Prolonged joint cavity retention of tranexamic acid achieved by a solid-in-oil-in-gel system: A preliminary study.

Tranexamic acid (TXA) is an anti-fibrinolysis agent widely used in postoperative blood loss management. As a highly water-soluble drug, TXA is suffering from rapid clearance from the action site, therefore, large amount of drug is required when administered either by intravenously or topically. In this study, a TXA preparation with prolonged action site residence was designed using the nano-micro strategy. TXA nanoparticles were dispersed in oil by emulsification followed by lyophilization to give a solid-in-oil suspension, which was used as the oil phase for the preparation of TXA-loaded solid-in-oil-in-water (TXA@S/O/W) system. The particle size of TXA in oil was 207.4 ± 13.50 nm, and the particle size of TXA@S/O/W was 40.5 µm. The emulsion-in-gel system (TXA@S/O/G) was prepared by dispersing TXA@S/O/W in water solution of PLGA-b-PEG-b-PLGA (PPP). And its gelling temperature was determined to be 26.6 ℃ by a rheometer. Sustained drug release was achieved by TXA@S/O/G with 72.85 ± 7.52 % of TXA released at 120 h. Formulation retention at the joint cavity was studied by live imaging, and the fluorescent signals dropped gradually during one week. Drug escape from the injection site via drainage and absorption was investigated by a self-made device and plasma TXA concentration determination, respectively. TXA@S/O/G showed the least drug drainage during test, while more than 70 % of drug was drained in TXA@S/O/W group and TXA solution group. Besides, low yet steady plasma TXA concentration (less than 400 ng/mL) was found after injecting TXA@S/O/G into rat knees at a dosage of 2.5 mg/kg, which was much lower than those of TXA dissolved in PPP gel or TXA solution. In conclusion, sustained drug release as well as prolonged action site retention were simultaneously achieved by the designed TXA@S/O/G system. More importantly, due to the steady plasma concentration, this strategy could be further applied to other highly water-soluble drugs with needs on sustained plasma exposure.

Research progress in nano-drug delivery systems based on the characteristics of the liver cancer microenvironment.

The liver cancer has microenvironmental features such as low pH, M2 tumor-associated macrophage enrichment, low oxygen, rich blood supply and susceptibility to hematotropic metastasis, high chemokine expression, enzyme overexpression, high redox level, and strong immunosuppression, which not only promotes the progression of the disease, but also seriously affects the clinical effectiveness of traditional therapeutic approaches. However, nanotechnology, due to its unique advantages of size effect and functionalized modifiability, can be utilized to develop various responsive nano-drug delivery system (NDDS) by using these characteristic signals of the liver cancer microenvironment as a source of stimulation, which in turn can realize the intelligent release of the drug under the specific microenvironment, and significantly increase the concentration of the drug at the target site. Therefore, researchers have designed a series of stimuli-responsive NDDS based on the characteristics of the liver cancer microenvironment, such as hypoxia, weak acidity, and abnormal expression of proteases, and they have been widely investigated for improving anti-tumor therapeutic efficacy and reducing the related side effects. This paper provides a review of the current application and progress of NDDS developed based on the response and regulation of the microenvironment in the treatment of liver cancer, compares the effects of the microenvironment and the NDDS, and provides a reference for building more advanced NDDS.

Adaptive cooperative guidance with seeker-less followers: A position coordination-based framework.

This paper addresses the problem of cooperative guidance for multiple flight vehicles, comprising a leader and seeker-less followers. All the flight vehicles are required to hit the target simultaneously at a desired impact time, even though the target information is unavailable to the followers. To achieve this, a fixed-time convergent guidance law is proposed for the leader, incorporating impact time control. We introduce an adaptive cooperative guidance strategy for the seeker-less followers through coordinated position location relative to the leader. The simulation results validate the effectiveness satisfactorily coinciding with the theoretical analysis.

Development of a UPLC-MS/MS method for simultaneous therapeutic drug monitoring of anti-hepatocellular carcinoma drugs and analgesics in human plasma.

In hepatocellular carcinoma treatment, sorafenib, oxaliplatin, 5-fluorouracil, capecitabine, lenvatinib, and donafenib are first-line drugs; regorafenib, apatinib, and cabozantinib are second-line drugs; and oxycodone, morphine, and fentanyl are commonly used analgesics. However, the high degree of inter- and intra-individual variability in the efficacy and toxicity of these drugs remains an urgent issue. Therapeutic drug monitoring (TDM) is the most reliable technical means for evaluating drug safety and efficacy. Therefore, we developed an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous TDM of three chemotherapy drugs (5-fluorouracil, oxaliplatin, and capecitabin), six targeted drugs (sorafenib, donafenib, apatinib, cabozantinib, regorafenib, and lenvatinib), and three analgesics (morphine, fentanyl, and oxycodone). We extracted 12 analytes and isotope internal standards (ISs) from plasma samples by magnetic solid phase extraction (mSPE) and separated them using a ZORBAX Eclipse Plus C18 column with water containing 0.1% formic acid and methanol containing 0.1% formic acid as the mobile phase. The analytical performance of our method in terms of sensitivity, linearity, specificity, carryover, precision, limit of quantification, matrix effect, accuracy, dilution integrity, extraction recovery, stability, and crosstalk of all the analytes under different conditions met all the criteria stipulated by the guidelines of the Chinese Pharmacopoeia and U.S. Food and Drug Administration. The response function was estimated at 10.0-10 000.0 ng/mL for sorafenib, donafenib, apatinib, cabozantinib, regorafenib, and lenvatinib, and 20.0-20 000.0 ng/mL for 5-fluorouracil, oxaliplatin, capecitabin, morphine, fentanyl, and oxycodone, with a correlation of > 0.9956 for all compounds. The precision and accuracy of all analytes were < 7.21% and 5.62%, respectively. Our study provides empirical support for a simple, reliable, specific, and suitable technique for clinical TDM and pharmacokinetics.

Development and validation of an UPLC-MS/MS method for simultaneous determination of fifteen targeted anti-cancer drugs in human plasma and its application in therapeutic drug monitoring.

In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously detect 15 targeted anti-cancer drugs: aletinib, afatinib, apatinib, icotinib, dasatinib, erlotinib, gefitinib, crizotinib, lapatinib, regorafenib, ceritinib, sorafenib, vemurafenib, imatinib, and N-desmethyl imatinib. Plasma samples were processed using a new magnetic solid phase extraction technique to extract each drug. The 15 analytes and four isotope internal standards were separated using an Agilent Eclipse XDB-C18 column (50.0 × 2.1 mm, 1.7 µm) with water containing 0.1% formic acid and acetonitrile as the mobile phase. The method verification included specificity, calibration curves, carryover, accuracy, crosstalk, precision, stability, recovery, dilution integrity, and matrix effects. The results showed that the developed UPLC-MS/MS method met the requirements of the U.S. Food and Drug Administration guidelines for methodological validation and could be used to monitor plasma concentrations. The response function was established for concentration range of 2.5-2500.0 ng/mL for aletinib, afatinib, apatinib, icotinib, dasatinib, crizotinib, regorafenib, vemurafenib, and N-desmethyl imatinib and 10.0-10,000.0 ng/mL for erlotinib, ceritinib, imatinib, sorafenib, gefitinib, and lapatinib, with a coeffificient of correlation of > 0.9977 for all the compounds. The precision and accuracy of all the analytes were < 6.88% and 5.29%, respectively. The percentage recovery and matrix effect of all the analytes were 91.3-103% and 93.8-102% for three QC concentrations levels. The recovery and matrix effect for all the ISs ranged from 93.7% to 98.8% and 94.6-101%. Meanwhile, we also found that the plasma concentrations of these targeted anti-cancer drugs showed large individual differences, which is not conducive to the treatment of tumors. Therefore, therapeutic drug monitoring (TDM) of these 15 targeted anti-cancer drugs is necessary, and this method could be used for TDM and exploration of pharmacokinetics of the aforementioned 15 targeted anti-cancer drugs.

Pharmacokinetic changes for newer antiepileptic drugs and seizure control during pregnancy.

OBJECTIVE: To investigate pharmacokinetic changes in newer antiepileptic drugs (AEDs) and assess seizure frequencies and risk factors of increased seizures during pregnancy in women with epilepsy (WWE). METHODS: A total of 56 pregnancies in 53 WWE who received newer antiepileptic drugs (AEDs) were enrolled. Data on seizure activity and types, daily dose, and AEDs blood levels were derived from routine clinical follow-up. Changes in AEDs clearance were compared between each trimester and nonpregnant baseline. The ratio of AED levels of each trimester to their targets (nonpregnant baseline) concentrations (RTC) was compared between patients with and without an increased seizure. A binary logistic regression was used to investigate the risk factors contributing to seizure worsening during pregnancy. RESULTS: Increased clearances of LTG, LEV, and OXC were observed in all trimesters versus nonpregnant baseline. The peak changes in the clearance of LTG (3.42-fold baseline clearance) (p < 0.001) and LEV (2.78-fold) (p < 0.001) occurred in the second trimester during pregnancy, followed by oxcarbazepine (2.11-fold) in the third trimester (p < 0.03). Plasma concentrations of LTG and LEV during pregnancy were significantly decreased compared to baseline levels, except for OXC. However, no significant differences in RTC values were observed between patients with and without seizure worsening. Some risk factors as seizures for the prior nine months could significantly affect seizure frequency during pregnancy. CONCLUSION: We found substantial changes in the pharmacokinetics of multiple newer AEDs in WWE, reinforcing the need for therapeutic drug monitoring (TDM) during pregnancy. We would encourage at least one monitoring every trimester and probably more frequently for women with poorly seizure control before pregnancy, and AEDs dose adjustment should keep up with clearance changes. In addition, a well-controlled seizure nine months before pregnancy could lower the risks of seizure during pregnancy, highlighting the importance of pre-pregnancy counseling and seizure management before pregnancy.

Ultra-performance liquid chromatography-tandem mass spectrometry for simultaneous determination of 12 anti-tumor drugs in human plasma and its application in therapeutic drug monitoring.

The effectiveness and safety of anti-tumor drugs are clinically important issues, and their therapeutic drug monitoring (TDM) is recommended. This study aimed to develop an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous TDM and exploration of clinical pharmacokinetics of anti-tumor drugs, including cyclophosphamide, ifosfamide, cisplatin, methotrexate, pemetrexed disodium, capecitabine, 5-fluorouracil, gemcitabine, doxorubicin, fulvestrant, tamoxifen, and irinotecan. After magnetic solid-phase extraction of plasma samples, the isotope internal standards and 12 anti-tumor drugs were separated using a ZORBAX Eclipse Plus C18 column (50.0 × 2.1 mm, 1.7 µm) with water containing 0.1% formic acid and acetonitrile as the mobile phase in a total run time of 5.0 min. The developed UPLC-MS/MS method was validated based on the Chinese Pharmacopoeia and the US Food and Drug Administration guidelines for bioanalytical method validation, including assessment of specificity, calibration curves, carryover, accuracy, crosstalk, precision, stability, recovery, dilution integrity, incurred sample reanalysis, and matrix effect. The results showed that a simple, fast, reliable, and specific UPLC-MS/MS method was developed and validated, and all the performance characteristics of the method met the requirements. The response function was established for concentration range of 0.10-25.00 µg/mL for gemcitabine, cyclophosphamide, ifosfamide, methotrexate, pemetrexed disodium, capecitabine, 5-fluorouracil, and cisplatin, and 0.05-12.50 µg/mL for doxorubicin, fulvestrant, tamoxifen, and irinotecan, with a coefficient of correlation of>0.9984 for all the compounds. The precision and accuracy of all the analytes were<6.5% and 5.9%, respectively. Hence, it could be used for TDM and exploration of pharmacokinetics of the aforementioned 12 anti-tumor drugs.

Circular RNA circ_DROSHA alleviates the neural damage in a cell model of temporal lobe epilepsy through regulating miR-106b-5p/MEF2C axis.

Temporal lobe epilepsy (TLE) is the most prevalent form of acquired epilepsy. Circular RNAs (circRNAs) have recently been highlighted as important regulators in TLE. Nevertheless, the role and mechanism of circRNA Drosha ribonuclease III (circ_DROSHA) in TLE pathogenesis are still unknown. Magnesium-free extracellular solution was used to establish the TLE cell model. The levels of circ_DROSHA, myocyte-specific enhancer factor 2C (MEF2C) and miR-106b-5p were determined by qRT-PCR and western blot. Cell proliferation was detected by the Cell Counting-8 Kit (CCK-8) assay, and cell apoptosis was measured by flow cytometry. Targeted relationships among circ_DROSHA, miR-106b-5p and MEF2C were confirmed by a dual-luciferase reporter or RNA immunoprecipitation (RIP) assay. Our data showed that circ_DROSHA was down-regulated in the serum samples of TLE patients and the TLE cell model. Circ_DROSHA up-regulation alleviated the cytotoxicity of the TLE cell model by enhancing cell proliferation and repressing cell apoptosis. Circ_DROSHA directly bound to miR-106b-5p. Moreover, miR-106b-5p represented a downstream effector of circ_DROSHA function. MEF2C was a direct target of miR-106b-5p, and miR-106b-5p knockdown relieved magnesium-free treatment-induced cell injury by up-regulating MEF2C. Furthermore, circ_DROSHA regulated MEF2C expression via sponging miR-106b-5p. Our study suggested that the enforced expression of circ_DROSHA alleviated the cell damage of the TLE cell model at least in part through the regulation of the miR-106b-5p/MEF2C axis.

Lysine-mediated hydroxyethyl starch-10-hydroxy camptothecin micelles for the treatment of liver cancer.

Liver cancer is a malignant tumor with extremely high morbidity and mortality. At present, traditional chemotherapy is still the most commonly used therapeutic approach. However, serious side effects lead to the treatment of liver cancer is not ideal. Therefore, it is imperative to develop a new drug delivery system based on nanotechnology and liver cancer microenvironment. In this study, a pH/reduction/α-amylase multi-sensitive hydroxyethyl starch-10-hydroxy camptothecin micelles (HES-10-HCPT-SS-Ly) targeting over-expressed amino acid (AA) transporters on the surface of liver cancer cell by applying lysine were successfully synthesized. The prepared micelles showed regular structure, suitable particle size, and intelligent drug release property. Compared with conventional HES-10-HCPT micelles and 10-HCPT injection, HES-10-HCPT-SS-Ly micelles demonstrated better in vitro anti-proliferative capability toward human liver cancer Hep-G2 cells and greater antitumor efficiency against nude mouse with Hep-G2 tumor. These findings suggest that HES-10-HCPT-SS-Ly micelles may be a promising nanomedicine for treatment of liver cancer.

Impact of Age and Genotype on Serum Concentrations of Valproic Acid and Its Hepatotoxic Metabolites in Chinese Pediatric Patients With Epilepsy.

BACKGROUND: The aim of the study was to investigate how age and genetic polymorphisms of UGT1A6 and UGT2B7 contribute to the concentrations of valproic acid (VPA) and its hepatotoxic metabolites in Chinese pediatric patients with epilepsy. METHODS: A total of 122 children with epilepsy were genotyped at 19T>G, 541A>G, and 552A>C in UGT1A6 and -161C>T and 802C>T in UGT2B7 using the polymerase chain reaction-restriction fragment length polymorphism method or direct sequencing method. The concentrations of VPA, 4-ene-VPA, and 2,4-diene-VPA were simultaneously determined using ultra-performance liquid chromatography-tandem mass spectrometry. RESULTS: Significant association was observed between the UGT2B7 802C>T genotype and dose-adjusted concentrations of VPA, 4-ene-VPA, and 2,4-diene-VPA. The younger children had increased concentrations of the hepatotoxic metabolites and decreased levels of VPA. The allele status of UGT2B7 802C>T had no influence on the metabolite ratios within age groups, but showed a significant difference among the age groups. CONCLUSIONS: The present study suggests that UGT2B7 802C>T polymorphism and age are factors affecting the concentrations of dose-adjusted VPA and its metabolites. No genotype-related differences were noted in the metabolite ratios of 4-ene-VPA and 2,4-diene-VPA within age-assigned groups. Therefore, careful administration is particularly necessary for younger patients who are UGT2B7 802C>T poor metabolizers.

Sorafenib-loaded hydroxyethyl starch-TG100-115 micelles for the treatment of liver cancer based on synergistic treatment.

Tumor microenvironment is closely related to the occurrence and development of liver cancer. Tumor-associated macrophages (TAMs) are an important part of tumor microenvironment promoting tumor deterioration and metastasis by inhibiting immune cells. Previous studies showed that PI3Kγ inhibitor could reverse the phenotype of TAMs, relieve immunosuppression and sensitize chemotherapy drugs, suggesting that the combination of PI3Kγ inhibitor and chemotherapeutics is likely to bring new breakthroughs in the treatment of liver cancer. Based on it, this paper builds HES-TG100-115-CDM-PEG micelles with tumor microenvironment responsiveness that simultaneously loaded sorafenib and TG100-115 to synergistically treat liver cancer. Pharmacokinetic study showed that the prepared micelles had longer half-life than that of the free drug solutions, which was favorable for high propensity of extravasation through tumor vascular fenestrations. Under low pH and high α-amylasereductive conditions, micelles could depolymerize quickly due to the sensitivity of bonds and enhance significantly cytotoxic activity against Hep-3B liver cancer cell. Additionally, micelles demonstrated higher levels of antitumor efficiency and better tolerance against nude mouse with Hep-3B cell than the free drug solutions. These findings reveal that HES-TG100-115-CDM-PEG micelles are a promising drug delivery system in clinical comprehensive therapy of liver cancer.

Preparation and in vitro-in vivo evaluation of intestinal retention pellets of Berberine chloride to enhance hypoglycemic and lipid-lowing efficacy.

Berberine chloride (BBR) is a pharmacokinetic profile of drug with poor bioavailability but good therapeutic efficacy, which is closely related to the discovery of BBR intestinal target. The major aim of this paper is to develop BBR intestinal retention type sustained-release pellets and evaluate their in vivo and in vitro behaviors base on the aspect of local action on intestinal tract. Here, wet milling technology is used to improve dissolution and dissolution rate of BBR by decreasing the particle size and increasing the wettability. The pellets are prepared by liquid layer deposition technology, and then the core pellets are coated with Eudragit® L30D-55 and Eudragit® NE30D aqueous dispersion. The prepared pellets show high drug loading capacity, and the drug loading up to 93%. Meanwhile, it possesses significant sustained drug release effect in purified water which is expected to improve the pharmacokinetic behavior of BBR. The pharmacokinetics results demonstrate that the half-life of BBR was increased significantly from 24 h to 36 h and the inter- and intra-subject variability are decreased compared to commercial BBR tablets. The retention test results indicate that the pellet size and Eudragit® NE30D plays an important role in retention time of the pellet, and it is found that the pellets with small particle size and high Eudragit® NE30D coating content can stay longer in the intestine than the pellets with large particle size. All in all, BBR intestinal retention type pellets are prepared successfully in this study, and the pellets show satisfactory in vivo and in vitro behaviors.

Pharmacokinetic interactions and tolerability of berberine chloride with simvastatin and fenofibrate: an open-label, randomized, parallel study in healthy Chinese subjects.

PURPOSE: Fenofibrate (Fbt) is a prodrug that has been used to reduce low-density-lipoprotein cholesterol, triglycerides, and increase high-density-lipoprotein cholesterol. Simvastatin (Svt) is a classic lipid-lowering drug that is widely used in the treatment of hypercholesterolemia and hypertriglyceridemia, while berberine chloride (Bbr) is a novel hypolipidemic agent and its blood-lipid-reducing mechanism is distinct from traditional drugs. Currently, drug combination is the trend in treating hyperlipidemia to improve clinical efficacy. The purpose of this study was to evaluate drug interaction from the perspective of pharmacokinetics between Bbr and Fbt/Svt and the tolerability of combined administration in healthy Chinese subjects. METHODS: Healthy subjects (n=60) were randomly allocated to five treatment groups: Bbr alone, Fbt alone, Svt alone, Bbr plus Fbt, and Bbr plus Svt. The experiment was divided into two parts: single-dose administration and multiple-dose administration. Bbr, Fbt, and Svt were taken once every 8 hours, 24 hours, and 24 hours, respectively, over 7 days in the multidose group. Plasma samples were collected and liquid chromatography-mass spectrometry/mass spectrometry was used to detect drug concentrations. RESULTS: No serious adverse reactions or intolerance were observed throughout the trial. More importantly, the combined-administration groups did not show an increase in incidence of side effects. Coadministration of Fbt and Svt with Bbr had no significant effect on the pharmacokinetic parameters of Bbr, except time to maximum concentration, apparent volume of distribution, and apparent clearance. Concurrent coadministration of Bbr had no obvious impact on the pharmacokinetic behavior of Fbt or Svt. Additionally, there was no significant correlation between sex and pharmacokinetic results. CONCLUSION: All treatments were well tolerated. No clinically obvious pharmacokinetic interactions between Bbr and Fbt/Svt were observed with combined administration. The results demonstrated that Bbr can be coadministered safely with Fbt and Svt without dose adjustment.

Associations of CYP2C9 and CYP2A6 Polymorphisms with the Concentrations of Valproate and its Hepatotoxin Metabolites and Valproate-Induced Hepatotoxicity.

The aim of this study was to compare genetic polymorphisms and concentrations of hepatotoxic metabolites in patients with epilepsy and liver injury and those with normal liver function receiving valproate monotherapy to identify risk factors for VPA-induced hepatotoxicity. A total of 279 Chinese patients with epilepsy were divided into an abnormal liver function (ANLFT) group (n = 79) and a normal liver function (NLFT) group (n = 200). Polymerase chain reaction-restriction fragment length polymorphism PCR-RFLP and nested PCR were applied to identify the frequency of two SNPs in candidate genes. Serum concentrations of VPA and its major metabolites were determined by Ultra-Performance Liquid Chromatography-tandem mass spectrometry UPLC-MS/MS. Significant differences were found in genotype distributions of CYP2A6 and CYP2C9 between the two groups. The values of 4-ene-VPA and 2,4-diene-VPA in the ANLFT group were significantly higher than in the NLFT group. Only CYP2A6 polymorphisms had associations with the concentrations of 4-ene-VPA and 2,4-diene-VPA. CYP2A6*1/*4 and CYP2A6*4/*4 variant carriers had higher CDR4-ene-VPA and CDR2,4-diene-VPA values than CYP2A6*1/*1 carriers. The logistic regression analysis showed that CYP2C9 and CYP2A6 were significant risk factors for hepatotoxicity by increasing the risk by 7.50 and 5.13 times, respectively. These findings provide preliminary evidence that CYP2A6 and CYP2C9 are associated with hepatotoxicity. However, only the CYP2A6 polymorphism was found to be associated with concentrations of 4-ene-VPA and 2,4-diene-VPA. Potential important risk factors include mutated genotypes of CYP2C9 and CYP2A6 and higher concentrations of VPA, 4-ene-VPA and 2,4-diene-VPA.

Effect of polymorphisms in CYP3A4, PPARA, NR1I2, NFKB1, ABCG2 and SLCO1B1 on the pharmacokinetics of lovastatin in healthy Chinese volunteers.

AIM: This study examined whether gene polymorphisms (CYP3A4, ABCG2, SLCO1B1, NR1I2, PPARA and NFKB1) influenced the pharmacokinetics of lovastatin in Chinese healthy subjects. PATIENTS & METHOD: Plasma concentrations of lovastatin and lovastatin acid were quantified using LC/MS/MS. RESULTS: PPARA c.208+3819 G allele carriers had approximately twofold higher AUC0-∞ and Cmax of lovastatin than wild-type (PPARA c.208+3819 AA) subjects. After adjustment for the PPARA variants, subjects with the SLCO1B1 521TT genotype had approximately 50% lower AUC0-∞ of lovastatin acid than those with 521TC/CC genotypes, while the AUC0-∞ of lovastatin lactone in NFKB1-94 DD wild-type carriers was twofold higher than in mutant homozygotes carriers. CONCLUSION: Gene polymorphisms of PPARA, SLCO1B1 and NFKB1 affected the pharmacokinetics of lovastatin.

Simultaneous Determination of Valproic Acid and Its Major Metabolites by UHPLC-MS/MS in Chinese Patients: Application to Therapeutic Drug Monitoring.

A specific and sensitive Ultra-high Performance Liquid Chromatography-tandem Mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of the concentrations of valproic acid (VPA) and its clinically relevant metabolites (4-ene-VPA, 2,4-diene-VPA and 2-ene-VPA) in human serum. After solid-phase extraction, VPA, its metabolites and the internal standard were subjected to chromatographic separation by gradient elution of acetonitrile and 10 mM ammonium acetate as mobile phase at a flow rate of 0.6 mL/min on an EC-C18 column. The method was validated over the concentration ranges of 1-200 µg/mL for VPA, 0.5-10 µg/mL for 2-ene-VPA, 10-500 ng/mL for 4-ene-VPA and 25-500 ng/mL for 2,4-diene-VPA. The inter-day and intra-day accuracy and precision were within the acceptable limits of <15 %. The recoveries and matrix effects met the requirement for the analysis of biological samples. No obvious degradation was observed under various storage conditions including room temperature for 12 h, three freeze-thaw cycles and -80°C for 1 month. The assay method was successfully applied to monitor the concentration of VPA and its three metabolites in epileptic patients. The UHPLC-MS/MS method demonstrated a good analytical performance essential for therapeutic drug monitoring, which would potentially lead to clinically relevant improvements in VPA dosage and patient management.

Long non-coding RNA CCAT1 promotes glioma cell proliferation via inhibiting microRNA-410.

BACKGROUND AND AIM: Long non-coding RNAs have been confirmed to play a critical role in various cancers. In the present study, the effect of long non-coding RNA (lncRNA) CCAT1 on glioma cell proliferation and its potential mechanism were investigated. METHODS AND RESULTS: Real-time PCR results showed that lncRNA-CCAT1 expression was significantly upregulated in glioma cancer tissues and cell lines compared with controls. After inhibiting CCAT1 expression in glioma cell line U251 with siRNA-CCAT1 (si-CCAT1), the cell viability and cell colony formation were decreased, the cell cycle was arrested in G1 phase, and the cell apoptosis was increased. As reported in bioinformatics software starbase2.0, a total of 22 microRNAs were potentially targeted by CCAT1. It was confirmed that miR-410 was altered most by si-CCAT1. After up-regulating CCAT1 expression in U251 cells, miR-410 level was decreased. Luciferase reporter assay confirmed that CCAT1 targeted miR-410. Correlation analysis showed that CCAT1 expression was negatively related to miR-410 expression in glioma cancer tissues. In addition, down-regulation of miR-410 reversed the inhibitory effect of si-CCAT1 on glioma proliferation. CONCLUSION: These data demonstrated that lncRNA-CCAT1 promoted glioma cell proliferation via inhibiting miR-410, providing a new insight about the pathogenesis of glioma proliferation.

Beta-asarone protects against MPTP-induced Parkinson's disease via regulating long non-coding RNA MALAT1 and inhibiting α-synuclein protein expression.

OBJECTIVE: Numerous long non-coding RNAs (lncRNA) have been identified in neurodegenerative disorders including Parkinson's disease (PD). Emerging evidence demonstrates that ß-asarone functions as neuroprotective effects in both in vitro and in vivo models. However, the role of ß-asarone and its potential mechanism in PD remain not completely clear. METHODS: MPTP-induced PD mouse model and SH-SY5Y cells subjected to MPP+ as its in vitro model were used to evaluate the effects of ß-asarone on PD. LncRNA MALAT1 and α-synuclein expression were determined by real-time PCR and western blot methods. RESULTS: ß-Asarone significantly increased the TH+ cells number and decreased the expression levels of MALAT1 and α-synuclein in midbrain tissue of PD mice. RNA pull-down and immunoprecipitation assays confirmed that MALAT1 associated with α-synuclein, leading to the increased stability of α-synuclein and its expression in SH-SY5Y cells. ß-asarone elevated the viability of cells exposed to MPP+. Either overexpressed MALAT1 or α-synuclein could canceled the protective effect of ß-asarone on cell viability. In PD mice, pcDNA-MALAT1 also decreased the TH+ cells number and increased the α-synuclein expression in PD mice with treatment of ß-asarone. CONCLUSION: ß-Asarone functions as a neuroprotective effect in both in vivo and in vitro models of PD via regulating MALAT1 and α-synuclein expression.

Association Analysis of Proteasome Subunits and Transporter Associated with Antigen Processing on Chinese Patients with Parkinson's Disease.

BACKGROUND: Proteasome subunits (PSMB) and transporter associated with antigen processing (TAP) loci are located in the human leukocyte antigen (HLA) Class II region play important roles in immune response and protein degradation in neurodegenerative diseases. This study aimed to explore the association between single nucleotide polymorphisms (SNPs) of PSMB and TAP and Parkinson's disease (PD). METHODS: A case-control study was conducted by genotyping SNPs in PSMB8, PSMB9, TAP1, and TAP2 genes in the Chinese population. Subjects included 542 sporadic patients with PD and 674 healthy controls. Nine identified SNPs in PSMB8, PSMB9, TAP1, and TAP2 were genotyped through SNaPshot testing. RESULTS: The stratified analysis of rs17587 was specially performed on gender. Data revealed that female patients carry a higher frequency of rs17587-G/G versus (A/A + G/A) compared with controls. But there was no significant difference with respect to the genotypic frequencies of the SNPs in PSMB8, TAP1, and TAP2 loci in PD patients. CONCLUSION: Chinese females carrying the rs17587-G/G genotype in PSMB9 may increase a higher risk for PD, but no linkage was found between other SNPs in HLA Class II region and PD.

Well-defined hydroxyethyl starch-10-hydroxy camptothecin super macromolecule conjugate: cytotoxicity, pharmacodynamics research, tissue distribution test and intravenous injection safety assessment.

10-Hydroxy camptothecin (10-HCPT) is an antitumor agent effective in the treatment of several solid tumors but its use is hampered by poor water solubility, low lactone stability, short plasma half-life and dose-limiting toxicity. These limits of 10-HCPT had been overcome by our group through preparing super macromolecule prodrug: 10-HCPT-hydroxyethyl starch (HES) conjugate. In this study, we mainly evaluated in vitro and in vivo behavior of the prodrug, containing cytotoxicity assay, pharmacodynamics study, vascular irritation test, hemolysis experiment and tissue distribution test of rats. The irritation test results achieved much lower irritation than the commercial injection. The tissue distribution results showed that HES-10-HCPT conjugate increased significantly the 10-HCPT concentration in the tumor, liver and spleen site, whereas decreased the drug concentration in the heart and kidney. The hemolysis effect of the prepared conjugate was not obvious. The pharmacodynamics results indicated that HES-10-HCPT prodrug had a better antitumor efficiency against mice with H22 tumor than the commercial injection, and the inhibition ratio of tumor was 85.2% and 31.1%, respectively at the same dosage. These findings suggest that HES-10-HCPT prodrug is a promising drug delivery system providing improved good injection safety, greater tolerance and antitumor effect.