聚乳酸载药纳米微粒的表面修饰及体外评价

本研究的目的是用O 羧甲基壳聚糖作乳化剂和表面修饰剂 ,采用超声乳化法制备聚乳酸载药纳米微粒 ,并对聚乳酸载药纳米微粒进行表面修饰 ,然后分别对载药纳米微粒的表面形貌、粒径分布、微粒结构、表面元素、体外释放和肿瘤细胞抑制率等微粒性能进行考察与评价。实验证明 ,O 羧甲基壳聚糖可用于制备纳米药物载体系统 ,对聚乳酸载药纳米微粒的制备起到很好的乳化性能和表面修饰作用。采用复乳法制备包载 5 Fu的PLA/O CMC纳米微粒的平均粒径在 5 0nm ,在PBS缓冲溶液中释放时间可达 12d。在对胃癌、乳腺癌和大肠癌三种肿瘤细胞的抑制率测定实验中 ,PLA/O CMC纳米微粒的肿瘤细胞抑制率分别可以达到 72 .8%、77.3%和 75 .6 % ,接近或等同于游离 5 Fu药物的抑制率。在作用时间上 ,PLA/O CMC载药纳米微粒也显示出良好的缓释效应。     

丙酸倍氯米松纳米微囊的肺内分布及清除的研究

目的研究丙酸倍氯米松（BDP）纳米微囊的肺内分布及清除特征，探讨BDP纳米微囊的肺沉积及缓释作用。方法①采用W／O／W乳化法和蒸法去溶剂法，以聚乳酸-聚乙醇酸的共聚物（PLGA）为囊材，制备BDP-PLGA纳米微囊并用扫描电镜测粒径及观察表面特征。②豚鼠雾化吸入^3H-BDP-PLGA纳米微囊，取肺组织切片，荧光显微镜下观察肺内分布。③56只昆明种小鼠随机分成2组（^3H-BDP组和^3H-BDP-PLGA纳米微囊组）。气管内给药后不同时间点取肺组织，通过液体闪烁计数器测放射性剂量。结果①BDP-PLGA纳米微囊呈表面光滑的球形，中位粒径220．4nm。豚鼠雾化吸入包有荧光素钠的纳米微囊后，下呼吸道末端及肺泡均可观察到沉积的荧光颗粒，并可维持数天。②肺内药物含量，给药后1、15min，BDP组与其PLGA纳米微囊组无统计学意义，随着时间的延长，BDP—PLGA纳米微囊组高于BDP组。结论①BDP-PLGA纳米微囊粒径小，雾化吸入后，在外周肺组织有广泛的沉积。②与原型药相比，BDP-PLGA纳米微囊在小鼠体内有良好的释药特征，随着囊壁的降解，逐步释放出药物。延长药物在肺内停留时间，在不增加剂量的情况下，更长时间发挥局部抗炎作用。     

纳米微囊型血液代用品的制备及体内外血液安全性评价

采用可生物降解的聚合物作为壳材料,血红蛋白(Hemoglobin,Hb),形成纳米尺度的血红蛋白微囊拟用作血液代用品.本实验采用可生物降解聚合物聚己内酯(PCL)作为壳材料,制成粒径在120～200 nm的载血红蛋白微囊,当内水相Hb浓度为50 g/L时,包封率达99.4%.对天然Hb和Hb微囊的红外分析表明制备过程没有影响Hb的结构.P50为27 mmHg表明此载Hb微囊的携氧能力.体内外血液安全性评价包括:浸提液与血清混合培养后,测定了其中C3含量无明显变化,说明无明显补体激活发生.溶血、凝血试验合格.微囊输注小鼠体内后,血小板计数无不良反应.载Hb纳米微囊的制备工艺对Hb的包埋有效,并且从结构和功能上模拟了天然红细胞,体内外血液安全性评价合格,是一种极具开发前景的血液代用品.     

血红蛋白基纳米微囊表面物质传递行为的研究

表面三维结构是影响血红蛋白基纳米微囊表面物质传递行为的重要因素.本研究采用改性复乳法工艺制备血红蛋白基纳米微囊血代品,以具有不同分子量大小的PEG分子为探针,考察制备过程中不同工艺条件对微囊表面三维结构影响的规律.结果表明,在二氯甲烷中引入乙酸乙酯、丙酮等亲水性溶剂可有效调控微囊表面孔的大小.随着亲水性溶剂比例的增加,微囊表面的孔径先增大再减小;外水相体积的增加、溶剂挥发时间的延长以及随着搅拌速率的加快均会增加微囊的孔径,而油相体积的增加和聚合物的PEG改性均会减小微囊表面的孔径.     

复乳化法制备磁性微囊工艺因素的研究

为了研究磁性微囊(MMC)药物释放的时空控制方法,我们用复乳化法研制了MMC.时空控制意指载药MMC在外加交变磁场时的控速释放行为和在外加静磁场和梯度磁场下的磁导向和浓集行为.方法:采用乙基纤维素为囊壁,以超顺磁性纳米四氧化三铁磁液为囊芯制备MMC,观察工艺因素对微囊质量的影响;研究了搅拌速度、搅拌时间、油相浓度和第二水相体积对微囊质量如粒径大小、分布、形态和缺陷的影响.结果:只要适当选择和控制主要工艺因素,粒径在3～30μm之间、大小和形态比较均匀的MMC是容易制备出来的.     

凝聚法制备明胶类磁性微囊

背景：与传统的给药方法相比,药物微囊系统可以控制药物的释放,具有良好的靶向性和生物相容性,可将药物浓聚在病灶组织,在临床上起到巨大作用。 目的：将不同囊材与明胶复凝聚制备达卡巴嗪磁性微囊(以下简称磁性微囊),探讨最佳囊材及制备工艺。 方法：采用化学共沉淀法制备Fe₃O₄磁性材料。采用溶液复凝聚法分别制备明胶-阿拉伯胶磁性微囊、明胶-海藻酸钠磁性微囊、明胶-羧甲基纤维素钠磁性微囊、明胶-壳聚糖磁性微囊;再分别采用乳液复凝聚法制备明胶-阿拉伯胶磁性微囊、明胶-海藻酸钠磁性微囊、明胶-羧甲基纤维素钠磁性微囊、明胶-壳聚糖磁性微囊;采用单凝聚法分别制备明胶及壳聚糖磁性微囊。以微囊的包埋率、磁化率、微囊尺寸和释放性能为评价指标,确定磁性微囊的最佳制备工艺。 结果与结论：溶液复凝聚法好于乳液复凝聚法,采用溶液复凝聚法制备磁性微囊较好的囊材是明胶-海藻酸钠,药物包埋率37.90%,收率72.31%,平均磁化强度8.53 emu/g,其次是明胶-壳聚糖。单凝聚法囊材明胶好于壳聚糖,药物包埋率51.58%、收率64.50%、平均磁化强度6.93 emu/g。单凝聚法制备工艺优于复凝聚法。     

纳米羟基磷灰石仿生骨材料的研究进展

纳米羟基磷灰石仿生骨材料因其与天然骨结构和成分相近,已成为组织工程领域研究的热点之一。介绍了纳米羟基磷灰石的各种制备方法及其复合材料的合成方法,并对纳米羟基磷灰石复合材料的特性进行了说明。通过将纳米羟基磷灰石表面修饰改性后,其复合材料有着广阔的应用前景,可用于修复骨缺损,也可以作为药物载体治疗肿瘤。对近年来纳米羟基磷灰石仿生骨材料的研究进展进行了综述。     

茶多酚缓释微囊的制备 Ⅱ提高微囊药物包封效率的研究

以乙基纤维素 ( EC)为囊材 ,采用乳液溶剂蒸发技术制备茶多酚 ( TP)缓释微囊。本文主要研究提高囊材对 TP的包封效率的方法。实验表明 ,在微囊制备过程中 ,将外相中的蒸馏水改为 TP水溶液 ,可使微囊的药物包封率得到较大的提高 :且所制得的 TP微囊对 TP有一定的保护作用及体外缓释效果     

甘草酸表面修饰万乃洛韦白蛋白纳米粒的制备及其肝靶向性研究

以万乃洛韦为模型药物 ,去溶剂化法制备普通载药纳米粒 ,结合高碘酸盐氧化法制备甘草酸 -万乃洛韦白蛋白纳米粒偶联物。对其表面甘草酸密度、形态、大小及其分布、体外释药特性、载药量、包封率、动物体内肝分布和体外肝细胞的摄取情况进行了研究。修饰纳米粒表面甘草酸密度为 9;平均粒径 d0 .5=2 6 8± 2 3nm;载药量1.35 % ;包封率 6 8.76 % ;体外释药符合双相动力学规律 ;对肝细胞具有选择靶向性。静注 15 min后 ,有 6 9.89%集中在肝脏 ,对照组为 6 4 .82 % ,二者之间存在显著差异 (P<0 .10 )。甘草酸表面修饰白蛋白纳米粒制备成功 ,为肝细胞靶向给药提供了新途径。     

金纳米棒的表面改性及生物相容性

背景：金纳米棒制备过程中加入的十六烷基三甲基溴化铵可促进棒状金纳米颗粒的形成,保证金纳米棒良好的分散性,但也会产生一定毒性。 目的：评价表面修饰后金纳米棒的生物相容性。 方法：运用种子介导生长法制备金纳米棒,以改良后的奥伯法对其表面进行二氧化硅修饰,采用紫外分光光度计和透射电子显微镜对其进行表征,将修饰后的金纳米棒配制成不同浓度(60,45,30,15 μmol/L),分别与肝癌bel-7402细胞及胃癌MGC-803细胞孵育,采用CCK-8法检测细胞相对增殖率,细胞毒性级别。 结果与结论：表面修饰后的金纳米棒分散性好,其特殊的光学性质未有改变,分别在500,825 nm处有强吸收峰。不同浓度金纳米棒处理后,肝癌bel-7402细胞的相对增殖率在95%-100%之间,胃癌MGC-803细胞的相对增殖率在99%-103%之间,两组细胞的毒性评级均为0级或1级,无细胞毒性。表明经二氧化硅表面修饰后的金纳米棒具有良好的生物相容性。     

静磁场靶向药物递送系统在肿瘤诊疗中的研究进展

化疗是治疗肿瘤的传统手段之一,但其具有组织非特异性,在抑制肿瘤细胞生长的同时也会对正常细胞产生毒副作用.磁靶向药物递送系统可通过具有生物相容性的、稳定的磁性纳米颗粒载体将抗癌药物在外磁场的引导下,靶向运输和浓聚在肿瘤组织.该技术不仅提高了药物运输的效率和药物的抗癌活性,还能降低药物用量和减轻毒副作用.载药磁性纳米颗粒和所应用的外磁场的性质是影响磁性纳米颗粒靶向肿瘤组织的重要影响因素.载药磁性纳米颗粒的靶向递送是否有效,主要依赖靶向目标位置处所应用的磁场和磁场强度是否足够吸引束缚载药磁性纳米颗粒在肿瘤组织中停留以及释放.对静磁场在引导磁性纳米颗粒靶向肿瘤组织研究的新进展进行综述,为静磁场在靶向肿瘤治疗方面提供一定的科研基础支持.     

PTX-loaded three-layer PLGA/CS/ALG nanoparticle based on layer-by-layer method for cancer therapy

Poly (lactic-co-glycolic acid) (PLGA) nanoparticles are an ideal paclitaxel (PTX)-carrying system due to its biocompatibility and biodegradability. But it possessed disadvantage of drug burst release. In this research, a layer-by-layer deposition of chitosan (CS) and sodium alginate (ALG) was applied to modify the PLGA nanoparticles. The surface charges and morphology of the PLGA, PLGA/CS and PLGA/CS/ALG particles was measured by capillary electrophoresis and SEM and TEM, respectively. The drug encapsulation and loading efficiency were confirmed by ultraviolet spectrophotometer. The nanoparticles were stable and exhibited controlled drug release performance, with good cytotoxicity to human lung carcinoma cells (HepG 2). Cumulatively, our research suggests that this kind of three-layer nanoparticle with LbL-coated shield has great properties to act as a novel drug-loaded system.     

Paclitaxel and iron oxide loaded multifunctional nanoparticles for chemotherapy, fluorescence properties, and magnetic resonance imaging

The multifunctional nanoparticles constructed from triphenylamine-poly(lactide-co-glycolide)-poly(ethyleneglycol)-poly(lactide-co-glycolide) (TPA-PEP) and folate-poly(2-ethyl-2oxazoline)-poly(D,L-lactide) (folate-PEOz-PLA) were developed in this study. Iron oxide nanoparticles (IOP) and paclitaxel (PTX) were coencapsulated in the nanoparticles with diameter less than 200 nm. The drug-loaded nanoparticles emit fluorescence peak at 460 nm when excited with wavelength of 350 nm. The in vitro antitumor activity of the drug-loaded nanoparticles was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays against HeLa cells. When the cells were exposed to the nanoparticles with different levels of folate but the same drug loading, cell viability decreases as the level of folate increases. Confocal laser scanning microscopy (CLSM) analysis shows that cellular uptake is lower for the non-folate-nanoparticles than that for the folate-nanoparticles. The in vitro and in vivo magnetic resonance imaging (MRI) studies indicate the better T2-Weighted images can be obtained for the folate-nanoparticles. In the anticancer effect evaluation, tumor-bearing mice administered with the 30%-folate-nanoparticles showed ~50% reduction in tumor volume after 23 days. The multifunctional nanoparticles as drug carrier with capabilities of both tumor-targeting and MRI present a new direction in drug delivery system development.     

Thermoresponsive magnetic composite nanomaterials for multimodal cancer therapy

The synthesis, characterization and property evaluation of drug-loaded polymer-coated magnetic nanoparticles (MNPs) relevant to multimodal cancer therapy has been studied. The hyperthermia and controlled drug release characteristics of these particles was examined. Magnetite (Fe₃O₄)–poly-n-(isopropylacrylamide) (PNIPAM) composite MNPs were synthesized in a core–shell morphology by dispersion polymerization of n-(isopropylacrylamide) chains in the presence of a magnetite ferrofluid. These core–shell composite particles, with a core diameter of ～13 nm, were loaded with the anti-cancer drug doxorubicin (dox), and the resulting composite nanoparticles (CNPs) exhibit thermoresponsive properties. The magnetic properties of the composite particles are close to those of the uncoated magnetic particles. In an alternating magnetic field (AMF), composite particles loaded with 4.15 wt.% dox exhibit excellent heating properties as well as simultaneous drug release. Drug release testing confirmed that release was much higher above the lower critical solution temperature (LCST) of the CNP, with a release of up to 78.1% of bound dox in 29 h. Controlled drug release testing of the particles reveals that the thermoresponsive property can act as an on/off switch by blocking drug release below the LCST. Our work suggests that these dox-loaded polymer-coated MNPs show excellent in vitro hyperthermia and drug release behavior, with the ability to release drugs in the presence of AMF, and the potential to act as agents for combined targeting, hyperthermia and controlled drug release treatment of cancer.     

The properties of mesoporous silica nanoparticles functionalized with different PEG-chain length via the disulfide bond linker and drug release in glutathione medium

In this paper, a novel drug-loaded material (MSNs-SS-PEG) was obtained by grafting the thiol-linked methoxy polyethylene glycol (MeOPEG-SH) onto the thiol-functionalized mesoporous silica nanoparticles (MSNs-SH) via the disulfide bond linker. In our designed experiment, three different chain lengths of PEG (PEG₁₀₀₀, PEG₅₀₀₀, and PEG₁₀₀₀-PEG₅₀₀₀) were used. The silica materials were characterized by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering, field emission scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption measurements, and X-ray diffraction. The morphology of the MSNs-SS-PEG was spherical with an average diameter of about 150 nm. Due to the covalent modification of hydrophilic MeOPEG, the MSNs-SS-PEG was coated by a thin polymer shell, showing stable and inerratic MCM-41 type mesoporous structure as well as high specific surface areas and large pore volumes. Moreover, the releases of doxorubicin hydrochloride (DOX) from these materials at 10 mM of glutathione were investigated. The PEG functionalization could effectively cap drugs in the mesoporous channels. The release of DOX from the MSNs-SS-PEG_n revealed redox-responsive characteristic. The obtained results showed that the MSNs-SS-PEG might be promising drug delivery carrier materials, which could play an important role in the development of drug delivery.     

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。     

Radiosensitization of paclitaxel, etanidazole and paclitaxel+etanidazole nanoparticles on hypoxic human tumor cells in vitro

Paclitaxel and etanidazole are hypoxic radiosensitizers that exhibit cytotoxic action at different mechanisms. The poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles containing paclitaxel, etanidazole and paclitaxel+etanidazole were prepared by o/w and w/o/w emulsification-solvent evaporation method. The morphology of the nanoparticles was investigated by scanning electron microscope (SEM). The drug encapsulation efficiency (EE) and release profile in vitro were measured by high-performance liquid chromatography (HPLC). The cellular uptake of nanoparticles for the human breast carcinoma cells (MCF-7) and the human carcinoma cervicis cells (HeLa) was evaluated by transmission electronic microscopy and fluorescence microscopy. Cell viability was determined by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical shape with size between 80 and 150 nm. The EE was higher for paclitaxel and lower for etanidazole. The drug release was controlled over time. The cellular uptake of nanoparticles was observed. Co-culture of the two tumor cell lines with drug-loaded nanoparticles demonstrated that released drug effectively sensitized hypoxic tumor cells to radiation. The radiosensitization of paclitaxel+etanidazole nanoparticles was more significant than that of single drug-loaded nanoparticles.     

Single-step surface functionalization of polymeric nanoparticles for targeted drug delivery

Targeted drug delivery using nanocarriers is achieved by functionalizing the carrier surface with a tissue-recognition ligand. Current surface modification methods require tedious and inefficient synthesis and purification steps, and are not easily amenable to incorporating multiple functionalities on a single surface. In this report, we describe a versatile, single-step surface functionalizing technique for polymeric nanoparticles. The technique utilizes the fact that when a diblock copolymer like polylactide–polyethylene glycol (PLA–PEG) is introduced in the oil/water emulsion used in polymeric nanoparticle formulation, the PLA block partitions into the polymer containing organic phase and PEG block partitions into the aqueous phase. Removal of the organic solvent results in the formation of nanoparticles with PEG on the surface. When a PLA–PEG–ligand conjugate is used instead of PLA–PEG copolymer, this technique permits a ‘one-pot’ fabrication of ligand-functionalized nanoparticles. In the current study, the IAASF approach facilitated the simultaneous incorporation of biotin and folic acid, known tumor-targeting ligands, on drug-loaded nanoparticles in a single step. Incorporation of the ligands on nanoparticles was confirmed by using NMR, surface plasmon resonance, transmission electron microscopy and tumor cell uptake studies. Simultaneous functionalization with both ligands significantly enhanced nanoparticle accumulation in tumors in vivo, and resulted in greatly improved efficacy of paclitaxel-loaded nanoparticles in a mouse xenograft tumor model. This new surface functionalization approach will enable the development of targeting strategies based on the use of multiple ligands on a single surface to target a tissue of interest.     

载药纳米粒子在组织工程领域的应用

载药纳米粒子作为一种新型药物和生物大分子输送载体,具有靶向性、通透性、控释性以及促细胞分化等优点.结合蛋白多肽的纳米粒子通过与生物专一性配基接合来输送靶向性药物;结合生长因子的纳米粒子可使生长因子更持久地维持其活性从而达到更好的疗效;结合基因序列的纳米粒子可有效运载目的基因为组织缺损区域提供"种子"细胞;在细胞培养中应用载药纳米技术可以构建三维纳米纤维结构促进细胞生长;表面偶联有特定基团或基因片段的磁性载药纳米粒子可用于物质分离及靶向定位.载药纳米粒子正日益广泛地应用于组织工程,发展潜力巨大,综述其在组织工程领域的应用进展.     

壳聚糖-明胶/聚乳酸-羟基乙酸联合载药水凝胶的体外抗结核作用

文题释义：基质细胞衍生因子1：是一种参与免疫细胞活化、分化和迁移及伤口愈合、角膜上皮再生和组织修复等过程的趋化因子,能促进干细胞的生长和发育,参与调节成骨分化,可通过细胞归巢提高干细胞向病灶区的趋化作用。而基质细胞衍生因子1的失活会损害成骨细胞的发育和分化。此外,其还与血管生成密切相关。 异烟肼：具有较高的杀菌活性,是治疗结核病的一线药物。世卫组织建议将异烟肼作为结核病的标准疗法,用于潜伏性结核病感染者的预防治疗,与利福平、吡嗪酰胺和乙胺丁醇一起用于治疗活动性肺结核。异烟肼的活化形式与脂肪酸生物合成Ⅱ型系统中的NADH依赖型烯醇酰基载体蛋白还原酶异烟肼a结合,阻断细菌细胞壁关键成分支原体酸的合成。 背景：抗结核化疗是目前治疗骨关节结核的主要手段,然而全身给药难以维持病灶区的有效浓度,治疗效果欠佳。 目的：制备一种原位、长期释放抗结核药物且兼备促成骨作用的壳聚糖-明胶/聚乳酸-羟基乙酸联合载药水凝胶。 方法：将亲水性的抗结核药物异烟肼和疏水性的基质细胞衍生因子通过复乳法负载到聚乳酸-羟基乙酸中,制备聚乳酸-羟基乙酸载药微球,共混至壳聚糖-明胶水凝胶支架中,制备壳聚糖-明胶/聚乳酸-羟基乙酸联合载药水凝胶。检测聚乳酸-羟基乙酸载药微球、壳聚糖-明胶/聚乳酸-羟基乙酸联合载药水凝胶的体外释药与抗结核杆菌的能力。将成骨前体细胞MC3T3-E1分别接种于载药微球与联合载药水凝胶表面,CCK-8法检测细胞活力,碱性磷酸酶活性检测细胞的成骨性能。 结果与结论：①载药微球中异烟肼1 h内的突释约为23.3%,2 d内的释放率约为42.6%,随后进入缓释期,25 d后进入平台期;基质细胞衍生因子1在1 h内的累积释放率约为19.8%,2 d内的释放率约为44.7%,随后进入缓释期,25 d后进入平台期;联合载药水凝胶中异烟肼和基质细胞衍生因子1最初1 h的释放分别为8.3%和8.5%,第2天的累计释放率分别为15.2%和17.6%,远低于聚乳酸-羟基乙酸微球;②体外4周后,联合载药水凝胶的抑菌直径大于载药微球,抑菌率高于载药微球(P < 0.05);③联合载药水凝胶与载药微球均具有良好的细胞相容性,细胞活力均约为100%;④培养5,10 d后,联合载药水凝胶表面的细胞碱性磷酸酶活性与载药微球比较差异无显著性意义(P > 0.05);⑤结果表明,原位壳聚糖-明胶/聚乳酸-羟基乙酸联合载药水凝胶有作为治疗骨关节结核及其他骨关节感染的潜力。 ORCID: 0000-0003-4166-2492(张贺龙) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程