Determination of doxorubicin in human plasma by excitation-emission matrix fluorescence and multi-way analysis

Direct determination of doxorubicin (DXR), a cytotoxic anthracycline antibiotic, in human plasma was accomplished based on excitation-emission matrix (EEM) fluorescence measurements and multi-way chemometric methods based on parallel factor analysis (PARAFAC) and N-PLS. Several different procedures, such as residual analysis, core consistency diagnostic (CONCORDIA) and split-half analysis were employed to determine the correct number of factors in PARAFAC. These procedures converged to a choice of two factors, attributed to DXR and to the sum of two fluorescence species present in the plasma. Sample PARAFAC loadings were employed to build a regression model against concentration, resulting in a RMSECV of 0.060 μg ml⁻¹. N-PLS using two factors produced a RMSECV of 0.045 μg ml⁻¹. Figures of merit (FOM), such as sensitivity (SEN), selectivity (SEL) and limit of detection (L_D) were determined for both PARAFAC and N-PLS.     

A Cyanine-based Liposomal Nanophotosensitizer for Enhanced Cancer Chemo-Photodynamic Therapy

Currently, chemotherapy is one of the most important treatment modalities for malignant tumors in the clinic, however, it exhibits some shortcomings, such as poor selectivity, limited efficacy and serious adverse effects. Therefore, synergistic therapy and accurate drug delivery at tumor sites become a promising strategy for achieving tumor eradication. Herein, a smart NIR fluorescence imaging-guided nanoliposome was fabricated by encapsulating a chemotherapeutic drug(doxorubicin, DOX), liposomes(L) and a near-infrared(NIR) photosensitizer(CY) to form L@CY@DOX, which could realize enhanced therapeutic efficacy of chemo-PDT in cancer therapy(PDT=photodynamic therapy). L@CY@DOX can induce mitochondrial apoptosis and produce severe toxicity at the cellular level, and L@CY@DOX can enrich in the tumor site, which significantly induces tumor death. In vitro and in vivo studies demonstrated that L@CY@DOX exhibited great antitumor efficacy compared with each one of these monotherapies, indicating that the combination of chemotherapy and PDT possessed potential development prospects and is anticipated in clinical application.     

叶酸靶向复合脂质体中阿霉素和维拉帕米含量的测定

建立叶酸靶向复合脂质体中阿霉素和维拉帕米含量测定的反相高效液相色谱法。阿霉素在0.5—60μg/mL范围内呈良好线性关系,平均回收率97.3%;维拉帕米在1.0—50.0μg/mL范围内呈良好线性关系,平均回收率97.2%。本方法灵敏度高,专属性强,重现性好,操作简便,能准确测定叶酸靶向复合脂质体中阿霉素和维拉帕米的含量。     

Selective determination of doxorubicin and doxorubicinol in rat plasma by HPLC with photosensitization reaction followed by chemiluminescence detection

A highly sensitive and selective high-performance liquid chromatography (HPLC) method was developed for the determination of doxorubicin (DXR) and its metabolite doxorubicinol (DXR-ol) in rat plasma. The method was based on photosensitization reaction followed by peroxyoxalate chemiluminescence detection (PO-CL). DXR and DXR-ol that were fluorescent quinones, served as a photosensitizer in the presence of a hydrogen atom donor such as ethanol under aerobic conditions to produce hydrogen peroxide. Then the generated hydrogen peroxide and DXR or DXR-ol were monitored through PO-CL reaction by mixing with aryloxalate as a single post-column reagent that enabled highly selective and sensitive determination of DXR and DXR-ol. The separation of DXR and DXR-ol by HPLC was accomplished isocratically on an ODS column within 15 min. The method involves a simple one step protein precipitation by methanol and a sample size of 50-μL was sufficient. Besides, it can detect accurately the low plasma concentrations. The detection limits (signal-to-noise ratio = 3) were 4.5 and 3.8 fmol for DXR and DXR-ol, respectively. The percentage recovery was found to be 90.7-102.4% and the inter- and intra-assay RSD values in rat plasma were 2.5-8.9%. The method has been successfully used to study pharmacokinetic profiles of DXR and DXR-ol in rats after a single-dose of DXR.     

Synthesis,characterization and biological evaluation of purine nucleoside analogues

We present a convenient route for the synthesis of C6-amino-C5′-N-cyclopropyl carboxamido-C2-alkynylated purine nucleoside analogues 11a–g via Sonogashira coupling reaction. The nine step synthesis is easy to perform, employing commercially available reagents. Compound 9 is used as key intermediate for the synthesis of analogues 11a–g. Synthetic intermediates and final products are appropriately characterized by IR, ¹H NMR, ¹³C NMR and Mass. The modified nucleoside analogues 11a–g is evaluated for in vitro anticancer activity against MDA-MB-231 and Caco-2 cell lines. Screening data reveals that compounds 11b and 11e displayed potent IC₅₀ value of 7.9, 6.8 µg/mL respectively against MDA-MB-231 and of 7.5, 8.3 µg/mL respectively against Caco-2 than the standard drug doxorubicin, thus establishing the potential anti-cancer properties of these newer derivatives.     

盐酸阿霉素分子印迹传感器的制备及识别特性

采用自组装以及电聚合的方法,在磷酸盐缓冲液(PBS)中以3,4-乙烯二氧噻吩(EDOT)为功能单体,盐酸阿霉素(DOX)为模板,在金电极表面电聚合制备DOX印迹敏感膜(MIPs),构建了一种选择性检测DOX的分子印迹电化学传感器.采用循环伏安法(CV)及交流阻抗法(EIS)对其性能进行了表征.优化实验条件后,在含0.005 mol/L K3[Fe(CN)_6]及0.1 mol/L KCl的PBS中,应用差分脉冲伏安法(DPV)测试了该传感器的响应性能.实验结果表明,该传感器检测DOX的线性范围为4.0×10~(-7)~1.0×10~(-6)mol/L,相关系数为0.9967,检出限(S/N=3)达6.5×10~(-8)mol/L;采用电化学洗脱法可使传感器再生,对DOX的测定具有良好重现性及稳定性;该传感器对于干扰物长春碱、放线菌素D及5-氟尿嘧啶有微弱的电流响应,显示出良好的选择性.将该传感器用于人体血样中盐酸阿霉素的分析,回收率为96.0%~106.7%,表明其具有潜在的实用价值.     

Voltammetric study of gold-supported lipid membranes in the presence of perfluorooctanesulphonic acid

The effect of perfluorooctanesulphonic acid (PFOS) on lipid membranes was studied using supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayer as the model membrane. Phospholipid bilayer was deposited on gold electrode using a combination of the Langmuir–Blodgett and Langmuir–Schaefer (LB/LS) techniques. Electrodes were modified with two different types of membranes: DMPC bilayers initially containing PFOS and pure DMPC bilayers later exposed to the PFOS solutions. Such approach allowed studying both the changes in membrane characteristic imposed by the perfluorinated compound present in the model membrane and the process of its incorporation into the membrane. Studies with anticancer drug doxorubicin revealed that PFOS inhibits drug transport through the phospholipid bilayer and its effect can be compared to that of cholesterol. Moreover, the different trends observed in the changes in electron transfer rate constant (k_s) calculated for ferricyanides and in peak current of hexaamineruthenium chloride showed that electrostatic interactions between electroactive probes and PFOS molecules incorporating into phospholipid bilayers play an important role and should be taken into account while explaining the interactions of perfluorooctanesulphonic acid with model biological membranes.     

Electrochemical Activity of Wedelolactone and Probing its Interaction with DNA Using Voltammetry at a Carbon Electrode

Wedelolactone (WLA) is a polyphenolic coumestan derivative found in extracts of plants used in traditional medicine. Due to its cytostatic activity, WLA is one of natural compounds tested as potential anticancer drugs. In this work we for the first time studied electrochemical properties of WLA using cyclic (CV) and square‐wave (SWV) voltammetry at the basal‐plane pyrolytic graphite electrode. A reversible pair of peaks, corresponding to catechol/o‐benzoquinone redox system, was observed using CV around 0.275 V vs. Ag|AgCl|3 M KCl reference electrode. Measurements of SWV signal of WLA in the presence of single‐ or double‐stranded DNA suggested a weak interaction without evident preference for double‐stranded DNA. An indirect assay, employing electroactive DNA intercalator doxorubicin as competitor, confirmed absence of intercalative DNA binding of WLA.     

Doxorubicin-containing microparticles comprising cinnamoyl gelatin-folic acid conjugate,cinnamoyl Pluronic F127, and cinnamoyl poly(β-cyclodextrin)

Microparticles comprising of cinnamoyl gelatin (type A) (CA-GelA), cinnamoyl gelatin (type B) (CA-GelB), cinnamoyl Pluronic F127 (CA-Plu), and cinnamoyl poly(β-cyclodextrin) (CA-P(βCD)) were prepared as a carrier for doxorubicin (DOX). Folic acid (FA) was covalently attached to CA-GelA as a targeting molecule for cancer cells. The covalent attachment of FA was confirmed by ¹H-NMR spectroscopy. On the TEM micrographs, the microparticles were almost circular and they were a few hundreds of nanometers in diameter. The release at pH7.4 of DOX from microparticle/DOX suspension was more extensive when the FA content of microparticles was lower and the temperature of release medium was higher. According to the flow cytometric analysis, the lager amount of FA seemed to make the interaction of the microparticle and KB cell more favorable. On confocal laser fluorescence micrograph, the cell treated with microparticle bearing FA showed relatively strong DOX fluorescence, indicating the strong interaction of the microparticle and KB cells.     

2-羟丙基-β-环糊精与二茂铁衍生物超分子胶束通过氧化还原响应控制药物释放

合成了新型的具有长链的二茂铁衍生物(P-Fc),并将其包络在2-羟丙基-β-环糊精(HP-β-CD)的空腔中,自组装形成超分子囊泡,并通过FTIR、1 HNMR、SEM和CV曲线对其进行结构形貌表征;分别以罗丹明6G(R6G)、盐酸阿霉素(DOX)作为药物,实现了R6G、DOX在囊泡中的成功装载。并通过加入氧化剂,将二茂铁氧化成二茂铁盐,将囊泡破坏,实现了 R6G 和 DOX 的快速定向释放,其药物装载量分别为6.89和39.06μg/mg,最大释放率分别为73.7%和88.2%。