舒林酸纳米混悬剂的制备及其体内外抗肿瘤作用研究

目的制备舒林酸纳米混悬剂,并考察其对肿瘤组织的抗肿瘤作用。方法以油酸钠为稳定剂,通过反溶剂沉淀法制备舒林酸纳米混悬剂,考察其粒径大小、分散指数、电位及颗粒形状,采用MTT比色法使用乳腺癌细胞MCF-7、4T1进行体外抗肿瘤药效评价,采用4T1荷瘤小鼠进行体内抗肿瘤评价。结果舒林酸纳米粒形状为球形,分散指数值小于0.3,平均粒径为(264.1±2.9)nm。相比较于游离药物,纳米粒显著提高了舒林酸对乳腺癌细胞的抑制作用,对MCF-7、4T1的IC50值分别为(22.1±4.6)、(19.2±1.2)μg/m L,体内抑瘤率为(35.4±18.8)%。结论将舒林酸制备成纳米粒后,拓宽了舒林酸的给药途径,显著增强其抗肿瘤作用。     

雷公藤红素新型衍生物体外抗肿瘤活性

目的探讨几种雷公藤红素新型衍生物的体外抗肿瘤活性。方法取对数生长期的大鼠肾上腺髓质嗜铬瘤分化细胞株PC12细胞以及大鼠神经胶质瘤C6细胞,加入雷公藤红素、雷公藤红素衍生物(Cel-1～Cel-13)及阳性对照药顺铂,48 h后,通过四甲基偶氮唑盐比色法,测定各化合物半数抑制浓度(IC50),用以观察雷公藤红素各衍生物对PC12细胞以及C6两种细胞株增殖的影响。结果雷公藤红素衍生物Cel-1、Cel-3、Cel-6和Cel-13对PC12细胞的IC50值分别为(1.6±0.3)、(2.2±0.3)、(1.3±0.3)和(2.4±0.1)μmol.L-1,明显小于母核雷公藤红素(3.2±0.4)μmol.L-1(P<0.05,P<0.01);Cel-1对C6细胞的IC50值为(0.6±0.2)μmol.L-1,明显小于母核雷公藤红素(1.5±0.3)μmol.L-1(P<0.05);而且Cel-1、Cel-3、Cel-6和Cel-13明显小于顺铂对PC12和C6的IC50[(11.6±0.8)、(59.0±4.0)μmol.L-1](P<0.01)。结论雷公藤红素新型衍生物中4个化合物有较好的体外抗肿瘤活性,比母体雷公藤红素活性强。     

雷公藤红素对IL—1和IL—2活性及PGE2释放的抑制作用

雷公藤红素0.1～1.0μg/ml在试管内能降低LPS诱导的小鼠腹腔巨噬细胞外和细胞内白细胞介素-1(IL-1)的活性,也能抑制ConA诱导的小鼠脾细胞产生白细胞介素-2(IL-2).动态观察表明,雷公藤红素经预处理8h和3h后已能分别抑制IL-1和IL-2的产生。此外,雷公藤红素能降低A23187刺激家兔滑膜细胞释放前列腺素E_2(PGE_2)。     

雷公藤甲素与雷公藤红素含药血清对小鼠巨噬细胞一氧化氮分泌的影响

目的研究雷公藤甲素与雷公藤红素抗炎作用量效关系。方法健康雄性Wistar大鼠灌胃给予雷公藤甲素与雷公藤红素的混合液,分别于给药前0h和给药后0.5、1.0、2.0、4.0、6.0、8.0和12.0h收集血清,利用液相色谱-质谱联用法检测大鼠血清中雷公藤甲素和雷公藤红素的浓度;采用小鼠腹腔巨噬细胞线RAW264.7,利用脂多糖(lipopolysaccharide,LPS)作为刺激剂构建炎症模型,向细胞模型中分别加入雷公藤甲素、雷公藤红素药液或含药血清,采用Griess试剂利用紫外分光光度法检测孵化液中一氧化氮(NO)的分泌情况。结果雷公藤甲素质量浓度高于200μg·L-1,即可抑制LPS对RAW264.7细胞的刺激,雷公藤红素药液质量浓度高于80μg·L-1时,也可产生此作用,并呈现浓度依赖关系。血清中雷公藤甲素的质量浓度在0.5和1.0h时高于300μg·L-1,雷公藤红素的血清质量浓度在0.5⁶.0h内维持在200μg·L-1左右。大鼠服用雷公藤甲素和雷公藤红素后0.56.0h内维持在200μg·L-1左右。大鼠服用雷公藤甲素和雷公藤红素后0.5⁶.0h内的含药血清能明显抑制LPS对RAW264.7细胞的刺激作用,6.0h后含药血清抑制效果不显著。结论雷公藤甲素、雷公藤红素药液及大鼠服用雷公藤甲素和雷公藤红素后的含药血清均具有抗炎作用,该作用与这2种化合物体内浓度相关。     

多烯紫杉醇纳米粒的制备、表征及其抗肿瘤作用研究

目的 制备多烯紫杉醇纳米粒,并进行体内外抗肿瘤作用。方法 采用反溶剂沉淀联合高压均质法制备DTX-G2 纳米粒;采用动态光散射法、扫描电镜考察粒径和形态,并对其体外释放、膜毒性、体外抗肿瘤活性进行研究;建立4T1荷瘤小鼠模型,以紫杉醇注射液为对照组,10 mg/kg iv 给药,考察体内抗肿瘤作用。结果 制备的DTX-G2 纳米粒粒径为(356.8±6.709)nm,PDI 值为(0.147±0.02),Zeta 电位为(-14.4±0.07)mV,载药量为(62.3±1.9)%。扫描电镜观察纳米粒为片状。DTX-G2 纳米粒体外缓慢释放,在192 h累积释放率达到80.4%;无溶血现象,可采用静脉注射法给药;MTT 结果显示DTX-G2 纳米粒对4T1细胞的毒性强于溶液(IC50, 2.374 μg/mL vs 5.664 μg/mL,P＜0.05);4T1细胞摄取结果显示DTX-G2 纳米粒的摄取量显著高于溶液(20.46 vs 11.01,P＜0.05);体内研究中DTX-G2 纳米粒对4T1 荷瘤小鼠的的抑瘤率显著高于注射液组(75.7% vs 52.4%,P＜0.05)。结论 制备的DTX-G2 纳米粒载药量高、稳定性好,显著提高了多烯紫杉醇的抗肿瘤效果,有望作为一种新型的药物输送系统应用到多烯紫杉醇的临床治疗中。     

青蒿精油作为纳米乳油相促进雷公藤红素透皮吸收的研究

目的 探究青蒿精油及其纳米乳对雷公藤红素体外透皮吸收的影响及促透机制。方法 首先建立雷公藤红素含量测定方法，其次制备以青蒿精油作为油相的纳米乳并表征，最后采用改良Franz扩散池法考察不同浓度青蒿精油及以青蒿精油作为纳米乳油相对雷公藤红素的促透效果，并用HE染色、差示扫描量热法探究促透机制。结果 雷公藤红素浓度在1.8~360 μg·mL^-1内线性关系良好，线性回归方程Y=16 494X–16 111(r=1.000)；精密度、稳定性的RSD<2%，平均加样回收率为99.26%，RSD为1.04%。雷公藤红素纳米乳平均粒径(19.93±0.19)nm，Zeta电位为(17.67±2.78)mV，多分散性指数为0.097。纳米乳、青蒿精油及含青蒿精油的纳米乳对雷公藤红素均有不同程度的促渗作用，对皮肤结构、相变温度均有不同程度改变。其中，含青蒿精油的纳米乳对雷公藤红素的促渗作用最强、对皮肤结构和相变温度影响最大。结论 青蒿精油及以青蒿精油作为纳米乳油相对雷公藤红素具有较好的促透作用，其促透机制与影响皮肤结构、改变热力学性质有关。     

雷公藤红素对转基因小鼠原代肝细胞HBV的抑制作用

目的:考察雷公藤红素对HBV转基因小鼠原代肝细胞的抗HBV作用。方法:改良的两步灌流法分离HBV转基因小鼠原代肝细胞;MTT法检测细胞毒性作用;药物作用24 h后取上清,分别应用ELISA法和荧光定量PCR法测定HBsAg和HBV-DNA。结果:雷公藤红素对原代肝细胞TC50为(6.49±0.8)μmol·L-1;雷公藤红素浓度低于0.8μmol·L-1时,对原代肝细胞没有明显毒性;在0.08～0.8μmol·L-1浓度范围内对HBsAg和HBV-DNA有显著抑制作用(P<0.05);随着雷公藤红素浓度的增加,对HBsAg和HBV-DNA的抑制作用增强。结论:雷公藤红素不仅能够抑制转基因小鼠原代肝细胞HBV-DNA的复制,而且可以有效抑制其HBsAg的表达。     

雷公藤红素对小鼠的免疫抑制作用及其对IL-6mRNA表达影响的研究

目的：研究雷公藤红素对小鼠的免疫抑制作用及对细胞因子IL-6mRNA表达的影响。方法：采用碳粒廓清、迟发型变态反应、血清溶血素测定和T淋巴细胞转化实验，观察雷公藤红素对小鼠免疫功能的影响；运用RT—PCR半定量法研究雷公藤红素对小鼠肝脏IL-6mRNA表达影响。结果：雷公藤红素能抑制小鼠血清溶血素水平（400μg／kg），且与剂量呈依赖关系；小鼠耳廓肿胀度研究表明，雷公藤红素能使迟发型变态反应程度减轻（400μg／kg）；雷公藤红素剂量在0．25μg／mL时，可以明显抑制植物血凝素（PHA）诱导的细胞增殖；雷公藤红素800μg／kg能对抗CCl4引起的急性肝损伤小鼠肝脏IL-6mRNA含量的升高。结论：雷公藤红素在一定程度上能抑制小鼠的免疫功能，能抑制炎症细胞因子IL-6基因的过度表达．     

西瑞香素纳米混悬剂的制备及其体外抗肿瘤作用研究

目的制备西瑞香素纳米混悬剂,并考察其对多种肿瘤细胞增殖的抑制作用。方法以粒径、Zeta电位、多分散性指数(PDI)为指标,考察稳定剂、药载比、超声温度、均质温度、均质次数对西瑞香素纳米混悬剂反溶剂沉淀法制备的影响,优化最佳处方和工艺条件。观察西瑞香素纳米混悬剂的透射电镜表征,并进行X射线衍射、差示扫描量热分析,考察其在血浆、PBS中的稳定性以及载药量、体外释放情况,采用MTT法比较其对BT474、SKBR-3、A549、He La、Hep G2细胞的体外细胞毒性。结果最佳处方和工艺条件:TPGS为稳定剂,药载比1∶1,共同溶解于DMSO中,在超声(25℃,250 W)条件下,缓慢滴注于去离子水中,透析除去有机溶剂,高压均质(25℃,150 MPa)20次,即得西瑞香素纳米混悬剂,其平均粒径为(163.1±5.4)nm,Zeta电位为(-11.4±0.7)m V,PDI为0.15±0.04。西瑞香素纳米混悬剂近乎为球形,大小较均匀;在血浆中稳定存在,不存在溶血现象,满足静脉注射需求,平均载药量为(39.16±1.09)%。西瑞香素纳米混悬剂对5种受试细胞的生长抑制作用显著提高,并呈现剂量相关性,尤其是对SKBR-3、A549、He La、Hep G2细胞,IC_(50)在2.1~3.4μg/m L。结论西瑞香素纳米混悬剂具有小粒径、高载药量、显著肿瘤细胞毒性等优点,在抗肿瘤研究方面具有良好的应用前景。     

柠檬苦素纳米混悬剂和冻干粉的制备及体外评价

目的:制备柠檬苦素纳米混悬剂及其冻干粉末，并进行体外评价。方法:以纳米混悬剂粒径为指标，单因素考察投药量、稳定剂用量、大豆磷脂(SPC)占稳定剂的比例等影响。采用Box-Behnken响应面法优化柠檬苦素纳米混悬剂的处方工艺，测定粒径及Zeta电位，并采用扫描电镜法观察纳米粒子形貌。冷冻干燥法制备柠檬苦素纳米混悬剂冻干粉，X射线粉末衍射法分析存在状态，平衡法测定溶解度，透析袋法评价其体外溶出度。结果:柠檬苦素纳米混悬剂最佳处方为：投药量为30 mg,稳定剂用量为88 mg,大豆磷脂占稳定剂比例为60%。平均粒径为(187.29±6.46)nm,与Box-Behnken响应面法预测值接近。Zeta电位值为(-31.58±1.77)mV,柠檬苦素纳米粒子外貌为球形或类球形。X射线粉末衍射法结果显示柠檬苦素纳米混悬剂冻干粉中以无定型状态存在，溶解度提高至95.63倍，纳米混悬剂在240 min累积溶出度达到96.11%。结论:将柠檬苦素制备成纳米混悬剂冻干粉可以提高其溶解度和溶出度，为进一步临床开发奠定了基础。     

Inhibition of IKKβ by celastrol and its analogues – an in silico and in vitro approach

Context: Alzheimer’s disease (AD) is the most common form of dementia affecting the aged population and neuroinflammation is one of the most observed AD pathologies. NF-κB is the central regulator of inflammation and inhibitor κB kinase (IKK) is the converging point in NF-κB activation. Celastrol is a natural triterpene used as a treatment for inflammatory conditions.

Objective: This study determines the neuroprotective and inhibitory effect of celastrol on amyloid beta_1-42 (Aβ_1-42) induced cytotoxicity and IKKβ activity, respectively.

Materials and methods: Retinoic acid differentiated IMR-32 cells were treated with celastrol (1?μM) before treatment with Aβ_1-42 (IC₃₀ 10?μM) for 24?h. The cytotoxicity and IKK phosphorylation were measured by MTT and western blotting analysis, respectively. We screened 36 celastrol analogues for the IKKβ inhibition by molecular docking and evaluated their drug like properties to delineate the neuroprotective effects.

Results: Celastrol (1?μM) inhibited Aβ_1-42 (10?μM) induced IκBα phosphorylation and protected IMR-32 cells from cell death. Celastrol and 25 analogues showed strong binding affinity with IKKβ as evidenced by strong hydrogen-bonding interactions with critical active site residues. All the 25 analogues displayed strong anti-inflammatory properties but only 11 analogues showed drug-likeness. Collectively, molecule 15 has highest binding affinity, CNS activity and more drug likeness than parent compound celastrol.

Discussion and conclusion: The decreased expression of pIκBα in celastrol pretreated cells affirms the functional representation of inhibited IKKβ activity in these cells. The neuroprotective potentials of celastrol and its analogues may be related to IKK inhibition.     

Inhibition of NF-kappa B activation through targeting I kappa B kinase by celastrol, a quinone methide triterpenoid

Celastrol, a quinone methide triterpenoid, was isolated as an inhibitor of NF-kappaB from Celastrus orbiculatus. This compound dose-dependently inhibited a variety of stimuli-induced NF-kappa B-regulated gene expression and the DNA-binding of NF-kappa B in different cell lines without affecting DNA-binding activity of AP-1. Preincubation of celastrol completely blocked the LPS-, TNF-alpha-, or PMA-induced degradation and phosphorylation of I kappa B alpha. Importantly, celastrol inhibited IKK activity and the constitutively active IKK beta activity in a dose-dependent manner without either affecting the NF-kappa B activation induced by RelA over-expression or directly suppressing the DNA-binding of activated NF-kappa B. However, mutation of cysteine 179 in the activation loop of IKK beta abolished sensitivity towards to celastrol, suggesting that celastrol suppressed the NF-kappa B activation by targeting cysteine 179 in the IKK. To verify that celastrol is a NF-kappa B inhibitor, we investigated its effect on some NF-kappa B target genes expressions. Celastrol prevented not only LPS-induced mRNA expression of iNOS and TNF-alpha, but also TNF-alpha-induced Bfl-1/A1 expression, a prosurvival Bcl-2 homologue. Consistent with these results, celastrol significantly suppressed the production of NO and TNF-alpha in LPS-stimulated RAW264.7 cells, and increased the cytotoxicity of TNF-alpha in HT-1080 cells. We also demonstrated that celastrol showed anti-inflammatory and anti-tumor activities in animal models. Taken together, this study extends our understanding on the molecular mechanisms underlying the anti-inflammatory and anti-cancer activities of celastrol and celastrol-containing medicinal plant, which would be a valuable candidate for the intervention of NF-kappa B-dependent pathological conditions.     

Celastrol induces apoptosis in non-small-cell lung cancer A549 cells through activation of mitochondria- and Fas/FasL-mediated pathways

Celastrol is a natural compound extracted from the traditional Chinese medicinal herb, Tripterygium wilfordii Hook. It has attracted interests for its potential anti-inflammatory and antitumor effects. However, the molecular mechanisms of celastrol-induced apoptosis in cancer cells remain unclear. In this study, we investigated the effects of celastrol on the human non-small-cell lung cancer (NSCLC) cell line A549 in vitro. Celastrol caused a dose- and time-dependent growth inhibition of A549 cells with an IC₅₀ of 2.12 μM at 48 h treatment. Celastrol induced A549 cells apoptosis as confirmed by annexin V/propidium iodide staining and DNA fragmentation. Celastrol-induced apoptosis was characterized by cleavage of caspase-9, caspase-8, caspase-3, and PARP protein, increased Fas and FasL expression, and a reduction in the mitochondrial membrane potential. Furthermore, celastrol induced the release of cytochrome c. Celastrol also up-regulated the expression of pro-apoptotic Bax, down-regulated anti-apoptotic Bcl-2, and inhibited Akt phosphorylation. These results demonstrate that celastrol can induce apoptosis of human NSCLC A549 cells through activation of both mitochondria- and FasL-mediated pathways.     

Toxic effects of celastrol on embryonic development of zebrafish (Danio rerio)

Celastrol is a terpenoid purified from Tripterygium wilfordii Hook F. As a natural product with pharmacological activities, this compound is a promising candidate for drug development. To provide more information about its toxicity for clinical trials, toxicity assessment of celastrol was conducted with zebrafish model in vivo. 1hour post-fertilization (hpf) embryos were treated with various concentrations of celastrol for 120h. Developmental phenotypes were observed and survival rates were recorded. The results showed that the hatching rates of embryos treated with 1.0μM or higher celastrol were significantly lower. Embryos exposed to 1.0μM celastrol had no blood flow in trunk vessels at 48hpf with a median effect concentration (EC(50)) of 0.94μM. At 72hpf serious edema in pericardial sac was observed in the surviving larvae (hatched from embryos treated with 1.5μM celastrol). Bent tails or hook-like tails were seen as 0.5μM celastrol and the EC(50) for tail malformation was 0.66 μM at 72hpf. The lethal effect of celastrol on zebrafish embryos was dose-dependent and the LC(50) values of celastrol on 1hpf embryos were approximately 1.40μM. These results indicate that celastrol affects the normal development of zebrafish embryo in μM concentrations.     

Spontaneous formation of drug-containing acrylic nanoparticles.

Nanoparticles containing ibuprofen, indomethacin or propranolol were formed spontaneously after the addition of solutions of the drugs and acrylic polymers (Eudragit RS or RL 100) in the water-miscible solvents, acetone or ethanol, to water without sonication or microfluidization. The colloidal dispersions were stabilized by quaternary ammonium groups and did not require the addition of surfactants or polymeric stabilizers. The nanoparticles were compared to nanoparticles prepared either by a microfluidization-solvent evaporation method with a water-immiscible organic solvent, methylene chloride, or by a melt method with respect to particle size and redispersibility of freeze- or spray-dried samples. Nanoparticles prepared by microfluidization or the melt method were easily redispersed while Eudragit RS nanoparticles prepared by spontaneous emulsification were not redispersible. Flexible films were formed from the nanosuspensions after the addition of 15 per cent triethyl citrate, a water-soluble plasticizer. The release of propranolol from the films increased with increasing proportion of RL, but was independent of the order of mixing of the two polymers or nanosuspensions during film preparation. The drug release from indomethacin films was increased by adding water-soluble polymers to the nanosuspension.     

无稳定剂修饰的汉防己甲素PLGA纳米粒制备及体外评价

目的:制备无稳定剂修饰的汉防己甲素PLGA纳米粒,研究其理化性质及细胞毒和细胞摄取特性。方法:以聚乳酸-羟基醋酸共聚物(PLGA)为载体材料,采用无稳定剂修饰的纳米沉淀法制备汉防己甲素纳米粒;通过单因素试验考察不同制备工艺对纳米粒理化性质的影响;通过载药量、包封率、累积释药量等指标考察其载药特性;采用MTT比色法检测其对人肺腺癌细胞株A549的细胞毒性;采用共聚焦显微镜技术考察其细胞摄取特性。结果:无稳定剂修饰的汉防己甲素PLGA纳米粒平均粒径169.3 nm,与有稳定剂的汉防己甲素PLGA纳米粒相比外观无明显改变。在一定范围内,随着PLGA用量的增加,纳米粒的粒径呈上升趋势;随着投药量的增加,纳米粒的载药量显著增加,包封率下降。在pH7.4的释放介质中,纳米粒释慢释药,96 h累积释药率60.44%。细胞毒试验显示,当培养时间为8 h时,汉防己甲素组的细胞毒性大于汉防己甲素纳米粒组;当培养时间延长至24 h时,汉防己甲素纳米粒组的细胞活性明显低于纯药物组;高剂量的空白纳米粒组始终表现较低的细胞毒性。激光共聚焦电镜断层扫描显示汉防己甲素纳米粒能够较好的被细胞摄取。结论:制备的无稳定剂修饰的汉防己甲素PLGA纳米粒大小均一,包封率高,体外释药表现出较好的缓释效果,易被细胞摄取,对A549细胞的增殖有明显的抑制作用。     

雷公藤红素抗肿瘤作用的研究进展

雷公藤红素为卫矛科植物雷公藤的主要活性成分之一,是一种醌甲基三萜类化合物,外观呈红色针状结晶体,具有多种生物学活性。2015年,雷公藤红素被发现具有显著减肥的作用,从而引起了大量学者的兴趣。近年来,越来越多的研究表明其在抗肿瘤方面具有较明显的药理活性,可通过多种信号通路抑制乳腺癌、前列腺癌、肺癌、结直肠癌、胃癌、肝癌等。本文就近年来雷公藤红素的抗肿瘤作用及其作用机理展开叙述,旨在为雷公藤红素的深入研究提供新的思路。     

A nanoparticulate drug-delivery system for 20(S)-protopanaxadiol: formulation,characterization, increased oral bioavailability and anti-tumor efficacy

As with many other hydrophobic anticancer agents, 20(S)-protopanaxadiol (PPD) has a very low oral bioavailability. In this study, a precipitation-combined ultrasonication technique was used to prepare PPD nanosuspensions. The mean particle size of the nanosuspensions was approximately 222?±?12?nm, the drug payload achieved 50% after lyophilization and the maximum PPD concentration can reach 100?mg/ml, which is over 30?000 times the solubility of PPD in aqueous solution (3?μg/ml). After oral administration, the C_max and AUC_last values of PPD nanosuspensions were approximately 3.66-fold and 3.48-fold as those of PPD coarse suspensions, respectively. In contrast to the free drug solution, PPD nanosuspensions showed higher in vitro anti-tumor activity against HepG-2 cells (an IC₅₀ value of 1.40 versus 5.83?μg/ml at 24?h, p?<?0.01). The in vivo study in H22-tumor-bearing mice demonstrated that PPD nanosuspensions showed good anti-tumor efficacy with an inhibition rate of 79.47% at 100?mg/kg, while 50?mg/kg of cyclophosphamide was displayed as positive control, and the inhibition rate was 87.81%. Considering the highest drug payload, oral bioavailability reported so far, significant anti-tumor efficacy and excellent safety of encapsulated drugs, PPD nanosuspensions could be used in potential effective strategies for anticancer therapy; further investigation is ongoing.     

Celastrol ameliorates HIV-1 Tat-induced inflammatory responses via NF-kappaB and AP-1 inhibition and heme oxygenase-1 induction in astrocytes

HIV-1 Tat causes extensive neuroinflammation that may progress to AIDS-related encephalitis and dementia. Celastrol possesses various biological activities such as anti-oxidant, anti-tumor, and anti-inflammatory activities. In this study, we investigated the modulatory effects of celastrol on HIV-1 Tat-induced inflammatory responses and the molecular mechanisms underlying its action in astrocytes. Pre-treatment of CRT-MG human astroglioma cells with celastrol significantly inhibited HIV-1 Tat-induced expression of ICAM-1/VCAM-1 and subsequent monocyte adhesiveness in CRT-MG cells. In addition, celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory chemokines, such as CXCL10, IL-8, and MCP-1. Celastrol decreased HIV-1 Tat-induced activation of JNK MAPK, AP-1, and NF-κB. Furthermore, celastrol induced mRNA and protein expression of HO-1 as well as Nrf2 activation. Blockage of HO-1 expression using siRNA reversed the inhibitory effect of celastrol on HIV-1 Tat-induced inflammatory responses. These results suggest that celastrol has regulatory effects on HIV-1 Tat-induced inflammatory responses by blocking the JNK MAPK-AP-1/NF-κB signaling pathways and inducing HO-1 expression in astrocytes.     

Nanosuspensions as advanced printing ink for accurate dosing of poorly soluble drugs in personalized medicines

Folic acid was used as a model drug to demonstrate the advantages of formulating poorly soluble drugs as nanosuspensions and their use in an inkjet-type printing technique to produce personalized medicines. 10% folic acid nanosuspensions stabilized with Tween 20, a stabilizer showing the best wetting potential for folic acid, were prepared via high pressure homogenization. The particle size of the folic acid nanosuspension was well below 5 μm being a prerequisite for inkjet type printing technique. A good reproducibility of the particle size of folic acid nanosuspension prepared via high pressure homogenization was found. As indicated by the zeta potential the formulation showed a good storage stability. High pressure homogenization had no influence on the crystalline state of folic acid. An increase in the saturation solubility by 53.7% was found reducing the particle size from the micrometer range to the nanometer range. The dissolution velocity of the folic acid nanosuspension was significantly enhanced compared to a folic acid suspension, i.e. after 5 min 78.6% of the folic acid was dissolved from the nanosuspension and only 6.2% from the suspension. Moreover, the printing of 10% folic acid nanosuspension could be successfully demonstrated.