Puerarin-loaded PEG-PE micelles with enhanced anti-apoptotic effect and better pharmacokinetic profile

Puerarin (PUE) is the most abundant isoflavonoid in kudzu root. It is widely used as a therapeutic agent for the treatment of cardiovascular diseases. However, the short elimination half-life, poor-bioavailability, and acute intravascular hemolysis of PUE are the main obstacles to its widespread clinical applications. Whereas PEG-PE micelles possess the ability to release medicine slowly, enhance the cellular uptake of drugs and improve their biocompatibility. Therefore, it was aim to fabricate puerarin-loaded PEG-PE (PUE@PEG-PE) micelles to improve the pharmaceutical properties of drugs. It can be observed from the TEM images that PUE@PEG-PE micelles appeared obvious core-shell structure and remained well-dispersed without aggregation and adhesion. PUE was successfully embedded in the core of PEG-PE micelles, which was confirmed by FT-IR and ¹H NMR spectra. In vitro studies showed that PUE@PEG-PE micelles exhibited a sustained release behavior in pH 7.4 PBS buffer and decreased hemolysis rate of PUE. Compared with PUE, PUE@PEG-PE micelles showed a 3.2-fold increase in the half-life of PUE and a 1.58-fold increase in bioavailability. In addition, the PUE@PEG-PE micelles exerted enhanced protective effect against isoprenaline-induced H9c2 cells apoptosis compared with PUE, as evident by decreased percentage of Hoechst-positive cells, Caspase 3 activity, Bax expression, and increased Bcl-2 expression. Notably, the PEG-PE micelles exhibited favorable cellular uptake efficiency on H9c2 cells, and this may account for their enhanced anti-apoptotic effect of the incorporated drug. Altogether, the PUE@PEG-PE micelles were not only able to control the drug release but also offered promise to enhance the pharmacokinetic and pharmacodynamic potential of PUE.     

重组人内皮抑素PEG-PE胶束的制备及抑瘤效应研究

目的:内皮抑素是强效的血管内皮细胞生长抑制剂,但其低溶解度限制了临床应用,通过采用聚乙二醇衍生化磷脂酰乙醇胺(PEG-PE)制备包载重组人内皮抑素的胶束,以期寻找内皮抑素的新药物载体.方法:研究PEG-PE内皮抑素胶束的理化性质,观察PEG-PE内皮抑素胶束对体外肿瘤细胞生长的作用及对鸡胚绒毛尿囊体内血管生长的影响.结果:制备的PEG-PE-内皮抑素胶束的粒径为(48.32±8.29)nm,Zeta电位为+3.2 mV.包封率为75%,该胶束可以抑制MCF-7肿瘤细胞的生长和增殖,内皮抑素浓度50 μg·mL-1时抑制率为31.4%,对鸡胚绒毛尿囊血管新生也有明显的抑制作用.结论:同单独用内皮抑素比较,用PEG-PE胶束作为药物载体运送内皮抑素直接抑制肿瘤细胞生长和抑制新生血管形成的效果更明显.     

葛根素PEG-PE纳米胶束的制备及降低红细胞溶血的初步研究

目的 采集葡萄糖-6-磷酸脱氢酶(glucose-6-phosphate ehydrogenase deficiency,G6PD)缺陷的动物模型血液,评价葛根素PEG-PE纳米胶束降低红细胞溶血的作用。方法 1%乙酰苯肼皮下注射大鼠制备G6PD缺陷的动物模型,取其红细胞制成混悬液,比较评价葛根素和葛根素PEG-PE纳米胶束的溶血作用、红细胞脆性及红细胞膜流动性。结果 葛根素出现了明显的红细胞溶血,且随着浓度变化和孵育时间延长具有增加的趋势,溶血率高达38%,而葛根素PEG-PE纳米胶束未见明显溶血;另外,红细胞脆性实验结果表明,葛根素PEG-PE纳米胶束对红细胞膜的作用非常轻微,H_50%为(42.1±1.1)%,显著小于葛根素的该数值(53.1±1.2)%,红细胞膜流动性结果表明,葛根素PEG-PE纳米胶束对红细胞膜的流动性影响非常轻微。结论 葛根素PEG-PE纳米胶束良好的血液相容性,为该药物的体内研究和进一步新型药物制剂开发奠定基础。     

ROS-sensitive calcipotriol nano-micelles prepared by methoxypolyethylene glycol (mPEG) – modified polymer for the treatment of psoriasis

Oxidative stress due to excessive reactive oxygen species (ROS) production in the skin microenvironment is one of the main mechanisms in psoriasis pathogenesis. A nano drug delivery system based on ROS-responsive release can enhance drug release at the target site. In this study, a ROS-sensitive material methoxypolyethylene glycol-thioether-thiol (mPEG-SS) was synthesized using mPEG as the parent structure with sulfide structural modification. An mPEG-SS-calcipotriol (mPEG-SS-CPT, PSC) nano-micelle percutaneous delivery system was prepared by encapsulating CPT. A small animal imaging system was used to study PSC’s the ROS-sensitive drug release process. It is shown that endogenous ROS mainly affects PSC and releases drugs. Finally, the therapeutic effect of PSC on psoriasis was explored by animal experiments. Ultimately, it ameliorates imiquimod-induced psoriasis-like inflammation. Overall, PSC is an effective ROS-sensitive transdermal drug delivery system that is expected to provide a new strategy for treating psoriasis.     

盐酸伊立替康纳米胶束制剂耐受性和药效学评价

探究盐酸伊立替康纳米胶束制剂相对于市售盐酸伊立替康注射液(商品名:Campto)在耐受性及药效学方面的改善。通过体外细胞毒性试验,比较两种制剂对于结直肠癌细胞COLO205、HT-29、HCT-8和SW480的体外生长抑制作用;构建COLO205荷瘤小鼠模型,尾静脉注射给予两种制剂,考察荷瘤小鼠对两种制剂的最大耐受剂量,进而探索在接近最大耐受剂量给药时,盐酸伊立替康纳米胶束制剂抗肿瘤药效的改善情况。结果显示,两种制剂对于4种结直肠癌细胞体外生长的抑制作用无明显差异;COLO205荷瘤小鼠对于盐酸伊立替康纳米胶束制剂及Campto的最大耐受剂量分别为432.0及276.5 mg/m²;药效试验中,在接近最大耐受剂量的剂量给药时,二者均表现出明显的抗肿瘤药效,其中,盐酸伊立替康纳米胶束制剂高剂量(345.6 mg/m²)的相对肿瘤增殖率及肿瘤湿重抑制率均显著优于Campto的两个给药剂量(177.0和221.2 mg/m²)(P<0.05)。     

紫杉醇纳米胶束冻干粉针剂的细胞毒性评价

目的对紫杉醇／聚乙二醇．聚谷氨酸苄酯（PEG-PBLG）纳米胶束冻干粉针剂的体外细胞毒性：进行研究评价。方法采用四噻唑蓝（MTT）法研究高分子嵌段共聚物PEG—PBLG、紫杉醇／PEG—PBLG冻干粉针剂对体外细胞毒性的影响。结果与增溶剂聚氧乙烯蓖麻油的较强细胞毒性相比,高分子材料PEG-PBLG安全性好,仅在200ug/mL浓度时才表现出有细胞毒性;当紫杉醇浓度≤10ug／mL时．紫杉醇／PEG—PBLG冻干粉针剂对2种人癌细胞的毒性均低于相应浓度的市售紫杉醇注射剂（P〈0．01）;结论与市售紫杉醇注射液相比,紫杉醇／PEG-PBLG冻干粉针剂能极大降低药物在体外的细胞毒性,并且该高分子嵌段共聚物本身毒性较低,安全性好,该纳米胶束制剂具有较为广阔的临床应用前景。     

川芎嗪PEG-PE纳米胶束的体外评价、细胞摄取及抗心肌细胞凋亡研究

目的 制备川芎嗪PEG-PE纳米胶束,并评价该纳米胶束的细胞摄取和抗心肌细胞凋亡效果。方法 采用薄膜水化法制备川芎嗪PEG-PE纳米胶束,并进行表征。采用体外释药、细胞摄取和细胞凋亡试验对该载药系统进行评价。结果 川芎嗪PEG-PE纳米胶束粒径为（15.8±0.9） nm,Zeta电势为-（20.5±0.4） mV,载药量为（5.7±0.3）%,包封率为（87.2±5.4）%。电镜结果表明川芎嗪PEG-PE纳米胶束呈形态规则的圆球型结构;采用芘测定法测定PEG-PE纳米胶束的临界胶束浓度约为5.3 μg·mL^-1;细胞摄取试验结果表明,PEG-PE纳米胶束可以增强药物的细胞摄取量,细胞外残留量减少;川芎嗪PEG-PE纳米胶束在10%胎牛血清DMEM培养基稳定性良好,采用异丙肾上腺素诱导心肌细胞凋亡,Hoechst染色提示凋亡心肌细胞出现了大量形态学改变,而川芎嗪PEG-PE纳米胶束可以明显减少凋亡细胞和促凋亡Caspase-3活性、抑制促凋亡蛋白Bax表达,提高抗凋亡蛋白Bcl-2表达,均显著优于川芎嗪（P<0.01）。结论 川芎嗪PEG-PE纳米胶束具有粒径小,载药量高,释药缓慢等优势,可很大程度上提高川芎嗪的心肌细胞摄取量,增强药物的抗心肌细胞凋亡作用。     

紫杉类药物温敏纳米胶束的小鼠LD50及其毒性差异

目的 研究紫杉醇(Pac)和多希紫杉醇(Doc)温敏纳米胶束的急性毒性作用及其在结合和未结合热疗情况下的毒性差异.方法 用不同剂量Doc和Pac温敏纳米胶束对昆明鼠行尾静脉注射,每个剂量分为热疗和非热疗组,观察小鼠用药后的急性毒副反应,计算半数致死量(LD50).分别以两种药物最大耐受剂量对相应实验组行小鼠尾静脉注射(对照组给予等剂量生理盐水),测定外周血的白细胞和血小板.结果 Doc温敏纳米胶束热疗和非热疗时小鼠尾静脉注射的LDF50分别为(330.94±23.58)mg/kg和(278.07±19.81)mg/kg,Pac温敏纳米胶束的LD50分别为(104.18±5.85)mg/kg和(95.50±5.10)mg/kg.Pac和Doc均可以引起外周血白细胞和血小板显著降低;而两种药物的温敏纳米胶束对外周血白细胞和血小板的影响较小,且热疗比非热疗时影响更小.结论 Pac和Doc温敏纳米胶束的急性毒性和对外周血白细胞和血小板的影响小于临床上常用的Pac和Doc注射液,且热疗时的毒性更小.     

多希紫杉醇温敏纳米胶束对人胃癌裸鼠移植瘤的靶向治疗作用

目的:探讨多希紫杉醇温敏纳米胶束治疗人胃癌裸鼠移植瘤的疗效.方法:采用裸鼠BGC-823胃腺癌动物模型,每组6只,随机分配至设立的多希紫杉醇非热疗和热疗组,多希紫杉醇温敏纳米胶束非热疗和热疗组以及生理盐水对照组等共8组,采用尾静脉给药方式,并恒温43℃对热疗组肿瘤部位进行热导向化疗,动态观察并测定肿瘤的体积、瘤质量抑瘤率,评价治疗效果,并观察实验期间动物的全身情况及相对体质量变化,评价毒副作用.结果:多希紫杉醇温敏纳米胶束热疗组人胃癌移植瘤表现出明显抑制,体积和瘤质量抑瘤率分别为81.5%和85.4%,显著高于多希紫杉醇温敏纳米胶束非靶向组(32.2%,37.5%)和多希紫杉醇注射液组(49.2%,58.0%)(P<0.05),且多希紫杉醇温敏纳米胶束热疗组的小鼠体质量与其他各组比较相对平稳,且饮食、活动正常,对正常组织的毒副作用明显减轻.结论:温敏纳米胶束具有良好的高效低毒体内抗肿瘤作用,作为一种新型的药物载体显示了良好的应用前景.     

The biological activity of cationic liposomes in drug delivery and toxicity test in animal models

In the study we made use of DOTAP (1,2-dioleoyl-3-trimethylammonium), DOPE (1,2-dioleoyl-snglycero-3-phosphoethanolamine) and PEG-PE (polyethylene glycol- polyethylene) to make cationic PEG-liposomes by ultrasonic dispersion method. The plasmid pGPU6 combined with cationic PEG-liposomes or Liopofectamin 2000 was used to transfect PC3 cells to judge the transfection efficiency. HE staining showed that the pGUP6-shAurora B plasmid/liposomes complex could significantly inhibit tumor growth in mice tumor model. The results indicated that there was no remarkable difference between the homemade liposomes and Lipofectamin 2000 after transfection, with transfection efficiency over 80%. And the homemade liposomes also had high transfection efficiency in vivo. No significant side effects were observed on weight, coat condition, behavior or appetite and the life span of mice treated with pGPU6-shAurora B were extended. Beyond that, there were no differences in mortality or in pathological changes to the heart, liver, spleen, lungs and kidneys among all the mice.