低密度脂蛋白吸附剂的研究.——Ⅱ.磺化葡聚糖凝胶珠吸附剂

本文研究了葡聚糖凝胶经磺化反应后接上磺酸基团并制成珠状的吸附剂,对血浆中低密度脂蛋白(LDL)和极低密度脂蛋白(VLDL)的选择性吸附。实验结果表明:该吸附剂可使血浆中的LDL+VLDL降低90％以上,而使高密度脂蛋白(HDL),总蛋白(TP)仅有较小的降低,并讨论了葡聚糖凝胶的交联度和磺化程度对其吸附性能的影响。     

聚(丙烯酰胺-丙烯酸)/聚(丙烯酰胺-二甲基二烯丙基氯化铵)聚电解质复合溶液动态光散射研究

通过动态光散射、粘度和透光率测定，研究了聚（丙烯酰胺 丙烯酸）［Ｐ（ＡＭ ＡＡ）］／聚（丙烯酰胺 二甲基二烯丙基氯化铵）［Ｐ（ＡＭ ＤＭＤＡＡＣ）］聚电解质复合溶液的结构和性能．结果表明，Ｐ（ＡＭ ＡＡ）与Ｐ（ＡＭ ＤＭＤＡＡＣ）复合比、溶液浓度和氯化钠用量影响溶液中复合物的构象和流体力学半径．Ｐ（ＡＭ ＡＡ）与Ｐ（ＡＭ ＤＭＤＡＡＣ）分子链间适度的库仑相互作用，可形成均相Ｐ（ＡＭ ＡＡ）／Ｐ（ＡＭ ＤＭＤＡＡＣ）聚电解质复合溶液，复合物具有较伸展的构象和较大的流体力学半径，因而溶液粘度较高．Ｐ（ＡＭ ＡＡ）与Ｐ（ＡＭ ＤＭＤＡＡＣ）分子链间过强的库仑相互作用或小分子电解质的屏蔽作用，可使复合物构象卷曲，结构紧缩，流体力学半径减小，甚至产生相分离，导致溶液粘度降低．     

疏水性多糖的合成及荧光法研究其在水中的自聚集行为

由胆固醇与１,６－已二异氰酸酯反应合成了１,６－已二异氰酸酯胆固醇单脂（Ｉ）,然后通过葡聚糖与（Ｉ）反应合成了具有自聚集性质的葡聚糖,测得葡聚糖主链上每１００个糖环含有３－５个胆固醇。我们采用探针式超声波来制得胆固醇修饰葡聚糖「ＣＨＤ」的水溶液,同时用Ｎ－苯基－α－萘胺「ＰＮＡ」作为荧光探针来研究ＣＨＤ自聚集过程。在实验中我们发现,每一种葡聚糖溶液,都存在着一个临界浓度。在此浓度之上,ＰＮＡ的荧光     

石英晶体微天平实时监测低密度脂蛋白在胆固醇修饰葡聚糖上的吸附及其动力学研究

利用石英晶体微天平实时监测低密度脂蛋白(LDL)在胆固醇修饰葡聚糖(CMD)上的吸附,并对其吸附动力学进行研究.结果表明,CMD与LDL之间的相互作用符合Langmuir吸附方程,当LDL浓度(ng/μL)为9.9,12.38和14.14时,其吸附平衡常数[K/(mol·L-1·s-1)]分别为0.0477,0.0536和0.0628,表面吸附量(ng/cm2)分别为107.6,139.6和167.9.最大吸附量达到284.8ng/cm2,吸附率为72.91%.     

葡聚糖为载体的双亲型LDL吸附剂吸附动力学研究

合成了以葡聚为载体，同时具有亲水性磺酸基和疏水性胆固醇两类配基的新型低密度脂蛋白（LDL）吸附剂。通过对LDL纯溶液中吸附等温线的测试，比较了以Dextran G-75为载体的双亲型LDL吸附剂与单一亲水型磺酸基配基，单一疏水型胆固醇基吸附剂吸附量和亲和吸附系数的关系。对双亲型LDL吸附剂的吸附动力学进行了初步研究，在LDL溶液中，亲水型磺酸基，疏水型胆固醇配基，双亲型LDL吸附剂对LDL的吸附曲线基本上符合Langmuir吸附方程，另外通过高离子强度NaCl洗脱实验，测定了双亲型LDL吸附剂上具有的磺酸基与胆固醇两类基在对低密脂蛋白吸附过程中所起的配合效果，为下一步作用力机制研究提供了参考依据。     

胆固醇酯转移蛋白在胆固醇酯转移中的结构与功能

人体胆固醇酯转移蛋白（CETP）会造成胆固醇酯从高密度脂蛋白（HDL）向低密度脂蛋白（LDL）或极低密度脂蛋白（VLDL）的转移,从而增加人体患心血管疾病的危险性。了解CETP在胆固醇酯转移过程中的作用和机理,是研发新的CETP抑制剂药物以预防和治疗心血管疾病的重要基础和关键步骤。本文综述了CETP结构与功能领域研究的最新进展,详细介绍了CETP与各类脂蛋白绑定结构的高分辨透射电子显微镜研究;并结合对CETP晶体结构的分析,以及生理溶液中CETP结构与动态特征、CETP与脂滴间相互作用的分子动力学模拟研究结果,阐述并讨论了CETP脂转移机理的“通道”模型;最后对尚待解决的关键问题与未来的研究方向进行了展望,以期促进CETP功能机理的研究和抑制药物的研制。     

聚（丙烯酰胺—丙烯酸）／聚（丙烯酰胺—二甲基二烯丙基氯化铵）聚电解质复…

通过动态光散射、粘度和透光率测定，研究了聚（丙烯酰胺－丙烯酸）［Ｐ（ＡＭ－ＡＡ）］／聚（丙烯酰胺－二甲基二烯丙基氯化铵）［Ｐ（ＡＭ－ＤＭＤＡＡＣ）］聚电解质复合溶液的结构和性能。结果表明，Ｐ（ＡＭ－ＡＡ）与Ｐ（ＡＭ－ＤＭＤＡＡＣ）复合比、溶液浓度和氯化钠用量影响溶液中复合物的构象和流体力学半径。Ｐ（ＡＭ－ＡＡ）与Ｐ（ＡＭ－ＤＭＤＡＡＣ）分子链间适度的库仑相互作用，可形成均相Ｐ（ＡＭ－ＡＡ）／Ｐ（Ａ     

聚乙烯醇衍生的聚离子复合物的研究 Ⅲ．乙烯－乙烯醇共聚物的化学修饰及其复合物

通过化学修饰，在乙烯－乙烯醇共聚物（ＥＶＡ）分子链上分别引入磺酸基、磷酸基或胺基等，制得具有聚离子性质ＥＶＡ衍生物．由这些聚离子复合而形成的聚离于复合物，即使在含水状态也很少失其强度．动态力学性能的测定表明，除了聚离子之间的静电相互作用外，ＥＶＡ中的乙撑链段及共聚物主链的结晶也对维持聚离子复合物的强度有贡献．在水－二甲基甲酰胺一无机强电解质三组分混合溶剂中，与使用ＮａＢｒ或ＵＢｒ的体系比较，聚离子复合物更易溶解于使用Ｃａ（ＳＯＮ）２、ＺｎＯ２或ＮａＳＣＮ的体系．     

葡聚糖分子量和接枝度对阿霉素/白蛋白-葡聚糖纳米粒子体外抗肿瘤效果的影响

以Maillard反应制备的牛血清白蛋白-葡聚糖共价接枝物作为载体, 通过调节混合溶液的pH值和温度制备负载阿霉素的白蛋白-葡聚糖纳米粒子. 利用分子量为5×10³, 10×10³和62×10³的葡聚糖制备了多种共价接枝物, 研究了共价接枝物分子量对载药纳米粒子的粒径和稳定性及载药量的影响. 用短链葡聚糖(分子量5×10³和10×10³)制备的纳米粒子粒径为60 nm左右, 用长链葡聚糖(分子量62×10³)制备的纳米粒子粒径约为200 nm; 阿霉素的包埋效率为81%~98%, 包埋量为7.4%~16.9%. 细胞实验结果表明, 共价接枝物具有很好的生物相容性; 与自由阿霉素相比, 纳米粒子可以促进阿霉素进入人口腔上皮癌细胞; 受缓释性质的影响, 纳米粒子在低浓度时的细胞毒性要小于自由阿霉素. 与长链葡聚糖纳米粒子相比, 接枝度高的短链葡聚糖纳米粒子由于具有较小的粒径、 密集的葡聚糖分子刷表面、 一定的自由阿霉素浓度和较快的阿霉素释放速率, 因而更容易进入细胞并具有更好的体外抗肿瘤活性.     

血脂、金属元素与脑中风关系的研究

脑中风是严重威胁中、老年人健康与生命的主要疾病之一．为了探讨中风发病机理和进行人群防治与疾病监测，作者于1990年9月至1992年5月进行了大规模人群调查和实验室研究工作．测定了中风高危人群8928人的血糖，胆固醇，低密度脂蛋白(LDL)、极低密度脂蛋白(VLDL)及血压、身体指数等．随机抽取1928人测定血清中金属元素，结果发现由东北到华南中风发病率逐渐降低的趋势与血清中钾钠含量和钙镁比值高有密切关系。     

Relationship between Apolipoprotein E Genotype and Lipoprotein Profile in Patients with Coronary Heart Disease

(1) Background: Apolipoprotein E(ApoE) plays a critical role in lipid transport. The specific allele of APOE being expressed is associated with the development of coronary heart disease (CHD), however the specific mechanisms by which ApoE drives disease are unclear. In this study, we investigated the relationship between APOE allele, lipoprotein metabolome, and CHD severity to provide evidence for the efficacy of clinical cholesterol-lowering therapy; (2) Methods: Blood samples were collected from 360 patients with CHD that were actively being treated with statins. The lipoprotein profile, including particle numbers, particle size, and lipoprotein composition concentrates, was measured by nuclear magnetic resonance (NMR) spectroscopy. The severity of CHD was determined by quantifying coronary angiography results using the Gensini scoring system; (3) Results: We found there was no significant difference in low-density lipoprotein cholesterol (LDL-C) levels among ε2+ (ε2 allele carriers, consisting of ε2/ε2 and ε2/ε3 genotypes), ε3 (consisting of ε3/ε3 and ε2/ε4 genotypes), and ε4+ (ε4 allele carriers, consisting of ε3/ε4 and ε4/ε4 genotypes) participants receiving statin treatment. Compared with the ε3 group, patients with the ε2+ genotype showed lower concentrations of total low-density lipoprotein (LDL), small-LDL, and middle-LDL particles, as well as a larger LDL size, higher very low-density lipoprotein (VLDL) composition concentrates, and higher intermediate density lipoprotein (IDL) composition concentrates. The ε4+ group showed higher concentrations of total LDL, small LDL particles, and LDL compositions with smaller LDL size. The higher level of small LDL concentration was associated with a high Gensini score (B = 0.058, p = 0.024). Compared with the ε3 group, the risk of increased branch lesions in the ε2+ group was lower (OR = 0.416, p = 0.027); (4) Conclusions: The specific allele of APOE being expressed can affect the severity of CHD by altering components of the lipoprotein profile, such as the concentration of small LDL and LDL size.     

聚二甲基硅氧烷(PDMS)/玻璃微流控芯片电泳快速分离血清高密度脂蛋白亚类及临床应用研究

经梯度密度超速离心,高密度脂蛋白(HDL)分为HDL2和HDL3两亚型。HDL2抑制低密度脂蛋白(LDL)氧化功能受损是冠心病(CHD)发生发展的关键因素。因此,通过对HDL亚类进行分离,从而达到预测和诊断CHD的目的。本研究建立了用PDMS/玻璃微流控芯片快速电泳分离HDL亚类的方法。选择N-十二烷基-β-D-麦芽糖苷(DDM)、十二烷基硫酸钠(SDS)和羟丙基纤维素(HPC)共同修饰脂蛋白和泳道表面。在以含0.3 mmol/L SDS的50 mmol/L 3-(N-吗啉代)丙磺酸(MOPS)(pH 8.0)为样品缓冲液,含0.6%HPC的50 mmol/L MOPS(pH 8.0)为分离缓冲液,分离电压为260 V/cm的优化条件下,HDL2和HDL3在4 min内得到基线分离,二者的出峰时间和峰面积的相对标准差(RSD)分别是2.0%和2.7%,2.0%和2.9%,具有较好的重复性。临床标本研究发现,正常人血清标本可分离出HDL2和HDL3双峰,而CHD患者的HDL2峰面积显著减小,甚至消失。PDMS/玻璃微流控芯片分离HDL亚类是一种简单、快速、高效的用于分析CHD危险因子的方法。     

SYNTHESIS AND FLUORESCENCE STUDY OF SELF—AGGREGATION PROCESS IN AQUEOUS SOLUTION OF HYDROPHOBILIZED POLYSACCHARIDE

Cholesterol modified dextran(CHD) having self-aggrgation or self-assembly property was synthesized from cholesterol and 1,6-hexyldiisocyanate.The degree of substitution of cholesteryl moiety in dextran main line is 3-5 cholesterols the 100 glucose units.We have prepared water solution of CHD using probe type sonifier and N-Phenyl-a-naphthylamine(PNA) as a fluorescent probe to study CHD self-aggregate process.For each solution of two samples,we found that the maximum emission of PNA in CHD concentration.This change corresponds to the formation of micelle-like clusters self-aggregated by the cholesterol moiety once the CHD concentration.This change corresponds to the formation of micelle-like clusters self-aggregated by the cholesterol moiety once the CHD concentration exceeds 0.01mg/ml.     

Lipoproteins modulate growth and differentiation of cultured human epidermal keratinocytes

The effects of various lipoproteins on the growth and the differentiation of cultured normal human keratinocytes were investigated. Primary cultures of human epidermal keratinocytes were obtained from neonatal foreskin, and then added with lipoproteins, very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL). Cell growth potential was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. VLDL and LDL enhanced keratinocytes growth and LDL receptor expression at the plasma membrane level. These effects were more remarkably observed in cells cultured with VLDL than in cells cultured with LDL. Apolipoprotein E (ApoE) was highly increased in VLDL treated cells. These results suggest that VLDL binds with high affinity to cell surface receptors and induces cell proliferation.     

Softness of atherogenic lipoproteins: a comparison of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) using elastic incoherent neutron scattering (EINS)

Apolipoprotein B100 (apoB100)-containing plasma lipoproteins (LDL and VLDL) supply tissues and cells with cholesterol and fat. During lipolytic conversion from VLDL to LDL the size and chemical composition of the particles change, but the apoB100 molecule remains bound to the lipids and regulates the receptor mediated uptake. The molecular physical parameters which control lipoprotein remodeling and enable particle stabilization by apoB100 are largely unknown. Here, we have compared the molecular dynamics and elasticities of VLDL and LDL derived by elastic neutron scattering temperature scans. We have determined thermal motions, dynamical transitions, and molecular fluctuations, which reflect the temperature-dependent motional coupling between lipid and protein. Our results revealed that lipoprotein particles are extremely soft and flexible. We found substantial differences in the molecular resiliences of lipoproteins, especially at higher temperatures. These discrepancies not only can be explained in terms of lipid composition and mobility but also suggest that apoB100 displays different dynamics dependent on the lipoprotein it is bound to. Hence, we suppose that the inherent conformational flexibility of apoB100 permits particle stabilization upon lipid exchange, whereas the dynamic coupling between protein and lipids might be a key determinant for lipoprotein conversion and atherogenicity.     

磺化羟乙基化交联壳聚糖对血清中低密度脂蛋白的吸附性能研究

磺化羟乙基化，交联壳聚糖，低密度脂蛋白，高密度脂蛋白，总蛋白，高脂蛋白血症     

Comparative analysis of foetal calf and human low density lipoprotein: relevance for pharmacodynamics of photosensitizers

The effects of differences in lipoprotein content on the distribution of the novel hydrophobic photosensitizer n-butyl-3-[18-(2-butylcarbamoyl-ethyl)-3,7,12,17-tetramethyl-18,13-divinyl-22,24-dihydro-porphin-2-yl]propionamide (PP-N-3) and haematoporphyrin ester (HpE), a relatively hydrophilic photosensitizer, in human (HS) and foetal calf sera (FCS), were investigated. The binding characteristics of human and foetal calf low-density lipoprotein (LDL) were characterised using a human fibroblast line (Vag 12). The uptake into cells of HpE and PP-N-3 was also examined. A comparison of the lipoprotein content, composition and receptor-binding characteristics of foetal calf and human serum was also carried out. LDL content was measured directly using sequential ultracentrifugation to isolate LDL. In our study, we found haematoporphyrin ester to bind to human very low-density lipoprotein (VLDL), LDL and high-density lipoprotein (HDL) in the ratio 2:31:65. In the case of PP-N-3 this ratio was 56:10:33. As VLDL was not detected in foetal calf serum, only binding to LDL and HDL was observed. Using the sequential ultracentrifugation technique, foetal calf serum was found to contain LDL which in turn did bind to human LDL receptors. The uptake of PP-N-3 and HpE in the presence of low density lipoprotein from foetal calf serum (FC-LDL) was not significantly different to values observed in the presence of human serum low density lipoprotein (HS-LDL).     

Comparison of gel permeation chromatography, density gradient ultracentrifugation and precipitation methods for quantitation of very-low-, low- and high-density lipoprotein cholesterol.

Human VLDL, LDL and HDL (very-low-, low-, and high-density lipoproteins) were isolated from plasma by gel permeation chromatography with one pre-ultracentrifugation step. The column effluent was monitored at 280 nm. The cholesterol content of the fractions correlated well with fractions from sequential ultracentrifugation (VLDL, r = 0.839; LDL, r = 0.924; HDL, r = 0.766) or precipitation (LDL, r = 0.975; HDL, r = 0.972) methods. The average triglyceride, phospholipid and protein compositions of the separated lipoprotein fractions were close to those of the ultracentrifugally isolated fractions reported previously. Apolipoproteins A1 and B were determined from fractions to confirm the right distribution between different lipoproteins.     

新型低密度脂蛋白吸附剂的合成及吸附性能研究

通过在交联聚乙烯醇水凝胶上固载牛磺酸合成了新型低密度脂蛋白吸附剂,体外吸附结果表明,该类吸附剂对低密度脂蛋白的吸附选择性与吸附率不仅与交联聚乙烯醇载体本身的交联度和牛磺酸的固载量有关,而且还受到不同病人血清及吸附剂的颗粒直径等因素的影响．该类吸附剂对血清总蛋白的影响较小．     

A heparin modified polypropylene non‐woven fabric membrane adsorbent for selective removal of low density lipoprotein from plasma

In the present work, a new porous low density lipoprotein (LDL) adsorbent membrane is prepared by ⁶⁰Co γ‐ray irradiation‐induced grafting copolymerization of polypropylene (PP) non‐woven fabric with acrylic acid, followed by immobilizing heparin covalently. The amount of carboxyl group and heparin on the resultant PP non‐woven fabric is determined by titration and colorimetry, respectively. The new adsorbent membrane is characterized by attenuated total reflection Fourier transform infrared spectroscopy, scanning electron microscope, and contact angle microscopy. Static adsorption and hemoperfusion tests indicate this new adsorbent can efficiently and selectively remove LDL from human plasma. Meanwhile, good adsorption of triglyceride (TG) is also obtained. The best result is achieved by the adsorbent membrane P_0.45‐A₁₅‐H, where 33.3 ± 2.9 µg of LDL‐C, 14.7 ± 1.9 µg of high density lipoprotein cholesterol (HDL‐C), 64.9 ± 4.3 µg of total cholesterol (TC), and 202.4 ± 5.7 µg of TG are removed from human plasma per square centimeter. Hemocompability and toxicity tests show this new adsorbent membrane has good blood compatibility and low toxicity. Considering the adsorbent performance, safety, low cost, and simple preparation, this new adsorbent membrane has potential clinical application for removal of LDL. Copyright © 2013 John Wiley & Sons, Ltd.