杂多阴离子SiW11对硅肺发生的抑制作用

本文观察了口服和雾化吸入ＳｉＷ（１１）杂多阴离子对实验性大鼠硅肺的防治作用及其病理形态变化，测定了大鼠肺匀浆中游离［Ｃａ（２＋）］及羟脯氨酸含量、肺泡无细胞灌洗液（ＢＡＬＦ）中乳酸脱氨酶（ＬＤＨ）含量及酸性磷酸酶（ＡＣＰ）活性和血清脂质过氧化物（ＬＰＯ）值．结果表明：ＳｉＷ（１１）杂多阴离子对石英的致硅肺作用有一定抑制效果．本文还初步讨论了这种抑制作用的原因．     

硅肺发病前期肺中钙量的变化

硅肺发病前期肺钙变化的研究是探索Ca~(2 )在硅肺发生中的作用的重要内容。本文以离子选择性电极和Tb~(3 )-荧光光谱法首次检测了硅肺大鼠发病前期肺组织的钙量。结果表明:大鼠在染尘后3.5-14天,肺游离[Ca~(2 )]显著升高;肺[Ca~(2 )]的上升部分来自肺组织线粒体Ca~(2 )的释放。     

肺Ca2+含量与硅肺的关系

本文用离子选择电极测定了实验性诱发硅肺大鼠的肺、脑、肾、肝和血清中的[Ca~(2+)]、[K~+]和[Na~+],还以荧光探针Tb~(3+)探讨了Ca~(2+)的作用。在硅肺形成后,大鼠的肺、脑、肾、肝和血清等组织中的游离[Ca~(2+)]均发生变化。荧光探针表明:硅肺大鼠肺Ca~(2+)增加部分来自线粒体Ca~(2+)的释放硅肺。大鼠肺中游离Ca~(2+)和线粒体Ca~(2+)的变化可能与巨噬细胞的损伤有关。     

聚己内酯/卵磷脂的纺丝支架构建组织工程血管

合成的聚己内酯(PCL)经天然的卵磷脂(Phosphatidylcholine,PC)填充改性后,通过电纺丝技术加工得到三维多孔的纤维支架。卵磷脂含有的两性离子基团,可以显著改善PCL支架材料的亲水性,进而提高支架材料的细胞相容性。体外细胞增殖实验表明,骨髓间充质干细胞(MSCs)在含有5wt%卵磷脂的改性支架表面生长得最好。作为种子细胞的MSCs在流动培养下,通过力学刺激在管状支架内壁形成了多层细胞。通过对样品染色切片和荧光照片的观察,种子细胞MSCs与对照组的血管平滑肌细胞(SMCs)一样,有向改性支架内部生长的趋势。本文以这种PC填充改性PCL材料的纤维支架作为组织工程血管,对其进行了初步的探索。     

甲基多巴透过POPC磷脂双层膜过程的分子动力学模拟

采用分子动力学模拟研究甲基多巴分子透过磷脂双层膜的动力学机制.研究所采用的磷脂双层膜是一种卵磷脂脂质分子双层膜,即1-棕榈酰-2-油酰-卵磷脂(POPC)双层膜,分子动力学模拟基于Gromacs程序.通过分子动力学模拟获得甲基多巴透过POPC双层膜的自由能垒是99.9 kJ·mol-1(310 K),显示甲基多巴分子可以透过细胞生物膜.模拟获得甲基多巴在POPC双层膜中间层扩散运动的自由能垒是16.9-27.7 kJ·mol-1(310 K),证明甲基多巴分子在细胞膜中间层容易扩散.研究工作加深了对甲基多巴治疗高血压病机制的理解,促进研发治疗高血压病的新药物.     

聚乙烯亚胺介导siRNA和顺铂协同抗肿瘤治疗

用聚乙烯亚胺(PEI)为载体,介导siRNA(siSurvivin)沉默肿瘤细胞抗凋亡基因survivin,并与抗癌药物(顺铂)进行协同抗肿瘤治疗.凝胶阻滞电泳实验显示,PEI能够对siRNA进行有效复合,在PEI/siRNA质量比为0.4时实现完全阻滞.细胞耐药性实验证明了耐顺铂细胞(A549DDP细胞)的survivin基因过度表达且耐顺铂能力是顺铂敏感细胞(A549细胞)的8倍.RT-PCR实验验证了PEI担载siSurvivin后对survivin基因实现了有效沉默,与顺铂药物共同作用后不影响基因沉默效果.细胞凋亡实验验证了基因与药物协同作用后细胞的凋亡率达到60.9％,而单独药物或PEI/siSurvivin复合物分别作用后的细胞凋亡率仅分别为30.2％和19.8％.细胞增殖实验进一步验证了PEI介导siSurvivin与顺铂联合治疗能够实现有效地协同抗肿瘤效果.     

卵磷脂中PE及不同种类PC的高效液相色谱分析

卵磷脂具有重要的生理功能,是人体正常新陈代谢和健康生存不可少的物质,能改善治疗神经系统疾病,增强记忆力,防止心血管疾病等。在临床上卵磷脂的主要的用途是用于治疗动脉粥样硬化、脂肪肝、神经衰弱、营养不良及静脉注射脂肪乳的乳化剂、胆固醇结石的防治药物,引。美国、欧洲、日本等已将磷脂在临床上用于防治脑、心、肝、肿瘤等疾病。     

以人血清白蛋白为载体的Ru(Ⅲ)和全反式维甲酸共运输纳米药物的构建及抗肿瘤转移作用

设计合成了一种以人血清蛋白纳米颗粒(HSANP)为载体, 共运输Ru(Ⅲ)配合物和全反式维甲酸(ATRA)的纳米药物Ru-ATRA-HSANP, 用于抗肿瘤转移治疗. 该药物在水中和生理条件下表现出优异的稳定性, 可以被细胞有效摄取, 具有较弱的细胞毒性, 但表现出优异的抗肿瘤转移效果. 因此, 构建了一种稳定、 低毒性的抗肿瘤转移纳米药物, 有望用于抗肿瘤转移治疗.     

磷酸胆碱基细胞膜仿生药物缓释涂层材料的研究

随着现代医学的飞速发展 ,各种微创介入医疗装置如医用导管 (Catheter)、手术导引线(Guidewires)、金属支架 (Stents)等已广泛地应用到各种医疗技术中 ,极大地丰富了现代医学诊疗手段 .然而在临床应用中 ,现有的装置依然不同程度地存在感染、凝血和术后组织增生等问题[1 ] .设计生物相容性聚合物基载药涂层和实现药物在预定部位的定向释放 ,为解决这些问题提供了有效途径 [2～ 5] .血红细胞膜具有由磷脂分子自组装形成的双层膜 .细胞生物学研究表明 ,细胞膜外层带有等量正电荷和负电荷的卵磷脂不会激活内源性凝血途径 .因此人们设计了磷酸…     

光化学反应-串联质谱法鉴定细胞中不饱和卵磷脂双键的位置

以二苯甲酮(Benzophenone,BP)为光化学反应的反应物,建立了乳腺细胞中不饱和卵磷脂双键位置和双键异构体相对含量的在线光化学反应-脉冲直流电喷雾串联质谱(PB-pulsed-dc-ESI-MS/MS)的检测方法.通过三相萃取法提取细胞中的脂类,在254 nm紫外光的照射下,使不饱和卵磷脂中的C詤C和BP中的羰基发生特异性的环加成反应(Paternó-Bǜchi,PB反应),将反应后的PB产物通过非接触式的脉冲直流电喷雾(Pulsed directed current electrospray,pulsed-dc-ESI)方式电离,并进行低能碰撞裂解得到二级串联质谱(MS/MS),从得到的二级谱图的子离子中可以获得双键位置以及双键异构体相对含量的信息.检测了癌细胞MCF-7和正常细胞MCF-10A中8种不饱和卵磷脂中的双键位置,且对其中4种双键异构体的相对含量进行分析,发现PC 16:018:1中△9异构体的含量在两种细胞中差异不明显,PC 18:018:1和PC 18:118:1中△9异构体的含量略有差异,LPC 18:1中△9异构体的含量在癌细胞和正常两种细胞中差异比较明显(56.0%±1.3%vs.71.7%±6.8%).本方法快速简易,可用于分析双键位置及双键异构体相对含量,有望对不同细胞状态以及不同疾病状态进行鉴别.     

CHARACTERISTIC PROPERTIES OF LECITHIN AS A SURFACTANT

Characteristic solution properties of lecithin were studied in 1) water+propanol/lecithin/hexadecane and 2) ethanol/lecithin/ hexadecane systems. 1) Solvent property of water changes by added alcohol and the hydrophile-lipophile property of lecithin is balanced in 13 wt% propanol aq.-hexadecane system. Three liquid phases, i.e. aqueous alcohol, lecithin and hexadecane are found. The volume fraction of the lecithin phase increases with its concentration and at 2.3 wt%/system, all solvent molecules are swelled and one microemulsion phase is obtained. 2) In ethanol/ lecithin/hexadecane system, lecithin is also insoluble in the solvent, and swells a large amount of hexadecane.     

Effects of emulsifying agents on the safety of titanium dioxide and zinc oxide nanoparticles in sunscreens

The use of titanium oxide (TiO₂) and zinc oxide (ZnO) nanoparticles (NPs) in sunscreen formulations has increased considerably, and might pose a serious health hazard worldwide. A thorough investigation into the toxicity induced by such components is highly necessary. In this study, the effects of TiO₂ and ZnO NPs on HaCaT cells were tested in the presence and absence of emulsifiers (cyclopentasiloxane, jojoba ester, and lecithin). Cell viability results revealed that the toxicity of NPs was highly dose dependent and influenced by the emulsifier type. The emulsifiers themselves are minimally toxic. However, when used in combination with TiO₂ and ZnO, they were highly toxic to HaCaT cells. Transmission electron microscopy revealed that the cells showed least permeability to NPs dispersed in lecithin compared to other emulsifiers. In conclusion, the toxicity of NPs may be highly dependent on the emulsifier type and be varied. In particular, lecithin can be used as a potential alternative emulsifier in sunscreens.     

Transdermal permeation of tetracaine hydrochloride by lecithin microemulsion: in vivo

In vivo transdermal permeation of tetracaine hydrochloride encapsulated in lecithin water-in-oil and oil-in-water microemulsion was studied. The effect of the composition of the lecithin microemulsion on analgesic response of tetracaine hydrochloride was evaluated on Wistar rats by tail flick method. To find out the toxicity of lecithin/n-propanol/isopropyl myristate/water/tetracaine hydrochloride microemulsion histopathological and irritation response were measured in Swiss mice. Time course studies were also conducted for the biochemical response of microemulsion by measuring catalase, glutathione and lipid peroxidation levels of the treated mice skin. The analgesic response was found to be dependent on the drug concentration and composition of the systems. The histopathological, irritation and biochemical findings reveal that lecithin/n-propanol/isopropyl myristate/water/tetracaine hydrochloride microemulsion is a safe carrier for transdermal drug delivery systems. Confocal laser scanning microscopy observation indicated that sweat gland and hair follicle also provided the path for transdermal permeation of lecithin/n-propanol/isopropyl myristate/water microemulsion.     

一种仿细胞膜聚合物用于碳纳米管表面改性

以新型含有磷酸胆碱基的仿细胞膜两亲聚合物——胆固醇封端的聚(2-甲基丙烯酰氧基乙基磷酸胆碱)(CPMPC)为表面稳定剂实现碳纳米管的表面改性,利用两亲聚合物中的胆固醇疏水段与碳纳米管表面进行非共价键的稳定结合,通过两亲聚合物中聚(2-甲基丙烯酰氧基乙基磷酰胆碱)(PMPC)亲水段实现其水溶性和生物相容性.并以商业可获得的典型两亲分子,末端为胆固醇的聚氧乙烯(CPEG)和卵磷脂,为对照进行研究.研究表明CPMPC和CPEG均具有比卵磷脂更高的对碳纳米管进行分散的能力.而CPMPC改性的碳纳米管比CPEG改性的碳纳米管具有更优的稳定性和生物相容性,通过新型仿细胞膜聚合物改性的碳纳米管在生物医用领域有潜在应用.     

FLUIDITY AND OXYGEN PENETRATION OF LIPID VESICLES STUDIED BY FLUORESCENCE PROBES

Abstract. –An analysis of the temperature dependence of trans -stilbene fluorescence yield in dipalmitoyl lecithin vesicles is used to obtain activation energies. The results are interpreted in terms of bilayer fluidity through and above the phase transition. Oxygen quenching of the fluorescence of pyrenebutyric acid (incorporated in dipalmitoyl lecithin and egg lecithin vesicles) is reported as a function of temperature and bulk oxygen concentration. Above the bilayer phase transition, quenching rates (determined by oxygen quenching) decrease with decreasing temperature. A reduction in oxygen quenching is observed through the dipalmitoyl lecithin phase transition.     

PROPERTIES OF CHLOROPH'YLL-LECITHIN VESICLES: ULTRACENTRIFUGATION, ABSORBANCE, EMISSION AND PHOTOBLEACHING

Abstract— Egg lecithin vesicles (liposomes) containing up to one Chl a per 11 lecithin molecules were prepared without sonication. Their absorbance and emission properties indicate that Chl is dispersed in the lecithin, that the vesicles are dispersed in the medium and that there is a strong quenching of fluorescence.
Their photobleaching and chemical bleaching show that there is a negligible amount of colloidal Chl present. In vesicles with a Chl:lecithin molar ratio higher than 0.05, there are probably some small aggregates of Chl a in the bilayer.
The ultracentrifugation of such vesicles shows that their sedimentation constant increases, though not regularly, with their relative Chl content     

ELLIPSOMETRY OF BLACK LIPID MEMBRANES OF EGG LECITHIN AND CHLOROPLAST EXTRACTS

Abstract— Ellipsometric angles and reflectivity of black lipid membranes containing either egg lecithin or chloroplast extracts were measured at a wavelength of 6328 Å. Evidence was found for positive uniaxial anisotropy in membranes of lecithin. If the thickness of those films is assumed to be 62 Å, the refractive index normal to the film surface is 1.471 ± 0.004, and the refractive index parallel to the film surface is 1.454 ± 0.003. The results for membranes of chloroplast extracts also indicate a positive anisotropy in the indices of absorption.     

硒酸酯多糖抗石英细胞毒性的研究

本文采用家兔肺泡巨噬细胞体外培养法，以ＡＲ－ＣＭ阳离子测定系统和荧光试剂Ｆｕｒａ－２，研究了石英细胞毒性与肺泡巨噬细胞胞胞浆游离Ｃａ＾２＋浓度（［Ｃａ＾２＋］ｉ）的关系，并以细胞存活率，乳酸脱氢酶活性和脂质过氧化物表征了由石英引起的ＡＭ毒性及硒酸酯多糖对其毒性的拮抗效应，初步讨论了硒酸酯多糖拮抗石英细胞毒性的可能机理。     

CdX(X=Se,Te,Te/ZnS)量子点脂质体的制备及毒性比较

在水相中以巯基乙酸(mercaptoacetic acid, MA)为稳定剂合成了CdSe、CdTe、CdTe/ZnS量子点及谷胱甘肽(glutathione, GSH)为稳定剂合成了CdTe量子点,然后通过卵磷脂和胆固醇修饰制得相应的量子点脂质体。溶血实验证实GSH修饰量子点的溶血率低于MA修饰的量子点45%;脂质体修饰后,量子点的溶血率＜5%,达到生物医用材料要求。不同表面修饰的量子点对小鼠毒性存在明显差异,荧光显微镜观察组织切片证实量子点在小鼠体内主要分布在肺、肾、胸腺等组织中,而脂质体量子点在脑组