BAPTA-AM脂质体抗D-GalN/LPS所致的小鼠急性肝衰竭

观察BAPTA-AM脂质体(BA-L)对D-GalN/LPS诱导的小鼠急性肝功能衰竭(ALF)保护作用并探讨其保肝作用机制.建立D-GalN/LPS致小鼠ALF模型,测定给予BA-L小鼠的24h死亡率,肝指数,肝含水质量分数,血清ALT和NO水平,肝匀浆GSH,GSH-Px,SOD,MDA水平,HE染色观察组织病理学改变,TUNEL法观察肝细胞凋亡并统计凋亡指数.结果表明:BA-L可显著减少小鼠死亡率,降低肝指数,血清ALT和NO值降低,可使肝匀浆GSH,GSH-Px,SOD升高,而MDA减少,HE染色可见肝组织病理情况明显改善,TUNEL染色可见肝细胞凋亡指数明显下降,其效果远优于甘草酸二铵,BA-L有上佳的抗ALF作用.     

Synthesis and characterization of surface-active compounds derived from cholesterol derivatives and glucose

The synthesis and characterization of surface-active compounds based on various steroid derivatives and glucose are presented. The hydrophobic and hydrophilic parts of the compounds were linked via glucosidic bonds. All compounds were found to have very low water solubility and only limited solubility in various organic solvents. The compounds were investigated according to their ability to interact with an anionic surfactant, sodium dodecylsulfate (SDS), in order to induce a decrease in the critical micelle concentration (CMC) of the surfactants. This synergistic effect was pronounced for cholestanol-6-on-β-D-glucopyranoside and for cholestan-3,6-diol-β-D-glucopyranoside. These two compounds lowered the CMC from 8 to 6 and 0.6 mM, respectively, for water solutions of SDS/glucoside with a molar ratio of 92∶8. Furthermore, the ability of the compounds to stabilize lipid membranes, in liposomes, at varying concentrations of Ca²⁺, was studied. The compounds were, as expected, found to induced stabilization similar to that of cholesterol.     

熊果苷脂质体的制备研究

采用逆相蒸发制备熊果苷脂质体,研究了熊果苷脂质体配方中不同成分的比例、水合介质及高压挤压工艺对脂质体包封率的影响。结果表明:较佳的配方组成为大豆磷脂PC、胆固醇、熊果苷的质量比为400∶34∶136;投药比越大,包封率越低;较佳的水合介质是葡萄糖溶液。高压挤压工艺不利于得到较高包封率的熊果苷脂质体。     

神经酰胺及其脂质体技术的国内外研究动态

介绍了Ceramides（神经酰胺）及其脂质体技术在化妆品、食品和药品等方面的应用，以及最新的研究进展。     

Permeability changes caused by surfactants in liposomes that model the stratum corneum lipid composition

The alterations caused by different surfactants in the permeability of liposomes formed by a lipid mixture that models the stratum corneum (SC) composition (40% ceramides, 25% cholesterol, 25% palmitic acid, and 10% cholesteryl sulfate) were investigated. The surfactant/lipid molar ratios (Re) and the bilayer/aqueous phase surfactant partition coefficients (K) were determined at two sublytic levels. The selected surfactant were sodium dodecyl sulfate (SDS); sodium dodecyl ether sulfate (SDES) to assess the influence of the ethylene oxide groups on the anionic surfactant’s behavior; Triton X-100 (OP-10EO) and dodecyl betaine (D-Bet) as representatives of nonionic and amphoteric surfactants. Permeability alterations were determined by monitoring the increase in the fluorescence intensity of liposomes due to the 5(6) carboxyfluorescein (CF) released from the interior of vesicles. The SC liposomes/surfactant sublytic interactions were mainly ruled by the action of surfactant monomers. OP-10EO showed the highest ability to alter the permeability of bilayers and the highest affinity with these structures, whereas D-Bet showed the lowest tendencies. Although SDS and SDES exhibited similar activity at 50% CF release (similar Re values), SDES appeared to be more active at 100% CF release, its affinity with bilayers being also increased. The different ability exhibited by SDS, SDES, and D-Bet (same alkyl chainlength) to alter the permeability of SC liposomes emphasizes the role played by the polar part of these surfactants in this interaction. Different trends in the evolution of Re and K were observed when comparing the results with those reported for phosphatidylcholine (PC) liposomes. Thus, whereas SC liposomes appeared to be more resistant to the action of surfactants, the surfactant affinity with SC bilayers was always greater than that reported for PC bilayers.     

Adaptation of a Biomineralization Strategy for Remineralization of Enamel and Dentin

1Introduction Theextra cellularphospholipidshavebeendetectedmainlyattheperipheryofthecalcifyingnodules.Matrix vesicles,whichareconsideredapossiblesourceofextra cellularphospholipids[1].Electronmicroscopystudiesofmineralizingtissueshaverevealedthattheiniti…     

Combination of doxorubicin with harmine-loaded liposomes exerting synergistic antitumor efficacy

Context: Long-circulation (PEGLip), pH-sensitive (PEOzLip), and active targeted liposomes (PEG-TATLip)-loading doxorubicin (DOX) and harmine (HM) were prepared. Their physicochemical properties and antitumor effect were investigated.

Objectives: The aims of the present study were to evaluate synergistic antitumor efficacy.

Materials and methods: Liposomes were prepared by using thin-film dispersion, active drug-loading and target post-insertion method. Subsequently physiochemical properties including particle size distribution, zeta potential, entrapment efficiency (EE), drug-loading content and in-vitro release were determined. Besides, the in vitro cytotoxicity of free drugs and drug-loaded liposomes was explored by using a Sulforhodamine-B Staining assay and the combination index values (CI Value) were calculated. Finally, the cellular uptake experiments by MCF-7cells were carried out via flow cytometry.

Results and discussion: All liposomes enhanced the antitumor effect significantly compared to free drugs. Among liposomes, PEG-TATLip enhanced the antitumor effect significantly compared to others. DOX and HM had moderate synergism with CI Value 0.85 for free drugs, 0.81 for PEGLip, 0.72 for PEOzLip, and 0.84 for PEG-TATLip respectively when the weight ratio of two drugs was 1:2. Moreover, the similarity between DOX and HM such as physicochemical properties, in vitro release modes and in vitro uptake kinetics characteristics when they were in the same formulations proved it possible for them to be delivered together.

Conclusion: Active targeting liposomes were the most effective delivery system as compared with pH-sensitive and long circulation liposomes. Additionally, DOX and HM could be co-delivered in liposomes and they could play moderate synergism effect in antitumor efficacy.     

溶胶-凝胶法固定化木瓜蛋白酶的活性保护

选择糖和脂质体作为溶胶-凝胶法固定木瓜蛋白酶(Papain)过程中的保护剂. 研究了蔗糖、葡萄糖、海藻糖、木糖、麦芽糖及构成脂质体的正癸烷溶液中胆固醇含量、卵/胆比等因素对固定化酶活性的影响. 结果表明,80 mL 20 mg/mL Papain溶液与15 mg木糖、500 mL正癸烷溶液[溶有1.5%(w)胆固醇,卵磷脂/胆固醇质量比为4.5:1]充分混合后制备的固定化酶活性最高. 在优化条件下制备的固定化酶包封率为42.0%,活力回收率为61.2%. SEM分析表明,固定化酶形态呈球状且大小均匀,内孔分布呈蜂窝状. 破膜剂对固定化酶活性发挥的影响研究表明,TritonX-100的效果最好.     

胆固醇对红景天苷脂质体的制备及物化稳定性的影响

本实验研究了胆固醇对红景天苷脂质体的作用,重点考查了包封率、Zeta电位、粒径大小、渗漏率和丙二醛（malondialdehyde,MDA）含量等指标。结果表明,红景天苷脂质体的包封率随着胆固醇嵌入量的增加呈现先增加后减小的趋势,但胆固醇的嵌入量对载量影响不大。4℃和30℃下贮藏一个月,没有任何胆固醇嵌入的脂质体渗漏率达到10%和15%,随着胆固醇嵌入量增加至1：5和1：2,脂质体的渗漏率分别下降为6%、5%和12%、10%。进一步增大胆固醇的嵌入量至1：1,其渗漏率又会明显增加。胆固醇和卵磷脂脂质量比1：2时,脂质体在4℃、30℃下贮藏一个月的物理稳定性最好。     

大豆磷脂阿奇霉素脂质体的制备及稳定性研究

利用大豆粉状磷脂,采用逆相蒸发结合冻融法制备阿奇霉素脂质体,以高效液相色谱法为分析手段,采用反透析法测定阿奇霉素脂质体的包封率。研究了阿奇霉素脂质体配方中不同成分的比例,以及水合介质对脂质体包封率的影响。阿奇霉素脂质体的最佳制备条件为：温度38℃,阿奇霉素：磷脂为1：20（质量比）,阿奇霉素：胆固醇为1：2．5（质量比）,最佳的水合介质是pH6．8的磷酸盐缓冲溶液,加入的磷酸盐缓冲溶液为20ml。在此条件下,阿奇霉素脂质体的包封率为72．86％。该方法准确,可用于大豆磷脂阿奇霉素脂质体的制备,并且制备的脂质体稳定。