Latest ArticlesThe aim of this study is to prepare porous γ-cyclodextrin metal-organic framework (CD-MOF) with good biocompatibility to improve the in vitro release properties of water-insoluble drugs. Different sizes of CD-MOF were obtained by controlling the self-assembly of γ-cyclodextrin and potassium ion and the rate of crystal growth. The poorly water-soluble diflunisal (DIF) was selected as the model drug and loaded into the interior of porous CD-MOF by the impregnation method. The DIF loaded CD-MOF (DIF-MOF) was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption and desorption, Fourier infrared spectrometer and thermogravimetric analysis. In addition, in vitro cytotoxicity and solubilizing capability of CD-MOF were investigated. It revealed that the obtained CD-MOF was cubic-like with a narrow size distribution and high porosity. Negligible cytotoxicity was found after incubation with RAW264.7 cells. Compared with the pure CD-MOF carrier, the morphology and crystal form of DIF-MOF was not damaged during the drug loading process. Moreover, the solubility and release rate of water-insoluble DIF from the DIF-MOF were significantly increased.
Liver fibrosis is a tissue repair compensatory response to liver injury caused by various chronic factors, ultimately leading to liver cirrhosis, liver failure and even hepatocellular carcinoma. Abnormal activation of hepatic stellate cells is the cellular basis of liver fibrosis development. Pepstatin Pr, the derivative of pepstatin A, was isolated from Streptomyces sp. CPCC 202950. Our purpose was to investigate the anti-fibrotic activity of pepstatin Pr and explore its molecular mechanism. Hepatic stellate cell LX-2 was stimulated by TGFβ1 and sub-sequently treated with pepstatin Pr. Its cytotoxicity was detected by sulforhodamine B (SRB) assay. The expression of COL1A1, α-SMA and cathepsin D, signaling proteins TGFβ, Smad and YAP/TAZ were detected by Western blot or real-time PCR. The results showed that pepstatin Pr was not cytotoxic to LX-2 cells. And pepstatin Pr significantly reduced the mRNA and protein expression of COL1A1 and α-SMA, which are important liver fibrosis markers. Pepstatin Pr also repressed the protein expression level of cathepsin D, TGFβ1, YAP/TAZ, the phospholation level of Smad2, and YAP nuclear translocation. In conclusion, pepstatin Pr exhibits anti-fibrotic effects in TGFβ1-stimulaed LX-2 cells by mediating YAP-TGFβ-Smad pathway.
The aim of this study is to investigate the influence of flufenamic acid (FFA) on the solubility, dissolution and bioavailability of sorafenib (SFN) in the combined administration of the MSNM@SFN and FFA. The MSNM@SFN&FFA was prepared by mixing the MSNM@SFN with FFA. The solubility, dissolution and bioavailability of SFN in the MSNM@SFN&FFA complex was investigated in comparison with those of the MSNM@SFN. This study was performed following the National Institutes of Health guidelines for the use of experimental animals; all care and handling of animals were performed with the approval of the Experimental Animal Center of Peking University Health Science Center. The MSNM@SFN&FFA showed no significant influence on the solubility, dissolution and bioavailability of SFN when compared with the MSNM@SFN. These data indicated that FFA had almost no influence on the solubility, dissolution and bioavailability of SFN in the combined administration of MSNM@SFN and FFA, thus providing an experimental foundation for the subsequent formulation research on the combined usage of drugs.
The aim of this study is to investigate the effect of nicotinamide (NIC) on the solubility/dissolution of a poorly soluble drug ibuprofen (IBU), and to explore the mechanism of the formed soluble complex by complexation model, fluorescence quenching and Raman spectroscope. The results showed that NIC could significantly improve the solubility of IBU, and exhibited an Ap type complexation profile. The calculated complexation constants of K1:1 and K1:2 were 0.24 and 4.00, respectively. In the solution, the fluorescent intensity of IBU gradually decreased with the increase of NIC, exhibiting the typical fluorescence-quenching phenomenon. The Raman spectrum showed stretching vibrations, bending vibrations, and rocking vibrations ascribed to benzene ring of IBU and pyridine ring of NIC disappeared or significantly shifted, suggested that the soluble complex was formed by dipole-dipole interaction force between the benzene group on IBU and pyridine group on NIC, resulting in the aqueous solubility enhancement of IBU. In comparison to IBU alone, the physical mixture of IBU and NIC showed significantly higher dissolution rate (1.6-fold) and extent.
This study was designed to prepare a novel lipid bilayer coated hollow mesoporous silica nanocarrier for co-delivery of gene drugs and chemotherapeutic drugs to enhance the inhibitory activity of antitumor drugs in hepatoma cells. Hollow mesoporous silica was synthesized by modified StÖber method. Lipid-fusion principle was used to prepare lipid-hollow co-loaded doxorubicin (DOX) and miR-375 (LHMSN-DOX/miR-375). Meanwhile, the morphology, particle size, surface potential, drug loading and release were characterized in vitro. The inhibition of cell proliferation, cell migration and invasion was then evaluated. The results indicated that the core-shell structure of LHMSN-DOX/miR-375 was clear with an intact outer lipid membrane and an ordered internal HMSN mesoporous structure. The drug release amount was pH responsive while the drug was rapidly released under simulated intracellular acidic conditions relative to normal physiological environment. Compared with free DOX, LHMSN-DOX/miR-375 can deliver DOX and miR-375 to liver cancer cells and inhibit the proliferation, migration and invasion of cells more effectively.
Using silica gel column chromatography, gel chromatography and HPLC, we isolated secondary metabolites in fermentation broth of a rifamycin resistant mutation strain Streptomyces sp. HS-NF-1046R. Based on spectroscopic data, the chemical structures of three compounds were identified as 3-hydroxyl-2-N-propionyl-anthranilamide (1), 2, 3-dihydro-8-hydroxy-2, 2-dimethyl quinazolin-4-(1H)-one (2) and 2-aminobenzamide (3). Compounds 1 and 2, as new entities, were evaluated for cytotoxicity against A549, HepG2, HCT-116 and K562 cells using the SRB assay. Compounds 1 and 2 exhibited no cytotoxicity with IC50 over 100 μmol·L-1.
Monoclonal antibodies (mAbs) have been widely used as therapeutic drugs for treating diseases such as cancers and auto-immune diseases. When using an IgG4 isotype, one of the challenges is the instability of its hinge which is prone to Fab-arm exchange (FAE). The hinge sequence of a wild type IgG4 is -CPSC-, however, a single point mutation S228P from -CPSC-to -CPPC-can effectively diminish FAE, thereby improving hinge stability of the IgG4 molecule. Sintilimab is the fully human anti-PD-1 monoclonal antibody designed and developed for immuno-oncology, in which serine 228 in the hinge was engineered to proline to mitigate FAE. In this study, LC-MS is used to study hinge stability of sintilimab in both in vitro (PBS and human serum) and in vivo (SCID mouse) studies. The studies demonstrate that LC-MS is a fast and simple way to monitor for the occurrence of FAE in vitro and in vivo, and FAE can be eliminated by antibody engineering with a single point mutation.
Gentiana section Cruciata (Gentianaceae) is a medicinally important section of herbs, including Chinese traditional medicine Gentianae Macrophyllae Radix and Tibetan herb Jieji. Here, we assess the taxonomic significance using mtDNA nad1/b-c and nad5/d-e sequence data. A total of 144 nad1/b-c and nad5/d-e sequences from 11 species within Gentianaceae were obtained, including 138 sequences from 10 species within Gentiana section Cruciata and 6 sequences from Halenia elliptica (outgroup). The results showed that mtDNA nad1/b-c has species-level resolution within the section of Cruciata, i.e. the variable in the position 45 "C" could be used as a stable marker locus to distinguish G. robusta from other taxa; the variable in the position 352 and 353 "GA" could distinguish G. crassicaulis and G. tibetica from other taxa within the section. Intraspecies genotype variability was detected in nad1/b-c sequences of G. officinalis and G. siphonantha, respectively. These genotypes could be used as potential DNA barcode. In addition, intraspecies genotype variability was detected in nad5/d-e sequences of G. macrophylla, G. officinalis and G. siphonantha, respectively. Based on the stable marker locus, a species-specific PCR protocol was developed using the primer PF to identifying G. robusta in the section. This study could expand the understanding of the diversity of mtDNA nad1/b-c and nad5/d-e in the genus Gentiana, and provide the essence for the species identification within Gentiana section Cruciata.
An ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) method was developed to evaluate the chemical consistency of triterpene acids in ethanol extracts of Poria and acetic ether extracts thereof. First, high resolution mass spectrometry data were obtained with Full scan mode, by comparing with MS data from the reference compounds and literatures, a total of 23 components were unequivocally or tentatively identified in ethanol extracts and acetic ether extracts thereof. Then, a mimic multiple reaction monitoring (mMRM) mode was established using UPLC-QTOF-MS/MS to quantify the triterpene acids in ethanol extracts and acetic ether extracts thereof. Eleven components were absolutely quantified with reference compounds, while 12 components without reference compounds were relatively quantified with peak areas, the transfer and enrichment rate of triterpene acids during liquid-liquid extraction were calculated. It was found all of the 23 triterpene acids identified in Poria ethanol extracts could be transferred into acetic ether extracts with high transfer and enrichment rate. The present study provides not only scientific evidence for further extraction of triterpene acids in Poria by acetic ether, but also an approach for comprehensive evaluation of the chemical consistency of herbal medicine extracts before and after the liquid-liquid extraction.
The solubility of nebivolol hydrochloride was determined in acidic aqueous media in the absence and presence of different concentration of NaCl, NaBr, or NaI at 37℃ in order to facilitate proper selection of dissolution media that have adequate discriminating power for enhancing the likelihood of a generic drug product to successfully pass in-vivo bioequivalence test. In the range of pH 5.0 to pH 1.0, the solubility of nebivolol hydrochloride decreased with the decrease in the pH of aqueous solution, and the solubility of nebivolol hydrochloride further decreased with the increase in the concentration of added sodium chloride. The solubility decrease of a few weakly basic drug molecules in acidic media and in higher concentration of added chloride was published previously by other researchers, and the observed decrease in the solubility in the presence of higher chloride concentration was interpreted in terms of common-ion effect. However, the results in this paper showed that the solubility of nebivolol hydrochloride also decreased when sodium chloride was replaced with sodium bromide or iodide. The approach described in this paper (i.e. substituting sodium chloride with sodium bromide or iodide) provides an effective method to verify whether common-ion effect is the true (or at least the sole) driving force behind the observed decrease in the solubility of nebivolol hydrochloride in the presence of sodium chloride. The solubility decrease reported in this paper can be interpreted in terms of salting-out effect of sodium chloride, bromide, and iodide. For hydrochloride salt of a weakly basic drug molecule like nebivolol hydrochloride, its solubility in an acidic dissolution medium can be purposely decreased to the lower end of sink condition by adding sodium chloride to make the resulting medium more discriminating. As shown in this paper, a medium at pH 1.2 with added sodium chloride is discriminating and this medium is shown to be bio-relevant to the in-vivo data collected under fasting condition (in-vivo study protocol was approved by Institutional Review Board).