含DNA配体的VT吸附剂结构及其血液相容性研究

 本文以异氰尿酸三烯丙酯 TAIC)为交联剂,醋酸乙烯酯(VAC)为单体合成的共聚物(VT),经皂化和活化后,固载上DNA,即得含DNA配体的VT吸附剂。测定了各产物的物理性能,表面形态,红外光谱和血液相容性。实验结果表明:聚合物具有较大平均孔径,皂化后亲水性增强,随活化而使比表面积增大,孔分布趋于均匀,固载DNA的能力高,致使最后产物表面DNA覆盖致密程度高,考察其血液相容性良好,对血小板粘附率约为10％,对白细胞无破坏,每克吸附剂清除抗-DNA蛋白2小时可达60％以上。     

一种新型低密度脂蛋白吸附剂的制备

研究表明,人体血浆中低密度脂蛋白(LDL)的含量过高会引起动脉硬化,进而诱发各种心脑血管疾病^[1].近年来,采用血液净化吸附剂去除LDL受到了广泛的关注^[2～10].目前临床上使用的吸附剂主要有固载LDL抗体的琼脂糖吸附剂及固载肝素或磺化葡聚糖的纤维素吸附剂,它们虽有较好的吸附效果,但由于存在配基昂贵、吸附剂成本高及机械强度差等问题,这些吸附剂的应用受到了很大的限制.本文以具有良好机械强度和血液相容性的聚乙烯醇(PVA)大孔珠状树脂为载体,以廉价易得的吲哚-3-乙酸(IAA)为配基,分别以不同长度的多胺为悬臂,制备了一种新型LDL吸附剂,并初步考察了其对LDL的吸附性能.     

用DNA-球形碳化聚合物吸附剂由血液灌流除去哺乳动物血中DNA抗体及其免疫复合物

DNA与兰四唑阳离子络合后与火棉胶混合最后吸附在大分子球形碳化聚合物吸附剂上,DNA固定的百分率是98-98.5％,它被应用到动物血液灌流能特异除去注入的DNA抗体及免疫复合物,功效在75％以上,而引起的非特异吸附仅低于10％,它有好的稳定性和血相容性,因此,它可能应用到临床治疗SLE上。     

ssDNA-碳化树脂类风显关H免疫吸附剂性能研究

研究了以火棉胶作为包埋材料将DNA配基固定于碳化树脂表面制备的类风湿关节炎免疫吸附剂的吸附性能,静态吸附条件下,当ssDNA的固定量在0.4mg/mL树脂时吸附性能最佳,对3种类风湿因子(RF)的最佳饱和吸附量分别为IgMRF:2458IU/mL、IgGRF:2877IU/mL、IgARF:1100IU/mL.吸附120分钟后达到吸附平衡,对血浆中白蛋白及总蛋白的清除率分别低于8%和6%,表现出较好的吸附选择性.吸附剂经毒理实验证明,使用安全性较高.对活犬进行体外血液灌流实验表明该吸附剂具有良好的血液相容性.     

球形纤维素固定化DNA制备免疫吸附剂

以球形纤维素为载体,经环氧氯丙烷活化后共价键联小牛胸腺DNA,制备DNA免疫吸附剂,通过血液灌流能够治疗系统性红斑狼疮.对病人血清的吸附实验结果表明,每毫升吸附剂与3mL病人血清混合,于37℃保温1 h,可吸附除去40%～70%致病抗体     

磁性珠状纤维素亲和吸附剂的制备与应用

采用反相悬浮包埋技术制备了粒径小于300um、粒径分布窄和湿态孔度高(85%～90%)的高顺磁性珠状纤维素,经高碘酸钠活化后,与具有生物活性的绒毛膜促性腺激素偶联,得磁性亲和吸附剂(每克磁性珠状纤维素上固载300～400IU绒毛膜促性腺激素).     

以聚乙烯基咪唑为配基的内毒素亲和吸附剂的研究

通过乙烯基咪唑(VI)在硅胶粒子表面的自由基接枝聚合制备了一种以聚乙烯基咪唑为配基的新型内毒素亲和吸附剂. 用FTIR检测样品中咪唑基的特征吸收, 用热重分析法(TGA)测定了PVI的接枝率. 实验发现, PVI在吸附剂中的含量对内毒素的吸附率影响很大. 当PVI的接枝率为2.5％左右时, 吸附剂对内毒素的去除率最大. 在离子强度小于1 mol/L和pH=7的中性条件下, PVI吸附剂对内毒素具有最佳的吸附性能. 该吸附剂具有良好的血液相容性. 内毒素在该亲和吸附剂上的吸附等温线符合Freundlich吸附方程, 其吸附动力学为二级反应.     

VT共聚物上DNA的固定化研究

本文采用醋酸乙烯醋(VAC)／异氰尿酸三烯丙酯(TALC)交联共聚物为载体。经环氧载丙烷活化处理使DNA键合到载体表面。讨论了DNA的固定化方法和条件以及DNA在共聚物表面的形态变化，结构特征和热稳定性，同时对其吸附特异性和吸附功效作了初步检测。     

乳化液膜清除未结合胆红素

高未结合胆红素症 (Ｈｙｐｅｒｂｉｌｉｒｕｂｉｎｅｍｉａ)是新生儿常见疾病 .胆红素在血液中的浓度过高 ,会伤害婴儿的大脑 (核黄疸 ) [1].肝昏迷患者的症状与胆红素在血液中含量过高也有直接关系 ,迅速有效地将其清除可使患者症状缓解[2 ],迄今为止 ,清除胆红素的研究主要集中在以吸附剂吸附为基础的血液灌流方法 ,所用的吸附剂主要有活性炭和大孔吸附树脂 ,活性炭的吸附选择性和血液相容性都比较差 ;大孔吸附树脂的吸附选择性和血液相容性等方面有待进一步提高[3],特别是在吸附未结合胆红素时 ,清除率低、清除速度慢 ,难以满足临床方面…     

基于多巴胺自聚合及肝素固定改善钛的血液相容性

利用多巴胺自聚合及肝素固定的方法对纯钛进行表面修饰, 以改善其血液相容性. 采用水接触角测量、 X射线光电子能谱(XPS)和甲苯胺蓝法(TBO)等方法对所修饰的材料进行了表征. 采用溶血实验检测了材料的溶血性能, 并结合活化部分凝血活酶时间(APTT)测试和血小板黏附实验对所修饰材料的血液相容性进行了评价. 结果表明, 多巴胺能够在钛表面实现自聚合, 肝素可以共价接枝在聚多巴胺层上, 经肝素修饰后的材料的表面亲水性显著提高, 而且具有较低的溶血率, APTT时间显著延长, 血小板的黏附数量和被激活程度也显著降低. 因此, 纯钛经多巴胺自聚合以及肝素接枝修饰后的血液相容性得到了显著改善, 有望成为具有抗凝血功能的新型心血管植入材料.     

以壳聚糖为载体的内毒素吸附剂

内毒素血症(Endotoxemia)可出现于多种疾病过程中,导致器官坏死、不可逆休克和死亡。如何及时并有效地清除患者体内的内毒素,是临床医学面临的一个难题．选用高效吸附剂,籍助血液灌流的方法从血液中直接清除内毒素,受到了人们越来越多的关注。     

Removal of lead from aqueous solutions using Cassia grandis seed gum-graft-poly(methylmethacrylate)

Using persulfate/ascorbic acid redox system, a series of Cassia grandis seed gum-graft-poly(methylmethacrylate) samples were synthesized. The copolymer samples were evaluated for lead(II) removal from the aqueous solutions where the sorption capacities were found proportional to the grafting extent. The conditions for the sorption were optimized using copolymer sample of highest percent grafting. The sorption was found pH and concentration dependent, pH 2.0 being the optimum value. Adsorption of lead by the grafted seed gum followed a pseudo-second-order kinetics with a rate constant of 4.64 x 10(-5) g/mg/min. The equilibrium data followed the Langmuir isotherm model with maximum sorption capacity of 126.58 mg/g. The influence of electrolytes NaCl, Na(2)SO(4) on lead uptake was also studied. Desorption with 2 N HCl could elute 76% of the lead ions from the lead-loaded copolymer. The regeneration experiments revealed that the copolymer could be successfully reused for at least four cycles though there was a successive loss in lead sorption capacity with every cycle. The adsorbent was also evaluated for Pb(II) removal from battery waste-water containing 2166 mg/L Pb(II). From 1000 times diluted waste water, 86.1% Pb(II) could be removed using 0.05 g/20 ml adsorbent dose, while 0.5 g/20 ml adsorbent dose was capable of removing 60.29% Pb from 10 times diluted waste water. Optimum Pb(II) binding under highly acidic conditions indicated that there was a significant contribution of nonelectrostatic interactions in the adsorption process. A possible mechanism for the adsorption has been discussed.     

Selective removal of DNA from protein solution with copolymer particles derived from N,N-dimethylaminopropylacrylamide

To remove nucleic acids from cellular products as drugs, cross-linked N,N-dimethylaminopropylacrylamide (DMP) particles with cationic functional groups were prepared. The particle's hydrophobicity and its anion-exchange capacity were easily adjusted by changing the cross-linking agent and the DMP ratio in the cross-linking, respectively. When divinylbenzene (DVB) was used as a cross-linking agent and the DMP ratio (in the cross-linking) was adjusted to 90 mol%, the particles (DMP-DVB, 90:10) showed the highest adsorbing activity of DNA (salmon spermary). Its adsorption capacity was 54 mg/ml adsorbent. On the other hand, the adsorption of bovine serum albumin (BSA) to the DMP-DVB extremely increased with increase in the adsorbent's pore size (molecular mass exclusions; M(lim)) from 2 x 10(3) to 1 x 10(4), but decreased with increase in the buffer's ionic strength (mu) to 0.2 or stronger. As a result, when the DMP-DVB (80:20) with M(lim) 2 x 10(3) was used as adsorbent by a column method at pH, 7.2 and mu = 0.17, it only selectively removed DNA from a BSA solution, including 1000 microg/ml of BSA and 10 microg/ml of DNA. The adsorbent decreased the concentration of DNA in the BSA solution to < 10 ng/ml, and the recovery rate of BSA was more 98%.     

含有二个聚醚软链段的聚醚聚酯嵌段共聚物的合成及其血液相容性的研究

本文报道了一类新的具有二种聚醚软链段(PTMGT和PEGT)和一种聚酯硬链段(PET)的混合聚醚-聚酯嵌段共聚物(MPEE)的合成和它的血液相容性,并与具有相同软、硬链段比及相同软链段组成比(PTMGT/PEGT)的二种聚醚聚酯嵌段共聚物(PTMGT-PET和PEGT-PET)的共混物(BPEE)的性质进行了比较,结果表明:(1)聚醚聚酯嵌段共聚物的血液相容性可以通过引入亲水性好的PEGT组分而得到提高;(2)在多数的组成比下,共聚型的MPEE具有比共混型的BPEE优良的血液相容性;(3)特定的组成比:PTMGT/PEGT=60/40(mol),共混型的BPEE:(60/40)呈现最好的血液相容性以及最佳的力学性质。研究中发现材料的微相分离结构同血液相容性有关,细微的相分离结构可导致优良的血液相容性。     

具有血液相容性的嵌段聚酯-聚醚接枝共聚物的合成

本文研究了嵌段聚酯-聚醚膜经紫外光活化后,于水溶液中铈盐引发亲水性单体丙烯酰胺在其表面上接枝共聚合反应。同时对接枝物进行了证实和表征。并通过活体动物血液灌流实验表明,此接枝共聚物具有良好的血液相容性。     

含有二个聚醚软链段的聚醚聚酯嵌段共聚物的合成及其血液相容性的研究

 本文报道了一类新的具有二种聚醚软链段(PTMGT和PEGT)和一种聚酯硬链段(PET)的混合聚醚-聚酯嵌段共聚物(MPEE)的合成和它的血液相容性,并与具有相同软、硬链段比及相同软链段组成比(PTMGT/PEGT)的二种聚醚聚酯嵌段共聚物(PTMGT-PET和PEGT-PET)的共混物(BPEE)的性质进行了比较,结果表明:(1)聚醚聚酯嵌段共聚物的血液相容性可以通过引入亲水性好的PEGT组分而得到提高;(2)在多数的组成比下,共聚型的MPEE具有比共混型的BPEE优良的血液相容性;(3)特定的组成比:PTMGT/PEGT=60/40(mol),共混型的BPEE:(60/40)呈现最好的血液相容性以及最佳的力学性质。研究中发现材料的微相分离结构同血液相容性有关,细微的相分离结构可导致优良的血液相容性。     

Mixed Polyether-Polyester Multiblock Copolymer and its Blood Compatibility

A new type of polyether-polyester block copolymer (MPEE) consisting of two components of polyethers (PTMGT and PEGT) as soft segment and one polyester (PET) as hard segment has been synthesized. It has also been investigated in comparison with blended polyether-polyester block copolymer (BPEE) consisting of the same composition ratio of hard and soft segments and both of the two polyethers (PTMG and PEG). It was found that 1) Improvement of blood compatibility of polyether-polyester block copolymer can be achieved by introducing the hydrophilic component PEG into it; 2) generally the blood compatibility of MPEE is better than that of BPEE; 3) at a specific molar ratio of PTMGT-PET to PEGT-PET (60/40), the blended copolymer (BPEE 60/40) shows the best blood compatibility, as well as the best mechanical properties. This might be related to smaller-size microphaseseparated structures. The relationship between blood compatibility and structure of the copolymer is discussed. Polyether-polyester block copolymer containing hydrophilic and hydrophobic components might be a useful material with antithrombogenicity.     

以赖氨酸为配基的内毒素吸附剂的研究

内毒素血症可出现于多种疾病中,如大面积烧伤、重症肝炎、肝硬化等疾病,使机体免疫功能严重受损,引起多器官功能衰竭等一系列严重的病理变化,最终导致不可逆休克和死亡,在美国每年都有超过10万人死于此病,临床上尚无有效的治疗方法,因此,及时、有效地清除或破坏患者体内的内毒素,     

Effect of porosity on sulfonation of macroporous styrene-divinylbenzene beads

Macroporous styrene-divinylbenzene beads having pore volume in the range of 0.1-2.2 ml/g were synthesized by o/w suspension polymerization using petroleum ether and cyclohexanone as porogen. As the pore volume was increased the pore size distribution shifted towards large pore diameter and the mechanical strength of the beads in the dry state decreased. The copolymers were converted into cation-exchange resins by sulfonation under controlled experimental conditions. The derived resins had the highest capacity when the base copolymers had pore volume in the range of 0.3-0.4 ml/g. The results are explained on the basis of the effect of the porogen on the spaces between chains and cross-links in the copolymer phase and the permanent pores in the beads.