Methoxy poly(ethylene glycol)‐block‐poly(D,L‐lactic acid) copolymer nanoparticles as carriers for transdermal drug delivery

This work evaluates the transdermal drug delivery properties of amphiphilic copolymer self‐assembled nanoparticles by skin penetration experiments in vitro. Paclitaxel‐loaded methoxy poly(ethylene glycol)‐block‐poly(D ,L ‐lactic acid) diblock copolymer nanoparticles (PNPs) were prepared by a solid dispersion technique and were applied to the surface of excised full‐thickness rat skin in Franz diffusion cells. HPLC, transmission electron microscopy, Fourier transform infrared spectroscopy and ¹H NMR were used to assay the receptor fluid. The results show that the amphiphilic copolymer nanoparticles with the entrapped paclitaxel are able to penetrate rat skin. Ethanol can improve the delivery of PNPs and increase the cumulative amount of paclitaxel in the receptor fluid by 3 times. Fluorescence microscopy measurements indicate that the PNPs can penetrate the skin not only via appendage routes including sweat ducts and hair follicles but also via epidermal routes. Copyright © 2007 Society of Chemical Industry     

PLGA携载紫杉醇涂层包被TiNi合金的表面特性与生物性能

系统研究了PLGA携载紫杉醇包被TiNi合金的表面特性与生物性能。采用原子力显微镜(AFM)和X射线光电子能谱(XPS)研究了药物涂层的表面形貌及化学成分;采用高效液相色谱(HPLC)研究了在pH为7.4的PBS溶液中紫杉醇从TiNi合金表面涂层中释放特性,并通过血小板粘附试验研究了药物涂层的血液相容性。试验结果表明经涂覆后TiNi合金表面化学组成及结构随着载药量的增加而改变。紫杉醇在涂层降解初期释放较快,随着时间的延长,累积释放量增加缓慢。血小板粘附试验表明载药量为0%、10%、20%和30%时涂膜样品表面血小板粘附数量均小于未涂膜样品表面。而随着载药量的增加,涂膜样品表面粘附的血小板数量增加,血小板变形严重,当载药量为30%时,血小板出现明显的聚集现象。     

紫杉醇在聚甲基丙烯酸树脂中的物化状态

研究了紫杉醇在聚甲基丙烯酸树脂中的化学稳定性、物理分布和物理状态,并分析了其影响因素.结果表明,紫杉醇在复合膜中没有与聚甲基丙烯酸树脂发生化学反应,释放后不改变化学结构;紫杉醇在复合膜中的物理分布受溶剂性质的影响,以四氢呋喃为溶剂,紫杉醇可均匀分布于复合膜中.紫杉醇在复合膜中的存在状态与紫杉醇含量及热处理制度有关.当紫杉醇的含量(质量分数)为10%时,在薄膜中不存在结晶态紫杉醇,当含量大于20%时,出现结晶态紫杉醇.在Tg点附近退火可使薄膜中结晶态紫杉醇的含量增加,从而提高紫杉醇的时效稳定性及其在复合膜中的扩散速度.     

Smart magnetic self-assembled micelle: an effective nanocarrier for thermo-triggered paclitaxel delivery

Magnetic micelle nanoparticles with thermoresponsive behavior were designed for thermo-triggered paclitaxel delivery. For this purpose, thermoresponsive triblock copolymer poly(N-isopropyl acrylamide)-b-polycaprolactone-b-poly(N-isopropyl acrylamide) was prepared. The magnetic micelle was formed by self-assembly of triblock copolymer on the magnetite which was coated by oleic acid. The size of the magnetic micelle was between 30–40?nm reported by transmission electron microscopy. Also, dynamic light scattering indicated the hydrodynamic diameter was thermal dependent. Moreover, the drug release profile showed thermo-triggered release of paclitaxel. Thus, the smart nanocarrier has potential to be applied in both chemotherapy and hyperthermia treatment.     

紫杉醇耐药卵巢癌细胞亚株的蛋白组学研究

目的: 建立卵巢癌细胞株与紫杉醇耐药卵巢癌细胞亚株的差异蛋白表达图谱,寻找对紫杉醇药物耐受的相关蛋白。方法: 以人卵巢浆液性囊腺癌细胞株(SKOV3)和对紫杉醇稳定耐药卵巢浆液性囊腺癌细胞亚株(SKOV3-TR30)为研究对象,应用双向电泳技术建立SKOV3与SKOV3-TR30的蛋白质差异表达图谱,并对图谱进行质谱分析。然后应用蛋白免疫印迹和免疫细胞化学方法对其中3个有差异的蛋白进行定量和定位检测。结果: (1)经过组内与组间3次重复,发现每次实验均有相似变化的差异点23个。其中与SKOV3细胞株相比,在SKOV3-TR30细胞株表达上调大于3倍的蛋白质点有16个(P<0.05),表达下调大于3倍的蛋白质点有7个(P<0.05)。(2)通过质谱分析和数据库搜索,其中7个蛋白点得到初步鉴定,分别为可溶性抗药性相关钙结合蛋白(Sorcin)、组织蛋白酶B前体(Cathepsin B)、调宁蛋白3、热休克蛋白27(HSP27)、波形纤维蛋白、尼克酰胺乙酰乙酸水解酶和血红蛋白β链。(3)蛋白免疫印迹结果显示,Sorcin、Cathepsin B及HSP27在SKOV3-TR30细胞中的表达显著高于SKOV3细胞株(P<0.05)。免疫细胞化学的结果表明,SKOV3及SKOV3-TR30均可检测到Sorcin、Cathepsin B及HSP27阳性表达的细胞,并且3个蛋白均分布在细胞浆内,以核周最为明显。结论: 低浓度紫杉醇诱导的上皮性卵巢癌耐药细胞亚株中存在细胞骨架相关信号转导分子表达上调,上调的细胞骨架相关信号转导分子在卵巢癌临床预示耐药与逆转耐药治疗中的作用值得进一步研究。     

Synergistic Interactions of Cannabidiol with Chemotherapeutic Drugs in MCF7 Cells: Mode of Interaction and Proteomics Analysis of Mechanisms

Cannabidiol (CBD), a nonpsychoactive phytocannabinoid, has recently emerged as a potential cytotoxic agent in addition to its ameliorative activity in chemotherapy-associated side effects. In this work, the potential interactions of CBD with docetaxel (DOC), doxorubicin (DOX), paclitaxel (PTX), vinorelbine (VIN), and 7-ethyl-10-hydroxycamptothecin (SN−38) were explored in MCF7 breast adenocarcinoma cells using different synergy quantification models. The apoptotic profiles of MCF7 cells after the treatments were assessed via flow cytometry. The molecular mechanisms of CBD and the most promising combinations were investigated via label-free quantification proteomics. A strong synergy was observed across all synergy models at different molar ratios of CBD in combination with SN−38 and VIN. Intriguingly, synergy was observed for CBD with all chemotherapeutic drugs at a molar ratio of 636:1 in almost all synergy models. However, discording synergy trends warranted the validation of the selected combinations against different models. Enhanced apoptosis was observed for all synergistic CBD combinations compared to monotherapies or negative controls. A shotgun proteomics study highlighted 121 dysregulated proteins in CBD-treated MCF7 cells compared to the negative controls. We reported the inhibition of topoisomerase II β and α, cullin 1, V-type proton ATPase, and CDK-6 in CBD-treated MCF7 cells for the first time as additional cytotoxic mechanisms of CBD, alongside sabotaged energy production and reduced mitochondrial translation. We observed 91 significantly dysregulated proteins in MCF7 cells treated with the synergistic combination of CBD with SN−38 (CSN−38), compared to the monotherapies. Regulation of telomerase, cell cycle, topoisomerase I, EGFR1, protein metabolism, TP53 regulation of DNA repair, death receptor signalling, and RHO GTPase signalling pathways contributed to the proteome-wide synergistic molecular mechanisms of CSN−38. In conclusion, we identified significant synergistic interactions between CBD and the five important chemotherapeutic drugs and the key molecular pathways of CBD and its synergistic combination with SN−38 in MCF7 cells. Further in vivo and clinical studies are warranted to evaluate the implementation of CBD-based synergistic adjuvant therapies for breast cancer.     

紫杉醇聚合物胶束的组织分布和生物学评价

目的: 研究紫杉醇（paclitaxel,PTX）聚合物胶束的荷瘤鼠组织分布和生物安全性。方法: 采用S180荷瘤小鼠模型研究静脉注射PTX聚合物胶束和Taxol的药动学参数变化、组织分布特征和抗肿瘤作用;通过动物实验研究PTX聚合物胶束的急性毒性、溶血性和静脉刺激性。结果: PTX聚合物胶束的t1/2和平均滞留时间（MRT）分别为Taxol的3.52和4.55倍,在肿瘤部位的相对摄取率为2.31,表明该胶束具有长循环和肿瘤靶向作用。PTX聚合物胶束对S180荷瘤小鼠的抑制显著强于Taxol（P<0.05）。生物安全性评价结果显示PTX聚合物胶束的最大耐受剂量和LD50均显著高于Taxol（P<0.05）,对兔耳缘静脉无明显血管刺激性。 结论: PTX聚合物胶束延长了药物体内循环时间、增强了肿瘤靶向性和抗癌活性,提高了生物安全性,期望为临床提供一种高效、低毒紫杉醇聚合物胶束靶向制剂。     

穗花杉树皮中紫杉醇的提取与含量测定

目的:建立并优化穗花杉树皮中紫杉醇的提取工艺并进行含量测定。方法:以紫外扫描和HPLC相结合的方法测定紫杉醇含量,采用正交实验法对提取过程中提取次数、提取溶剂、提取时间、料液比四因素进行优选实验。结果:影响从穗花杉中提取紫杉醇的主次因素为:提取次数提取溶剂提取时间料液比。结论:正交结果分析得提取次数为3,提取溶剂为75%丙酮,提取时间为2 h,料液比为1∶7为优化选出的紫杉醇最佳提取工艺,穗花杉树皮中紫杉醇的百分含量为0.0034%。     

Paclitaxel-induced microtubule stabilization causes mitotic block and apoptotic-like cell death in a paclitaxel-sensitive strain of Saccharomyces cerevisiae

Wild-type Saccharomyces cerevisiae tubulin does not bind the anti-mitotic microtubule stabilizing agent paclitaxel. Previously, we introduced mutations into the S. cerevisiae gene for beta-tubulin that imparted paclitaxel binding to the protein, but the mutant strain was not sensitive to paclitaxel and other microtubule-stabilizing agents, due to the multiple ABC transporters in the membranes of budding yeast. Here, we introduced the mutated beta-tubulin gene into a S. cerevisiae strain with diminished transporter activity and developed the first paclitaxel-sensitive budding yeast strain. In the presence of paclitaxel, cytoplasmic microtubules were stable to cold depolymerization. Paclitaxel-treated cells showed evidence of a mitotic block, with an increase in large-budded cells and cells with a 2N DNA content and DNA fragmentation, identified by FACS analysis and the TUNEL assay. In the presence of paclitaxel, the number of dead cells in cultures increased three-fold and cells containing reactive oxygen species were present. We conclude that paclitaxel blocks mitosis in this strain, leading to an apoptotic-like cell death. This strain will also be useful in further studies of the effect of microtubule dynamics on various cellular processes in S. cerevisiae.     

Treatment of symptomatic coronary artery disease in patients with end‐stage renal disease on hemodialysis with paclitaxel‐eluting TAXUS stent

Percutaneous coronary intervention (PCI) utilizing drug‐eluting stents is becoming a very common revascularization technique in the dialysis cohort; therefore, we sought to identify the impact of dialysis on outcomes in this group of patients. This is a multicenter registry comparing results of 290 patients (186 with normal kidney function, 104 on dialysis) who underwent PCI with exclusive use of paclitaxel‐eluting TAXUS stent. The primary endpoint was an assessment of major adverse cardiac events (MACE) at 1‐ and 2‐year observation. Mean follow‐up was 23.3 ± 6.1 months. Results at 12 months showed: MACE 11.8% vs. 7.7% (P = not significant [ns]), composite major adverse cardiac and cerebrovascular events (MACCE) 12.4% vs. 11.5% (P = ns), all‐cause death 2.7% vs. 8.6% (P < 0.05), cardiac death 2.7% vs. 1.9% (P = ns), target vessel revascularization (TVR) 9.1% vs. 6.7% (P = ns), acute myocardial infarction (AMI) 3.8% vs. 2.9% (P = ns), cerebrovascular events (CVA) 0.5% vs. 1.0% (P = ns); and results at 24 months showed: MACE 17.7% vs. 18.3% (P = ns), MACCE 21.5% vs. 26.0% (P = ns), all‐cause death 4.3% vs. 14.4% (P < 0.01), cardiac death 3.2% vs. 1.9% (P = ns), TVR 14.0% vs. 16.3% (P = ns), AMI 5.4% vs. 5.8% (P = ns), CVA 3.2% vs. 2.9% (P = ns) for non–end‐stage renal disease (ESRD) and dialysis group, respectively. Prior coronary artery bypass graft (CABG) was found to be single risk factor for MACE, TVR, and MACCE in patients with ESRD, while dialysis and prior CABG were found to be single risk factors for death in the entire population. PCI with TAXUS is a feasible procedure and presents promising results in dialysis‐dependent patients.