载TK基因纳米粒在小鼠体内靶向性的研究

采用液体闪烁计数方法研究DNA—PLGA—NP在动物脏器中的分布，研究结果表明，小鼠尾静脉注射^32P—DNA—PLGA—NP后30min，肝脏的放射活性即达到总放射量的70％以上，是^32P—DNA给药后肝脏分布量的1．4倍，皮下给药2h后肝脏的放射活性也达到总放射量的70％以上，是^32P—DNA给药后肝脏分布量的1．6倍。     

叶酸靶向载紫杉醇磷脂-聚合物杂化纳米粒的制备及其体外细胞评价

目的 制备具有叶酸靶向性的载紫杉醇磷脂-聚合物杂化纳米粒(PTX-FLPNPs),并研究其对乳腺癌细胞EMT-6的细胞毒性及体外细胞吞噬.方法 以聚己内酯-聚乙二醇-聚己内酯(PCL-PEG-PCL)、二硬脂酰基磷脂酰乙醇胺-甲氧基聚乙二醇(DSPE-mPEG2000)和叶酸偶联的磷脂(Folate-PEG(2000)-DSPE)为药物载体,通过薄膜水化法自组装制备PTX-FLPNPs,并对其进行表征;使用激光扫描共聚焦显微镜观察比较叶酸受体高表达的乳腺癌细胞EMT-6对叶酸靶向及无靶向杂化纳米粒的吞噬作用;采用MTS法研究PTX-FLPNPs对EMT-6细胞的细胞毒性.结果 成功制备了PTX-FLPNPs,其呈球形,粒径均匀,具有明显的“核-壳”结构.投药量为30％的PTX-FLPNPs的平均粒径为(279.9±8.7)nm,多分散系数为0.173±0.021,Zeta电位为(-17.5±1.1)mV,载药量为(27.36±0.91)％,包封率为(91.16±1.12)％.细胞吞噬实验表明,叶酸受体高表达的EMT-6细胞对叶酸靶向的杂化纳米粒的吞噬作用明显强于无靶向的杂化纳米粒(P＜0.05).细胞毒性实验结果表明,PTX-FLPNPs的细胞毒性低于紫杉醇注射剂,且对肿瘤细胞的抑制效果优于无靶向的杂化纳米粒.结论 PTX-FLPNPs具有较高载药量及包封率,粒径均匀,可通过主动靶向作用介导肿瘤细胞内吞,并增加药物在肿瘤细胞内的浓度,是一种能有效抑制肿瘤的靶向载药纳米制剂.     

脑主动靶向载内吗啡肽纳米粒的制备及其镇痛作用的实验研究

目的 制备新型载镇痛药物内吗啡肽的耦联脑主动靶向抗体OX26纳米粒,研究其镇痛作用.方法 利用新型材料超支化聚甘油-聚乳酸-聚乙醇酸(HBPG-PLGA)通过复合乳液法制备载镇痛药内吗啡肽的纳米粒,在其表面耦联转铁蛋白受体单克隆抗体OX26,通过扫描电子显微镜等进行表征;通过尾静脉注射不同配方纳米粒,考察纳米粒透过血-脑屏障及其对慢性坐骨神经结扎(CCI)大鼠模型镇痛作用.结果 载内吗啡肽HBPG-PLGA纳米粒制备方法稳定,在扫描电子显微镜下呈核壳结构,平均粒径(170±20)nm,Zeta电位约-27 mV,与抗体OX26的耦联效果较好,药物可以缓慢释放72 h以上.尾静脉注射耦联抗体OX26载内吗啡肽纳米粒对CCI大鼠具有较好的镇痛作用,未耦联抗体OX26纳米粒只在给药后45 min时间点显示微弱镇痛作用,静脉注射内吗啡肽和空白纳米粒未显示镇痛作用.结论 耦联抗体OX26载内吗啡肽纳米粒制备稳定,达到较好透血-脑屏障作用,对CCI大鼠有良好镇痛作用.     

运动对米托蒽醌载药纳米粒治疗早期乳腺癌疗效的影响

运动作为一种辅助治疗手段,在癌症诊治过程中受到了广泛关注。本研究旨在观察运动对米托蒽醌载药纳米粒治疗早期乳腺癌疗效的影响。60只接种了BCAP-37乳腺癌细胞的Balb/c雌性小鼠被随机分成4组:(a)空白对照组;(b)无药运动组;(c)药物组;(d)运动+药物组。运动组小鼠每天以15 m/min的速度跑转笼30 min,每周跑6 d,持续4周。每周测试2次肿瘤体积以观察肿瘤的生长情况。通过血常规检验观察药物副作用。相比于空白对照组,在药物组和运动+药物组发现肿瘤体积的增长趋势明显减缓(P0.05;P0.01),运动+药物组最终的肿瘤体积与药物组相比有统计学差异(P0.05)。药物组小鼠的HGB与运动+药物组相比出现显著差异(P0.05)。运动可以增强载药纳米粒的治疗效果并且降低化疗的副作用。在癌症的治疗过程中,运动是一种有效的辅助治疗手段。     

叶酸偶联白蛋白纳米粒的制备工艺研究

采用去溶剂化法制备普通白蛋白纳米粒 ,利用叶酸活性酯在微碱性条件下与白蛋白纳米粒表面的氨基反应 ,制得叶酸偶联白蛋白纳米粒。采用葡聚糖凝胶柱色谱法及紫外分光光度法验证偶联是否成功 ,并测定叶酸偶联的程度。通过葡聚糖凝胶柱色谱法可以清楚地看到叶酸偶联白蛋白纳米粒与未反应的叶酸活性酯完全分离 ,叶酸偶联白蛋白纳米粒与叶酸白蛋白机械混合物的胰蛋白酶水解液在 35 8nm处的紫外吸收图谱基本一致 ,说明叶酸已经成功地偶联于白蛋白纳米粒的表面。纳米粒形态圆整 ,平均粒径为 6 6 nm。叶酸偶联白蛋白纳米粒制备成功 ,作为叶酸受体表达丰富的多种肿瘤细胞的主动靶向给药的潜在途径 ,值得进一步的关注和研究     

5-氟尿嘧啶载自组装水凝胶纳米粒的制备及体外释放

本实验以乙酰化普鲁兰(PA)为基质材料,采用透析法制备新型自组装水凝胶纳米粒,用以增强5-氟尿嘧啶的药物靶向性及药物选择活性,从而达到降低其毒副作用的目的。用傅立叶红外光谱仪(FT-IR)、动态光散射仪(DLS)和场发射扫描电镜(FE-SEM)对其进行表征。分别测量不同浓度、温度以及储存时间下,PA纳米粒的粒径的变化情况,以研究环境因素的改变对PA纳米粒的粒径及其粒径分布的稳定性影响。使用透析方将5-氟尿嘧啶(5-FU)物理包封于自组装纳米粒中,并模拟人体环境进行了体外释放研究。结果表明,PA纳米粒在不同环境条件下,粒径基本保持恒定,具有良好的稳定性;PA纳米粒的粒径在100nm左右,具有良好的表面球形度且分布均匀;不同环境条件变化下,粒径基本保持恒定,具有良好的稳定性;在18h内,5-FU释放量达70%左右,具有明显的缓释作用。乙酰化程度越低,5-FU的缓释效果越好,但载药量略有下降。PA纳米粒是非常具有应用前景的新型5-FU药物载体。     

阿糖胞苷纳米粒的制备及其释药规律研究

采用乳化聚合法制备阿糖胞苷纳米粒，研究其体内外释药特性。结果表明阿糖胞苷纳米粒体外释药规律符合双指数方程，有明显的缓释作用。在家兔体内的药物动力学过程符合二室模型，与阿糖胞苷注射剂相比，t1／2β和MRT延长，CL降低，表明阿糖胞苷纳米粒可显著延长阿糖胞苷在体内存留时间，具有明显的缓释特征。     

肿瘤靶向纳米递药系统的研究进展

该文就纳米粒的发展、纳米技术在肿瘤靶向药物递送中的应用进行综述,并对其存在的问题和发展趋势进行了探讨.     

载表柔比星的壳聚糖纳米粒的制备及其特性研究

目的 制备经聚乙二醇修饰的壳聚糖纳米粒(PEG/CS NP),并负载表柔比星(EPI),研究载表柔比星的壳聚糖纳米粒(PEG/CS-EPI NP)体外释药性能.方法 应用阴离子凝聚法制备PEG/CS-EPI NP,透射电镜观察纳米粒的形态特征,激光粒度分析仪测定粒径大小,紫外分光光度法测定纳米粒的载EPI量,动态透析法考察载EPI纳米粒的体外释放特性.结果 当壳聚糖与三聚磷酸钠质量比为6∶1,壳聚糖与EPI质量比为8∶1时,制备的PEG/CS-EPI NP呈圆形或椭圆形,分散性良好,平均粒径(322.1±14.4)nm,载EPI量为(13.9±1.1)%,包封率(74.2±1.8)%,72 h累积释药率达(82.0±2.1)%.结论 采用阴离子凝聚法制备的PEG/CS-EPI NP形状规则、粒度分布均匀,具有较高包封率和较好缓释性能.     

聚乙烯亚胺纳米粒制备及其应用的研究进展

基因治疗已经成为现代医疗中极具发展潜力的治疗手段。选择合适的运转载体是基因治疗成功与否的关键之一。尽管病毒载体转染效率很高,但是其免疫源性和安全性等问题限制了它的应用。通过化学反应制备而成的纳米粒作为非病毒转染载体有效解决了上述问题,从而提高了基因转染效率。近年来,大量的研究表明以聚乙烯亚胺为基础的纳米粒已经成为基因转...     

Regulating the surface poly(ethylene glycol) density of polymeric nanoparticles and evaluating its role in drug delivery in vivo

Poly(ethylene glycol) (PEG) is usually used to protect nanoparticles from rapid clearance in blood. The effects are highly dependent on the surface PEG density of nanoparticles. However, there lacks a detailed and informative study in PEG density and in vivo drug delivery due to the critical techniques to precisely control the surface PEG density when maintaining other nano-properties. Here, we regulated the polymeric nanoparticles' size and surface PEG density by incorporating poly(ε-caprolactone) (PCL) homopolymer into poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG–PCL) and adjusting the mass ratio of PCL to PEG–PCL during the nanoparticles preparation. We further developed a library of polymeric nanoparticles with different but controllable sizes and surface PEG densities by changing the molecular weight of the PCL block in PEG–PCL and tuning the molar ratio of repeating units of PCL (CL) to that of PEG (EG). We thus obtained a group of nanoparticles with variable surface PEG densities but with other nano-properties identical, and investigated the effects of surface PEG densities on the biological behaviors of nanoparticles in mice. We found that, high surface PEG density made the nanoparticles resistant to absorption of serum protein and uptake by macrophages, leading to a greater accumulation of nanoparticles in tumor tissue, which recuperated the defects of decreased internalization by tumor cells, resulting in superior antitumor efficacy when carrying docetaxel.     

Effects of mannose density on in vitro and in vivo cellular uptake and RNAi efficiency of polymeric nanoparticles

To evaluate the effects of mannose density on in vitro and in vivo cellular uptake and RNA interference (RNAi) efficiency of polymeric nanoparticles (NPs) in macrophages, mannose-modified trimethyl chitosan-cysteine (MTC) conjugates with mannose densities of 4%, 13%, and 21% (MTC-4, MTC-13, and MTC-21) were synthesized. Tumor necrosis factor-alpha (TNF-α) siRNA loaded MTC NPs with particle sizes of ∼150 nm exhibited desired structural stability and effectively protected siRNA from enzymatic degradation. Generally, cellular uptake and RNAi efficiency were affected by mannose density. As expected, MTC-21 NPs presented the maximum in vitro uptake and RNAi efficacy in Raw 264.7 cells among all NPs tested. However, MTC-4 NPs exhibited the optimal in vivo uptake by peritoneal exudate cell macrophages (PECs). In the inflammation model of acute hepatic injury, orally delivered MTC-4 and MTC-13 NPs worked better in silencing TNF-α expression and alleviating liver damage than MTC-21 NPs. As for the ulcerative colitis model, MTC-4 NPs outperformed MTC-13 and MTC-21 NPs with respect to TNF-α knockdown and therapeutic efficacy following oral administration. These results highlighted the importance of ligand density in cellular uptake and RNAi efficiency, which could serve as a guideline in the rational design of targeted nanocarriers for anti-inflammation therapy.     

Oral delivery of shRNA and siRNA via multifunctional polymeric nanoparticles for synergistic cancer therapy

Galactose modified trimethyl chitosan-cysteine (GTC) conjugates with various galactose grafting densities were developed for oral delivery of Survivin shRNA-expression pDNA (iSur-pDNA) and vascular endothelial growth factor (VEGF) siRNA (siVEGF) in the synergistic and targeted treatment of hepatoma. iSur-pDNA and siVEGF loaded GTC nanoparticles (NPs) were prepared via electrostatic complexation and showed desirable stability in physiological fluids and improved intestinal permeation compared to naked genes. Galactose grafting density of GTC NPs significantly affected their in vitro and in vivo antitumor activities. GTC NPs with moderate galactose grafting density, termed GTC2 NPs, were superior in facilitating cellular uptake, promoting nuclear distribution, and silencing target genes, leading to notable inhibition of cell growth. In tumor-bearing mice, orally delivered GTC2 NPs could effectively accumulate in the tumor tissues and silence the expression of Survivin and VEGF, evoking increased apoptosis, inhibited angiogenesis, and thus the most efficient tumor regression. Moreover, compared with single gene delivery, co-delivery of iSur-pDNA and siVEGF showed synergistic effects on inhibiting in vitro cell proliferation and in vivo tumor growth. This study could serve as an effective approach for synergistic cancer therapy via oral gene delivery, and highlighted the importance of ligand grafting density in the rational design of targeted nanocarriers.     

Cancer stem cell therapy using doxorubicin conjugated to gold nanoparticles via hydrazone bonds

Nanoparticle-mediated delivery of chemotherapies has demonstrated enhanced anti-cancer efficacy, mainly through the mechanisms of both passive and active targeting. Herein, we report other than these well-elucidated mechanisms, rationally designed nanoparticles can efficiently deliver drugs to cancer stem cells (CSCs), which in turn contributes significantly to the improved anti-cancer efficacy. We demonstrate that doxorubicin-tethered gold nanoparticles via a poly(ethylene glycol) spacer and an acid-labile hydrazone bond mediate potent doxorubicin delivery to breast CSCs, which reduces their mammosphere formation capacity and their cancer initiation activity, eliciting marked enhancement in tumor growth inhibition in murine models. The drug delivery mediated by the nanoparticles also markedly attenuates tumor growth during off-therapy stage by reducing breast CSCs in tumors, while the therapy with doxorubicin alone conversely evokes an enrichment of breast CSCs. Our findings suggest that with well-designed drug delivery system, the conventional chemotherapeutic agents are promising for cancer stem cell therapy.     

基于改性复合多糖的载阿霉素纳米粒子的制备及其靶向肝癌细胞的研究

目的 制备一种具有氧化还原敏感性的载阿霉素(DOX)纳米粒子,并研究其体外释放及靶向肝癌细胞的性能.方法 以1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐/N-羟基琥珀酰亚胺为催化剂,使透明质酸(HA)侧链接枝胱胺,进一步通过Schiff碱反应偶联β-环糊精(β-CD)制备β-环糊精接枝透明质酸(HACD).然后以HACD为载体材料,采用透析法制备载DOX纳米粒子(HACD/DOX),并对其载药量、包封率、粒径及分布、zeta电位等理化性质及体外释放行为进行表征;采用细胞计数试剂盒(CCK-8)检测HACD/DOX纳米粒子对肝癌细胞HepG2的毒性作用;通过流式细胞术及激光共聚焦显微镜(CLSM)研究HACD/DOX纳米粒子对HepG2细胞的靶向作用.结果 成功制备了HACD,其可携载DOX形成形态均匀的纳米粒子.DOX在纳米粒子中的载药量为(16.1±0.2)％,包封率为(64.2±0.9)％.透射电子显微镜结果显示其为球形结构;粒度分析结果表明,HACD/DOX纳米粒子的平均粒径为(203.1±2.5) nm,多分散系数为0.202,zeta电位为(-29.1±0.8)mV.该纳米粒子的体外释放行为具有明显的氧化还原敏感性.体外毒性结果显示,空白载体材料HACD对肝癌细胞无明显毒性,而HACD/DOX纳米粒子可有效杀伤肝癌细胞,48 h的半数抑制浓度(IC50)值为0.38 μg/ml.流式细胞术和CLSM结果均显示HACD/DOX纳米粒子是通过HA的介导而发挥肝癌靶向作用的.结论 制备的HACD/DOX纳米粒子具有适宜的粒径、高载药量和包封率,能在还原剂刺激下释放药物,且具有明显靶向肝癌细胞的作用,有望成为一种具有良好应用前景的靶向治疗肝癌的药物递送系统.     

ALA和HMME水凝胶栓剂的制备和体内外释药研究

目的 制备光敏剂5-氨基酮戊酸(ALA)和血卟啉单甲醚(HMME)水凝胶栓剂,评价其对直肠肿瘤组织的光敏剂递送效率.方法 将皮下移植人直肠癌细胞SW837的BALB/c小鼠随机分为水凝胶栓剂直肠局部给药组、皮肤局部给药组、瘤内注射给药组和静脉注射给药组.用荧光光谱仪测量直肠壁、皮肤和皮下肿瘤中原卟啉(PpⅨ)和HMME的浓度,荧光光谱系统测定相应的光敏剂分布情况.结果 ALA水凝胶栓剂直肠局部给药组的PpⅨ浓度分别是皮肤局部给药组的9.76倍(1 h)和5.80倍(3 h),差异均具有统计学意义(均P＜0.05).皮肤局部给药后2h,ALA在肿瘤组织内达到最大穿透深度(3～6 mm).而HMME水凝胶栓剂直肠局部给药后,直肠壁中的HMME浓度极低,且皮肤局部给药后的最大肿瘤穿透深度不足2 mm.结论 与皮肤相比,ALA更易穿透黏膜屏障,以水凝胶栓剂形式直肠局部给药有望成为ALA用于光动力疗法治疗直肠癌的一种给药方式.     

Nanodiamonds-mediated doxorubicin nuclear delivery to inhibit lung metastasis of breast cancer

Lung metastasis is one of the greatest challenges for breast cancer treatment. Here, a nanodiamonds (NDs)-mediated doxorubicin (DOX) delivery system was first designed to inhibit the lung metastasis of breast cancer effectively. DOX was non-covalently bound to NDs via physical adsorption in an aqueous solution, then DSPE-PEG 2K was coated to the NDs-DOX complex (NDX) to increase the dispersibility and prolong the circulation time. DSPE-PEG 2K coating NDX (DNX) displayed high drug loading and excellent ability to deliver DOX to the nucleus, thereby significantly enhancing cytotoxicity and inducing cell apoptosis. Furthermore, DNX showed good histocompatibility and could improve drug accumulation in lung, as a result, markedly inhibited the lung metastasis of breast cancer. The high anti-metastasis efficacy with the decreased systemic toxicity suggested that DNX could be a promising drug delivery system for the therapy of lung metastasis of breast cancer.     

Biophysical inhibition of pulmonary surfactant function by polymeric nanoparticles: Role of surfactant protein B and C

The current study investigated the mechanisms involved in the process of biophysical inhibition of pulmonary surfactant by polymeric nanoparticles (NP). The minimal surface tension of diverse synthetic surfactants was monitored in the presence of bare and surface-decorated (i.e. poloxamer 407) sub-100 nm poly(lactide) NP. Moreover, the influence of NP on surfactant composition (i.e. surfactant protein (SP) content) was studied. Dose-elevations of SP advanced the biophysical activity of the tested surfactant preparation. Surfactant-associated protein C supplemented phospholipid mixtures (PLM-C) were shown to be more susceptible to biophysical inactivation by bare NP than phospholipid mixture supplemented with surfactant protein B (PLM-B) and PLM-B/C. Surfactant function was hindered owing to a drastic depletion of the SP content upon contact with bare NP. By contrast, surface-modified NP were capable of circumventing unwanted surfactant inhibition. Surfactant constitution influences the extent of biophysical inhibition by polymeric NP. Steric shielding of the NP surface minimizes unwanted NP–surfactant interactions, which represents an option for the development of surfactant-compatible nanomedicines.     

Nanoparticle-directed sub-cellular localization of doxorubicin and the sensitization breast cancer cells by circumventing GST-Mediated drug resistance

Resistance to single or multiple chemotherapeutic drugs is a major complication in clinical oncology and is one of the most common treatment limitations in patients with reoccurring cancers. Nanoparticle (NP)-based drug delivery systems (DDS's) have been shown to overcome drug resistance in cancer cells mainly by avoiding the activation of efflux pumps in these cells. We demonstrate in this work that polyester-based hyperbranched dendritic-linear (HBDL)-based NPs carrying doxorubicin (Dox) can effectively overcome microsomal glutathione transferase 1 (MGST1)-mediated drug resistance in breast cancer cells. Our DDS was much more effective at considerably lower intracellular Dox concentrations (IC₅₀ 6.3 μm vs. 36.3 μm) and achieved significantly greater reductions in viability and induced higher degrees of apoptosis (31% vs. 14%) compared to the free drug in the resistant cells. Dox-loaded HBDL NPs were found to translocate across the membranes of resistant cells via active endocytic pathways and to be transported to lysosomes, mitochondria, and the endoplasmic reticulum. A significantly lower amount of Dox accumulated in these cytoplasmic compartments in resistant cells treated with free Dox. Moreover, we found that Dox-HBDL significantly decreased the expression of MGST1 and enhanced mitochondria-mediated apoptotic cell death compared to free Dox. Dox-HBDL also markedly activated the JNK pathway that contributes to the apoptosis of drug-resistant cells. These results suggest that HBDL NPs can modulate subcellular drug distribution by specific endocytic and trafficking pathways and that this results in drug delivery that alters enzyme levels and cellular signaling pathways and, most importantly, increases the induction of apoptosis. Our findings suggest that by exploiting the cell transport machinery we can optimize the polymeric vehicles for controlled drug release to overcome drug resistance combat drug resistance with much higher efficacy.     

Passive and active hepatoma tumor targeting of new N-(2-hydroxypropyl)methacrylamide copolymer conjugates: synthesis,characterization, and evaluation in vitro and in vivo

Human hepatocellular carcinoma (HCC) is one of the major causes of death worldwide. To investigate the relative importance of active and passive targeting strategies, the synthesis, characterization, in vitro uptake, and in vivo biodistribution of specific sulfapyridine HPMA (HPMA: N-(2-hydroxypropyl methacrylamide)) copolymer (sulfapyridine: SPD) conjugates, nonspecific HPMA copolymer conjugates, and DTPA are described in this study. The poly(HPMA)-SPD-DTPA (DTPA: diethylenetriaminepentaacetic acid), poly(HPMA)-DTPA, and DTPA conjugates were radiolabeled with the radionuclide ^99mTc and tested for uptake by cultured H22 cells. The cellular accumulation of poly(HPMA)-SPD-DTPA-^99mTc complex was found to be time-dependent. The poly(HPMA)-SPD-DTPA-^99mTc tracer exhibited rapid uptake kinetics in cell culture with a t _1/2 of ～5?min. The uptake of poly(HPMA)-SPD-DTPA-^99mTc was significantly higher than that of poly(HPMA)-DTPA-^99mTc, indicating that the uptake of the poly(HPMA)-SPD-DTPA-^99mT was active binding. The uptake of poly(HPMA)-DTPA-^99mTc was significantly higher than that of DTPA-^99mTc, suggesting that the uptake of the poly(HPMA)-DTPA-^99mT was passive binding. Twenty-four hour necropsy data in the hepatocellular carcinoma tumor model showed significantly higher (p?<?0.001) tumor localization for poly(HPMA)-SPD-DTPA-^99mTc (4.98?±?0.48%ID/g [percentage injected dose per gram tissue]) compared with poly(HPMA)-DTPA-^99mTc (2.69?±?0.15% ID/g) and DTPA-^99mTc (0.83?±?0.03%ID/g). Moreover, higher T/B for poly(HPMA)-SPD-DTPA-^99mTc indicated reduced extravazation of the targeted polymeric conjugates in normal tissues. Specific molecular targeting and nonspecific vascular permeability are both significant in the relative tumor localization of poly(HPMA)-SPD-DTPA-^99mTc. Extravascular leak in nonspecific organs appears to be a major factor in reducing the T/B for the sulfapyridine molecules. Thus, the poly(HPMA)-SPD-DTPA is expected to be used as the potential macromolecular targeting carrier for hepatoma carcinoma in mice.