肾靶向雷公藤内酯醇与2-氨基葡萄糖结合物的合成

目的 合成雷公藤内酯醇与2-氨基葡萄糖的结合物(TPG).方法 将雷公藤内酯醇与丁二酸酐反应生成雷公藤内酯醇丁二酸单酯,其游离羧基与2-脱氧-2-氨基-D-吡喃葡萄糖氨基乙苷1位上的氨基形成酰胺键,得到TPG前药,并鉴定其结构.结果 成功制备了TPG,其所含2-氨基葡萄糖具有肾靶向性,并改善了其水溶性.结论 该前药的合成路线可行性高,TPG具有肾靶向性,雷公藤内酯醇的水溶性得到了改善.     

甘草酸-低分子壳聚糖偶联物大鼠体内组织分布研究

目的：研究甘草酸-低分子壳聚糖（GA-LMWC）偶联物在大鼠体内组织分布特征,探讨GA-LMWC偶联物作为肾靶向药物的可行性。方法：将甘草酸溶液和GA-LMWC偶联物溶液分别经尾静脉注射按剂量10 mg·kg^-1给予SD大鼠,并于给药后1,4,8 h取各组织（心、肝、脾、肺、肾）,采用HPLC测定各组织（心、肝、脾、肺、肾）中甘草酸的含量。结果：大鼠尾静脉注射GA-LMWC偶联物后1,4,8 h在肾脏中的分布较甘草酸组显著提高,分别为甘草酸组的1.34倍（P<0.05）、1.46倍（P<0.001）和2.83倍（P<0.01）;在肝脏和脾脏的分布较甘草酸组显著降低（P<0.01）。结论：与游离甘草酸相比,GA-LMWC偶联物改变了甘草酸大鼠体内分布特征,显著增加了GA在肾脏的分布,延长了其肾脏滞留时间,增强了甘草酸的肾脏靶向性。     

肾靶向给药系统的研究进展

肾脏是人体的重要器官之一。由于多数肾脏药物都具有较大的毒性,为了降低药物的系统毒性,很多药学工作者已经对肾靶向给药系统进行了深入的研究。采用了低分子质量蛋白质(LMWP)、微粒、糖基复合物等药物转运载体,前体药物和抗体以及基因治疗等多种手段,以最终实现肾脏靶向给药的目的。本文通过系统地介绍肾脏的生理功能及特点,对上述各类肾脏靶向给药系统的研究成果和进展进行了全面的总结和评价。     

雷公藤内酯醇抗生育作用的有效性与安全性研究

［摘要］目的探讨雷公藤内酯醇的抗生育作用部位和安全性。方法选用健康雄性Wistar大鼠，观察雷公藤内酯醇对其精子生成及对睾丸、附睾和心、肝、肾等的影响。实验分两个阶段，第一阶段给实验组大鼠喂服雷公藤内酯醇0.05 mg·kg-1·d-1［用1%二甲亚砜（DMSO）配制］，每周6 d，连续8周,对照组喂服1% DMSO 2 mL·kg-1·d-1；第二阶段给实验组大鼠分别喂服雷公藤内酯醇0.10，0.05，0.03 mg·kg-1·d-1，每周6 d，连续8周，对照组喂服1%DMSO 2 mL·kg-1·d-1。每周称量体重，取材观察睾丸生精细胞凋亡情况，附睾精子活力及对心、肝、肾、睾丸的影响。结果实验组精子活性明显下降，雷公藤内酯醇剂量≥0.05 mg·kg-1·d-1时，大鼠精子活性为0，睾丸内精曲小管生精上皮损伤，管腔内上皮脱落，对照组大鼠形态学观察未见明显异常。实验组与对照组睾丸生精细胞凋亡差异无显著性，不同剂量雷公藤内酯醇对实验组和对照组的体重影响差异无显著性。结论雷公藤内酯醇是一种有效的抗生育药，对组织器官的毒性较小，且避孕作用是可逆性的。［关键词］雷公藤内酯；生育力 ；避孕； 大鼠     

Synthesis of tri - sulfhydrylglucose - cholesterol as a kidney targeting ligand for liposomes

目的 设计并合成一种新型的具有肾靶向性的三巯基葡萄糖-胆固醇偶联物脂质体配体.方法 以胆固醇与癸二醇的缩合产物为原料,与分支试剂四(ω-甲磺酰氧丙氧甲基)甲烷缩合成醚,再与1,2,3,4-四-O-乙酰基-1-巯基-吡喃葡萄糖在碘化钾和DIPEA的作用下成醚,最后经甲醇钠溶液脱保护后得到目标配体.结果 成功制备了一个胆甾三巯基葡萄糖偶联物.结论 目标化合物经IR、1HNMR、MS确证.     

雷公藤内酯醇对雄性大鼠生殖毒性的机制研究(Ⅱ)

目的：考察雷公藤内酯醇对大鼠睾丸细胞相关凋亡基因mRNA表达的影响,研究雷公藤内酯醇生殖毒性的分子机制。方法：以低（0.025 mg·kg^-1）、中（0.05 mg·kg^-1）、高（0.1 mg·kg^-1）剂量的雷公藤内酯醇对健康雄性Wistar大鼠连续灌胃染毒30 d,每天一次,于末次染毒24 h后处死大鼠,取睾丸组织进行病理学检查,并通过实时荧光定量PCR测定Bcl-2、Bax、Fas、FasL、CREM和Caspase-3基因mRNA的表达情况。结果：与阴性对照组相比,雷公藤内酯醇染毒组睾丸组织生精细胞明显减少,精索内几乎无精子;高剂量组Bcl-2、CREM mRNA表达降低;而Bax mRNA表达水平在中、高剂量组时呈显著地高表达;Fas和FasL mRNA表达水平在高剂量组显著上升;Caspase-3 mRNA表达水平呈现依赖剂量的高表达,中、高剂量时呈现显著性差异。结论：提示在本实验染毒剂量范围内,特别是高剂量的雷公藤内酯醇能够使生殖细胞相关凋亡基因Bcl-2、Bax、Fas、FasL、CREM和Caspase-3不同程度的表达异常,这很可能是雷公藤内酯醇诱导大鼠生殖细胞凋亡的重要原因,为进一步深入阐述雷公藤内酯醇雄性生殖毒性的分子机制提供了依据。     

雷公藤内酯醇在大鼠体内的组织分布

目的：建立雷公藤内酯醇的反相高效液相色谱分析方法,并对其在大鼠的组织分布进行测定。方法：用HPLC紫外检测方法测定大鼠i.v.雷公藤内酯醇后各组织中药物的含量。结果：大鼠i.v.200μg/kg的雷公藤内酯醇后药物在体内分布广泛,以肺、肝、肾中分布较高,各组织的药物含量于给药后5min最高,60min后显著下降。结论：雷公藤内酯醇在大鼠体内分布快且广泛,消除也快,且可穿越血脑屏障和血睾屏障分布到脑和睾丸中。     

表面修饰的鼻用聚乳酸载药纳米粒的制备及体外性质研究

目的 研究壳聚糖盐酸盐、吐温80、聚乙二醇20000、冰片薄荷低共溶物多重修饰的茴拉西坦聚乳酸鼻腔给药脑靶向纳米粒的制备工艺,并初步评价其体外稳定性.方法 采用溶剂扩散-蒸发法制备多重修饰的载药纳米粒,筛选并优化了其处方,考察了粒径分布、Zeta电位、包封率、载药量、稳定性及体外累积释药百分率.结果 壳聚糖盐酸盐、吐温80、聚乙二醇20000三重修饰的纳米粒形态圆整,粒径分布141.5±30.4 nm,Zeta电位20.4 mV,包封率98.14％,载药量为11.57％.所制纳米粒在溶菌酶和大鼠鼻洗液中稳定,在pH7.4和pH4.0的磷酸盐缓冲液中的24 h内累计释药百分率小于88％.结论 壳聚糖盐酸盐、吐温80、聚乙二醇20000、冰片薄荷低共溶物多重修饰的载药纳米粒包封率较高,性质稳定.     

9-硝基喜树碱在大鼠组织中的分布及内酯稳定性

考察9-硝基喜树碱(9-NC)静脉注射后在人鼠组织中的分布及内酯稳定性.建立了HPLC法间时测定组织和血浆中9-NC内酯浓度和总浓度.大鼠静脉注射9-NC溶液后测定各时间点组织中内酯浓度、总浓度和内酯比例.大多数组织中的9-NC内酯比例明显高于血浆;肝中的内酯比例最低,甚至低于血浆;血浆、肾和小肠中的内酯比例随时问延长而下降.9-NC在肝以外的组织中内酯稳定性显著优于血浆.     

9-硝基喜树碱内酯型在大鼠体内外的稳定性

目的考察9-硝基喜树碱内酯型在大鼠体内和离体大鼠血浆中的稳定性.方法建立利用HPLC法测定大鼠血浆中9-硝基喜树碱内酯型浓度和总浓度的方法;利用此法测定9-硝基喜树碱在离体大鼠血浆、全血及体内血浆中的内酯型比例变化以及大鼠尾静脉注射后不同时间点的内酯浓度和总浓度;并对体内外实验结果进行比较以确定影响血浆中内酯型稳定性的主要因素.结果9-硝基喜树碱内酯型在大鼠体内的稳定性显著优于体外,在体外全血中的稳定性显著优于血浆.结论血细胞具有稳定9-硝基喜树碱内酯型的作用;药物从血浆中的清除是影响体内大鼠血浆中9-硝基喜树碱内酯型比例的主要因素;9-硝基喜树碱内酯型浓度和总浓度在大鼠体内的药代动力学过程符合二室模型,而羧酸盐型浓度符合一室模型.     

Synthesis, characterization andin vitro evaluation of triptolide-lysozyme conjugate for renal targeting delivery of triptolide

A triptolide-lysozyme (TP-LZM) conjugate was synthesized to achieve renal specific delivery and to reduce the side effects of triptolide. Triptolide was coupled to lysozyme through succinic via an ester bond with an average coupling degree of 1 mol triptolide per 1 mol lysozyme. The lysozyme can specifically accumulate in the proximal tubular cells of the kidney, making it a potential carrier for targeting drugs to the kidney. The structure of triptolide succinate (TPS) was confirmed by IR, 1H-NMR, MS and UV. The concentrations of triptolide in various samples were determined by reversed-phase high-performance liquid chromatography (HPLC). In this study, the physicochemical and stability profiles of TP-LZM under various conditions were investgated the stability and releasing profiles of triptolide-lysozyme (TP-LZM) under various conditions. In vitro release trails showed triptolide-lysozyme was relatively stable in plasma (less than 30% of free triptolide released) and could release triptolide quickly in lysosome (more than 80% of free triptolide released) at 37 degrees C for 24 h. In addition, the biological activities of the conjugate on normal rat kidney proximal tubular cells (NRK52E) were also tested. The conjugate can effectively reduce NO production in the medium of NRK52E induced by lipopolysaccharide (LPS) but with much lower toxicity. These studies suggest the possibility to promote curative effect and reduce its extra-renal toxicity of triptolide by TP-LZM conjugate.     

不同分子量葡聚糖-地塞米松连接物的体外靶向释药特性不同分子量葡聚糖-地塞米松连接物的体外靶向释药特性

目的筛选具有结肠靶向性的葡聚糖-地塞米松连接物,探讨葡聚糖分子量对连接物体外释药特性的影响。方法将不同分子质量葡聚糖-地塞米松连接物与大鼠胃肠道不同部位内容物稀释液一起孵育,采用反相高效液相色谱法检测地塞米松及地塞米松琥珀酸单酯的释放情况。结果在160 min孵育过程中,胃内容物中未检测到释放的地塞米松及地塞米松琥珀酸单酯;DexD26和DexD50在结肠及盲肠内容物中释放出地塞米松(包括地塞米松琥珀酸单酯)的总量分别是其在小肠近端及小肠远端内容物中释放总量的4.0和3.6倍;DexD2和DexD7.6在结肠及盲肠内容物中释放出地塞米松(包括地塞米松琥珀酸单酯)的总量分别是其在小肠近端及小肠远端内容物中释放总量 的2.0和1.9倍。结论葡聚糖分子质量对连接物的体外释药特性有明显影响,大分子质量葡聚糖-地塞米松连接物具有较大的结肠定位释放潜力。     

复方中药舒胸速释微丸的制备

目的制备复方中药舒胸速释微丸,筛选速释微丸的最佳制备工艺和处方,使理化性质差异较大的各成分达到同步释放。方法采用挤出滚圆法制备复方中药舒胸速释微丸,以阿魏酸、红花黄色素、三七总皂苷为体外溶出考察的主要指标性成分,对微丸中加入的崩解剂种类和用量、粘合剂和表面活性剂等处方因素进行筛选,并采用正交设计试验以筛选最优处方。结果在处方中加入复合崩解剂(20%泡腾崩解剂、5%羧甲基淀粉钠),以70%乙醇(含2%十二烷基硫酸钠)为粘合剂,可使制备的舒胸速释微丸在1 m in内迅速崩解。在模拟人体胃肠道生理条件下,舒胸速释微丸中红花黄色素和三七总皂苷体外释放的f2值为77.34,红花黄色素和阿魏酸的f2值为58.67,三七总皂苷与阿魏酸的f2值为67.83,表明三者的释放度差异无显著性。结论通过加入复合崩解剂,可以使采用挤出滚圆法制备的舒胸速释微丸迅速崩解,从而使复方中药中理化性质差异较大的各种成分达到同步释放。     

以氨基酸为连接子的吉西他滨-聚谷氨酸偶合物设计、合成及评价

目的设计、合成抗肿瘤药物吉西他滨与聚谷氨酸的偶合物,通过调节连接子的结构以控制药物的释放,提高抗肿瘤药物的疗效。方法首先合成吉西他滨3′-或5′-的氨基酸酯衍生物,然后在DCC作用下,氨基酸的氨基与聚谷氨酸分子中的羧基缩合,得到以氨基酸为连接子的吉西他滨-聚谷氨酸偶合物;用紫外法测定偶合物载药量;用HPLC法测定偶合物在水溶液或血浆中的稳定性。结果与结论共合成目标化合物11个,载药量为25%~30%。稳定性试验结果表明,偶合物在水溶性或血浆中能够稳定地释放游离药物,氨基酸类型及连接位置可影响药物的释放速率,偶合物PG-Ala-3′-Gem的释放速率最快,4h释放50%的药物,而PG-Val-3′-Gem和PG-Ala-5′-Gem在48h分别释放30.3%和43.5%;偶合物在血浆中的释放速率略快于水溶液中的释放速率。     

In vitro Drug release characteristics of methotrexate-human serum albumin and 5-fluorouracil-acetic acid-human serum albumin conjugates

The release rates of methotrexate (MTX) from MTX-human serum albumin (HSA) conjugate, and 5-fluorouracil (5-FU) from 5-FU acetic acid (AA)-HSA conjugate were determined after incubation of the conjugates in various conditions. The concentrations of 5-FU released from the conjugate increased monoexponentially, however those of MTX increased biexponentially in all studies. It indicated that there are two distinct types of MTX-HSA linkage, weakly and tightly bound linkages. The release rates of 5-FU were lower than those of MTX in all studies indicating that the bond of 5-FU-AA-HSA conjugate is very stable, which is supported by the higher value of activation energy (39.9 vs 10.7 Kcal/mole) using Arrhenius equation. The release rates of MTX and 5-FU from the conjugates increased with incubation temperatures. Proteolytic enzyme and liver homogenates accelerated significantly the release rates of MTX and 5-FU. Approximately 1.30 and 22.0% of MTX were released after 12 hours of incubation in the absence and presence of protease, respectively. The corresponding values for 5-FU were 1.0 and 17.0% Approximately 10.3 and 11.9% of 5-FU and MTX, respectively were released after 12 hours of incubation with rat liver homogenates which were diluted 6 times with phosphate buffer of pH 6.0. The MTX-HSA and 5-FU-AA-HSA conjugates were very stable in rat plasma.     

Growth inhibition, drug load, and degradation studies of gelatin/methotrexate conjugates

Macromolecular gelatin-methotrexate conjugates have potential therapeutic advantages over the free drug. Conjugates with MTX:gelatin molar ratios (MR) ranging from 1:1 to 27:1 were examined for cell growth inhibition, stability, degradation, and methotrexate (MTX) release. Conjugate growth inhibition was less than that of free MTX whose IC(50) value of 1.3 x 10(-8) M was about 10-fold less. Cell uptake of fluorescein labeled gelatin (145 kD) was observed by 24-30 h. Higher MR conjugates produced less growth inhibition, measurably greater stability at pH 7.4 based on MTX release, and had less gelatin degradation in the conjugate by the lysosomal enzyme Cathepsin B (Cat B) compared to low MR conjugates. Cat B conjugate degradation was greater at the in vitro lysosomal pH of 4.8 than the intra-tumor pH of 6.5. The presence of Cat B did not meaningfully affect MTX release, but less MTX was released at pH 4.8 than pH 6.5. The maximum MTX release was a relatively low 7% after 72 h at pH 6.5 for the low MR conjugate. Low molecular weight conjugate fragments were also produced and were also influenced by pH and MR. Reduced growth inhibition by high MR conjugates may be due to a hindered enzymatic degradation in the lysosomes. A strong peptide conjugate bond at lysosomal pH and a 24-30 h delayed gelatin uptake may contribute to reduced growth inhibition of the conjugate compared to free MTX. MTX release under these in vitro conditions occurs by aqueous hydrolysis, not by Cat B cleavage of the conjugate bond.     

Preparation andIn vitro release characteristics of hydrophilic albumin microspheres containing methotrexate and methotrexate-human serum albumin conjugates

Release characteristics of five different types of hydrophilic albumin microspheres (HAM) containing different ratios of methotrexate-albumin (MTX-HSA) conjugates to free MTX; 1∶0 (HAMC), 3∶1 (HAMC3F), 1∶1 (HAMCF), 1∶3 (HAMCF3) and 0∶1 (HAMF) were investigated in the absence or presence of protease using dissolution tester. In all the HAMs studied except HAMC, the MTX was released bi-exponentially in the absence of protease; an initial fast release period up to approximately 6 h, and thereafter the release rate was very much slower. The fast release of MTX from the HAMs (such as HAMC3F, HAMCF, HAMCF3 and HAMF) at the initial phase is probably due to the release of “physically associated” MTX on the surface and/or entrapped in the near inner surface of HAMs and the slow release at the second phase is due to the release of entrapped free MTX from the core of the HAMs. The initial rate constants were 7.2, 8.7, 8.5 and 5.9 times greater than the second rate constants for HAMF, HAMCF3, HAMCF and HAMC3F, respectively. MTX release from HAMC was very slow and mono-phasic. It was at most 2.2% of the total entrapped amount by 24 h. The protease accelerated the release of MTX from the HAMs. The percentages of MTX released from HAMs up to 24 h were 100, 89.0, 75.0, 66.0 and 61.0% for HAMF, HAMCF3, HAMCF, HAMC3F and HAMC, respectively in the presence of protease and the corresponding values in the absence of protease were 30.2, 19.0, 10.0, 6.5 and 2.2%, respectively.In vitro release of MTX in the presence of protease varied according to the ratios of MTX-HSA conjugates to MTX; the data set from HAMF, HAMCF3 and HAMCF fits better to monophasic first-order profile more adequately than to zero-order profile, that of HAMC3 F to mono-phasic zero-order, and that of HAMC to bi-phasic zero-order. Above results suggested that zero-order release rate can be achieved by adjusting the ratio of MTX-HSA conjugates to MTX in the preparation of HAMs such as HAMC3F.     

HPMA copolymer-1,5-diazaanthraquinone conjugates as novel anticancer therapeutics

1,5-diazaanthraquinones (DAQs) are promising anticancer drugs, however, their clinical potential is limited due to poor solubility. Conjugation of anticancer agents to hydrophilic water-soluble polymers can overcome this problem and has already been used to generate conjugates with demonstrated clinical benefit. Here a library of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates containing a novel amino-functionalised 1,5-diazaanthraquinone derivative (amino-DAQ) have been synthesised. The conjugates were fully characterised by UV, HPLC, SEC, FT-Raman and NMR spectroscopy. Conjugation to HPMA copolymers improved amino-DAQ aqueous solubility (>7-fold). The HPMA copolymer-amino-DAQ conjugates were slightly less haemolytic than the parent compound (2% Hb released in 1 h for conjugate HPMA copolymer-GFLG (5 mol%)-amino-DAQ conjugate compared to 13% obtained with amino-DAQ). When conjugates were incubated with isolated rat liver lysosomal enzymes (Tritosomes) the rate of amino-DAQ release was influenced by both drug loading and the composition of the peptidyl side chain used to link the drug to the carrier. The higher the drug loading the lower the rate of drug release. Whereas the GG linker did not release amino-DAQ, up to 26% of the amino-DAQ was released from a GFLG linker over 24 h. The in vitro cytotoxicity of these conjugates was evaluated against two different cell lines, B16F10 murine melanoma and MCF-7 human breast cancer cells. HPMA copolymer-amino-DAQ conjugates, which are internalised by cells by the endocytic pathway, showed much lower in vitro cytotoxicity (IC50 for HPMA copolymer-GFLG (5 mol%)-amino-DAQ conjugate>397 microM drug-equiv.) than the free drug (the IC50 for amino-DAQ was 12.6 and 2.8 microM against the B16F10 murine melanoma and the MCF-7 breast cancer cell line, respectively). Nonetheless, the observed lysosomal activation of the HPMA copolymer-GFLG-amino-DAQ conjugates, suggests that evaluation of the antitumour potential in vivo is warranted.     

Synthesis and characterization of the tumor targeting mitoxantrone-insulin conjugate

Anticancer drugs have serious side effects arising from their poor malignant cells selectivity. Since insulin receptors highly express on the cytomembrane of some kind of tumor cells, using insulin as the vector was expected to reduce serious side effects of the drugs. The objective of this study was to evaluate the tumor targeting effect of the newly synthesized mitoxantrone-insulin conjugate (MIT-INS) with the drug loading of 11.68%. In vitro stability trials showed MIT-INS were stable in buffers with different pH (2-8) at 37 degrees C within 120 h (less than 3% of free MIT released), and were also stable in mouse plasma within 48 h (less than 1% of free MIT released). In vivo study on tumor-bearing mice showed that, compared with MIT [75.92 microg x h/g of the area under the concentration-time curve (AUC) and 86.85 h of mean residence time (MRT)], the conjugates had better tumor-targeting efficiency with enhanced tumor AUC of 126.53 microg x h/g and MTR of 151.95 h. The conjugate had much lower toxicity to most other tissues with targeting indexes (TIC) no larger than 0.3 besides good tumor targeting efficiency with TIC of 1.67. The results suggest the feasibility to promote the curative effect in cancer chemotherapy by using insulin as the vector of anti-cancer drugs.     

Synthesis and in vitro studies of cross-linked hydrogel nanoparticles containing amoxicillin

In this paper, we report the synthesis and characterization of a novel cross-linked N-isopropylacrylamide-acrylic acid-hydroxyethyl methacrylate [P (NIPASM-AA-HEM)] hydrogel nanoparticles (NPs) containing amoxicillin. The aim of present study was to investigate whether these hydrogel NPs have the potential to be used in antibiotic delivery to stomach for treatment of Helicobacter pylori. Amoxicillin-loaded hydrogel NPs were prepared using cross-linked P (NIPASM-AA-HEM) as mucoadhesive polymer for the potential use of treating gastric and duodenal ulcers. Aiming at predicting the in vivo behavior of the amoxicillin-loaded NPs, the physicochemical properties in terms of entrapment efficiency (EE%), mean diameter, and morphology of NPs was evaluated. The dependence of the EE% of the drug on the organic to aqueous phase ratio was also studied. The profile of amoxicillin release from P (NIPASM-AA-HEM) NPs system was studied under various conditions. In all these experiments, amoxicillin release in the free form was studied by ultraviolet (UV) spectrophotometric analysis. Experimental results showed that at pH 7.4, drug release rises when polymer concentration in the formulation increases; in human plasma on the contrary, drug release is reduced as concentration of the polymer in the formulation rises. In vitro amoxicillin release rate was also higher in pH 1 than that in pH 7.4. About 88.5% of amoxicillin entrapped in the NPs was released in 4 h in the pH 1.0 medium, whereas in phosphate buffer at pH 7.4 no more than 45% was released after 4 h incubation at 37 °C. Amoxicillin concentration in rat's gastric tissue was determined. The results of in vivo studies showed that the hydrogel NPs enhance drug concentration at topical site than powder amoxicillin. Thus, amoxicillin-loaded hydrogel NPs may provide therapeutic concentration at a much lower dose that may reduce the adverse effects of amoxicillin in high doses.