditions. Mobile phase was a mixture of 0.1% formic acid in water and methanol at a flow rate of 0.4 mL ·min-1. The analysis was conducted on the mass spectrometer using an electrospray interface (ESI) in the positive ionization model. The calibration range was 20.0-400 ng·mL-1 with the correlation coefficients (r2) ≥ 0.99. The inter-and intra-assay precision (relative standard deviation, RSD%) of quality control samples was within 3.77%-8.35% and relative error (RE%) for accuracy was between -2.04% and 2.62%. Recovery (97.67%-104.2%) and matrix effect (104.8%-113.9%) were consistent, precise, and reproducible at different quality control levels in accordance with FDA guidance. The assay was successfully used in the cellular pharmacokinetics study of DOX-S-DOX, which may provide a clue to explore analytical methods of other prodrug forms of DOX.
Microspheres (MS) are an excellent transarterial chemoembolization carrier for cancer treatment. Then the Bletilla striata polysaccharide (BSP) that was isolated from the rattan of Bletilla striata was used as skeleton material, and the matrine (ME) loaded Bletilla striata polysaccharide microspheres (ME-BSPMS) were prepared by emulsify-chemical crosslinking method. ME-BSPMS was characterized for appearance shape, particle size, drug loading, swelling ratio, suspension property, drug entrapment condition and in vitro release characteristics. The results showed that the ME-BSPMS appeared as round spherical and smooth shape by SEM, with an average size of (85 ±7) μm. ME-BSPMS with a good suspension in physiological saline and the swelling ratio could reach upwards of (53 ±4.2)% in 20 minutes, also with a large amount of drug loading of (30.12 ±3.25)%. The results of DSC scanning indicate that good compatibility exists between the ME and BSP, and the ME could be embedded fully in the matrix of the ME-BSPMS. The accumulation drug release from ME-BSPMS was (25.38 ±1.57)% at 12 h, this suggests that the ME-BSPMS has a good sustained release effect. These results indicate that the ME-BSPMS may be a promising transarterial chemoembolization carrier for cancer treatment.
Beads, a novel drug delivery system self-assembled by cyclodextrins (CDs) and oil, has potential applications in the solidification of oil drugs and improving the bioavailability of lipid-soluble drugs. However, very few researches were dedicated to the mechanism of beads formation. In this study, three-dimensional structures of beads were visualized and investigated using synchrotron radiation X-ray microcomputed tomography (SR-μCT). The structural changes of beads attributed by drying process were analyzed and confirmed via visualization results of SR-μCT. Productively, it was proposed that Pickering emulsion droplets obtained during beads formation process were spatially localized orderly. Moreover, the effects of loading lipid soluble drug, namely, vitamin K1, on the structural changes of beads were also analyzed. It is well known that the surface tension of oil phase could be changed by the addition of lipid soluble constituents. It was reasonable that the three-dimensional structure of beads might be altered during the drug loading of vitamin K1 into the beads. However, although the morphologies of beads were changed to some extent, the ordered Pickering emulsion droplets during the process of beads formation was successfully illustrated based on the SR-μCT results. Conclusively, according to the three-dimensional structural analysis of the beads, this study revealed the organized architecture for Pickering emulsion droplet assembly and beads formation in cyclodextrin semi-inclusion complex, which significantly complements the formation mechanism of beads, and provides a structural basis for the further study of beads.
Based on the natural affinity between macrophages and atherosclerotic lesions, we made a novel macrophage membrane-coated polylactic acid-glycolic acid copolymer (PLGA) nanoparticle (MPLNPs), and examined its ability targeting atherosclerotic lesions. PLGA nanoparticle (PLGANPs) were prepared by precipitation and MPLNPs were prepared by membrane extrusion. Their morphology, particle size and retainment of functional proteins were characterized. Their targeting capabilities were investigated with cell uptake assay in vitro and fluorescence imaging in vivo. The results showed that MPLNPs were spherical, with obvious core/shell structure, the average particle size was (167 ±6.12) nm, and integrin α4β1 was retained on the surface. Vascular cell adhesion molecule 1 (VCAM-1) receptor was highly expressed in the LPS (lipopolysaccharides)-HUVEC (human umbilical vein endothelial cells) and atherosclerotic lesions in ApoE-/- mouse model, and the nanoparticles could effectively recognize the VCAM-1 receptor and had good targeting properties in vitro and in vivo. The results suggest that the cell membrane biomimetic nano-carrier may provide a new approach for the targeting strategy in the treatment of atherosclerosis and related diseases.
The calcineurin B-like protein (CBL)-interacting protein kinase (CIPK) plays a vital role in the growth, development, and stresses adaptation in plants by interaction with the calcium signaling. In this study, four full length cDNAs of CIPKs genes, namely DoCIPK1, DoCIPK2, DoCIPK3 and DoCIPK4 (GenBank accession No. KT957557, KT957558, KT957559 and KT957560, respectively) were cloned from the rear and medicinal plant, Dendrobium officinale, by rapid amplification of cDNA ends (RACE) for the first time. The corresponding encoded proteins, consisting of 473, 449, 451 and 440 amino acids (aa), respectively, with a molecular weight of 53.50, 50.93, 51.50 and 50.16 kDa, and an isoelectric point (pI) of 7.99, 9.25, 8.81 and 9.11, respectively, shared 70%-90%, 69%-80%, 78%-93%, and 66%-82% identities CIPKs with various plants. Each deduced protein contained a conserved protein kinase domain (respectively at 21 -275, 14-268, 16-271 and 12-266 aa position), a CIPKs family characteristic NAF/FISL domain (respectively at 335-391, 313-370, 310-369 and 305-362 aa position) and some functional motifs. The four DoCIPK proteins, without signal peptide or transmembrane region, were located in the plasma membrane and endoplasmic reticulum at the subcellular level. The three dimensional structure of the proteins were similar to that of Arabidopsis AtCIPK24. DoCIPK1 and DoCIPK3 were respectively clustered in the group E and A of the Arabidopsis and rice CIPK evolutionary tree, while DoCIPK2 and DoCIPK4 belonged to group C. The relative expression of DoCIPK1 showed no significant difference in the leaves and stems, and its transcripts in the roots was 0.35 fold over that in the leaves. The abundance of DoCIPK3 transcripts in the stems and the roots were 3.36 fold and 3.47 fold higher, respectively, than those in the leaves. DoCIPK2 exhibited similar expression pattern to DoCIPK4. Their relative expression in the leaves and the stems had no apparent difference, and the transcript levels were higher in the roots than that in the leaves, with 2.08 fold and 7.86 fold, respectively. Cloning, bioinformatics analyses, and expression patterns of the four DoCIPK genes provide a basis for functional elucidation of these genes further during the physiological responses in D. officinale.
Geographic information system for global medicinal plants (GMPGIS) and MaxEnt modeling are adopted to analyze the ecological suitability of the endangered plant Acanthopanax senticosus. Response curves were created by the raster data of 6 ecological factors, including mean annual temperature, mean temperature of warmest quarter, mean temperature of coldest quarter, mean annual precipitation, mean annual humidity, and mean annual radiation. The relationship between the syringin content of this plant and these ecological factors was analyzed using a redundancy analysis method (RDA), which could be used to predict the most relevant ecological factors influencing the active constituents of Acanthopanax senticosus plants. GMPGIS and MaxEnt results suggest that China, Russia, Japan, and North Korea, are the main producing areas in the world for Acanthopanax senticosus, while there are also other potential areas with maximum similarities of ecological distribution in the United States, Canada, Ukraine, Romania, Hungary, Germany and 22 other countries. In addition, the genuine producing areas in China mainly include Heilongjiang, Jilin and Liaoning, while there are the maximum similarities of ecological distribution of Acanthopanax senticosus in Hebei, Shanxi, Shaanxi and Sichuan. RDA results suggest that the mean annual humidity, precipitation, temperature are the most important eco-factors positively affecting the content of syringin in Acanthopanax senticosus. Our research provides scientific support to the utilization of ecological suitability areas for endangered plant Acanthopanax senticosus and the resource regeneration.
Follow-on drug approach is to follow-up and make-up of the innovation of pioneering drugs. Since the millennium new molecular entities (NME) have experienced ample optimization, and the patents have claimed in wide ranges, as well as the drug administration requires NME being superior or non-inferior to the existing drugs of the same class. These situations have made the space of follow-on drug innovation narrow and smaller than before. The follow-on drug approach can be concisely differentiated into two aspects:one is to start from the chemistry of small molecules, which are performed with a niche-targeting manipulation to optimize the safety, efficacy and (or) convenience for dose superior to the existing drugs; another proceeds with the macromolecule targets. Based on the knowledge of the mechanism of action or of target mutation, active compounds are constructed through complementary binding or by the reaction mechanism. In this article successful examples are briefly described to illustrate the features of follow-on drug approach.
CRISPR/Cas9 system, consisting of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins, is a prokaryotic immune system that confers resistance to foreign genetic elements such as those present within plasmids and phages. A simple version of the CRISPR/Cas system, type Ⅱ CRISPR, has been modified to edit genomes. By delivering the Cas9 nuclease together with a synthetic guide RNA (sgRNA) into cells, genome can be edited at desired loci site. CRISPR/Cas genome editing techniques have been widely implemented in various species and research areas. In this review, we summarize the several applications of CRISPR/Cas9 in the field of drug discovery and development, which include target gene screening and editing, drug target screening and validation, generation of animal models and treatment of genetic disease, etc. The defects and improvements of CRISPR/Cas9 technology is discussed as well.
Ginsenoside Rg1 is one of the main active components of ginseng with various pharmacological activities including anti-inflammatory, anti-oxidation, anti-aging, anti-tumor and anti-apoptosis. Ginsenoside Rg1 plays a protective role in multiple tissues and organs, which shows the multiple targeting properties of the pharmacological effects. Recently, a number of studies have demonstrated that ginsenoside Rg1 has a protective role in the liver due to its multiple pharmacological effects. In chemical liver injury models, or in other liver injury models, ginsenoside Rg1 can alleviate liver necrosis induced by oxidative stress and inflam-mation. This article provides a review of the recent studies on the efficacy of ginsenoside Rg1 in the treatment of various liver damage and the molecular mechanism.
The New Delhi metallo-β-lactamase-1 (NDM-1) was first reported in 2010, detected in a Klebsiella pneumoniae isolate from a Swedish patient of Indian origin. It has recently attracted extensive attention for its biological activities to catalyze the hydrolysis of almost all of β-lactam antibiotics. The gene for NDM-1 can spread from one strain of bacteria to another by horizontal gene transfer. The most troubling aspect is that there are currently no clinically available inhibitors to block the metallo-β-lactamase action. Therefore, there is urgent need to develop new NDM-1 inhibitors, which can protect β-lactam antibiotics from the hydrolysis effect of NDM-1. In this review, the current research, drug-assistant mechanism and potential NDM-1 inhibitors are summarized.