双重响应二硫化钼纳米载药体系的制备及其性能研究

摘要 目的：制备肿瘤微环境响应释放的靶向二硫化钼纳米载药体系,并评价其载药量和释药性能。方法：以水热法合成的MoS₂纳米片为基底,利用MoS₂纳米片上的S空缺位点连接硫辛酸聚乙二醇羧酸,然后通过酰胺反应连接精氨酸-甘氨酸-天冬氨酸（RGD）靶向分子,再连接上交联剂3-(2-吡啶二硫代)丙酸N-琥珀酰亚胺酯（SPDP）,得到药物载体MoS2-PEG-RGD-SPDP（MPRS）,MPRS进一步与巯基化的阿霉素（DOX）反应,形成MPRS-DOX纳米载药体系。通过透射电子显微镜（TEM）,X-射线光电子能谱仪（XPS）以及纳米粒度电位仪对合成的材料进行表征;利用紫外可见分光光度计测试MPRS的载药性能,采用荧光分光光度计考察MPRS-DOX的释药性能。结果：成功合成MPRS-DOX纳米载药体系,其粒径大小在200 nm左右,Zeta电位为+28.2 mV;其载药效率为86.8%,载药量为53.5%。体外释药实验表明,在10 mM 谷胱甘肽（GSH）和pH=5.5的条件下DOX释放量最多。结论：成功制备了粒径合适的MPRS-DOX纳米载药体系,MPRS-DOX具有GSH和pH双重响应性,可实现预期的模拟肿瘤微环境内控制释放药物。这种GSH和pH双重响应的纳米载药体系为新一代刺激响应型纳米载药系统的构建提供了新的思路。     

胆甾醇基γ-聚谷氨酸负载阿霉素纳米胶束的制备与体内外释药性能评价

笔者制备了胆甾醇基γ-聚谷氨酸负载阿霉素纳米胶束(DOX/NPs),并考察了该载药纳米胶束体系的形态与粒径、载药量、包封率以及体内外释药的特性。结果表明:DOX/NPs的最佳载药量为22.4%,包封率为90.2%,平均粒径为(312.3±7.2)nm,电镜下观察呈现明显的核壳结构。体外释药结果显示,DOX/NPs能延缓阿霉素的释放,并具有p H敏感的释药特性。小鼠体内释药结果表明:阿霉素经包埋后其消除半衰期(t1/2)、药时曲线下面积(AUC)、平均滞留时间(MRT)均明显大于游离阿霉素,达到了药物缓释的目的。     

超声和pH响应的药物共转运纳米胶束的制备及其生物学性能初探

目的:制备一种超声和p H双重响应的同时载有阿霉素(DOX)与石胆酸(LA)的纳米胶束,实现两种药物的共转运。方法:将叠氮化的石胆酸(LA-(N3)_2)与两个丙炔胺化β-环糊精(β-CD-C≡CH)通过点击反应结合,得到一种两亲性β-环糊精二聚体(LA-(CD)_2)。该环糊精二聚体在水溶液中发生自组装,同时包裹疏水性药物阿霉素,最终得到阿霉素与石胆酸共转运的纳米胶束(LA-CD2/DOX)。通过核磁共振光谱和飞行时间质谱表征LA-(CD)2的结构,透射电镜(TEM)和动态光散射(DLS)表征共转运纳米粒的形貌和大小,动态透析法模拟体外释药,监测在不同p H值和超声作用下纳米胶束的释药特性,同时采用人口腔表皮样癌细胞(KB细胞)测定LA-(CD)2/DOX的细胞毒性。结果:1经核磁共振和飞行时间质谱表征LA-(CD)2成功合成。2透射电镜和动态光散射证实LA-(CD)2自组装成形态规整的纳米胶束,Dz=128 nm,PDI=0.21。3体外释药实验结果表明DOX的释药具有p H和超声双重响应性,而LA的释药只具有p H响应性。4细胞实验证实LA-CD2/DOX的细胞毒性高于DOX和LA。结论:LA-(CD)2/DOX可有望成为一种p H和超声双重响应的抗肿瘤药物共转运纳米载体。     

酸敏阿霉素脂质纳米粒的制备及其体外抗肿瘤活性研究

目的:本研究旨在制备具有被动靶向和酸敏特性的脂质混合纳米粒,以期提高阿霉素(doxorubicin,DOX)的靶向递药效率,降低DOX的毒副作用,提高抗肿瘤活性。方法:采用微乳法制备磷酸钙纳米粒核,薄膜分散法制备脂质混合纳米粒,硫酸铵梯度法包封DOX。采用透射电镜观察外观形态,用zeta电位及纳米粒度分析仪测定纳米粒的粒径及zeta电位,透析法评价阿霉素脂质纳米粒体外释药特征。用MTT方法研究阿霉素脂质混合纳米粒对A549细胞的细胞毒性。采用流式细胞仪和激光共聚焦显微镜观察A549细胞对阿霉素脂质纳米粒的摄取。结果:体外释药结果显示阿霉素脂质纳米粒具有酸敏特性。流式结果说明A549细胞对阿霉素脂质纳米粒的摄取具有明显的时间依赖性,激光共聚焦显示阿霉素脂质纳米粒能将阿霉素递送至细胞核中。结论:阿霉素脂质体对A549细胞有明显的细胞毒性,为进一步进行体内实验提供了基础。     

新型γ-聚谷氨酸自组装纳米胶束的制备及用于蛋白载体的研究

对水溶性的γ-聚谷氨酸(γ-PGA)进行了接枝改性,合成了两亲性γ-聚谷氨酸(γ-PGA)接枝衍生物,采用超声探头法制备胆甾醇基γ-PGA自组装胶束,并以卵清蛋白(OVA)作为模型蛋白,研究其载药和释药性能.结果表明,制备的两亲性胆甾醇基γ-PGA自组装胶束平均粒径为299.6+ 27.3nm,粒径的多分散系数较窄(0.17),且具有较低的细胞毒性;其疏水核-亲水壳的纳米微结构对蛋白药物显示了良好载药性能,对OVA载药量可达118.8 μg/mg,包封率33.5％;体外释药结果显示,负载OVA的甾醇基γ-PGA自组装胶束能延缓蛋白的释放,释药速率与介质pH密切相关.     

藤黄酸聚乳酸纳米粒的研制

以新型材料聚乳酸(PLA)为载体,研制出质量稳定的藤黄酸聚乳酸纳米粒(GA-PLA-NPs)乳液制剂,并对其安全性进行评价。采用改良的溶剂蒸发法制备藤黄酸聚乳酸纳米粒(GA-PLA-NPs);用透射电子显微镜（TEM）观察纳米粒的形态;用激光粒度分析仪测定其平均粒径大小和分布;经超速离心后用紫外分光光度计测定纳米粒的包封率与载药量;考察藤黄酸纳米粒的体外释放特性;经急性毒性实验考察藤黄酸纳米粒的安全性。得到确定处方工艺为：水相∶有机相为2∶1（v/v）,表面活性剂在有机相中的浓度为0.5%（w/v）,藤黄酸（GA）在有机相中的浓度为0.1%（w/v）,GA∶PLA为1∶4（w/w）。处方条件下制备的纳米粒平均粒径为51.36 nm;平均包封率与载药量分别为98.87%和13.3%;藤黄酸纳米粒的体外释药分为两相：突释期和缓释期;急性毒性试验测得藤黄酸纳米粒的ID50为26.3mg/kg。制备的藤黄酸聚乳酸纳米粒（GA-PLA-NPs）质量稳定、分散性良好。聚乳酸可能成为藤黄酸的新型载体。     

氟维司群纳米聚合物胶束的制备与表征

目的:本文目的是制备氟维司群纳米聚合物胶束,并对其体外特性进行表征。方法:采用生物可降解材料甲氧基聚乙二醇-b-聚D,L-丙交酯(m PEG-b-PDLLA),并用固体分散法制备氟维司群聚合物胶束。利用透射电子显微镜与马尔文激光粒度测定仪分析胶束的形态与粒径。用X射线单晶体衍射仪定性测试胶束包封性。建立并验证氟维司群高效液相色谱(HPLC)分析方法,定量测定胶束载药量与包封率。采用透析袋法分析胶束体外释放情况。结果:氟维司群聚合物胶束形态圆整、分散均匀无粘连,粒径为89.97±4.33 nm,多分散指数为0.162±0.023,载药量与包封率达8.95%±0.86%与97.25%±0.86%。胶束释药具有明显的缓释特点。结论:成功制备氟维司群胶束并显著提高其水溶性,表现良好的缓释行为,能够开发为氟维司群的新型纳米制剂。     

反义寡核苷酸pH敏前体脂质体的制备及性质分析

为了提高反义寡核苷酸的稳定性和生物利用度及避免在溶酶体内降解,采用旋转蒸发-薄膜水化、超声-挤压、冻干三步法完成pH敏前体脂质体的制备,研究了体外释药规律;以反义寡核苷酸为实验对象,测定了包封率.制得的pH敏前体脂质体复水后形成的pH敏脂质体形态圆整,粒径12.3～389.9 nm范围内,平均粒径为22.7 nm;三批pH敏脂质体的平均包封率为68.3%;体外释药方程为Q=1.8382－2.5186×10^－2T (r=0.9913);结果说明制备的pH敏前体脂质体水合形成的pH敏脂质体粒度适宜,可用于反义寡核苷酸的包封.     

姜黄素共聚物胶束的制备与体外细胞毒评价

目的:制备一种姜黄素共聚物胶束以提高姜黄素的水溶性及其抗肿瘤活性。方法:采用乳化溶剂挥发法制备了载姜黄素的共聚物胶束(Cur/PTL1胶束),对其粒径、载药量、包封率和体外药物释放行为进行了考察;并采用MTT法考察了PTL1空白胶束和Cur/PTL1胶束的体外细胞毒作用。结果:制备了粒径在40 nm左右的载姜黄素共聚物胶束,载药量为9.78±0.29%,包封率为97.24±2.68%。体外药物释放实验表明,游离姜黄素在24 h内的药物累积释放率达到90%以上,而Cur/PTL1胶束在24 h内药物累积释放率为23.8%,能够持续释放14天,14天内累积释放率为85.9%,具有一定的缓释能力。MTT实验结果表明,当PTL1空白胶束浓度达到1 mg/mL时,细胞的存活率仍在90%以上;Cur/PTL1胶束组IC50为4.73±0.23μg/mL,游离姜黄素组IC50为6.42±0.35μg/mL。结论:实验结果表明,Cur/PTL1胶束可以作为一种有前景的纳米药物输送系统。     

载HCPT纳米粒的制备及其体外抗肿瘤活性研究

目的:制备载羟基喜树碱(HCPT)的PLGA-hyd-PEG-FA纳米粒(HCPT@PLGA-hyd-PEG-FA),并对其体外抗肿瘤活性进行研究。方法:采用乳化溶剂挥发法制备HCPT@PLGA-hyd-PEG-FA,通过单因素试验考察超声功率、聚合物浓度、PVA浓度、水相和油相体积比及投药量对纳米粒粒径的影响;采用zeta电位及激光粒度分析仪测定纳米粒的粒径及zeta电位,用透射电镜(TEM)观察其形态;采用透析法评价HCPT@PLGA-hyd-PEG-FA的体外释药特性;采用MTT法测定HCPT@PLGA-hyd-PEG-FA对HepG2细胞的细胞毒性。结果:HCPT@PLGA-hyd-PEG-FA平均粒径约为109±3 nm,zeta电位为-11.57 mV,载药量为5.6%,TEM显示其为球形;体外释药结果表明HCPT@PLGA-hyd-PEG-FA对HCPT的释放具有p H值依赖性;HCPT和HCPT@PLGA-hyd-PEG-FA的IC50值分别为474.6 ng/mL和286.0 ng/mL。结论:HCPT@PLGA-hyd-PEG-FA体外释药性能良好,HCPT@PLGA-hyd-PEG-FA的细胞毒性明显大于游离的HCPT,值得进一步研究。     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE₂, PGD₂, PGF_2α, TXB₂ and 6-keto-PGF_1α. In all types studied PGE₂ and TXB₂ were the major products formed. The identification of PGE₂ and TXB₂ was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.     

人血管能抑素基因的克隆、表达及其表达产物的纯化和生物活性测定

以人胎盘脐带组织为材料,提取组织总RNA,用netRTPCR方法合成人血管能抑素cDNA基因,将该cDNA克隆进pSP72载体获得重组质粒pSP72C, DNA序列分析结果与预期序列一致。用BamHⅠ和NdeⅠ双酶切,切下pSP72C上的血管能抑素cDNA,插入pET3c载体的相应位点获得重组表达质粒pETC, 转化E. coli BL21(DE3), SDSPAGE分析显示：在IPTG诱导下,血管能抑素基因获得了高效表达,表达量约占菌体总蛋白的 27.9 %,主要以包涵体形式存在。包涵体经过洗涤、裂解、蛋白复性以及Sephadex G75凝胶过滤层析等步骤后,获得了纯度达91.4 %的人血管能抑素。CAM实验证明10 μg纯化蛋白就能显著抑制鸡胚新生血管生成。     

Vascular volumes and hematology in male and female runners and cyclists

To examine the hypothesis that foot-strike hemolysis alters vascular volumes and selected hematological properties is trained athletes, we have measured total blood volume (TBV), red cell volume (RCV) and plasma volume (PV) in cyclists (n = 21) and runners (n = 17) and compared them to those of untrained controls (n = 20). TBV (ml x kg(-1)) was calculated as the sum of RCV (ml x kg(-1)) and PV (ml x kg(-1)) obtained using 51Cr and 125I-labelled albumin, respectively. Hematological assessment was carried out using a Coulter counter. Peak aerobic power (VO2peak) was measured during progressive exercise to fatigue using both cycle and treadmill ergometry. RCV was 15% higher (P < 0.05) in male cyclists [35.4 (1.0), mean (SE); n = 12] and runners [35.3 (0.98); n = 9] compared to the controls [30.7 (0.92); n = 12]. Similar differences existed between the female cyclists [28.2 (2.1); n = 9] and runners [28.4 (1.0); n = 8] compared to the untrained controls [24.9 (1.4); n = 8]. For the male athletes, PV was between 19% (cyclists) and 28% (runners) higher (P < 0.05) in the trained athletes compared to the untrained controls. The differences in PV between the female groups were not significant. Although the males had a higher (P < 0.05) TBV, RCV and PV than the females, no differences between cyclists and runners were found for either gender. Mean cell volume was not different between the athletic groups. VO2peak (ml x kg(-1) x min(-1)) was higher (P < 0.05) in both male [68.4 (1.5)] and female [54.8 (2.1)] runners when compared to the untrained males [47.1 (1.0)] and females [40.5 (2.1)]. Although differences existed between the genders in VO2peak for both cyclists and runners, no differences were found between the athletic groups within a gender. Since the vascular volumes were not different between cyclists and runners for either the males or females, foot-strike hemolysis would not appear to have an effect on that parameter. The significant correlations (P < 0.05) found between VO2peak and RCV (r = 0.64 and 0.64) and TBV (r = 0.82 and 0.63) for the males and females, respectively, suggests a role for the vascular system in realizing a high aerobic power.