泊洛沙姆188复验后再使用研究

目的:研究泊洛沙姆188复验期后放置时间对其品质和细胞培养的影响,为泊洛沙姆188复验期的确定提供依据.方法:分别对复验期后6个月、24个月和36个月的泊洛沙姆188进行pH、内毒素含量测定、拉曼鉴别和细胞培养测试,评估其作为培养基组分对细胞生长和重组蛋白表达的影响.结果:泊洛沙姆188在复验期后36个月以内的pH、内...     

阿托伐他汀钙泊洛沙姆188固体分散体的制备及表征

目的:制备阿托伐他汀钙泊洛沙姆188(AC-P188)固体分散体,并对其进行表征。方法:以P188和聚乙二醇6000(PEG6000)为载体材料,采用溶剂挥发法制备AC-P188固体分散体,以载药率、水中溶解度、体外累积释放度为指标,采用单因素试验筛选处方中P188、PEG6000用量;利用差示扫描量热(DSC)法、X射线衍射(XRD)仪、傅里叶红外光谱(FT-IR)仪考察所制固体分散体中的晶型变化。结果:处方为0.5 g AC,4 g P188,4 g PEG6000;所制AC-P188固体分散体的载药率为89.97%,水中溶解度为1.57 mg/ml,体外累积释放度为92.69%;表征结果显示,AC可能以分子或无定形态均匀分散于载体中,AC与载体材料之间可能以氢键形式缔合。结论:成功制得AC-P188固体分散体,为提高阿托伐他汀钙的溶出和生物利用度提供了一定的理论基础。     

盐酸小檗碱泊洛沙姆188固体分散体的制备

目的:制备盐酸小檗碱泊洛沙姆188固体分散体。方法:采用熔融法制备固体分散体,考察药物和载体的比例、熔融温度、冷却温度对溶出率的影响,比较固体分散体和物理混合物的溶出率的区别。结果:药物和载体比例达到1∶1时,载体的量足够使药物分散均匀;熔融温度对溶出率影响不大;冷却温度对溶出率影响较大,0℃时溶出率最快。与物理混合物相比,固体分散体将盐酸小檗碱的溶出率提高了近1倍。结论:盐酸小檗碱泊洛沙姆188固体分散体提高了盐酸小檗碱的体外溶出率。     

白藜芦醇-泊洛沙姆188固体分散体的制备及其性能研究

目的:制备白藜芦醇-泊洛沙姆188固体分散体(RES-P188-SD),并对其体外溶出特性及抑菌性进行研究。方法:以P188为载体,采用溶剂法制备RES-P188-SD。以药物与载体质量比、熔融温度、筛孔目数为考察因素,以RES溶解度与收率为考察指标,设计L9(34)正交试验优选其制备工艺。以考察指标的综合评分进行结果分析,并进行验证试验。根据最优工艺制备RES-P188-SD后采用篮法测定其溶出度并计算累积溶出度,扫描电镜法分析物相表征,管碟法测定其抑菌性。结果:最优工艺为药物与载体质量比1∶10,熔融温度70℃,筛孔目数80目。按最优工艺所制样品的平均溶解度为0.51 mg/ml(RSD=1.96%,n=3),平均收率为91%(RSD=0.64%,n=3),15 min的平均累积溶出度即达83%(RSD=0.69%,n=3);其药物以非晶形式均匀分散在载体中;RES-P188-SD对金黄色葡萄球菌和大肠埃希菌均有抑制作用。结论:优选工艺稳定、可行。成功制得RES-P188-SD,可为提高RES的溶解度、溶出速率及抑菌性提供依据。     

吲哚美辛-泊洛沙姆188固体分散体的制备

目的制备吲哚美辛-泊洛沙姆188固体分散体,提高吲哚美辛的溶出度。方法以泊洛沙姆188为载体,采用溶剂-熔融法制备固体分散体。用差示热分析(DTA)、扫描电子显微镜(SEM)考察药物在载体中的存在状态,并进行体外溶出度研究。结果吲哚美辛以微晶或无定形分散在载体中,药物的溶出度随载体比例增加而增加。结论制备的固体分散体吲哚美辛的溶出度和溶出速率显著提高。     

泊洛沙姆188对体外神经元损伤后线粒体损害的作用研究

目的探讨泊洛沙姆188(Poloxamer 188,P188)对体外神经元损伤引起的细胞死亡及线粒体损害可能发挥的作用机制。方法采用小鼠的原代神经元培养并建立体外神经元离心损伤模型(VCID),在损伤后10 min加入P188,观察神经元的形态变化,MTT法与LDH法检测P188对体外神经元损伤引起细胞死亡的影响。分离线粒体亚成分,采用免疫印记法检测损伤后6 h与24 h线粒体内与胞质中CytC的表达情况,并检测P188对体外神经元损伤后caspase-3表达的影响。结果显微镜观察到:与正常组相比,损伤组在外伤后24 h出现了一些结构与形态上的改变。P188处理过的神经元在损伤后24 h,在形态特征上发生明显的恢复,与对照组的形态特征类似。MTT法与乳酸脱氢酶(LDH)法结果显示:P188能明显减轻损伤引起的神经元死亡与乳酸脱氢酶漏出率。Western blot结果显示:在损伤后6 h与24 h,P188处理后均能明显抑制损伤后线粒体成分中CytC蛋白水平的下调(P<0.05),及胞质成分中CytC蛋白水平的上调(P<0.05),提示P188能明显抑制外伤引起CytC蛋白的释放。同时,P188也能抑制外伤引起的激活型caspase-3(p20)的上调(P<0.05)。结论 P188对体外神经元损伤引起的细胞死亡及线粒体损害具有明显的神经保护作用,这种保护作用可能与抑制线粒体膜完整性破坏和抑制凋亡的线粒体途径有关。     

叶酸受体及二氢叶酸还原酶与人乳腺癌细胞MCF-7/ADR多药耐药的关系

目的以人乳腺癌多药耐药细胞系MCF-7/ADR及其敏感亲本系MCF-7为对象,探讨叶酸受体(FOLRα)及其下游基因二氢叶酸还原酶(DHFR)的表达与乳腺癌细胞多药耐药的关系。方法 MTT法测定阿霉素的细胞毒性作用及DHFR抑制剂对MCF-7/ADR细胞多药耐药的逆转作用;RT-PCR检测细胞FOLRα和DHFR mRNA的表达水平;免疫细胞化学检测FOLRα、P-gp的表达水平。结果 MCF-7细胞增殖速度快于MCF-7/ADR细胞,MCF-7细胞FOLRα mRNA转录水平较MCF-7/ADR细胞高,而MCF-7/ADR细胞DHFR mRNA较MCF-7细胞转录水平高;免疫细胞化学显示MCF-7细胞FOLRα的表达高于MCF-7/ADR细胞,而MCF-7/ADR细胞P-gp的表达较MCF-7细胞高;MCF-7/ADR对甲氨蝶啶无耐药性,甲氨蝶啶对MCF-7/ADR细胞多药耐药有逆转作用。结论 MCF-7/ADR细胞FOLRα的表达水平下调可能与细胞增殖水平有关,其下游基因DHFR表达水平与MCF-7/ADR细胞的MDR可能存在相关性。     

泊洛沙姆诱导急性高脂血症小鼠模型的药效学研究

目的通过泊洛沙姆诱导建立急性高脂血症小鼠模型。方法 ICR小鼠单次腹腔注射不同剂量的泊洛沙姆407（P-407）（用量依次为0.25 g/kg、0.50 g/kg、1.0 g/kg、2.0 g/kg）,然后在指定的时间点（次）从眼窝丛收集血液样本,测定血清中TG、TC、AST、ALT、HDL、LDL及血糖水平并观察经阿托伐他汀预处理后的血脂水平。结果 P-407可诱发ICR小鼠血脂水平出现异常,其中0.25、0.50和1.0 g/kg剂量组小鼠ALT、AST以及血糖水平并无显著改变,但2.0 g/kg剂量组小鼠ALT水平显著升高;阿托伐他汀能有效改善0.25和0.50 g/kg剂量P-407诱发的血脂异常。结论 0.25和0.50 g/kg剂量的P-407可用于复制急性高脂血症小鼠模型,此模型可用于药物的筛选,其对血糖水平和肝功能不受影响。     

膜表面活性剂泊洛沙姆188抗神经兴奋性毒性的作用及机制

目的研究泊洛沙姆188(poloxamer188,P188)在NM-DA受体介导的神经兴奋性毒性中的作用及其机制。方法采用脑立体定位纹状体内注射喹啉酸(quinolinic acid,QA),建立NMDA受体介导的大鼠神经兴奋性毒性模型,尼式染色法和细胞计数法观察P188舌下静脉预防给药对模型大鼠纹状体神经元的保护作用。Western blot法检测P188对模型大鼠纹状体IκB-α、DRAM和LAMP-2蛋白表达的影响。结果尼式染色和细胞计数结果显示P188给药组与QA模型组相比,损伤面积明显减小(P<0.01),神经元数目明显增加(P<0.01)。Western blot结果显示大鼠纹状体注射QA后,模型大鼠纹状体内IκB-α蛋白水平明显降低,而DRAM和LAMP-2蛋白表达增加,P188预给药可抑制QA引起的大鼠纹状体中IκB-α,DRAM和LAMP-2蛋白表达的变化。结论 P188有拮抗神经兴奋性毒性的作用,这种神经保护作用可能与抑制IkB-α降解防止NF-κB激活和抑制自噬活性有关。     

A Novel Submicron Emulsion System Loaded with Doxorubicin Overcome Multi-Drug Resistance in MCF-7/ADR Cells

The purpose of the present study was to develop the Solutol HS15-based doxorubicin submicron emulsion with good stability and overcoming multi-drug resistance. In this study, we prepared doxorubicin submicron emulsion, and examined the stability after autoclaving, the in vitro cytotoxic activity, the intracellular accumulation and apoptpsis of doxorubicin submicron emulsion in MCF-7/ADR cells. The physicochemical properties of doxorubicin submicron emulsion were not significantly affected after autoclaving. The doxorubicin submicron emulsion significantly increased the intracellular accumulation of doxorubicin submicron emulsion and enhanced cytotoxic activity and apoptotic effects of doxorubicin. These results may be correlated to doxorubicin submicron emulsion inhibitory effects on efflux pumps through the progressive release of intracellular free Solutol HS15 from doxorubicin submicron emulsion. Furthermore, these in vitro results suggest that the Solutol HS15-based submicron emulsion may be a potentially useful drug delivery system to circumvent multi-drug resistance of tumor cells.     

Promising galactose-decorated biodegradable poloxamer 188-PLGA diblock copolymer nanoparticles of resibufogenin for enhancing liver cancer therapy

Liver cancer is one of the major diseases affecting human health. Modified drug delivery systems through the asialoglycoprotein receptor, which is highly expressed on the surface of hepatocytes, have become a research focus for the treatment of liver cancer. Resibufogenin (RBG) is a popular traditional Chinese medicine and natural anti-cancer drug that was isolated from Chansu, but its cardiotoxicity and hydrophobicity have limited its clinical applications. Galactosyl-succinyl-poloxamer 188 and galactosyl-succinyl-poloxamer 188-polylactide-co-glycolide (Gal-SP188–PLGA) were synthesized using galactose, P188, and PLGA to achieve active liver-targeting properties. RBG-loaded Gal-SP188–PLGA nanoparticles (RGPPNs) and coumarin-6-loaded Gal-SP188–PLGA nanoparticles (CGPPNs) were prepared. The in vitro cellular uptake, cytotoxicity, and apoptosis of nanoparticles in HepG2 cells were analyzed. The in vivo therapeutic effects of nanoparticles were assessed in a hepatocarcinogenic mouse model. The results showed that Gal-SP188–PLGA was successfully synthesized. The cellular uptake assay demonstrated that CGPPNs had superior active liver-targeting properties. The ratio of apoptotic cells was increased in the RGPPN group. In comparison to the other groups, RGPPNs showed superior in vivo therapeutic effects and anticancer efficacy. Thus, the active liver-targeting RGPPNs, which can enhance the pharmacological effects and decrease the toxicity of RBG, are expected to become a promising and effective treatment for liver cancer.     

肿瘤微环境响应型纳米凝胶递药系统的研究进展

肿瘤微环境响应型纳米凝胶因其独特的凝胶三维网状结构,同时具备良好的生物相容性、体内循环时间长等特性,使其在纳米药物递送领域受到越来越多的关注。根据不同的肿瘤微环境,主要可分为生物微环境响应型纳米凝胶及物理微环境响应型纳米凝胶2大类。通过对这2大类肿瘤微环境响应型纳米凝胶在药物递送中的研究进展的综述,以期为更精准智能的纳米凝胶递药系统的研发提供参考。     

A Novel System Based on a Poloxamer/ PLGA Blend as a Tetanus Toxoid Delivery Vehicle

Purpose. Previous work on the encapsulation of proteins and antigens in poly(lactic-co-glycolic acid) (PLGA) microspheres has led to the conclusion that microencapsulated antigens are frequently inactivated due to their interaction with the polymer. To improve the compatibility of the antigen with the polymer, we have devised a novel microencapsulated system consisting of a blend of PLGA 50:50 and poloxamer 188 (Pluronic^® F68) and applied it to the delivery of tetanus antigen. Methods. Tetanus toxoid was encapsulated in microspheres containing different amounts of poloxamer using an anhydrous procedure based on an oil-in-oil solvent extraction process. The compatibility of the polymers was studied by Fourier transform infrared (FT-IR) spectroscopy. Microspheres were assayed in vitro and in vivo for their ability to deliver active antigen for extended periods of time. Results. Analysis by FT-IR spectroscopy evidenced the miscibility of both polymers by a hydrogen bonding mechanism. In vitro release studies revealed that microspheres containing poloxamer released anti-genically active TT, in a pulsatile manner, for up to 50 days. In addition, it was observed that the intensity and duration of the pulses were dependent on both poloxamer content and TT loading in the microspheres. The in vivo evaluation of this new system showed that the neutralizing antibodies elicited by the TT encapsulated in poloxamer-PLGA microspheres were considerably higher and more prolonged than those obtained after administration of the aluminum phosphate-adsorbed toxoid. Conclusions. These results indicate the importance of devising new microencapsulation approaches specially adapted for preserving the activity of protein antigens incorporated within PLGA microspheres.     

Novel Central Nervous System Drug Delivery Systems

For decades, biomedical and pharmaceutical researchers have worked to devise new and more effective therapeutics to treat diseases affecting the central nervous system. The blood–brain barrier effectively protects the brain, but poses a profound challenge to drug delivery across this barrier. Many traditional drugs cannot cross the blood–brain barrier in appreciable concentrations, with less than 1% of most drugs reaching the central nervous system, leading to a lack of available treatments for many central nervous system diseases, such as stroke, neurodegenerative disorders, and brain tumors. Due to the ineffective nature of most treatments for central nervous system disorders, the development of novel drug delivery systems is an area of great interest and active research. Multiple novel strategies show promise for effective central nervous system drug delivery, giving potential for more effective and safer therapies in the future. This review outlines several novel drug delivery techniques, including intranasal drug delivery, nanoparticles, drug modifications, convection‐enhanced infusion, and ultrasound‐mediated drug delivery. It also assesses possible clinical applications, limitations, and examples of current clinical and preclinical research for each of these drug delivery approaches. Improved central nervous system drug delivery is extremely important and will allow for improved treatment of central nervous system diseases, causing improved therapies for those who are affected by central nervous system diseases.     

穿膜肽提高纳米银穿膜活性的研究

目的合成纳米银,在其表面修饰穿膜肽(TAT),并检测修饰后纳米银粒对人乳腺癌耐阿霉素细胞(MCF-7/ADR)的穿膜活性。方法通过化学还原法制备纳米银(AgNP),并通过Ag-S共价键与TAT连接修饰AgNP。通过粒度仪、透射电镜、激光共聚焦显微镜、流式细胞仪以及二喹林甲酸法等仪器及方法对其表征、共价连接及TAT的介导活性进行测定。结果成功制备了10 nm以下的AgNP,且修饰TAT后的AgNP(AgNP-TAT)表现出了比AgNP更强的穿膜活性。结论 TAT修饰AgNP后能显著提高其穿膜活性。     

高胰岛素对 MCF-7/ADR 细胞化疗敏感性的影响

摘要:目的 分析高胰岛素对 MCF-7/ADR 细胞 P-糖蛋白（P-gp）表达和功能的影响, 并初步探讨胰岛素对 MCF-7/ADR 细胞化疗敏感性的影响。方法 用不同胰岛素浓度（0.001、 0.005、 0.01、 0.05、 0.10 μmol/L）的全细胞培 养基干预 MCF-7/ADR 细胞, 分别采用 Real-time PCR 法检测细胞中 P-gp mRNA 表达, Western Blot 法检测细胞中 P-gp 蛋白表达水平, 罗丹明 123 荧光实验测定 P-gp 的外排功能变化, MTT 法检测 MCF-7/ADR 细胞活性及化疗敏 感性。结果 0.10 μmol/L 的胰岛素可促进 MCF-7/ADR 细胞增殖, 0.05 及 0.10 μmol/L 浓度的胰岛素可增加 MCF-7/ ADR 细胞 P-gp mRNA 及蛋白水平表达, 并能增加 P-gp 的外排功能, 降低 MCF-7/ADR 细胞对表阿霉素的化疗敏感 性。结论 高浓度胰岛素可能通过促进 MCF-7/ADR 细胞 P-gp 的表达和功能, 增加乳腺癌细胞化疗耐药性, 从而降 低 MCF-7/ADR 细胞的化疗敏感性。     

蛇床子素对耐阿霉素人乳腺癌细胞耐药的逆转作用

目的:研究蛇床子素(Ost)对人乳腺癌细胞阿霉素耐药株多药耐药(MDR)的逆转作用及其机制。方法:采用MTT比色法测定药物的细胞毒性,高效液相-紫外检测法检测细胞内ADR浓度。结果:Ost对MCF-7及MCF-7/ADR细胞均有增殖抑制作用,IC50值分别为(58.1±2.3)μmol.L-1和(59±5)μmol.L-1;在5~15μmol.L-1范围内,Ost可以不同程度地增强ADR对MCF-7细胞杀伤作用,与ADR联合用药降低ADR对MCF-7/ADR的IC50值,显著增加MCF-7/ADR细胞内ADR的积累。结论:Ost对人乳腺癌细胞株MCF-7及其阿霉素耐药株MCF-7/ADR细胞均有增殖抑制作用,而且Ost通过明显增加MCF-7/ADR细胞内ADR的浓度,逆转其阿霉素耐药性。     

纳米粒在目艮部给药系统中的研究近况

介绍了近年来纳米粒在眼部给药系统中的研究情况。传统眼用制剂的主要缺陷为生物利用度低,药物在眼部保留时间短,刺激性较强,且药物一般只能到达眼前段组织;而新型纳米粒制剂不但能克服传统眼用统制剂存在的问题,还可实现靶向给药,故极具开发价值。     

基于纳米金的肿瘤靶向给药系统的研究进展

化疗是目前临床癌症治疗的主要手段之一,主要通过静脉给药细胞毒药物,在杀伤肿瘤细胞的同时,往往会导致健康器官和组织的全身细胞毒性.最新研究表明,纳米金是一种高效的抗肿瘤药物载体,能够携带药物穿透血管和组织屏障进入肿瘤病灶,并特异性积蓄于肿瘤组织,有效降低化疗药物的机体不良反应.此外,金纳米粒子具有易修饰性,相比于其他纳米...