二巯基丁二酸修饰的Fe3O4纳米颗粒对人血管内皮细胞的作用研究

目的研究二巯基丁二酸修饰的Fe3O4纳米颗粒(dimercaptosuccinic acid-magnetite nanoparticles,DMSA-Fe3O4)对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)功能的影响。方法利用动态光散射法表征DMSA-Fe3O4的粒径及表面电荷;采用普鲁士蓝染色、邻二氮菲铁定量和透射电镜观察方法研究HUVECs对DMSA-Fe3O4的摄取规律;利用细胞计数试剂盒(Cell Counting Kit-8,CCK-8)检测DMSA-Fe3O4对内皮细胞活性的影响;通过酶联免疫吸附试剂盒测定DMSA-Fe3O4对内皮细胞血管内皮生长因子(vascular endothelial growth factor,VEGF)分泌量的影响。结果HUVECs能够大量吞噬DMSA-Fe3O4,其吞噬量具有孵育时间和剂量依赖性;短时间内所测剂量范围DMSA-Fe3O4对细胞活性无显著影响,但长时间高剂量条件使细胞活性明显降低。此外,在高剂量DMSA-Fe3O4暴露下(200μg/mL),内皮细胞分泌VEGF的量约为对照组的3倍。结论DMSA-Fe3O4易于被HUVECs吞噬;高浓度DMSA-Fe3O4与HUVECs长时间培养使细胞活性降低,并刺激内皮细胞分泌VEGF。     

生物医用无机纳米颗粒的表面修饰研究进展

纳米材料由于其极小的尺寸,拥有许多常规材料所不具备的优良特性,如光学性能、电磁学性能、热力学性能、量子力学性能等,使其在诸多领域尤其是在生物医学领域具有广阔的应用前景。生物医用无机纳米颗粒是指纳米级的无机纳米核分散于溶剂中所形成的胶体分散系统。无机核的组成包括贵金属（如 Au、Ag、Pt、Pb等）,半导体材料（如 CdSe、CdS、ZnS、TiO2、PbS等）,磁性材料（如 Fe2O3或 Co纳米颗粒）以及复合材料（如 FePt、CoPt等）。依据其组成材料的不同,纳米颗粒可具有一系列独特性质,诸如高电子密度、强光学吸收性质、磷光或荧光性质及具有磁矩等。     

PEG分子量对二氧化钛纳米晶的影响

溶胶凝胶法制备二氧化钵胶体，按ω=1％用量分别加入分子量为4000．10000，20000的聚乙二醇PEG表面活性剂。钛胶80℃干燥研磨后于500℃烧结得到TiO2粉末。采用X射线、SEM表征分析不同分子量PEG对TiO2晶型、粒径、形貌的影响。     

氧化铁纳米颗粒对巨噬细胞极化效应影响的研究进展

巨噬细胞是机体免疫系统中重要的免疫效应细胞,具有显著的可塑性和异质性,在正常生理条件下和炎症反应过程中均发挥着重要作用。研究发现,巨噬细胞极化涉及多种细胞因子,是免疫调控的关键环节。纳米颗粒靶向巨噬细胞可对多种疾病的发生发展产生一定影响,其中氧化铁纳米颗粒因其特性被作为癌症诊断和治疗的介质与载体,可充分利用肿瘤的特殊微环境,将药物主动或被动地聚集于肿瘤组织,具有良好的应用前景。但利用氧化铁纳米颗粒重编程巨噬细胞的具体调控机制仍需深入探究。本文首先阐述了巨噬细胞的分类、极化效应及代谢机制,其次对氧化铁纳米颗粒的应用以及诱导巨噬细胞重编程进行综述,最后讨论了氧化铁纳米颗粒的研究前景和面临的困难与挑战,为进一步探讨纳米颗粒对巨噬细胞极化效应的机制研究提供基础数据和理论支持。     

纳米颗粒与骨细胞的作用及其在骨科中的应用

生物材料在骨再生治疗及组织工程领域的应用日益广泛.基于不同的构成、大小及形状,纳米颗粒与骨细胞之间的作用具有显著的独特性.因此,详细地分析纳米颗粒对细胞功能的作用,有利于选择更适于促进骨再生的材料.通过系统回顾纳米颗粒对间充质干细胞(MSCs)、成骨细胞及破骨细胞的作用,发现纳米颗粒对这些骨相关细胞具有十分重要的影响.其在骨缺损填充、作为药物和基因运输载体等方面具有广阔的应用前景,是促进骨再生及治疗骨疾病的良好选择.     

氧化铁纳米颗粒对静止状态白血病细胞的作用研究

目的 研究二巯基丁二酸修饰的四氧化三铁纳米颗粒(DMSA-Fe₃O₄NPs)对静止状态白血病细胞的作用及机制。方法 利用透射电镜观察纳米颗粒形貌;用低血清培养基诱导细胞进入静止状态,采用普鲁士蓝染色法与邻二氮菲铁定量法检测DMSA-Fe₃O₄NPs进入Kasumi-1细胞的情况;通过乳酸脱氢酶法、细胞氧化应激荧光探针和凋亡检测试剂分析DMSA-Fe₃O₄NPs对Kasumi-1细胞的作用。结果 DMSA-Fe₃O₄NPs可进入静止状态的Kasumi-1细胞,细胞内铁含量与DMSA-Fe₃O₄NPs浓度成正比;与此同时,细胞活性降低,细胞内活性氧(reactive oxygen species,ROS)与脂质过氧化物水平升高,细胞发生凋亡。正常培养的Kasumi-1细胞活性和氧化应激水平不受DMSA-Fe₃O₄NPs的影响。结论...     

银纳米颗粒对神经元的毒性研究

目的 研究不同浓度的银纳米颗粒对神经元毒性的剂量-效应关系,探索银纳米颗粒对神经元的毒性机理.方法 首先培养一种活性好、生长状态优良的原代神经元,将不同浓度（2.5～500μg/mL）的银纳米颗粒加入神经元中作用24h后,通过MTT法计算细胞增殖率,并分析不同浓度的银纳米颗粒对神经元毒性的剂量-效应关系.结果 在25～250μg/mL范围内,细胞数量与形态呈现不同的变化,银纳米颗粒浓度与细胞增殖率呈负相关.结论 在25～250μg/mL的浓度范围内,银纳米颗粒对神经元细胞的毒性呈剂量-效应关系.     

载磁性氧化铁CA-PLGA纳米颗粒对宫颈癌细胞的影响

目的 研究纳米四氧化三铁(Fe3O4)颗粒包裹不同外壳材料对宫颈癌细胞HeLa毒性的影响.方法 通过无溶剂热分解法制备磁性纳米Fe3O4颗粒并分别使用聚乳酸-羟基乙酸共聚物(PLGA)和胆酸(CA)修饰的PLGA(CA-PLGA)星型共聚物包裹,对其进行验证表征后,使用激光共聚焦显微镜观察HeLa细胞对纳米颗粒的摄取,并用噻唑蓝(MTT)法测定上述两种材料包裹的纳米Fe3O4颗粒对HeLa细胞的毒性作用.结果 制备的单个纳米Fe3O4颗粒粒径约7 nm,载Fe3O4的PLGA和CA-PLGA纳米颗粒均呈球状,粒径约200 nm,理论载药量为10％.当Fe3O4纳米颗粒的质量浓度相同(25 μg/ml)时,载Fe3O4的CA-PLGA纳米颗粒对HeLa细胞的毒性小于对应的PLGA纳米颗粒.结论 CA-PLGA星型共聚物可降低磁性纳米Fe3O4颗粒的细胞毒性,在生物体内具有广阔的应用前景.     

杂化细胞膜仿生纳米药物递送体系用于肿瘤治疗的研究进展

利用细胞膜包覆纳米颗粒的仿生策略不仅能保留纳米颗粒的物理化学性质,而且表现源细胞膜的生物学特性,可进一步增强纳米药物在肿瘤治疗中的作用。杂化细胞膜是将2种或2种以上不同类型的细胞膜融合在一起。与单型细胞膜相比,杂化细胞膜使纳米颗粒衍生出多种源细胞的生物功能,为多功能仿生纳米药物递送体系的广泛研究提供了基础,有望拓宽仿生纳米技术在药物递送体系的应用。综述了近年来用于构建纳米药物递送体系的杂化细胞膜类型,制备和表征方法以及用于肿瘤治疗的研究进展。     

TiO2纳米颗粒注射昆明鼠的抗电离辐射作用研究

目的 评价TiO2纳米颗粒对小鼠的辐射防护作用.方法 对6～8周龄昆明鼠,给予6.5 Gyγ-射线一次性全身照射.用不同剂量TiO2纳米颗粒10、20、40 mg/kg,在小鼠照射前2d、1d和照射后1d连续给药3次.在照射后第8天取外周血、胸腺、肝、脾、肺和两侧股骨.血液细胞分析仪分析白细胞数（WBC）、血小板数（PLT）和血红蛋白数（HGB）;计数股骨有核细胞（BMNC）和骨髓细胞DNA含量以及肝肺的超氧化物歧化酶（SOD）和丙二醛（MDA）含量;脏器称重计算相关的脏器系数,评价TiO2纳米颗粒的抗辐射损伤效应.结果 与空白对照组相比,除MDA外,各实验组的WBC、PLT、HGB、BMNC、SOD和骨髓细胞DNA指标均有所增加,且高剂量实验组与对照组的差异具有统计学意义（P＜0.05）.结论 高剂量TiO2纳米颗粒对6.5 Gy辐射损伤的昆明鼠有辐射防护作用.     

Influence of polyethylene glycol density and surface lipid on pharmacokinetics and biodistribution of lipid-calcium-phosphate nanoparticles

The pharmacokinetics (PK) and biodistribution of nanoparticles (NPs) are controlled by a complex array of interrelated, physicochemical and biological factors of NPs. The lipid-bilayer core structure of the Lipid-Calcium-Phosphate (LCP) NPs allows us to examine the effects of the density of polyethylene glycol (PEG) and the incorporation of various lipids onto the surface on their fate in vivo. Fluorescence quantification estimated that up to 20% (molar percent of outer leaflet lipids) could be grafted on the surface of LCP NPs. Contrary to the common belief that high level of PEGylation could prevent the uptake of NPs by the reticuloendothelial system (RES) organs such as liver and spleen, a significant amount of the injected dose was observed in the liver. Confocal microscopy revealed that LCP NPs were largely localized in hepatocytes not Kupffer cells. It was further demonstrated that the delivery to hepatocytes was dependent on both the concentration of PEG and the surface lipids. LCP NPs could be directed from hepatocytes to Kupffer cells by decreasing PEG concentration on the particle surface. In addition, LCP NPs with 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) exhibited higher accumulation in the hepatocytes than LCP NPs with dioleoylphosphatidylcholine (DOPC). Analysis of the proteins bound to NPs suggested that apolipoprotein E (apoE) might serve as an endogenous targeting ligand for LCP–DOTAP NPs, but not LCP–DOPC NPs. The significant uptake of NPs by the hepatocytes is of great interest to formulation design for oncologic and hepatic drug deliveries.     

Computer simulation of the role of protein corona in cellular delivery of nanoparticles

Understanding the role of serum protein in the process of nanoparticle delivery is of great importance in biomedicine. Here, by using dissipative particle dynamics simulations, we systematically investigate the interactions between the nanoparticle-protein corona complex and cell membranes of different types. It is found that the human serum albumin (HSA) will just adsorb onto charged (especially for positively charged) and hydrophobic nanoparticle surface. More importantly, we also provide specific insights into the effect of HSA adsorption on the in vivo transportation of nanoparticle (i.e., immune response and targeted cellular uptake). Our results show that the protein corona can change the interaction modes of hydrophobic nanoparticles and enhance the interaction of charged nanoparticles with macrophage cell membranes, while it may also cause the failure of insertion of hydrophobic nanoparticles and the loss of targeting specificity of charged nanoparticles with cancer cell membranes. These results can help better understand the biological significance of protein corona and may give some useful suggestions on better design of future nanoparticles in drug delivery.     

Polyethylene glycol effect on the oxygenated and hypoxic isolated perfused rat kidney

Summary Polyethylene glycol protects against O₂ deprivation after clamping of the renal artery or norepinephrine infusion and in hypoxic primary cell culture. Isolated perfused kidneys under hypoxic conditions develop morphological alterations in all segments of the proximal tubule and medullary thick ascending limb. In an attempt to ameliorate the effect of hypoxia, rat kidneys were perfused for 90 min with regularly oxygenated (95% O₂+5% CO₂) or hypoxic perfusate (95% N₂+ CO₂) supplemented with 8–12% polyethylene glycol (MW 8000). In oxygenated and hypoxic kidneys, polyethylene glycol produced similar changes in S₁–S₂ segments consisting of reduction of cell thickness and organelle compaction with internalization of brush border into the tubulo-vesicular system. In the S₃ segment, the cellular volume loss was more limited; the brush border was transformed to membranous whorls and the cytoplasm contained large, irregular, clear zones. Mitochondrial swelling was pronounced in the hypoxic proximal tubules. Polyethylene glycol quantitatively increased and emphasized the damage in the medullary thick ascending limb. Inclusion of 10^–2 M ouabain preserved the medullary thick ascending limb from hypoxic injury and polyethylene glycol had no effect on this undamaged epithelium. Thus, polyethylene glycol affects renal tubules on the basis of their known water permeability and does not protect against but rather worsens hypoxic injury in the medullary thick ascending limb.     

小分子醇类对磷脂水合和脂质体形成的影响研究EI北大核心CSCD

脂质体由于组分可控,是自然生物膜的良好替代模型。磷脂分子发生水合作用形成规则的膜结构是脂质体形成的先决条件。本文以乙醇分子为模型,考察了小分子醇类对磷脂水合(包括水合过程和水合结果)与脂质体形成的影响,以及醇分子与氯化钠共存时的影响。实验发现,磷脂膜水合过程中乙醇与氯化钠的作用恰好相反。氯化钠会抑制脂质体形成,而乙醇则在一定浓度范围内促进脂质体形成。对比不同乙醇及氯化钠含量时膜上荧光强度和膜连续度的变化,发现当二者同时出现在磷脂膜所处液体环境时,两者对磷脂水合起叠加作用。本研究结果可为人工生物膜的制备提供参考信息。     

The effect of chain length on the solid-state polymerization of N-alkylmaleimides

N-alkylmaleimides from the N-methyl to the N-octadecyl derivative were polymerized in the solid state by γ-radiation. Polymerization during irradiation generally showed sigmoidal conversion curves with high rates and complete conversion 10°C below the melting point. Post-irradiation rates were lower and showed the typical approach to a “limiting” conversion. The polymerization rates increased with temperature and radiation dose and with the length of the alkyl chain. N-methylmaleimide had a high rate of in-source polymerization which was attributed to the volatility of the monomer.     

人参对巨噬细胞影响的定量细胞化学研究

本文利用图象分析系统(Texture Analysis System TAS)和环核苷酸免疫荧光细胞化学技术研究了人参对小鼠腹腔巨噬细胞的影响。TAS的定量细胞化学表明人参可显著提高巨噬细胞内PAS阳性物质,AcPase、ATPase和ANAE的含量。同时,环核昔酸免疫荧光细胞化学亦显示人参可增加巨噬细胞内cGMP免疫荧光的强度,而CAMP免疫荧光强度下降。本文对结果的意义进行了讨论。     

Parametric study of the regulatory capabilities of rats with rostromedial zona incerta lesions: Responsiveness to hypertonic saline and polyethylene glycol

Rats with lesions in the dorsomedial zona incerta (ZI): (1) were hypodipsic; (2) drank little or nothing during periods of food deprivation; (3) drank little or nothing after injections of 5 ml of 0.50 M, 0.75 M, 1.0 M or 2.0 M NaCl solutions (some animals displayed delayed responses to the highest dose, 6 and 24 hr after the injection); (4) drank normal quantities of water or saline after 5 ml of 15%, 20%, or 30% PG (half of the animals that had shown absent or severely impaired responses to hypertonic saline; the other half did not drink saline or water in response to any dose of PG except the highest—5 ml of 30%); (5) sharply reduced or abolished sodium appetite; (6) reduced or abolished the feeding response to 2-DG without affecting ad lib food intake. Similar effects on 2-DG eating and sodium appetite (but not on water intake under ad lib or food-deprivation conditions, or on drinking in response to hypertonic saline or PG) were produced by lesions in ventral thalamus or dorsomedial hypothalamus.     

0X26偶联载内吗啡肽超支化聚甘油－聚乳酸－聚乙醇酸纳米粒透血脑屏障机制实验研究

目的 制备新型包载内吗啡肽（EM）的偶联脑主动靶向抗体OX26的超支化聚甘油-聚乳酸-聚乙醇酸（HBPG-PLGA）纳米粒,通过脑毛细血管内皮细胞（BMEC）研究其透血脑屏障（BBB）机制.方法 利用新型材料HBPG-PLGA通过复合乳液法制备载EM的纳米粒,在其表面偶联转铁蛋白受体单克隆抗体OX26,通过透射电镜等进行表征;采用流式细胞术和激光共聚焦显微镜研究不同配方纳米粒透过BBB的机制.结果 制备的载EM HBPG-PLGA纳米粒稳定,电镜下呈核壳结构,平均粒径（170±20） nm,Zeta电位约-27 mV,与OX26抗体的偶联效果较好,药物可以缓慢释放72 h以上.流式细胞术结果表明载EMHBPG-PLGA纳米粒具有良好的透BBB能力,其机制与细胞内吞作用有关;激光共聚焦显微镜结果显示纳米粒被内吞后,EM与纳米材料在细胞内分离,EM进入BBB,产生药理作用.结论 制备的偶联OX26载EM纳米粒稳定,能达到较好的透BBB作用,其机制与BMEC内吞作用有关,内吞后药物分离,进入脑内产生药理作用.     

电场刺激联合聚乙二醇治疗大鼠脊髓损伤的实验研究EI北大核心CSCD

外加直流电场刺激(EFS)可抑制脊髓损伤(SCI)后损伤组织局部Ca2+内流,有效抑制脊髓继发性损伤的发生。但电场刺激结束后,损伤局部Ca2+会重新开始内流并激发后续病理生理学连锁反应,影响了EFS治疗SCI的效果。聚乙二醇(PEG)是一种亲水性的高分子材料,具有促进细胞膜融合及受损细胞膜修复的作用。本文旨在研究EFS联合PEG治疗Sprague-Dawley(SD)大鼠SCI的效果。脊髓损伤后的SD大鼠被随机分为对照组(无治疗,n=10)、电场组(EFS治疗30 min,n=10)、PEG组(浸润50%PEG的明胶海绵覆盖损伤处5 min,n=10)和联合组(电场刺激和PEG联合治疗,n=10)。术后不同时间进行运动诱发电位(MEP)测量、运动行为学评分以及脊髓切片染色分析。研究结果表明,术后8周联合组大鼠MEP潜伏期差和波幅差以及脊髓空洞面积比均显著低于对照组、电场组和PEG组,而运动功能评分和脊髓神经组织残余面积比均显著高于对照组、电场组和PEG组。以上结果提示,联合治疗方法能减轻大鼠脊髓损伤后的病理损伤程度,促进大鼠电生理及运动功能的恢复,其疗效优于EFS和PEG单独使用时的效果。     

邻苯二甲酸二丁酯对巨噬细胞吞噬能力的影响研究

目的:近期台湾地区食品及饮料中添加邻苯二甲酸酯类(塑化剂)的安全问题受到广泛关注,已有研究证实邻苯二甲酸酯类物质能影响人类生殖系统发育,但其对人体免疫系统影响尚不清楚。本文研究邻苯二甲酸二丁酯对巨噬细胞吞噬能力的影响,以期揭示其对人类健康的危害。方法:使用不同浓度邻苯二甲酸二丁酯体外处理小鼠腹腔巨噬细胞24小时,然后进行巨噬细胞对细菌E.coli以及诱导凋亡的小鼠胸腺细胞的吞噬实验,并检测其吞噬率和吞噬指数,从而评价其对巨噬细胞吞噬能力的影响。用流式细胞仪检测邻苯二甲酸二丁酯对巨噬细胞表面吞噬相关分子CD11b、CD54、CD36、TLR4和CD64的影响;利用siRNA技术对吞噬相关受体CD36进行表达干扰,验证其在邻苯二甲酸二丁酯抑制巨噬细胞吞噬能力中的作用。结果:经过24小时体外处理,不同浓度邻苯二甲酸二丁酯对巨噬细胞吞噬能力均有抑制作用,并且具有剂量依赖性。此外,邻苯二甲酸二丁酯能显著降低巨噬细胞清道夫受体CD36的表达。结论:研究结果证实邻苯二甲酸二丁酯通过降低细胞膜表面CD36表达从而抑制巨噬细胞吞噬能力。