Population Pharmacokinetics of High-Dose Methotrexate in Patients With Primary Central Nervous System Lymphoma.

The intra- and inter-individual variances of methotrexate (MTX) pharmacokinetics are extremely large, and the pharmacokinetic property of MTX in patients with primary central nervous system lymphoma (PCNSL) is unestablished. A total of 701 MTX plasma concentrations from 98 patients with PCNSL under high-dose MTX therapy were used to develop the population pharmacokinetic (popPK) model of MTX by using the nonlinear mixed-effects modeling method. A 2-compartment model was employed to describe the pharmacokinetic property of MTX. In the final popPK model, inclusion of serum creatinine and body surface area significantly reduced objective function value for clearance over the base model (p <0.001), and inclusion of age significantly reduced objective function value for distribution volume of central compartment (Vc) over the base model (p <0.001). In the final popPK model, the inter-individual clearance = 6.67 × (SCR/68.1)-0.48 × (BSA/1.75)1.17; Vc = 24.46 × (age/57.16)0.81. The precision of all parameters was acceptable (relative standard error <28.61%). Bootstrap and visual predictive check results indicated that the final popPK model was stable with acceptable predictive ability. The popPK model may be useful for personalized medication in PCNSL patients under high-dose MTX therapy. Further studies are warranted to confirm the results.

UPLC-MS/MS Analysis of Methotrexate in Human Plasma and Comparison with the Fluorescence Polarization Immunoassay.

Methotrexate (MTX) plasma concentration is routinely monitored to guide the dosage regimen of rescue drugs. This study aims to develop and validate an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for plasma MTX analysis, and to establish its agreement with the fluorescence polarization immunoassay (FPIA) in patients with high-dose MTX therapy. Separation was achieved by gradient elution with methanol and water (0.05% formic acid) at 40°C with a run time of 3 min. The intra- and inter-day inaccuracy and imprecision of the UPLC-MS/MS method were -4.25 to 3.1 and less than 7.63%, respectively. The IS-normalized recovery and matrix effect were 87.05 to 92.81 and 124.43 to 134.57%. The correlation coefficients between UPLC-MS/MS and FPIA were greater than 0.98. The UPLC-MS/MS method was in agreement with the FPIA at high levels of MTX (1.0 - 100 µmol/L), but not at low levels (0.01 - 1.0 µmol/L). Further studies are warranted to confirm these results.

Loading cisplatin onto 6-mercaptopurine covalently modified MSNS: a nanomedicine strategy to improve the outcome of cisplatin therapy.

In the treatment of cancer patients, cisplatin (CDDP) exhibits serious cardiac and renal toxicities, while classical combinations related to CDDP are unable to solve these problems and may result in worse prognosis. Alternately, this study covalently conjugated 6-mercaptopurine (6MP) onto the surface of mercapto-modified mesoporous silica nanoparticles (MSNS) to form MSNS-6MP and loaded CDDP into the holes on the surface of MSNS-6MP to form MSNS-6MP/CDDP, a tumor-targeting nano-releasing regime for CDDP and 6MP specifically. In the S180 mouse model, the anti-tumor activity and overall survival of MSNS-6MP/CDDP (50 mg·kg-1·day-1, corresponding to 1 mg·kg-1·day-1 of 6MP and 5 mg·kg-1·day-1 of CDDP) were significantly higher than those of CDDP alone (5 mg·kg-1·day-1) or CDDP (5 mg·kg-1·day-1) plus 6MP (1 mg·kg-1·day-1). The assays of serum alanine aminotransferase, aspartate aminotransferase and creatinine, as well as the images of myocardium and kidney histology, support that MSNS-6MP/CDDP is able to completely eliminate liver, kidney and heart toxicities induced by CDDP alone or CDDP plus 6MP.

Design, synthesis and evaluation of VEGF-siRNA/CRS as a novel vector for gene delivery.

Small interfering RNA (siRNA) delivery is a prospective method in gene therapy, but it has application limitations such as negative charge, water solubility and high molecular weight. In this study, a safe and efficient nano-vector, CRS, was designed and synthesized to facilitate siRNA delivery. Physical and chemical properties of VEGF-siRNA/CRS were characterized by methods including scanning electron microscopy (SEM), transmission electron microscopy, zeta potential (ζ) measurement, drug-releasing rate measurement, gel electrophoresis and confocal microscopy. The biological activities were evaluated using cell viability assay, gene-silencing efficacy assay in vitro, real-time polymerase chain reaction, enzyme-linked immunosorbent assay (ELISA) and antitumor tests in vivo. The mean nanoparticle size of VEGF-siRNA/CRS was 121.4±0.3 nm with positive ζ potential of 7.69±4.47 mV. The release rate of VEGF-siRNA from VEGF-siRNA/CRS was 82.50% sustained for 48 h in Tris-ethylenediaminetetraacetic acid buffer (pH 8.0). Real-time polymerase chain reaction was used to analyze the efficiency of the transfection, and the result showed that VEGF mRNA expression had been knocked down by 82.36%. The expression of VEGF protein was also recorded to be downregulated to 14.83% using ELISA. The results of cytotoxicity measured by Cell Counting Kit-8 assay showed that VEGF-siRNA/CRS had significant inhibitory effect on HeLa cells. The results of antitumor assays indicated that VEGF-siRNA/CRS exhibited tumor cell growth inhibition in vivo. The results demonstrated that VEGF-siRNA could be delivered and transported by the designed carrier, while siRNA could be released constantly and led to an increasing gene-silencing effect against VEGF gene. In conclusion, VEGF-siRNA/CRS is a promising carrier for siRNA delivery, and further studies are warranted.

Gene-silencing effects of anti-survivin siRNA delivered by RGDV-functionalized nanodiamond carrier in the breast carcinoma cell line MCF-7.

Nanodiamond (ND) is a renowned material in nonviral small interfering RNA (siRNA) carrier field due to its unique physical, chemical, and biological properties. In our previous work, it was proven that ND could deliver siRNA into cells efficiently and downregulate the expression of desired protein. However, synthesizing a high-efficient tumor-targeting carrier using ND is still a challenge. In this study, a novel carrier, NDCONH(CH2)2NH-VDGR, was synthesized for siRNA delivery, and its properties were characterized with methods including Fourier transform infrared spectrometry, transmission electron microscopy, scanning electron microscopy, gel retardation assay, differential scanning calorimetry, confocal microscopy, releasing test, real-time polymerase chain reaction (PCR) assay, enzyme-linked immunosorbent assay (ELISA), flow cytometry, cytotoxicity assay, and gene-silencing efficacy assay in vitro and in vivo. The mechanism of NDCONH(CH2)2NH-VDGR/survivin-siRNA-induced tumor apoptosis was evaluated via flow cytometer assay using Annexin V-fluorescein isothiocyanate/propidium iodide staining method. The NDCONH(CH2)2NH-VDGR/survivin-siRNA nanoparticle with 60-110 nm diameter and 35.65±3.90 mV zeta potential was prepared. For real-time PCR assay, the results showed that the expression of survivin mRNA was reduced to 46.77%±6.3%. The expression of survivin protein was downregulated to 48.49%±2.25%, as evaluated by ELISA assay. MTT assay showed that NDCONH(CH2)2NH-VDGR/survivin-siRNA had an inhibitory effect on MCF-7 cell proliferation. According to these results, the survivin-siRNA could be delivered, transported, and released stably, which benefits in increasing the gene-silencing effect. Therefore, as an siRNA carrier, NDCONH(CH2)2NH-VDGR was suggested to be used in siRNA delivery system and in cancer treatments.

Nanomedical strategy to prolong survival period, heighten cure rate, and lower systemic toxicity of S180 mice treated with MTX/MIT.

In spite of the usual combination form of methotrexate (MTX)/mitoxantrone (MIT) and various complex combination regimens of MTX/MIT with other anticancer drugs, the survival period, cure rate, and systemic toxicity still need to be improved. For this purpose, a nanostructured amino group-modified mesoporous silica nanoparticles (MSNN)-MTX/MIT was designed. In the preparation, the surface of mesoporous silica nanoparticles (MSNs) was modified with amino groups to form MSNN. The covalent modification of the amino groups on the surface of MSNN with MTX resulted in MSNN-MTX. The loading of MIT into the surface pores of MSNN-MTX produced nanostructured MSNN-MTX/MIT. Compared with the usual combination form (MTX/MIT), nanostructured MSNN-MTX/MIT increased the survival period greatly, heightened the cure rate to a great extent, and lowered the systemic toxicity of the treated S180 mice, significantly. These superior in vivo properties of nanostructured MSNN-MTX/MIT over the usual combination form (MTX/MIT) were correlated with the former selectively releasing MTX and MIT in tumor tissue and inside cancer cells in vitro. The chemical structure and the nanostructure of MSNN-MTX/MIT were characterized using infrared and differential scanning calorimeter spectra as well as transmission electron microscope images, respectively.

RGD(F/S/V)-Dex: towards the development of novel, effective, and safe glucocorticoids.

Dexamethasone (Dex) is an effective glucocorticoid in treating inflammation and preventing rejection reaction. However, the side effects limit its clinical application. To improve its druggable profile, the conjugates of RGD-peptide-modified Dex were presented and their enhanced anti-inflammation activity, minimized osteoporotic action, and nanoscaled assembly were explored. (RGD stands for Arg-Gly-Asp. Standard single letter biochemical abbreviations for amino acids have been used throughout this paper.) In respect of the rejection reaction, the survival time of the implanted myocardium of the mice treated with 1.43 µmol/kg/d of the conjugates for 15 consecutive days was significantly longer than that of the mice treated with 2.5 µmol/kg/d of Dex, and the conjugates, but not Dex, exhibited no toxic action. At a single dose of 14.3 µmol/kg (100 times minimal effective dose, 0.143 µmol/kg), the conjugates induced no liver, kidney, or systemic toxicity. At the dose of 1.43 µmol/kg, the conjugates, but not Dex, prolonged the bleeding time of the mice, and inhibited the thrombosis of the rats. In water and rat plasma, the conjugates formed nanoparticles of 14-250 and 101-166 nm in diameter, respectively. Since the nanoparticles of ~100 nm in size cannot be entrapped by macrophages in the circulation, RGDF-Dex would particularly be worthy of development, since its nanoparticle diameter is 101 nm.

Aqueous extract of Rabdosia rubescens leaves: forming nanoparticles, targeting P-selectin, and inhibiting thrombosis.

The hot water extract of Rabdosia rubescens was traditionally used as an antithrombotic medicine. To explore its antithrombotic utility and mechanism, we carried out a series of in vitro and in vivo assays in this study. In vitro platelet aggregation assay showed that the half maximal inhibitory concentration values of aqueous extract of R. rubescens leaves (AERL) inhibiting platelet aggregation induced by thrombin, arachidonic acid, adenosine diphosphate, and platelet-activating factor ranged from 0.12 mg/mL to 1.43 mg/mL. The minimal effective oral dose of AERL inhibiting the rats from forming thrombus was 25 mg/kg. Both in vitro and in vivo actions were correlated with AERL concentration-dependently inhibiting sP-selectin release. In water, AERL formed nanoparticles, and their size depended on the concentration. Docking the five nucleotides, 21 phenolic acids, and four diterpenoids identified by high-performance liquid chromatography-photodiode array detector/(-)electrospray ionization-tandem mass spectrometry analysis into the active site of P-selectin, rosmarinic acid was predicted to be the antithrombotic ingredient of AERL. In flow cytometry analysis, 1 µM of rosmarinic acid effectively inhibited sP-selectin release in arachidonic acid-activated platelets. In a rat model, 5 mg/kg of oral rosmarinic acid effectively inhibited thrombosis.

Modifying tetramethyl-nitrophenyl-imidazoline with amino acids: design, synthesis, and 3D-QSAR for improving inflammatory pain therapy.

With the help of pharmacophore analysis and docking investigation, 15 novel 1-(4,4,5,5-tetramethyl-2-(3-nitrophenyl)-4,5-dihydroimidazol-1-yl)-oxyacetyl-L-amino acids (6a-o) were designed, synthesized, and assayed. On tail-flick and xylene-induced ear edema models, 10 µmol/kg 6a-o exhibited excellent oral anti-inflammation and analgesic activity. The dose-dependent assay of their representative 6f indicates that the effective dose should be 3.3 µmol/kg. The correlation of the three-dimensional quantitative structure-activity relationship with the docking analysis provides a basis for the rational design of drugs to treat inflammatory pain.

RGDS covalently surfaced nanodiamond as a tumor targeting carrier of VEGF-siRNA: synthesis, characterization and bioassay.

A nonviral tumor targeting vector for siRNA transfer is of importance. Here, a novel delivery system consisting of a covalent conjugate of NDCO-RGDS and VEGF-siRNA, NDCO-RGDS/VEGF-siRNA, was presented. In vitro, NDCO-RGDS/VEGF-siRNA released and transferred VEGF-siRNA in a long-acting manner. Compared to the control, NDCO-RGDS/VEGF-siRNA decreased the expression of VEGF mRNA and protein in HeLa cells by 88.41 ± 3.49% and 83.94 ± 2.00%, respectively. In vivo, NDCO-RGDS/VEGF-siRNA exhibited gene silencing and slowed tumor growth. FT-MS spectrum analysis revealed that NDCO-RGDS/VEGF-siRNA mainly distributed in tumor tissue of the treated S180 mice. Therefore NDCO-RGDS could be considered a promising nonviral tumor-targeting vector for siRNA transfer in tumor therapy.

Pyrolo[1,2:4,5]-1,4-dioxopyrazino[1,2:1,6]pyrido[3,4-b]indoles: a group of urokinase inhibitors, their synthesis, and stereochemistry-dependent activity.

Antifibrinolytic agents are required during complex surgeries to decrease bleeding; their pro-thrombotic potency and efficacy in causing hemostasis has attracted much attention. To discover new inhibitors of urokinase with high selectivity for antifibrinolytic effects over pro-thrombotic effects, the 12-position of (5aS,12S,14aS)- and (5aS,12R,14aS)-5,14-dioxo-1,2,3,5,5a,6,11, 12,14,14a-decahydro-5H,14H-pyrolo[1,2:4,5]pyrazino[1,2:1,6]pyrido[3,4-b]indoles were modified with L-Ala, L-Asp, L-Phe, L-Trp, L-Lys, L-Ser, Gly, and L-Leu to provide 16 (5aS,12S,14aS) and (5aS,12R,14aS) derivatives. In a murine bleeding model, the (5aS,12S,14aS) derivatives containing L-Ala, L-Asp, L-Phe, and L-Trp induced blood coagulation for the treated mice; they also stimulated thrombus formation in a rat thrombosis model, but the other derivatives inhibited thrombosis. The most potent compound, the L-Asp derivative, showed a good therapeutic window: the minimum effective dose for coagulation was <1 nmol kg(-1), whereas at 10 nmol kg(-1), no pro-thrombotic effect was observed. This type of coagulation action was correlated with a mechanism of urokinase inhibition, and these results could lead to the discovery of novel urokinase inhibitors.

HPLC-MS aided PC12 cell systems: to quantitatively monitor the conversion of nitronyl nitroxide in biological systems with and without NO.

Nitronyl nitroxides are capable of preventing cells, tissues, and organs from radical-induced damage through scavenging NO˙, ˙O(2)(-) and ˙OH. In order to explore the conversions of nitronyl nitroxides in biological systems with and without NO˙, HPLC-MS aided PC12 cell systems were developed, and the conversions of 2-(3'-nitrophenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl -3-oxide (3-nitro-PTIO), 1-oxyl-2-(3'-nitrophenyl)-4,4,5,5-tetramethylimidazoline (3-nitro-PTI), and 1-hydroxyl-2-(3'-nitrophenyl)-4,4,5,5-tetramethylimidazoline (3-nitro-PTIH) were quantitatively monitored. In these systems 3-nitro-PTIO and 3-nitro-PTI were time-dependently converted to 3-nitro-PTIH, while no conversion of 3-nitro-PTIH was detected. Free radical NO˙ donors (sodium nitroprusside, SNP) accelerated the conversions, but had no effect upon the conversion product. In the in vitro and in vivo assays the 3-nitro-PTIH treated cells and mice exhibited no toxic response.

A class of 3S-2-aminoacyltetrahydro-beta-carboline-3-carboxylic acids: their facile synthesis, inhibition for platelet activation, and high in vivo anti-thrombotic potency.

3S-Tetrahydro-beta-carboline-3-carboxylic acid (TCCA) effectively inhibits ADP-induced platelet activation. This paper used TCCA as a lead, modified its 2-position with amino acids, and provided 20 novel 3S-2-aminoacyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acids (5a-t). With the in vitro assay, it was demonstrated that this modification diminished the IC(50) values from 701 nM of TCCA to 10 nM of 5a-t. With the in vivo assay, it was demonstrated that this modification reduced the efficacious dose from 5.0 micromol/kg of TCCA to 0.1 micromol/kg of 5a-t. Comparing the Cerius based conformation of them with that of their analogues, the 3-position modified TCCA, it was suggested that the comparatively unfolded conformation was one of the important factors of enhancing the in vivo antithrombotic potency.