羟基磷灰石—阿霉素缓释剂在兔肝脏释放的测定

阿霉素为目前临床常用抗肿瘤药物之一,但因毒性较大.而限制其临床应用.本研究目的在于通过羟基磷灰石-阿霉素抗癌复合物局部注入兔肝脏,观察该药物在兔体内药物动力学改变、以探讨其治疗肝脏肿瘤的可行性.1 材料与方法1.1 缓释剂制备 称取羟基磷灰石0.3g(北京化工厂,AR).加注射用水5ml装入干净青霉素小瓶分装密封后高压灭菌,保存待用.阿霉素(广东汕头鲍滨制药厂,10mg/瓶、批号931024)应用前将羟基磷灰石与阿霉素充分混匀,在4℃放置15min、制成羟基磷灰石-阿霉素缓释剂.1.2 实验方法与标本收集 新西兰白兔37只.体重2.0～2.5kg(本院实验动物室提供 )B超引导下进行肝左叶内注射实验.阿霉素用量2mg/kg.注射后局部加压包扎2h.实验组(19只)肝内注射羟基磷     

阿霉素缓释剂局部植入动物体内的药物动力学

研究盐要霉素缓释剂在大鼠和犬体内的药物动力学。方法：用高效液相色谱法测定血浆阿霉素的浓度。结果：大鼠皮下植入盐酸阿霉素缓释剂后，血浆要霉素可持续、缓慢释放、犬皮下植入２ｍｇ．ｋｇ     

纳米羟基磷灰石的制备及对阿霉素载药性能的考察

目的合成药物载体纳米羟基磷灰石(nano-hydroxyapatite,nHAP),考察其对于模型药物阿霉素的载药性能。方法采用化学共沉淀法,以Ca(NO3)2·4H2O和(NH4)2HPO4分别为钙、磷源,用氨水调控溶液p H值合成nHAP,考察温度、反应时间和陈化时间对于nHAP合成的影响。采用X射线衍射仪、扫描电镜、红外光谱仪、动态光散射粒度测定仪对于产品的晶相、晶貌、化学组成和粒径进行表征。采用溶液吸附法考察nHAP用量、溶液质量浓度和p H值对于nHAP负载阿霉素的影响。结果当反应温度60℃、反应时间2 h、陈化时间16 h时,所制备的nHAP为长(138±35)nm,宽(39±8)nm棒状纳米粒,晶体形貌规则,结晶良好。负载阿霉素的研究表明,所合成的nHAP载药性能良好,载药量达到42.43 mg·g~(-1)。结论 nHAP对于阿霉素具有良好的承载能力,可作为阿霉素的优良载体。     

含庆大霉素羟基磷灰石涂层假体的体外药物释放试验的药物浓度监测

目的：探讨含庆大霉素羟基磷灰石涂层假体的体外药物释放试验的药物浓度监测。方法：用仿生溶液法制备出含庆大霉素羟基磷灰石涂层假体,在生理盐水体外释放实验中检测其释放的庆大霉素的浓度和持续时间。采用荧光偏振免疫分析法测定假体庆大霉素体外释放的药物浓度。结果：在庆大霉素体外释放药物浓度监测中,按释放的不同时间点进行测定,共分别测得药物浓度值为：1 h为3.58μg.mL^-1,24 h为5.36μg.mL^-1,48 h为5.45μg.mL^-1,72 h为5.14μg.mL^-1,120 h为5.13μg.mL^-1,192 h为4.64μg.mL^-1,216 h为0.44μg.mL^-1,240 h为0.31μg.mL^-1。结果显示,体外庆大霉素释放速度快,1 h内就已经达到了金葡菌的最低抑菌浓度（MIC为0.25μg.mL^-1）,且持续释放到第10天时,药物浓度仍高于MIC。体外庆大霉素释放药物浓度可持续达药物浓度时间约8 d。结论：开展抗生素药物浓度监测分析,可为临床提高合理用药水平及降低关节置换术后的感染提供可靠的依据,确保临床用药安全、合理、有效。     

壳聚糖-纳米羟基磷灰石复合材料修复兔胫骨缺损的成骨效果

目的探讨壳聚糖-纳米羟基磷灰石复合材料(CTS-nHA)植入动物体内修复骨缺损时,观察成骨效果和材料吸收速度。方法新西兰大白兔18只,随机分为3组,实验组(A组):复合材料;实验对照组(B组):纳米羟基磷灰石(N-HA);空白对照组(C组):不植入任何材料,于兔双侧后肢胫骨制造约直径0.5 cm大小的骨缺损,分别植入相应的材料或不植入任何材料,于术后2、4、6、10周取骨缺损标本,进行大体和组织学观察。结果在各时间段CTS-nHA组新的骨基质生成量均明显高于n-HA组和空白组,其中n-HA组又高于空白组,只有在2周时n-HA组和空白组相似。同时复合材料在体内吸收速度比n-HA组快,复合材料的吸收与新骨生成速度协调性似乎欠佳。结论复合材料植入的缺损区具有较强的成骨活性,但在体内吸收速度比较快。     

羟基磷灰石的临床研究进展

羟基磷灰石(Hydroxyapatite,HA)是动物和人体骨骼的主要无机矿物成分,随着现代技术的进步,针对HA的生物学特性以及它的缺点做出了很大的改进应用于临床。本文综述了近年来国内外学者对羟基磷灰石的改造及临床研究。     

羟基磷灰石生物陶瓷前牙种植的研究

本文报告羟基磷灰石生物陶瓷(HA)种植前牙一次性植入的动物实验和临床研究.拔除家兔上前牙,即刻植入HA 种植牙,固定并观察3个月和6个月的标本电镜观察见种植界面为骨性结合,紧密嵌合。临床应用于25例患者28颗(?),根据术前牙片与模型选HA 成品根,在其上作光固化冠修复成为牙整体。拔除患牙,将消毒的HA 种植(?)立即植入新鲜拔牙窝内,结扎固定。所做种植手术均获成功。     

纳米羟基磷灰石和纳米羟基磷灰石／聚酰胺66直接盖髓术的组织学对比观察

随着科学技术的发展，生物材料在口腔领域引起了人们的广泛关注，羟基磷灰石因与生物体硬组织如骨、牙中的无机成份相似而具有良好的生物相容性，已被广泛用于植骨和盖髓研究。而纳米仿生材料的出现为盖髓剂的研究开拓了一个全新的领域。nHA—PA66作为新型纳米仿生材料的代表成为研究的热点，它已通过前期实验表明具有较好的生物安全性、生物相容性和生物活性其有机物和无机物的组成比例及力学性能与牙本质相似，本实验通过对比纳米羟基磷灰石和纳米羟基磷灰石聚酰胺66作狗牙直接盖髓术的组织学反应，为临床筛选理想的盖髓材料提供组织学依据。     

多孔羟基磷灰石生物活性玻璃修复兔颌骨缺损

目的 探讨羟基磷灰石/生物活性玻璃复合多孔材料(HA-BG)修复兔下颌骨缺损的机理.方法 兔下颌骨贯通性骨缺损,分别以HA-BG及羟基磷灰石HA修复,分批处死动物,进行X光密度、组织学及新骨面积百分比观察.结果 4周、8周、12周修复区密度逐渐减小;组织学观察,随时间延长新骨呈渐进性成熟,新骨面积百分比逐渐增长,各期HA-BG组新骨面积百分比均高于HA组.结论 HA-BG具有良好的生物相容性、生物降解性及引导成骨活性.     

自制羟基磷灰石模拟体液中实验研究

目的：通过模拟体液实验研究观察自制羟基磷灰石的生物相容性。方法：选择接近人体环境的溶液，观察羟基磷灰石的表面变化、离子浓度、pH值变化情况。结论：自制羟基磷灰石具有很好的生物相容性。     

共振瑞利散射法测定多柔比星脂质体中游离多柔比星的含量

目的:建立共振瑞利散射法(RRS)测定多柔比星(DOX)脂质体中游离 DOX 含量。方法:在 pH 2.6的 Britton-Robinson(BR)缓冲液中,刚果红(CR)与 DOX 通过分子间作用力形成离子缔合物,在λ_(ex)=λ_(em)=380 nm 波长时能使 RRS 信号显著增强。结果:RRS 法在1～12 μg·mL~(-1)范围内呈线性关系,检出限为0.05~(-1)g·mL~(-1)。对6个不同批号的 DOX 脂质体混悬液中游离 DOX 的含量测定,结果与紫外可见分光光度法相符,RSD(n=6)为1.9%～3.2%,平均回收率为94.3%。结论:此方法灵敏度较高,可以用于测定 DOX 脂质体中游离 DOX 的含量。     

Study of biodistribution and systemic toxicity of glucose functionalized SPIO/DOX micelles

The present study examined the cytotoxicity and magnetic resonance imaging (MRI) distribution of cancer-targeted, MRI-visible polymeric micelles that encapsulate doxorubicin (DOX) and superparamagnetic iron oxide (SPIO) and are conjugated with glucose as a targeting ligand. In this study, the micelles were investigated the clinical potential of glucose-micelles, in vitro cytotoxicity assays of nonencapsulating or SPIO-and-DOX-coencapsulating micelles were performed on L929 mouse fibroblasts, and we found that glucose-micelles did not exert in vitro cytotoxic effects. Next, in vitro MRI detectability of glucose SPIO micelles was evaluated at the loaded SPIO content of 2.5% and 50%, and it was found that glucose-micelles can increase MRI relaxivity (r₂*) at high SPIO loading. Furthermore, 50% SPIO micelles persisted in the blood circulation for up to 5 days (slow liver clearance) as determined by in vivo MRI. For in vivo toxicity evaluation, 50% SPIO/DOX micelles at a dose up to 18 (mg DOX)/(kg body weight) showed no impact on animal health according to clinical chemistry and clinical hematology laboratory testing. Altogether, these results indicate that glucose-micelles can serve as an effective and safe drug delivery system.     

液相色谱-质谱联用法同时测定大鼠血浆中柔红霉素和汉防己甲素的浓度

目的:建立一种灵敏快速的LC-MS/MS方法,能够同时测定大鼠血浆中的柔红霉素(DNR)和汉防己甲素(Tet)含量。方法:色谱柱使用的是BDS HYPERSIL-C₈柱(2.1 mm×100 mm,3 μm);采用乙腈-5 mmoL·L^-1醋酸铵(46:54 V/V)作为流动相, 其中含千分之四的甲酸;流速设为0.2 ml·min^-1。采用醋酸乙酯对血浆样品进行液液萃取,选择阿霉素(DOX)为内标,进行HPLC-MS/MS分析,正离子扫描, MRM模式检测。DNR、Tet和IS的定量检测离子对分别为m/z 528.4→321.3,m/z 623.1→381.8,m/z 544.4→397.6。结果:大鼠血浆中检测DNR及Tet的线性范围分别为2~500 ng·ml^-1,0.5~400 ng·ml^-1,DNR与Tet高、中、低浓度提取回收率均>86%,日内精密度RSD<7.3%,日间精密度RSD<4.9%,准确度RE在-0.4%~4.5%范围内。结论:本方法可灵敏、快速地测定大鼠血浆中DNR及Tet 浓度。     

Transferrin as a drug carrier: Cytotoxicity,cellular uptake and transport kinetics of doxorubicin transferrin conjugate in the human leukemia cells

Leukemias are one of most common malignancies worldwide. There is a substantial need for new chemotherapeutic drugs effective against this cancer. Doxorubicin (DOX), used for treatment of leukemias and solid tumors, is poorly efficacious when it is administered systemically at conventional doses. Therefore, several strategies have been developed to reduce the side effects of this anthracycline treatment. In this study we compared the effect of DOX and doxorubicin–transferrin conjugate (DOX–TRF) on human leukemia cell lines: chronic erythromyeloblastoid leukemia (K562), sensitive and resistant (K562/DOX) to doxorubicin, and acute lymphoblastic leukemia (CCRF-CEM). Experiments were also carried out on normal cells, peripheral blood mononuclear cells (PBMC). We analyzed the chemical structure of DOX–TRF conjugate by using mass spectroscopy. The in vitro growth-inhibition assay XTT, indicated that DOX–TRF is more cytotoxic for leukemia cells sensitive and resistant to doxorubicin and significantly less sensitive to normal cells compared to DOX alone. During the assessment of intracellular DOX–TRF accumulation it was confirmed that the tested malignant cells were able to retain the examined conjugate for longer periods of time than normal lymphocytes. Comparison of kinetic parameters showed that the rate of DOX–TRF efflux was also slower in the tested cells than free DOX. The results presented here should contribute to the understanding of the differences in antitumor activities of the DOX–TRF conjugate and free drug.     

吗丙嗪增强阿霉素的体外抗肿瘤细胞毒作用(英文)

吗丙嗪(Pro)0.313,0.625和1.25μg·ml~(-1)可增强阿霉素(Dox)体外对艾氏腹水癌(EAC)的细胞毒作用;Pro 116.5,233和466 μg·ml~(-1)也可明显增加EAC细胞中的Dox含量,在S_(37)荷瘤小鼠中Pro可降低肝细胞线粒体而增加肿瘤细胞线粒体中Dox诱发的MDA含量。提示Pro的增效作用可能与其增加肿瘤细胞中Dox积聚有关,或许与MDA含量亦有关。     

Self-assembled nanoparticles of reduction-sensitive poly (lactic-co-glycolic acid)-conjugated chondroitin sulfate A for doxorubicin delivery: preparation,characterization and evaluation

In this study, reduction-sensitive self-assembled polymer nanoparticles based on poly (lactic-co-glycolic acid) (PLGA) and chondroitin sulfate A (CSA) were developed and characterized. PLGA was conjugated with CSA via a disulfide linkage (PLGA-ss-CSA). The critical micelle concentration (CMC) of PLGA-ss-CSA conjugate is 3.5?µg/mL. The anticancer drug doxorubicin (DOX) was chosen as a model drug, and was effectively encapsulated into the nanoparticles (PLGA-ss-CSA/DOX) with high loading efficiency of 15.1%. The cumulative release of DOX from reduction-sensitive nanoparticles was only 34.8% over 96?h in phosphate buffered saline (PBS, pH 7.4). However, in the presence of 20?mM glutathione-containing PBS environment, DOX release was notably accelerated and almost complete from the reduction-sensitive nanoparticles up to 96?h. Moreover, efficient intracellular DOX release of PLGA-ss-CSA/DOX nanoparticles was confirmed by CLSM assay in A549 cells. In vitro cytotoxicity study showed that the half inhibitory concentrations of PLGA-ss-CSA/DOX nanoparticles and free DOX against A549 cells were 1.141 and 1.825?µg/mL, respectively. Therefore, PLGA-ss-CSA/DOX nanoparticles enhanced the cytotoxicity of DOX in vitro. These results suggested that PLGA-ss-CSA nanoparticles could be a promising carrier for drug delivery.     

Effects of anticancer drugs on the metabolism of the anticancer drug 5,6-dimethylxanthenone-4-acetic (DMXAA) by human liver microsomes

AIMS: To investigate the effects of various anticancer drugs on the major metabolic pathways (glucuronidation and 6-methylhydroxylation) of DMXAA in human liver microsomes. METHODS: The effects of various anticancer drugs at 100 and 500 microM on the formation of DMXAA acyl glucuronide (DMXAA-G) and 6-hydroxymethyl-5-methylxanthenone-4-acetic acid (6-OH-MXAA) in human liver microsomes were determined by high performance liquid chromatography (h.p.l.c.). For those anticancer drugs showing significant inhibition of DMXAA metabolism, the inhibition constants (Ki) were determined. The resulting in vitro data were extrapolated to predict in vivo changes in DMXAA pharmacokinetics. RESULTS: Vinblastine, vincristine and amsacrine at 500 microM significantly (P < 0.05) inhibited DMXAA glucuronidation (Ki = 319, 350 and 230 microM, respectively), but not 6-methylhydroxylation in human liver microsomes. Daunorubicin and N-[2-(dimethylamino)-ethyl]acridine-4-carboxamide (DACA) at 100 and 500 microM showed significant (P < 0.05) inhibition of DMXAA 6-methylhydroxylation (Ki = 131 and 0.59 microM, respectively), but not glucuronidation. Other drugs such as 5-fluoroucacil, paclitaxel, tirapazamine and methotrexate exhibited little or negligible inhibition of the metabolism of DMXAA. Pre-incubation of microsomes with the anticancer drugs (100 and 500 microM) did not enhance their inhibitory effects on DMXAA metabolism. Prediction of DMXAA-drug interactions in vivo based on these in vitro data indicated that all the anticancer drugs investigated except DACA appear unlikely to alter the pharmacokinetics of DMXAA, whereas DACA may increase the plasma AUC of DMXAA by 6%. CONCLUSIONS: These results indicate that alteration of the pharmacokinetics of DMXAA appears unlikely when used in combination with other common anticancer drugs. However, this does not rule out the possibility of pharmacokinetic interactions with other drugs used concurrently with this combination of anticancer drugs.     

The mechanism for cellular uptake,storage and release of daunorubicin: Studies on fibroblasts in culture

The mechanism for uptake, storage and release of daunorubicin have been studied in cultured fibroblasts. Analysis by high performance liquid chromatography of cells incubated with daunorubicin revealed that the major part of the accumulated drug did not undergo metabolic transformation. Small amounts of daunorubicinol and aglycone were formed. [³H]-daunorubicin was used to study membrane fluxes of the drug under different conditions. Metabolic inhibitors enhanced the influx of [³H]-dauno-rubicin and, under certain conditions, also reduced its efflux, indicating that the cells have an active mechanism for the outward transport of the drug. The very high intracellular drug accumulation is due to trapping in nuclei and lysosomes. Cell fractionation techniques have been used to study drug trapping under various conditions. Nuclear storage of daunorubicin is probably due to binding to DNA. Metabolic inhibitors, as well as lowering the incubation temperature, reduced the lysosomal trapping, supporting the hypothesis that the low pH in these organelles is maintained by a proton pump and that the drug is trapped in the protonated form. A hypothesis is presented, which by combining the mechanisms for membrane transport and intracellular storage of daunorubicin, gives also an explanation for the observed differences in the cellular accumulation and subcellular distribution of daunorubicin and its 14-hydroxy derivative, doxorubicin. Daunorubicin is more lipophilic than doxorubicin and will therefore diffuse faster through the cell membrane. Assuming that both substances have the same affinity for the proposed active outward transport mechanism, this will lead to a higher steady-state level of daunorubicin in the cytosol and as a consequence to a higher lysosomal storage level if the drug in the lysosomes is in equilibrium with that in the cytosol. The similarity in nuclear storage capacity for the two substances can be explained by saturation of the available storage sites.     

盐酸多柔比星脂质体注射液联合注射用紫杉醇(白蛋白结合型)致严重皮肤损害1例分析

目的 提醒临床医生在联合使用多柔比星脂质体和紫杉醇(白蛋白结合型)时应密切关注用药安全.方法 分析了1例43岁女性患者联合使用多柔比星脂质体和紫杉醇(白蛋白结合型)后出现3级手足综合征和2级皮肤擦烂样皮炎的病例,文献回顾上述2种药物所致皮肤毒性的临床表现、发病机制和防治措施.结果 该患者的手足综合征很可能由多柔比星脂质...     

透骨消痛颗粒含药血清对兔软骨细胞增殖影响的研究

目的：探讨透骨消痛颗粒含药血清对兔软骨细胞增殖的影响。方法：取4周龄新西兰兔膝关节关节软骨Ⅱ型胶原酶消化,建立软骨细胞体外培养体系,体外培养第3代软骨细胞随机分为5组,分别加入培养液、空白血清和中药血清低、中、高剂量继续培养24、48、72 h后,采用流式细胞仪检测软骨细胞周期的变化。结果：流式细胞仪细胞周期检测显示中药血清中、高剂量能够刺激软骨细胞由G0/G1期进入S期和G2/M期,并呈现时间的依赖性,干预48 h后G0/G1期细胞比例降低,S期与G2/M期细胞之和增加,与低量组、空白组相比差异有统计学意义（P〈0.05）。结论：透骨消痛颗粒含药血清能有效促进软骨细胞的增殖。