柑橘皮渣/淀粉基复合发泡材料的纳米改性研究

目的在柑橘皮渣/淀粉基复合材料中添加纳米材料,对其进行纳米改性研究。方法分别将质量分数为1%,3%,5%,7%等4种纳米蒙脱土添加到柑橘皮渣/淀粉复合材料中,采用双螺杆挤出制备复合发泡材料,并检测复合发泡材料的膨胀率、表观密度、压缩强度、吸湿性能、微观结构和红外光谱。结果添加质量分数为1%和3%的纳米蒙脱土,均能显著增强复合发泡材料的压缩强度,且添加质量分数为3%的纳米蒙脱土,能使复合发泡材料具有最大膨胀率、最低表观密度和丰富的泡孔结构,而添加质量分数为5%和7%的纳米蒙脱土,并不利于复合发泡材料的挤出成型。结论添加适量的纳米材料可以提高柑橘皮渣/淀粉基复合材料的发泡效果,增强力学性能。     

TiO2纳米管阵列膜对牛血清白蛋白的吸附与脱附

采用电化学阳极氧化法以含氟的乙二醇溶液为电解液阳极氧化纯钛制备出排列规则的高长径比TiO2纳米管阵列膜,并用扫描电镜(SEM)、比表面积仪表征了TiO2纳米管阵列膜的形貌和比表面积。结果表明,所制得的TiO2纳米管阵列的管径约180nm,管长可达230μm,比表面积约59.8m2/g。以牛血清白蛋白(BSA)为药物蛋白分子的模型,并研究了TiO2纳米管阵列膜对BSA的吸附和脱附行为,考察了溶液pH值、BSA初始浓度和溶液离子强度对BSA吸附的影响与吸附态的BSA在不同pH值的PBS溶液中的释放行为。结果表明,BSA分子在其等电点(pH值=4.8)附近较容易吸附到TiO2纳米管上,吸附量随着BSA初始浓度的增加而增加,较高的离子强度会降低BSA的吸附,碱性条件下吸附态的BSA容易从TiO2纳米管上脱附,并由于纳米管的扩散限制效益呈现一定程度的缓释。     

N-组氨酸壳聚糖多孔支架对牛血清白蛋白的吸附性能

通过改变组氨酸/壳聚糖的配比及壳聚糖的相对分子质量合成了6种N-组氨酸壳聚糖(NHCS)多孔支架,考察其在模拟体液中吸附牛血清白蛋白(BSA)的能力,用紫外-可见分光光度法测定NHCS不同温度的吸附等温线和不同起始浓度下的吸附动力学曲线等。结果表明,在37.0℃、BSA的初始浓度为2.5 mg/mL时,壳聚糖的相对分子质量为50×103、组氨酸/壳聚糖的摩尔比为3∶1制得的50kD-NHCS-3多孔支架吸附BSA效果最好,吸附容量(Qe)为820.90 mg/g;吸附遵循Langmuir吸附等温式和准一级动力学方程,且是一个自发、熵增、吸热的物理吸附过程。50kD-NHCS-3多孔支架可以重复使用,有望用于BSA或其他蛋白的分离纯化。     

水相合成 CdS纳米晶标记牛血清白蛋白

利用水相中直接合成的CdS纳米晶，与牛血清白蛋白(BSA)进行偶连标记。通过分子筛层析对标记后的牛血清白蛋白进行纯化，在紫外灯下即可观察到标记蛋白的荧光。对CdS纳米晶标记后的牛血清白蛋白的荧光光谱的研究表明，标记蛋白后的CdS纳米晶其荧光无明显淬灭。     

N-组氨酸壳聚糖/聚乳酸支架吸附牛血清白蛋白研究?

采用二次相分离制备7种 N-组氨酸壳聚糖/聚乳酸(NHCS/PLLA)支架,考察其在模拟体液中对牛血清白蛋白(BSA)的吸附性能,并研究其吸附等温式、吸附动力学和热力学行为等.结果表明,在37．0℃、BSA 的初始浓度为2．5 mg/mL 时,50 kD-NHCS-3与PLLA质量比为5/5制得的 NPs3支架对BSA 的吸附容量最大,达928．53 mg/g;吸附遵循Langmuir吸附等温式和准一级动力学方程,可为分离纯化BSA提供借鉴.     

柑橘皮渣 / 淀粉基可降解复合缓冲材料的制备及性能表征

在淀粉基材中添加不同含量的柑橘皮渣共混挤出,制备可降解复合缓冲包装材料,通过对半径膨胀率、表观密度、压缩强度、扫描电镜、吸湿率和红外光谱性能的分析,对比材料之间存在的结构差异,探索柑橘皮渣含量对复合材料性能的影响。研究表明:柑橘皮渣的添加降低了淀粉基复合材料的表观密度及压缩强度;柑橘皮渣质量分数为30%和50%的试样能较快达到吸湿平衡状态,且吸湿量低于纯淀粉材料;质量分数为30%的试样具有最大的半径膨胀率,并呈现最佳的泡孔状态。     

柑橘皮渣/淀粉基复合发泡材料加工工艺优化

目的利用响应面分析法对柑橘皮渣/淀粉基材料加工工艺进行优化。方法在单因素实验基础上选取试验因素与水平,设计响应面试验进行挤出工艺优化,通过考察成形材料的膨胀率、表观性能和压缩强度,筛选出具有较好发泡效果和一定压缩性能的材料成形工艺配方。结果甘油和水分含量对柑橘皮渣/淀粉基复合发泡材料的成形具有显著影响。柑橘皮渣/淀粉基复合发泡材料的最佳工艺优化参数为皮渣、甘油、水分质量分数分别为30%,30%,35%。在此参数条件下得到的材料其表观密度为0.942 g/cm3,膨胀率为287.82%,压缩强度为210.58 k Pa。结论利用响应面法分析并优化柑橘皮渣/淀粉基材料加工工艺的方法可行,获得的响应面模型可用于预测真实值。     

交联玉米醇溶蛋白纳米纤维膜对牛血清白蛋白的吸附性能研究

将Fe3+固载在交联玉米醇溶蛋白(Zein)纳米纤维膜上,制备了亲和吸附材料(Zein-Fe3+),并研究了其对牛血清白蛋白(BSA)的吸附特性。利用扫描电子显微镜(SEM)观察了交联Zein纳米纤维膜的结构形貌,采用傅里叶变换衰减全反射红外光谱仪(ATR-FTIR)和X射线能谱仪(EDAX)分析纳米纤维与金属离子的配合机理,利用考马斯亮蓝染色法检测膜对蛋白质的吸附量。结果发现Fe3+螯合交联Zein纳米纤维膜对牛血清白蛋白具有较高的吸附量,表明其在蛋白质分离纯化领域的潜在应用价值。     

有机磷酸酯改性钛表面的蛋白质吸附行为

通过磷酸三乙酯对钛表面进行改性,使表面含有机磷并且具有一定的疏水性。考察了不同初始浓度、温度和pH值条件下,小牛血清白蛋白（BSA）在钛表面的吸附行为,通过紫外分光光度计表征了BSA吸附的动力学特征。研究发现,在与含磷钛表面接触的前40 min内,BSA发生迅速吸附,随后逐渐达到动态平衡。根据Langmiur理论计算获得吸附等温线和最大吸附量。通过红外光谱和X射线光电子能谱分析表明BSA化学吸附到表面。对BSA在改性钛表面的吸附机制进行了初步的分析。      

汽巴蓝功能微球对人血清白蛋白的吸附性能研究

通过分散共聚制得了聚苯乙烯接枝聚醋酸乙烯酯(PSt-g-PVAc)微球,粒径控制在500～700nm之间.在碱性条件下将PSt-g-PVAc微球表面的PVAc链醇解为聚乙烯醇(PVA),得到了PSt-g-PVA微球,提高了其在水中的分散稳定性.使汽巴蓝(CB)与PSt-g-PVA表面的羟基进行亲核反应,制得了CB作为配体的新型吸附剂汽巴蓝功能微球(CB微球),元素分析测得CB微球表面的CB最大含量为139.22μmol/g,探讨了其在不同人血清白蛋白(HSA)浓度、pH值和吸附时间下对HSA的吸附性能.当HSA浓度为1.0mg/mL、pH为5.14时,CB微球对HSA的最大吸附量为40.9mg/g,并分析了CB微球与HSA的相互作用机理.由NaSCN进行解吸试验,发现可将吸附在CB微球上的HSA解吸92.11%以上,且CB微球的重复使用性能良好.     

离子液体双水相中PB与BSA的作用研究

运用荧光光谱,研究了在离子液体双水相体系中吡罗红B(PB)与牛血清白蛋白(BSA)的相互作用。结果表明,在离子液相中PB对BSA产生了荧光猝灭作用,且属于静态猝灭过程。计算得到在298K和308K下的结合常数分别为5.80×105Lomol-1和4.42×105Lomol-1,结合位点数分别为1.18和1.17。热力学参数表明PB与BSA之间的相互作用为静电作用力。用同步荧光法探讨了PB对BSA构象的影响。     

基于牛血清白蛋白LB膜模板仿生合成碱式硝酸锌薄膜

结合仿生矿化的方法,通过牛血清白蛋白Langmuir膜板矢量控制和氨水动态控制相结合,合成了大面积连续致密具有(200)晶面取向的多孔Zn_5(OH)_8(NO_3)_2薄膜。经扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)及X射线光电子能谱分析仪(XPS)等测量手段,分析了Zn_5(OH)_8(NO_3)_2薄膜样品的表面形貌和结晶性能,并结合生物矿化原理推测了双重模板的控制机制。本文提供了一种全新的在室温下制备具有良好结晶度且适于大面积生产薄膜的方法。     

Study of Biodistribution of Methotrexate-Loaded Bovine Serum Albumin Nanospheres in Mice

Nanospheres made from natural hydrophilic polymers have been proved efficient in terms of better drug-loading capacity, biocompatibility, and possibility less opsonization by reticuloendothelial system (RES) through an aqueous stearic barrier. Hence, nanospheres containing methotrexate were prepared from bovine serum albumin (BSA) by a novel pH coacervation method. A drug-to-polymer ratio study was carried out to determine the carrier capacity. The batch with the highest drug loading was subjected to in vitro analysis. It was found to provide a slow release after an initial burst release. Biodistribution of nanosphere-bound drug was compared with that of free drug in mice. It was observed that the percentage increase in drug distribution to the lungs, liver, and spleen was markedly high from the nanosphere when compared to free drug.     

BSA和FN在纳米化钛表面的蛋白吸附及释放行为

通过阳极氧化技术, 在钛表面制备一层管径为100nm左右的氧化钛纳米管. 选取小牛血清白蛋白(BSA)和纤维连接蛋白(FN)两种蛋白质进行蛋白吸附实验, 并在仿生条件下进行蛋白质的体外释放. 对吸附了蛋白的纳米管试样表面进行红外和荧光定性分析, 同时采用考马斯亮蓝法对纳米管表面的蛋白吸附进行定量检测, 实验发现纳米管试样更有利于蛋白质的吸附, 且FN在试样表面吸附时的吸附率大于BSA. 氧化钛纳米管的蛋白释放分为突释和缓释两个阶段, 其释放机制符合Fickian扩散.     

Cationic Bovine Serum Albumin Based Self‐Assembled Nanoparticles as siRNA Delivery Vector for Treating Lung Metastatic Cancer

It is generally believed that intravenous application of cationic vectors is limited by the binding of abundant negatively charged serum components, which may cause rapid clearance of the therapeutic agent from the blood stream. However, previous studies show that systemic delivery of cationic gene vectors mediates specific and efficient transfection within the lung, mainly as a result of interaction of the vectors with serum proteins. Based on these findings, a novel and charge‐density‐controllable siRNA delivery system is developed to treat lung metastatic cancer by using cationic bovine serum albumin (CBSA) as the gene vector. By surface modification of BSA, CBSA with different isoelectric points (pI) is synthesized and the optimal cationization degree of CBSA is determined by considering the siRNA binding and delivery ability, as well as toxicity. The CBSA can form stable nanosized particles with siRNA and protect siRNA from degradation. CBSA also shows excellent abiliies to intracellularly deliver siRNA and mediate significant accumulation in the lung. When Bcl2‐specific siRNA is introduced to this system, CBSA/siRNA nanoparticles exhibit an efficient gene‐silencing effect that induces notable cancer cell apoptosis and subsequently inhibits the tumor growth in a B16 lung metastasis model. These results indicate that CBSA‐based self‐assembled nanoparticles can be a promising strategy for a siRNA delivery system for lung targeting and metastatic cancer therapy.     

[Bmim]BF叔水相中苋菜红与牛血清白蛋白作用研究

在离子液体四氟硼酸1-丁基-3-甲基咪唑（[Bmim]BF4）和NaH2PO4形成的双水相体系中,研究了离子液相中食用色素苋菜红（AT）与牛血清白蛋白（BSA）复合物的光谱行为。实验了离子液体用量、盐的浓度、溶液酸度、反应时间及共存物质对体系测定的影响。结果表明,在pH6．0的条件下,苋菜红牛血清白蛋白（BSA）复合物的最大吸收波长在540nm处,比单纯AT红移15nm,复合物表观摩尔吸光系数为2．81x10^4L·mol^-1·cm^-1,用摩尔比法求得最大结合数为150。应用加入无机离子及不同类型表面活性剂方法,初步探讨了食用色素苋菜红与牛血清白蛋白之间的作用机理。     

[Bmim]BF_4双水相中苋菜红与牛血清白蛋白作用研究

在离子液体四氟硼酸1-丁基-3-甲基咪唑([Bmim]BF4)和NaH2PO4形成的双水相体系中,研究了离子液相中食用色素苋菜红(AT)与牛血清白蛋白(BSA)复合物的光谱行为。实验了离子液体用量、盐的浓度、溶液酸度、反应时间及共存物质对体系测定的影响。结果表明,在pH6.0的条件下,苋菜红牛血清白蛋白(BSA)复合物的最大吸收波长在540nm处,比单纯AT红移15nm,复合物表观摩尔吸光系数为2.81x104L.mol-1.cm-1,用摩尔比法求得最大结合数为150。应用加入无机离子及不同类型表面活性剂方法,初步探讨了食用色素苋菜红与牛血清白蛋白之间的作用机理。     

A Study on the Preparation and Anti-Tumor Efficacy of Bovine Serum Albumin Nanospheres Containing 5-Fluorouracil

ABSTRACT

The therapeutic profile of many anti-cancer drugs has been improved by their modified distribution through a colloidal carrier system. Hence, bovine serum albumin nanospheres containing 5-fluorouracil were prepared by pH-coacervation methods. To select the most suitable cryoprotector for the formulated nanosphere system, a study on the effect of cryoprotectors in the prevention of particle agglomeration was done. Using glucose and mannitol at various concentrations during freeze drying, glucose at a concentration of 5% was observed to be relatively more effective in the prevention of particle agglomeration than the other cryoprotectors. The carrier capacity was determined through the drug-to-albumin ratio. The particle size of all the drug-loaded batches was analyzed before and after freeze drying. The batch of nanospheres with uniform size distribution, and highest drug loading, was used for other subsequent studies. The effect of surfactant in drug loading was estimated through various concentrations of sodium lauryl sulfate, and it was observed that the surfactant has no influence on drug loading at the selected concentrations. The batch of nanospheres with highest drug loading was evaluated for its in-vitro release, and the drug release was found to be in a bi-phasic pattern. To evaluate the efficacy of 5-fluorouracil-loaded nanospheres against cancer cells, an in vitro cytotoxicity study was carried out using HEp-2 cell lines. The nanosphere-bound drug was observed to produce a better cytotoxic effect than the free drug. The anti-tumor efficacy of drug-loaded nanosphere was investigated in DLA tumor-induced mice models, and the percentage tumor inhibition was relatively higher in animals treated with nanosphere-bound drug than with free drug.     

Evaluation of Arsenic Trioxide-Loaded Albumin Nanoparticles as Carriers: Preparation and Antitumor Efficacy

Bovine serum albumin (BSA) nanoparticles containing arsenic trioxide (As₂O₃) were prepared by a pH-coacervation method. To investigate the properties of the As₂O₃-loaded BSA nanoparticles, a study on drug-to-polymer ratio was done to determine the drug loading (DL), and a H-600 transmission electron microscope (TEM) was used to examine the particle sizes. The results showed that the DL was 27.8% and the average particle size was about 734 nm. The drug release in vitro test was done, which revealed that the drug release was found to provide a slow release after an initial burst release and the cumulative percentage release reached close to 95%. In vitro cytotoxicity test was carried out using APL NB4 cell lines (acute promyelocytic leukemia), and the anticancer efficacy in vivo against mouse H22 hepatoma cells was evaluated on kungming mice. The results indicated that the anticancer efficacy of the As₂O₃-loaded BSA nanoparticles was very obvious.     

荧光光谱法研究桑色素与人血清白蛋白的相互作用

采用荧光猝灭光谱、紫外-可见吸收光谱研究了桑色素与人血清白蛋白(HSA)的结合作用。实验表明桑色素对HSA的荧光猝灭属于单一静态猝灭反应,在溶液中以摩尔比1:1牢固结合,各结合反应的平衡常数Kp>105,结合常数Kb>104;根据F rster非辐射能量转移机理,求算HSA与桑色素间距离r为3.81~3.58nm,能量转移效率E为0.18~0.13。并根据结合反应的热力学常数推测了药物与HSA之间的主要作用力类型为疏水作用力和偶极-偶极作用力。