纳米铁酸锌(ZnFe2O4)的表面改性

采用化学修饰方法,以二氧化硅为内层修饰材料,r-氨丙基三甲氧硅烷(APS)偶联剂为外层修饰材料,对磁性ZnFe2O4纳米粒子进行了双层修饰。并采用XRD、IR、Zeta电位对未包裹粒子,二氧化硅包裹的磁纳米粒子,APS和二氧化硅双层包修饰的纳米磁粒进行表征。同时也比较了三种粒子的耐酸性能。结果显示硅包裹的纳米磁粒Zeta电位明显向酸性方向移动,而双层的纳米磁粒Zeta电位向碱性方向移动。包裹的纳米磁粒在pH2.0的酸中具有很好的耐酸性能,而未处理的纳米粒子在酸溶液中发生了溶解。     

新型氨基化磁性纳米粒子的合成

通过嫁接方法在包有二氧化硅的纳米CoFe2O4磁粒表面进行氨基化修饰,制备出一种可用于生物医学领域的新型氨基化纳米磁粒,采用TGA-DTA,IR,VSM和Zeta-potential等测定方法,对氨基化和未氨基化的CoFe2O4纳米粒子进行了表征。元素分析结果显示,有0.98 mmol/g的有机分子固定在纳米粒子表面;红外和热分析数据显示,带氨基的有机分子嫁接到磁粒表面的二氧化硅壳层上;Zeta电位数据也显示,带氨基的有机分子嫁接到纳米磁粒表面;样品的磁性参数显示,氨基化纳米磁粒仍具有好的磁学性能。     

RGD肽修饰的pH响应型中空介孔二氧化硅纳米粒子的制备与评价

以聚多巴胺(PDA)为反应平台,对中空介孔二氧化硅纳米粒子(HMSN)进行RGD肽和聚(2-乙基-2-噁唑啉)(PEOz)双重修饰,构建了RGD肽和PEOz共同修饰的中空介孔二氧化硅纳米载体(HMSN-PEOz-RGD),以盐酸阿霉素(DOX)为模型药物构建载药体系DOX@HMSN-PEOz-RGD,用红外光谱法(FTIR)对载体进行结构表征,考察载药体系的载药量、包封率及载体的形态、粒径及Zeta电位,通过体外释药实验研究载药体系在不同pH值下的响应性释放,以人乳腺癌细胞MCF-7为模型,考察载体的生物相容性及载药体系的细胞毒性及细胞摄取过程。结果表明,HMSN-PEOz-RGD的平均粒径为(256.1±26.5) nm,粒径分布较均匀;DOX@HMSN-PEOz组和DOX@HMSN-PEOz-RGD组的体外释药都表现出明显的pH依赖性,即酸性(pH值5.0)条件下药物快速释放,而在生理pH值(pH值7.4)条件下药物释放缓慢;生物相容性实验结果显示,各载体在2.5～80μg·mL~(-1)的浓度范围内,与MCF-7细胞共培养24 h后,细胞存活率均在89%以上,表明载体具有良好的生物相容性;体外抗肿瘤活性实验结果表明,相比于其余载药制剂组,DOX@HMSN-PEOz-RGD组细胞的生长明显得到抑制,RGD修饰显著促进了DOX的细胞摄取。本研究所构建的纳米载体能够特异性靶向递送DOX,具有一定的应用前景。     

DNA修饰纳米金溶胶的稳定性

纳米金在分子生物学、生物传感器等领域具有广阔的应用前景.针对纳米金在电解质溶液中易形成不可逆聚集的问题,通过紫外光谱、TEM、Zeta电位测试等表征,研究了DNA分子修饰对纳米金溶胶稳定性的影响.结果表明,所制备的纳米金粒子的初始Zeta电位与粒径有关,平均粒径为13 nm的金粒子对应-44.4 mV的电位;当加入钠离子缓冲液后,纳米金粒子迅速聚集沉积.紫外光谱的动力学特性曲线表明,经过与巯基相连的DNA修饰后,纳米金粒子能够在钠离子缓冲液中稳定存在.     

壳聚糖复合纳米基因载体的制备

目的制备壳聚糖复合纳米基因载体,并探讨其理化性质、细胞毒性、稳定性及体外转染效率。方法采用复凝聚法制备包封聚乙烯亚胺(Polyethylenimine,PEI)/DNA复合物的壳聚糖复合纳米基因载体,用纳米粒度分析仪测定其粒径和Zeta电位;透射电镜观察其形态;MTT法检测其细胞毒性;在PBS溶液(pH 7.4)及含10%小牛血清的RPMI1640培养基中,于37℃条件下放置0、1、3、5 d,1%琼脂糖凝胶电泳检测其稳定性;体外转染CNE细胞,评价其转染活性。结果当N(PEI的氨基)/P(DNA的磷酸根)≥6时,能够形成稳定的壳聚糖复合纳米粒,平均粒径约为300 nm,表面电荷约为30 mV;壳聚糖复合纳米基因载体呈球形,圆整且分散性好;复合纳米基因载体的细胞毒性较低;1%琼脂糖凝胶电泳分析显示,DNA被完全包裹在复合纳米载体中,且5 d内无游离DNA释放;体外转染活性与壳聚糖/DNA复合物相比,提高了约1 000倍,且转染能力不受血清的干扰。结论制备的壳聚糖复合纳米基因载体是一种高效、低毒的非病毒载体,具有作为体内基因治疗载体的应用潜力。     

Fe_3O_4/MPTS@CdSe/CdS纳米离子的制备及其性能

经过修饰、加工处理过的纳米颗粒能够满足不同领域的应用需求,因此对纳米颗粒表面进行修饰成为纳米材料领域研究的热点问题。在水相内,通常使用化学共沉淀法制备Fe_3O_4纳米粒子,将其添加至正硅酸乙脂的醇水体系内,使磁性纳米粒子表面形成一层SiO_2包覆层,并采用丙基三甲氧基硅烷进行修饰处理,确保磁性纳米粒子表面连接丰富的功能双键,与乙二胺修饰后的CdSe/CdS量子点进行连接,制得磁性荧光双功能纳米微球,对其进行表征及其性能测试。实验结果证实,粒径为40nm的磁性纳米颗粒,饱和磁化强度为32.2emu/g,荧光强度是450a.u,磁性荧光双功能纳米材料在细胞分离、免疫检测等领域应用广泛。     

纳米磁性微粒(流体)的制备及性能

纳米磁性微粒(流体)是制备磁性无极或有极靶向药物载体的基本原料。用化学沉淀法成功合成出纳米磁性微粒(流体)。用X射线衍射、透射电子显微镜对制备的磁性微粒进行了表征,测试了磁性微粒和流体的磁性能。研究表明:合成的磁性粒子主要成分为面心结构的反尖晶石Fe3O4,磁性颗粒的粒径一般为2~10 nm,以5 nm居多;纳米磁性液体性能稳定,长期放置不发生絮凝;纳米磁性微粒磁化率为0.32,纳米磁性流体磁化率为8.9×10-3。该磁性材料磁响应力较强,剩磁较弱,属软磁性纳米材料。     

基于叶酸受体介导的磁性荧光靶向纳米探针的制备及其性能研究

拟采用一步溶剂热法先制备出带有无定型碳层包覆的磁性Fe3O4纳米粒子;然后通过静电结合法,将巯基丙酸修饰的水溶性Cd Te量子点组装到其表面;为了使所制备的磁性探针具有较好的稳定性和生物相容性,通过Stober法在纳米粒子最外层包裹上生物相容性和结构稳定的带有胺基修饰的二氧化硅壳层;最后与叶酸(FA)进行耦合,制得具有磁性和荧光的双功能靶向纳米探针。分别利用荧光光谱,傅里叶变换红外光谱(FTIR),X射线衍射(XRD),扫描电镜(SEM),透射电子显微镜(TEM)和振动样品磁强计(VSM)等对所制备的磁性荧光复合纳米粒子的形态、大小、化学成分及磁性能进行表征。实验结果表明:所得产物粒径大小约200 nm,磁化强度约21.9 emu·g-1,仍然保持有较强的荧光性能,在生物成像方面具有潜在的应用价值。     

金磁纳米颗粒的制备与表征

金作为一种惰性贵金属,具有生物相容性好,易于功能化等特点,目前已被广泛应用于磁性纳米颗粒的表面的功能化.利用反胶束方法制备了金包铁(Fe/Au)结构的磁性纳米复合颗粒,表征结果显示Fe/Au具有明显的核壳结构,其平均粒径为15 nm.无磁滞现象,其剩余磁化强度与矫顽力均为零.这表明所得的Fe/Au MNPs为超顺磁性颗...     

叶酸受体介导的CdS纳米颗粒的生物成像

以巯基乙酸为修饰剂,合成了具有特殊光学性质的水溶性硫化镉( CdS)纳米颗粒.通过红外吸收光谱、荧光光谱和透射电子显微镜对产物的光学性能和晶体结构进行了表征,结果表明经巯基乙酸改性、聚乙烯亚胺及叶酸修饰的CdS纳米颗粒为球形,粒径约180 nm左右,并且有较高产率,同时具有良好的分散性、稳定性及生物相容性;利用激光扫描...     

In vitro release of rifampicin and biocompatibility of oleoylchitosan nanoparticles

Oleoylchitosan (OCS) self‐assembled nanoparticles as a carrier system for hydrophobic drug delivery was proposed. The OCS nanoparticles were prepared by an o/w emulsification method. Mean diameter of the OCS nanoparticles was around 275.3 nm. All the OCS and OCS nanoparticles have good biocompatibility from the cytotoxicity testing and erythrocyte toxicity assay. And the biocompatibility of OCS nanoparticles was better than OCS. Rifampicin, as a model drug, was investigated for its release properties in vitro. The release of rifampicin from solution with pH 6.0 and 6.8 was characterized by a faster release than from solution with pH 3.8. The increase of sodium tripolyphosphate could slower the release of drug. The sample with low concentration of rifampicin, released faster and entirely. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

生物基可降解荧光聚酯的制备及性能研究

以天然生物基材料蓖麻油(CO)、柠檬酸(CA)和L-半胱氨酸(L-Cys)或L-丝氨酸(L-Ser)为原料,合成一系列生物基可降解荧光聚酯(BBPP-Cys、BBPP-Ser)。采用FTIR、~1HNMR、紫外-可见光谱和荧光光谱对其结构和荧光特性进行表征。同时,测量了聚酯的水接触角、粒径大小、力学性能、降解性能以及细胞毒性。研究结果表明,悬挂在聚酯主链上独特六元环状结构是其产生荧光特性的原因。BBPP-Cys在265 nm处有最强紫外吸收,在445 nm处有最强荧光发射;BBPP-Ser在266 nm处有最强紫外吸收,在460 nm处有最强荧光发射。所合成聚酯具有良好的亲水性和较小粒径,拉伸强度范围为1.21～1.95 MPa,在0.1 mol/L NaOH溶液中7 d降解率达到60%以上。采用MTT法对荧光聚酯进行细胞毒性实验的结果表明,细胞增殖率均大于90%,证明其具有良好的生物相容性。     

含胆酸聚合物的合成及其修饰制备肝癌细胞靶向纳米粒

为利用肝细胞表面胆酸转运蛋白对胆酸分子的强的特异性识别及亲和作用,设计并合成了一种侧链含胆酸的聚合物——聚[3α-(对乙烯基苯甲酯)-7α,12α-二羟基-5β-胆烷酸](PVBCA)。该材料具有两亲性,通过乳化-溶剂挥发法可将其包覆于聚乳酸羟基乙酸共聚物(PLGA)纳米粒表面,所得纳米粒平均粒径约350 nm。以人肝癌细胞SMMC-7721评价了该材料薄膜对肝细胞的吸附能力及其所修饰纳米粒被肝癌细胞吸附和摄取的能力:细胞在该材料薄膜表面的吸附率较其在聚苯乙烯培养皿表面提高2倍以上;采用该材料修饰的纳米粒递送荧光物质Coumarin 6,可使细胞内Coumarin 6的浓度较未修饰纳米粒提高了近6倍。结果表明,PVBCA与肝细胞有较强的亲和力,作为纳米载药系统的表面修饰材料,可显著提高纳米粒对肝癌细胞的靶向性能。     

新型氟硼二吡咯纳米粒子荧光探针的合成与性能

为了解决氟硼荧类染料(BODIPY)在肿瘤诊断中吸收波长短、水溶性和生物相容性差的问题,设计开发了2种吸收波长达到近红外区的BODIPY分子,并通过与DSPE-PEG2000-MAL-RGD(PC-RGD)自组装形成具有良好水溶性和生物相容性的纳米粒子.研究了纳米粒子的荧光成像能力,结果表明:单取代分子3a和双取代分子...     

Highly bright and photostable cyanine dye-doped silica nanoparticles for optical imaging: Photophysical characterization and cell tests

Spherical silica nanoparticles containing fluorescent trimethine indocyanine dyes (λ_abs = 547 nm, λ_em = 570 nm) were prepared using a water-in-oil microemulsion method. The nanoparticles were of 50 nm diameter and were almost monodispersed in aqueous solution at pH 5.5. Entrapment of dye molecules in the silica matrix stabilised photoemission over several hours of continuous irradiation. The photoemission intensity of the indocyanine was increased 13-fold over that recorded in solution. As each nanoparticle contained 110 dye molecules, the photoemission brightness of each particle was enhanced by three orders of magnitude. The fluorescent nanoparticles have been tested as imaging tools in in vitro tests. As an example of non-macrophagic cells, a highly differentiated neuronal cell line (GT1-7) was used and the results showed that the prepared nanoparticles can be incorporated into these cells with no apparent toxicity for up to three days.     

硫化铜纳米颗粒的原位合成及摩擦学性能

采用原位合成的方法合成了硫化铜纳米微粒,通过静置及高低速离心测试,证明硫化铜纳米微粒在基础油石蜡中具有良好的分散稳定性。TEM研究证明合成的纳米颗粒粒径约为20 nm。通过FT-IR表征合成样品,发现油酸分子-COOH部分和硫化铜表面发生了化学性吸附,增强了硫化铜纳米微粒在基础油中的油溶性。用高速环-块磨损机考察了含硫化铜颗粒的基础油的摩擦学性能,发现添加有油酸修饰的硫化铜纳米颗粒有显著的抗磨减摩效果。     

羟基化氮化硼纳米管的表征及对L02细胞的影响

纳米材料的生物相容性与其形貌、缺陷、表面性能以及杂质息息相关。本文先后采用HCl溶液和HNO3溶液对氮化硼纳米管(BNNTs)进行纯化和氧化，制备了羟基化的BNNTs (BNNTs-OH)。采用XPS、FTIR、TG、TEM、Zeta电位和PL对BNNTs-OH的形貌、结构和性能进行了表征。结果表明，BNNTs被成功氧化并截短，在B位点引入了—OH。BNNTs-OH在水溶液中具有很好的分散性，平均水合粒径约为1246.7 nm。BNNTs-OH具有特殊的荧光特性，在一定的激发波长下可以发红色的光，实现材料在细胞内的定位。细胞毒性测试表明，BNNTs-OH对人胚胎肝细胞系L02细胞未呈现毒性。     

Biocompatibility of hydrophilic silica-coated CdTe quantum dots and magnetic nanoparticles

Fluorescent magnetic nanoparticles exhibit great application prospects in biomedical engineering. Herein, we reported the effects of hydrophilic silica-coated CdTe quantum dots and magnetic nanoparticles (FMNPs) on human embryonic kidney 293 (HEK293) cells and mice with the aim of investigating their biocompatibility. FMNPs with 150 nm in diameter were prepared, and characterized by high-resolution transmission electron microscopy and photoluminescence (PL) spectra and magnetometer. HEK293 cells were cultured with different doses of FMNPs (20, 50, and 100μ g/ml) for 1-4 days. Cell viability and adhesion ability were analyzed by CCK8 method and Western blotting. 30 mice were randomly divided into three groups, and were, respectively, injected via tail vein with 20, 60, and 100 μg FMNPs, and then were, respectively, raised for 1, 7, and 30 days, then their lifespan, important organs, and blood biochemical parameters were analyzed. Results show that the prepared water-soluble FMNPs had high fluorescent and magnetic properties, less than 50 μg/ml of FMNPs exhibited good biocompatibility to HEK293 cells, the cell viability, and adhesion ability were similar to the control HEK293 cells. FMNPs primarily accumulated in those organs such as lung, liver, and spleen. Lung exposed to FMNPs displayed a dose-dependent inflammatory response, blood biochemical parameters such as white blood cell count (WBC), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), displayed significant increase when the FMNPs were injected into mice at dose of 100μg. In conclusion, FMNPs exhibit good biocompatibility to cells under the dose of less than 50 μg/ml, and to mice under the dose of less than 2mg/kg body weight. The FMNPs' biocompatibility must be considered when FMNPs are used for in vivo diagnosis and therapy.     

Preparation and characteristics of pH‐sensitive derivated dextran hydrogel nanoparticles

An optimized procedure was used to prepare erythromycin (EM)‐loaded pH‐sensitive glycidyl methacrylate derivatized dextran (dex‐GMA)/acrylic acid (AAc) nanoparticles. The size distribution and drug release profile at different pH demonstrated that poly(dex‐GMA/AAc) nanoparticles possessed pH‐sensitivity. At pH 1.2, the mean diameter of nanoparticles was about 60 nm. While at pH 7.4 it increased approximately to 250 nm. The release of EM was about 7% of initial loading after 2 h at pH 1.2. However, at pH 7.4 it reached to 17.8%, 30.9% after 2 and 6 h, respectively. The results demonstrated that poly(dex‐GMA/AAc) nanoparticles could release EM slightly while passing through acerbic stomach, whereas in the alkaline intestine the drug is released considerably. The prepared nanoparticles were partially degradable and also had satisfactory biocompatibility. This study suggests that the poly(dex‐GMA/AAc) nanoparticles are potential colon‐specific targeting carriers, which can keep promising pharmaceutical dosage form of EM. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers