磁性阳离子高分子脂质体结合野生型p53投递系统的构建

目的用合成的磁性阳离子高分子脂质体与野生型p53(WTp53)基因质粒结合,构建靶向纳米载体投递系统,为进一步行静脉内皮细胞转染奠定基础。方法应用大肠杆菌重组质粒扩增法扩增WTp53质粒DNA,合成的磁性阳离子高分子脂质体为羧甲基壳聚糖十八烷基季铵盐/胆固醇(OQCMC/Chol)包覆油溶性Fe3O4的载体粒子。在不同的pH值及不同的WTp53质粒DNA和载体粒子质量比的条件下,将WTp53质粒DNA与OQCMC/Chol超微磁性载体粒子进行混合,并分别进行DNA结合实验和沉淀实验。观察电泳结果,并用SPSS 13.0统计软件进行数据分析。在DNaseⅠ模仿体内酶的环境下,将其加入制备好的超微载体投递系统中,电泳后观察投递系统对DNA的保护作用。应用透析系统模拟体内环境,观察超微投递系统载体与基因分离情况,并利用紫外分光光度计测量超微载体投递系统累积缓释曲线。结果应用透射电镜观察OQCMC/Chol超微磁性载体粒子和WTp53结合后的投递粒子。在pH 7条件下,WTp53质粒DNA和载体粒子质量比为1∶0.6,p53质粒DNA与OQCMC/Chol超微磁性载体粒子经过直接静电作用几乎100%结合,并证实该投递系统对DNA具有较好的保护作用。超微载体投递系统在7～12 h左右有明显的突释波峰,到第54小时以后,超微载体释放浓度变化缓慢,并可持续释放9 d以上。结论成功构建磁性阳离子高分子脂质体结合WTp53投递系统,将为进一步行细胞转染奠定可靠的基础,并为构建血管内靶向定位基因投递新方法和新技术提供可靠理论依据。     

穿膜肽TAT修饰载丹酚酸B脂质体的制备及其抑制人皮肤成纤维细胞增殖与迁移初步研究

目的制备具有防治增生性瘢痕(HS)作用的载丹酚酸B的穿膜肽TAT修饰脂质体(SAB-TAT-LIP),建立其质量评价方法,并初步考察其对体外人皮肤成纤维(HSF)细胞增殖和迁移的影响。方法采用pH梯度逆向蒸发法制备脂质体,超滤法测其包封率,以包封率为评价指标,采用Box-Behnken响应面法优化脂质体的处方工艺;考察其形态、粒径、Zeta电位、体外释放、体外透皮吸收和稳定性等理化性质;在此基础上采用MTT法考察其对HSF细胞增殖的作用,采用划痕法和Transwell小室法考察其对HSF细胞迁移和侵袭的作用。结果 SAB-TAT-LIP的药物包封率为(86.70±0.85)%,平均粒径为(219.90±5.09)nm,Zeta电位(-9.25±0.92)m V,体外24h累积释放率为62.49%,无突释效应,体外32h皮肤累积透过率为17.21%,透过速率为(28.33±4.9)μg/(cm2·h),真皮层滞留量为(44.39±6.87)μg/cm2,4℃放置10d稳定性良好。SAB-TAT-LIP能够显著地抑制HSF细胞的增殖、迁移和侵袭,与对照组相比,差异显著(P0.01)。结论优化得到的SAB-TAT-LIP包封率较高、粒径较小,体外释放和透皮行为均满足局部透皮给药制剂的体外释放和透皮规律,对体外HSF细胞的增殖、迁移和侵袭具有抑制作用。     

Dibucaine in Ionic-Gradient Liposomes: Biophysical,Toxicological, and Activity Characterization

Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of DBC.     

基于pH梯度载药技术的咪喹莫特脂质体的制备工艺研究

目的 根据咪喹莫特的理化性质,利用pH梯度主动载药技术制备脂质体,考察其性状、粒径、表面电荷及体外释药特征。方法 葡聚糖凝胶滤过法测定脂质体的包封率,以包封率与成型性为主要指标筛选制备方法,考察水化液的种类、pH值、离子强度及pH梯度载药、磷脂-胆固醇比例、脂药比、维生素E用量对包封率的影响;正交试验优化咪喹莫特脂质体的处方,考察脂质体样品在0~4℃下的稳定性。结果 按处方咪喹莫特50 mg、大豆卵磷脂400 mg、胆固醇130 mg、油酸10 mg、维生素E 5 mg、柠檬酸pH 2.5缓冲液5 mL,采用薄膜分散法工艺制备脂质体样品,并进行pH梯度主动载药,pH值调至7.0。制得的咪喹莫特脂质体呈白色均匀的混悬液,脂质体微粒圆整,分散性好,粒径（347±21）nm,包封率（81.2±1.9）%,Zeta电位（-12.19±1.7）mV。结论 pH梯度主动载药技术适于咪喹莫特脂质体的制备。     

紫杉醇脂质体与紫杉醇分别联合卡铂治疗卵巢癌疗效的Meta分析

摘 要 目的：系统评价紫杉醇脂质体与普通紫杉醇制剂分别联合卡铂治疗卵巢癌的有效性和安全性。方法: 计算机检索中国知识资源总库（CNKI）、中国生物医学文献数据库（CBM）、中文科技期刊数据库（VIP）、中国学术期刊数据库（万方数据）、PubMed、Cochrane Library、Embase 中紫杉醇脂质体联合卡铂与紫杉醇联合卡铂化疗治疗卵巢癌的临床随机对照试验,检索范围均为建库至2017年7月12日。2名研究者根据Cochrane系统评价手册5.1.0,按纳入与排除标准独立进行文献筛选、资料提取、质量评价,并使用RevMan5.3软件Meta分析。 结果:共纳入8篇随机对照试验,共计793例受试者。结果显示,在卵巢癌的治疗中,紫杉醇脂质体联合卡铂与紫杉醇联合卡铂比较,客观缓解率有统计学意义（P=0.02）。在不良反应方面,紫杉醇脂质体联合卡铂与紫杉醇联合卡铂比较：血小板减少（P=0.02）、恶心呕吐（P＜0.000 01）、肌肉关节痛（P＜0.000 01）、皮疹（P＜0.000 01）、呼吸困难（P=0.000 8）和面部潮红（P=0.001 0）,差异有统计学意义;而白细胞减少（P=0.13）、血红蛋白减少（P=0.28）、腹泻便秘（P=0.15）、脱发（P=0.62）,差异无统计学意义。结论:紫杉醇脂质体联合卡铂化疗治疗卵巢癌的疗效优于紫杉醇联合卡铂化疗,且能减轻患者不良反应,提高用药有效性和安全性。     

Selective induction of apoptosis in MCF7 cancer-cell by targeted liposomes functionalised with mannose-6-phosphate

Liposomes are versatile platforms to carry anticancer drugs in targeted drug delivery; they can be surface modified by different strategies and, when coupled with targeting ligands, are able to increase cellular internalisation and organelle-specific drug delivery. An interesting strategy of antitumoral therapy could involve the use of lysosomotropic ligand-targeted liposomes loaded with molecules, which can induce lysosomal membrane permeabilization (LMP), leakage of cathepsins into the cytoplasm and subsequent apoptosis. We have previously demonstrated the ability of liposomes functionalised with a mannose-6-phosphate to reach lysosomes; in this research we compare the behaviour of M6P-modified and non-functionalised liposomes in MCF7 tumour cell and in HDF normal cells. With this aim, we first demonstrated by Western blotting the overexpression of mannose-6-phosphate/insulin-like growth factor (M6P/IGF-II) receptor in MCF7. Then, we prepared calcein-loaded liposomes and we revealed the increased uptake of M6P-functionalised liposomes in MCF7 cells respect to HDF cells by flow cytometry analysis. Finally, we loaded functionalised and not functionalised liposomes with N-hexanoyl-d-erythro-sphingosine (C6Cer), able to initiate LMP-induced apoptosis; after having studied the stability of both vesicles in the presence of serum by Dynamic Light Scattering and Spectrophotometric turbidity measurements, we showed that ceramide-loaded M6P-liposomes significantly increased apoptosis in MCF7 with respect to HDF cells.     

Multiseed liposomal drug delivery system using micelle gradient as driving force to improve amphiphilic drug retention and its anti-tumor efficacy

To improve drug retention in carriers for amphiphilic asulacrine (ASL), a novel active loading method using micelle gradient was developed to fabricate the ASL-loaded multiseed liposomes (ASL-ML). The empty ML were prepared by hydrating a thin film with empty micelles. Then the micelles in liposomal compartment acting as ‘micelle pool’ drove the drug to be loaded after the outer micelles were removed. Some reasoning studies including critical micelle concentration (CMC) determination, influencing factors tests on entrapment efficiency (EE), structure visualization, and drug release were carried out to explore the mechanism of active loading, ASL location, and the structure of ASL-ML. Comparisons were made between pre-loading and active loading method. Finally, the extended drug retention capacity of ML was evaluated through pharmacokinetic, drug tissue irritancy, and in vivo anti-tumor activity studies. Comprehensive results from fluorescent and transmission electron microscope (TEM) observation, encapsulation efficiency (EE) comparison, and release studies demonstrated the formation of ML-shell structure for ASL-ML without inter-carrier fusion. The location of drug mainly in inner micelles as well as the superiority of post-loading to the pre-loading method , in which drug in micelles shifted onto the bilayer membrane was an additional positive of this delivery system. It was observed that the drug amphiphilicity and interaction of micelles with drug were the two prerequisites for this active loading method. The extended retention capacity of ML has been verified through the prolonged half-life, reduced paw-lick responses in rats, and enhanced tumor inhibition in model mice. In conclusion, ASL-ML prepared by active loading method can effectively load drug into micelles with expected structure and improve drug retention.     

Enhanced selective cellular uptake and cytotoxicity of epidermal growth factor-conjugated liposomes containing curcumin on EGFR-overexpressed pancreatic cancer cells

Pancreatic cancer is one of the most malignant cancers with a high mortality rate. Some types of pancreatic cancer cells overexpress epidermal growth factor receptor (EGFR), which is a potential target for anticancer agents. In this study, we examined the effect of epidermal growth factor (EGF)-conjugated liposomes containing curcumin (EGF-LP-Cur) on three different EGFR-expressed human pancreatic cancer cell lines, BxPC-3, Panc-1 and Mia Paca-2. We have demonstrated that it is feasible to prepare liposomal vesicles of EGF-LP-Cur and that it is stable in the liquid vehicle at ambient conditions for three weeks. In addition, the formulation of curcumin had higher cytotoxicity on BxPC-3 than on any other cells. It is also shown that the cellular uptake of curcumin on BxPC-3, which is essential for the cytotoxicity, is associated with EGFR-mediated mechanism of action. In summary, our results have showed that targeting EGFR with EGF-conjugated curcumin liposomes enhanced the antitumor activity of curcumin against human pancreatic cancer cells.     

Improvement of chemosensitivity and inhibition of migration via targeting tumor epithelial-to-mesenchymal transition cells by ADH-1-modified liposomes

How to overcome drug resistance and prevent tumor metastasis is key to the success of malignant tumor therapy. In this paper, ADH-1 peptide-modified liposomes (A-LP) have been successfully constructed for restoring chemosensitivity and suppressing cancer cell migration. With a particle size of about 90?nm, this functionalized nanocarrier was loaded with fluorescent probe or paclitaxel (PTX). Cellular uptake studies showed that A-LP facilitated the delivery of anticancer drug to tumor cells undergoing EMT. Interestingly, this nanocarrier enhanced chemosensitivity by assessing the cell activity using CCK-8 assay. Further, the results of Wound scratch assay and Transwell migration assay showed the inhibition effect of this nanocarrier on tumor cell migration. Moreover, this nanocarrier exhibited significant tumor-targeting ability and anti-tumor efficacy in vivo. Collectively, A-LP might be a novel targeted drug delivery system to enhance the efficacy of chemotherapy and prevent tumor metastasis.