A sensitive and rapid liquid chromatography tandem mass spectrometry method for quantitative determination of 7-ethyl-10-hydroxycamptothecin (SN-38) in human plasma containing liposome-based SN-38 (LE-SN38)

7-Ethyl-10-hydroxycamptothecin (SN-38) is an active metabolite of Irinotecan (CPT-11), an anticancer pro-drug. To support clinical pharmacokinetic studies for liposome based formulation of SN-38 (LE-SN38) in cancer patients, a rapid, simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantification of total SN-38 in human plasma. Sample preparation was carried out by one-step protein precipitation using cold acetonitrile with 0.5% acetic acid (v/v). Camptothecin was used as an internal standard (IS). Chromatographic separation of SN-38 and IS was achieved using a Synergi Hydro-RP column (C(18), 50 x 2 mm, 4 micro m), with a gradient elution of acetonitrile and 0.1% acetic acid. After ionization in electrospray source (positive ions), the acquisition was performed in the multiple reactions monitoring mode. Quantitation was accomplished using the precursor-->product ion combinations of m/z 393.1-->349.2 for SN-38 and 349.1-->305.1 for IS. The quantification limit of 0.05 ng/mL was achieved by using much lower volume (0.2 mL) of plasma and in the presence of LE-SN38. The method was validated over the concentration range of 0.05-400 ng/mL. Accuracy was within +/-12% of nominal at all concentration levels. Inter-day and intra-day precisions expressed as percentage coefficient of variation (%CVs) for quality control (QC) samples were less than 14 and 5%, respectively.     

荧光法研究盐酸拓扑替康、盐酸依利替康喜树碱类药物和牛血清白蛋白的相互作用

用荧光光谱法、分光光度法研究了盐酸拓扑替康(Topotecan hydrochloride, 简记为THC)与盐酸依利替康(Irinotecan hydrochloride, 简记为IHC)两种喜树碱类药物与牛血清白蛋白(Bovine serum albumins, BSA)的相互结合反应. 实验表明喜树碱类药物与牛血清白蛋白的相互结合作用为单一的静态猝灭过程, 在溶液中二者以物质的量比1∶1牢固结合, 25 ℃时其结合反应的平衡常数K₀分别为: K_0,THC＝7.73×10⁵ L•mol^－1, K_0,IHC＝4.73×10⁵ L•mol^－1. 根据Förster非辐射能量转移机理, 求算了给体(BSA)与受体(喜树碱类药物)间距离r和能量转移效率E分别为: r_THC＝3.75 nm, r_IHC＝3.08 nm, E_THC＝0.26, E_IHC＝0.51. 并研究了五种离子对喜树碱类药物与BSA结合作用的影响, 推测了二者之间的主要作用力为疏水作用和偶极-偶极相互作用.     

三维荧光二阶校正同时测定人体液中伊立替康及其代谢物7-乙基-10-羟基喜树碱的含量

提出了激发发射矩阵荧光光谱与化学计量学二阶校正方法相结合用于同时快速定量人体液(血浆和尿液)中的伊立替康(CPT11)和其主要代谢产物7-乙基-10-羟基喜树碱(SN38)的绿色、高灵敏分析策略. 尽管其分析物之间以及分析物和背景之间的光谱存在严重重叠现象, 采用基于交替归一加权残差(ANWE)算法的二阶校正方法进行解析仍能得到令人满意的定性定量分析结果. 当该体系的组分数选取为3时, 可以得到血浆和尿液中CPT11的平均回收率分别为(96.8±6.3)%和(101.7±1.1)%, SN38在血浆和尿液中的平均回收率分别为(100.4±4.9)%和(101.6±1.1)%. 另外, 通过品质因子, 如灵敏度(SEN)、选择性(SEL)、检测下限(LOD)和定量检测限(LOQ)评估了该方法的准确性. 实验结果表明, 该方法能以“数学分离”代替繁琐的“物理和化学分离”, 成功地解决实际复杂体系中内源干扰物质与分析物光谱重叠所引起的难分辨的问题, 可用于人体液中CPT11和SN38含量的直接快速定量测定.     

Prominin‐1‐Specific Binding Peptide‐Modified Apoferritin Nanoparticle Carrying Irinotecan as a Novel Radiosensitizer for Colorectal Cancer Stem‐Like Cells

Resistance of cancer stem cells to radiotherapy remains a major obstacle to successful cancer management. Prominin‐1 (PROM1) is a cancer stem cell marker. Nanoparticle (NP) chemotherapeutics preferentially accumulate in tumors and are able to target cancer and cancer stem‐like cells through cancer cell‐specific ligands, making them uniquely suited as radiosensitizers for chemoradiation therapy. Using a biocompatible apoferritin NP, a PROM1‐targeted NP carrying irinotecan (PROM1‐NP) is engineered. The synergistic effect of the NP and irradiation is evaluated in PROM1‐overexpressing HCT‐116 colorectal cancer cell lines in vitro and in vivo. PROM1‐NP has a size of 17.2 ± 0.2 nm and surface charge of ?13.5 ± 0.2 mV. It demonstrates higher intracellular uptake than nontargeted NP or irinotecan alone. Treatment with PROM1‐NPs decreases HCT‐116 cell proliferation in a dose‐ and time‐dependent manner. In vitro radiosensitization reveals that PROM1‐NP is significantly more effective as a radiosensitizer than nontargeted NP or irinotecan. HCT‐116 tumor xenograft growth is markedly slower following treatment with PROM1‐NP plus irradiation, suggesting that PROM1‐NP is more effective as a radiosensitizer than irinotecan and nontargeted NP in vivo. This study provides the first preclinical evidence of the effectiveness of PROM1‐targeted NP formulation of irinotecan as a radiosensitizer.     

Neobavaisoflavone May Modulate the Activity of Topoisomerase Inhibitors towards U-87 MG Cells: An In Vitro Study

Despite many advances in therapy, glioblastoma (GB) is still characterized by its poor prognosis. The main reason for this is unsuccessful treatment, which slightly extends the duration of remission; thus, new regimens are needed. One of many types of chemotherapeutics that are being investigated in this field is topoisomerase inhibitors, mainly in combination therapy with other drugs. On the other hand, the search for new anti-cancer substances continues. Neobavaisoflavone (NBIF) is a natural compound isolated from Psoralea corylifolia L., which possesses anti-oxidant, anti-inflammatory, and anti-cancer properties. The aim of this study was to evaluate the effect of NBIF in human U-87 MG glioblastoma cells in comparison to normal human NHA astrocytes, and to examine if it influences the activity of irinotecan, etoposide, and doxorubicin in this in vitro model. We demonstrated that NBIF decreases U-87 MG cells viability in a dose-dependent manner. Furthermore, we found that it inhibits cell growth and causes glutathione (GSH) depletion more intensely in U-87 MG cells than in astrocytes. This study also provides, for the first time, evidence of the potentialization of the doxorubicin effect by NBIF, which was shown by the reduction in the viability in U-87 MG cells.     

Characterisation and antiproliferative activity of irinotecan and sulphonatocalixarene inclusion complex

The interaction between water-soluble sulphonatocalix[4]arene (SC4A) and irinotecan (CPT-11) was investigated by using UV spectrophotometry. Inclusion complex of SC4A with CPT-11 was confirmed by ¹H NMR and DSC analysis. Water solubility study showed that SC4A has remarkable solubilisation on CPT-11 and the complex has good water solubility. The antiproliferative activity of the complex was evaluated. The results showed that the complexation of CPT-11 with SC4A increases the antiproliferative activity of CPT-11.     

UGT1A1*28基因多态性与伊立替康治疗晚期非小细胞肺癌的毒副反应及疗效的关系研究

目的探讨UGT1A1*28基因多态性与CPT-11治疗晚期NSCLC的毒副反应与疗效的关系。方法外周血检测2015年6月至2016年6月在九江市第一人民医院所收治的50例晚期NSCLC患者UGTIA1*28 TATA盒基因序列,并对所有50例患者接受CPT-11为基础化疗方案的患者出现的不良反应和近期疗效随访记录,比较不同基因型之间的差别。结果 50例晚期NSCLC患者中UGTIA1*28位点突变型可以增加发生3级以上腹泻(P=0.007)和3级以上血小板减少(41.7%VS 10.5%,P=0.027)的风险。结论在CPT-11化疗的患者中,UGTl Al*28基因型TA6/7,或TA7/7基因型可增加晚期NSCLC患者发生Ⅲ度以上腹泻及血小板减少的风险,然而不影响化疗的近期疗效。     

Voltammetric Characterisation of Anticancer Drug Irinotecan

Electrochemical reduction of irinotecan was investigated on a static mercury drop electrode using square‐wave voltammetry. The mechanism of irinotecan electroreduction is a complex, pH‐dependent, quasireversible process and includes the transfer of two electrons and two protons. In acidic medium, the first electron transfer reaction is followed by the chemical reaction, and the product of this chemical reaction undergoes further electrochemical reduction at more negative potentials. Both irinotecan and the product of its reduction adsorb on the mercury electrode surface. Based on the adsorptive character of irinotecan, a new adsorptive stripping square‐wave voltammetric method for its electroanalytical determination has been proposed. The voltammetric response could be used to determine irinotecan in the concentration range from 1×10⁻⁷ mol/L to 1.5×10⁻⁶ mol/L and from 5×10⁻⁹ mol/L to 1.2×10⁻⁷ mol/L, if the accumulation time is 20 s and 300 s, respectively. The calculated limit of detection for irinotecan was found to be 8.7×10⁻⁹ mol/L (if t_acc=300 s).     

Synthesis and characterization of magnetic nanocomposite for in vitro evaluation of irinotecan using human cell lines

In this study, magnetic O-carboxymethyl chitosan (MOCC) nanocomposite was synthesized and characterized as a drug delivery system for loading the anticancer drug irinotecan (CPT-11). To increase the drug loading capacity, MOCC was synthesized by linking the carboxyl group functionally to chitosan. Also, several critical factors such as concentration, the dose of MOCC, and contact time for optimum drug loading condition were investigated. The loading capacity of CPT-11 onto MOCC was calculated as 5.6 mg/g, and the loaded drug concentration was calculated as 0.04787 mM at pH value of 5. Besides, the cytotoxic properties of MOCC, CPT- 11 loaded MOCC (MOCC-CPT-11), and free CPT-11 were studied on glioblastoma multiforme cell lines, including U87 and U373. According to the results, the MOCC-CPT-11 showed at least as toxic effect as free CPT-11 even at very low concentrations, while the MOCC showed slight toxicity (cell viability of 96% to 78%) on U373 cell lines at all concentrations and for 24 h and 48 h incubation times. Moreover, the results showed that the MOCC indicated significant toxicity in increasing concentrations and incubation times, and the MOCC-CPT-11 is as toxic as free CPT-11 on U87 cells at all concentrations and incubation times.     

Square Wave Cathodic Adsorptive Stripping Voltammetric Determination of the Anticancer Drugs Flutamide and Irinotecan in Biological Fluids Using Renewable Pencil Graphite Electrodes

A sensitive electrochemical method based on square wave cathodic adsorptive stripping voltammetry (SWCASV) using pencil graphite electrodes (PGE) was developed for the individual and simultaneous determination of the anticancer drugs flutamide (Flu) and irinotecan (Irino) in biological fluids. Calibration curves showed an excellent linear response with limits of detection of 1.68×10^?9 and 1.55×10^?8 M Irino and Flu, respectively. The statistical evaluation of within‐day repeatability (n=5) and day to day precision (n=5) showed satisfactory accuracy and precision. SWCASV using a PGE for individual and simultaneous determination of both drugs in bulk form, human urine and serum samples was demonstrated.