聚氨酯表面构建磺胺两性离子结构及其抗血小板粘附性的研究

通过己二异氰酸酯(HDI)在聚醚氨酯(PU)表面构建磺铵两性离子结构，以改善其不凝血性能。首先用HDI活化PU表面，生成PU—NCO衍生物；然后通过N，N—二甲基乙醇胺(DMEEA)中的-OH和PU表面的-NCO反应生成PU—N（CH3）2；最后用丙磺酸内酯(PS)进行开环。生成磺铵两性离子结构。用ATR—IR表征了各步反应，对构建前后材料的抗血小板粘附性能进行了比较，结果表明，磺铵两性离子结构具有优异的抗血小板粘附性。     

UV光引发表面接枝两性离子水凝胶层的制备及抗细菌黏附性能

采用聚合和交联的SiO₂有机/无机杂化溶胶作为基材, 通过与两性离子单体层之间的过渡层, 在紫外光作用下引发杂化溶胶和两性离子单体溶液中的双键反应, 使生成的杂化层在基材和表面的两性离子聚合物之间形成辅助性黏接作用, 从而在基材表面构筑两性离子水凝胶层. 通过傅里叶红外光谱(FTIR)、 原子力显微镜(AFM)和接触角测试等方法对所制备的两性离子水凝胶层和杂化层的表面进行了表征. 以空白玻璃片为对照样品, 以金黄色葡萄球菌和大肠杆菌为试验菌, 研究了用两性离子凝胶层修饰的玻璃表面的抗细菌黏附性能. 结果表明, 在SiO₂杂化过渡层中引入线型-Si-(CH₂)₂-O-链段可有效提高杂化过渡层对基材的附着力, 并改善其柔韧性. 与对照样品相比, 用两性离子凝胶层修饰的玻璃表面具有优异的抗菌黏附性能.     

聚苯乙烯共价键合磷铵两性离子的结构修饰及血液相容性

利用形成碳-氧键将磷铵两性离子(1)共价键合到聚苯乙烯(PS)材料表面, 改善其抗凝血性能. 首先对PS进行氯甲基化反应, 生成苄氯结构, 然后通过自合成化合物1中的-OH与氯甲基化聚苯乙烯的-CH₂Cl反应形成醚键, 将两性离子接枝在PS上. 表征了产物结构, 并通过水接触角和血小板黏附实验对结构修饰前后材料的亲水性和抗凝血性能进行了比较. 结果表明, 磷铵两性离子结构修饰的聚苯乙烯材料可以有效地提高其血液相容性.     

含羟基的2-烷氧基-2-氧代-1,3,2-二氧磷杂环戊烷及其磷酰胆碱系列的合成与表征

不凝血生物材料(Nonthrombogenic Biomaterials)是生物医学材料R/D的核心内容之一[1～3]. 不凝血生物材料在分子设计与合成上必须解决两个基本问题: 一是不凝血分子结构的设计与合成; 二是不凝血分子结构在生物材料表面构建的分子设计与合成. 根据"维持正常构象"学说, 聚乙二醇链结构及两性离子, 如磺-铵, 磷-铵及羧-铵等结构应具有较好的不凝血性[2～4]. 磷-铵两性离子结构的代表之一是磷酰胆碱结构. Ishihara等[5]从模拟细胞膜表面分子结构的角度出发, 最早设计并合成了2-甲基丙烯酰氧基乙基磷酰胆碱(MPC). MPC和其它单体的共聚物与一般生物材料相比, 其抗血小板的粘附性有很大的提高, 但其力学性能欠佳[6～9]. 因此, 应将其构建在力学性能优异的生物材料(如聚醚氨酯)的表面上. 为此, 设计与合成含有羟基等适当官能团的磷酰胆碱便是关键. 有关这类磷酰胆碱尚未见文献报道. 本文报道这类新的含羟基磷酰胆碱系列及其前体的合成与表征. 合成路线如下:     

聚砜共价键合磷铵两性离子的结构修饰及其血液相容性的研究

利用形成碳-氧键将磷铵两性离子(1)共价键合到聚砜(PSF)材料表面,改善其抗凝血性能.首先对聚砜(PSF)进行氯甲基化反应,生成苄氯结构,然后通过自合成两性离子化合物1中的—OH与氯甲基化聚砜的—CH2Cl反应形成醚键,将两性离子结构接枝在PSF上.用ATR-FTIR、EA和1H-NMR表征了产物结构,并通过水接触角、溶血实验和血小板黏附实验对结构修饰前后材料的亲水性和抗凝血性能进行了比较.改性PSF材料的表面亲水性提高,几种改性PSF材料的溶血率均低于5%,PSF-18.1%1材料的表面几乎没有血小板黏附.结果表明,磷铵两性离子结构修饰的聚砜材料可以显著提高其血液相容性,在血液相容性材料等领域具有潜在的应用价值.     

SiO2纳米管的合成及表面功能修饰研究

在氨水的负催化作用下, 用酒石酸氢铵作模板剂, 原硅酸四乙酯(TEOS)经水解、缩聚, 生成SiO₂纳米管. 利用硅烷偶联剂KH-570对SiO₂纳米管进行表面修饰, 将乙烯基(-CH＝CH₂)引入SiO₂纳米管表面, 改善其表面功能性. 通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和傅立叶红外(FT-IR)等分析测试手段研究了SiO₂纳米管的形貌结构及其表面修饰性能. 结果表明: 溶液的pH值是影响SiO₂纳米管形貌的最主要因素, 最合适的酸碱度是4.5≤pH≤5.0; 纳米管平均外径300 nm, 内径100 nm, 长度10 µm以上, 管径均匀, 管壁表面光滑平坦, 没有出现裂纹等缺陷, 为无定形结构. KH-570功能修饰前后的纳米管形貌没有发生任何变化.     

血液相容生医材料的合成研究15——苯乙烯型磺酸铵内盐单体的合成及其聚合物的抗血小板粘附性能

两性离子不凝血生物材料;血液相容生医材料的合成研究15——苯乙烯型磺酸铵内盐单体的合成及其聚合物的抗血小板粘附性能     

原位共沉淀法制备Ni-Mg-Al-LDHs/γ-Al2O3催化前驱体在甲烷二氧化碳重整反应体系中的性能评价

通过原位共沉淀的方法在γ-Al₂O₃表面上合成了Ni-Mg-Al-LDHs (水滑石), 合成的Ni-Mg-Al-LDHs/γ-Al₂O₃作为催化前驱体经过不同的热处理还原方式得到催化剂Cat-1、Cat-2和Cat-3. 用X射线衍射(XRD)、透射电镜(TEM)、N₂吸附-脱附测试(BET)以及热重-差热分析(TG-DTA)对催化剂的形貌结构和抗积碳能力进行了表征测试; 通过甲烷二氧化碳重整反应体系对催化剂的反应活性和稳定性进行了评价. 结果表明催化剂前驱体的预处理方式对催化剂的反应性能具有较大的影响. Ni-Mg-Al-LDHs/γ-Al₂O₃ 直接经过H2/Ar 常压高频冷等离子体炬的分解还原所获得的催化剂Cat-3 表现出了最佳的催化活性和稳定性. TEM表征表明催化活性组分在Cat-3上的分散性更好, 颗粒粒径更小. BET结果证明Cat-3具备较大的比表面积(195.8 m²·g^-1). Ni-Mg-Al 水滑石的结构赋予了催化剂活性组分在载体γ-Al₂O₃上均匀的分散性, 同时常压高频冷等离体炬对催化剂的表面结构以及活性组分的还原具有进一步的优化作用, 两者的协同作用使Ni-Mg-Al-LDHs/γ-Al₂O₃在甲烷二氧化碳反应体系中具备优良的催化活性和抗积碳性能.     

Ni2P/Cu(OH)2催化剂的制备及其全解水性能研究

通过化学处理法在泡沫铜基底表面生成Cu(OH)₂纳米线,大大增加了基底材料的表面积和导电性.采用水热法在Cu(OH)₂纳米线表面制备片状Ni-CH/Cu(OH)₂前驱体,对Ni-CH/Cu(OH)₂前驱体进行低温磷化得到多级结构Ni₂P/Cu(OH)₂催化剂.通过扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)和X射线衍射仪(XRD)对催化剂的物质结构和表面形貌进行了表征.采用线性伏安法、恒电位等技术对催化剂的电化学性能进行测试.在1.0 mol·L^-1 KOH碱性溶液中,当电流密度为10 mA·cm^-2时,Ni₂P/Cu(OH)₂的析氢反应(HER)和析氧反应(OER)过电位分别为133和333 mV,且均具有较好的稳定性.将这种多级结构Ni₂P/Cu(OH)₂催化剂分别用作阳极和阴极进行全解水电解,电流密度达到10 ...     

磺化纤维素纳米纤维多孔膜支撑的高通量纳滤膜的制备及脱盐性能

以细菌纤维素为原材料, 先后通过NaIO₄和NaHSO₃氧化还原反应制备了表面部分磺酸化的细菌纤维素(SBC)纳米纤维. 利用SBC纳米纤维多孔膜替代传统的超滤膜作为支撑底膜, 结合界面聚合反应调控制得复合纳滤膜, 并对其纳滤性能进行研究. 结果表明, 制备得到了对Na₂SO₄和MgSO₄具有高截留率(>96%)和超高分离通量(>320 L·m ^-2·h ^-1·MPa ^-1)的新型纳滤膜.     

GRAFTING OF SULFOBETAINE ONTO A POLYURETHANE SURFACE TO IMPROVE BLOOD COMPATIBILITY

On the molecular level, it is believed that polymers containing zwitterionic structures should be compatible withblood. In this work polyurethane films were grafted with sulfobetaine by a three-step procedure. In the first step, the films'surfaces were treated with hexamethylene diisocyanate (HDI) in toluene at 50℃ in the presence of di-n-butyl tin dilaurate(DBTDL) as a catalyst. The extent of the reaction was monitored by ATR-IR spectra; a maximum number of free NCOgroups was obtained after a reaction time of 90 min. In the second step, the hydroxyl groups of N,N-dimethylethylethanolamine (DMEA) were allowed to react in toluene with NCO groups bound on the surface. In the thirdstep, sulfobetaines were formed on the surface through the ring-opening reaction between tertiary amine of DMEA and 1,3-propanesultone (PS). The surfaces of the films were characterized by ATR-IR and XPS showing that the grafted surfaceswere composed of sulfobetaine. The results of the contact angle measurement show that the surface was strongly hydrophilic.The platelet adhesion test demonstrated that the films grafted with sulfobetaine have excellent blood compatibility.     

Platelet adhesive resistance of polyurethane surface grafted with zwitterions of sulfobetaine

A possible approach to improve the blood compatibility of poly(etherurethane)s (PU) involves the covalent attachment of key molecular on its surface. Recently, polymer tailed with zwitterions was found having good blood compatibility. The purpose of present study was to design and synthesis a novel nonthrombogenic biomaterial by modifying the surface of poly(etherurethane) with zwitterions of sulfobetaine via HDI spacer. The films of polyurethane were grafted with sulfobetaine by a three-step procedure. In the first step, the film surfaces were treated with hexamethylene diisocyanate (HDI) in toluene at 50 degrees C in the presence of di-n-butyl tin dilaurate(DBTDL) as a catalyst. The extent of the reaction was measured by ATR-IR spectra; a maximum number of free NCO group was obtained after a reaction time of 2.5 h. In the second step, the primary amine group of N,N-diethylethylenediamine (DEA) or N,N-dimethylethylenediamine (DMA) was allowed to react in toluene with isocyanate groups bound on surface. In the third step, two kinds of sulfobetaines were formed in the surface through the ring-opening reaction between tertiary amine of DMA or DEA and 1,3- propanesultone (PS). The reaction process was monitored with ATR-IR spectra and XPS spectra. The wettability of films was investigated by water contact angle measurement. A platelet adhesion experiment was conducted as a preliminary test to confirm the improved blood compatibility of PU. The number of platelets adhering to PU decreased greatly compared to original after 1 h and 3 h of contact with human plate-rich plasma.     

Blood compatibility of polyurethane surface grafted copolymerization with sulfobetaine monomer

Surface modification is an effective way to improve the hemocompatibility and remain bulk properties of biomaterials. Recently, polymer tailed with zwitterions was found having good blood compatibility. In this study, the grafting copolymerization of sulfobetaine onto polyurethane surface was obtained through two steps. In the first step, polyurethane film coupled with vinyl groups was obtained through the reaction between the carboxyl group of acrylic acid (AA) and the NH-urethane group of polyurethane by dicyclohexylcarbodiimide (DCC). In the second step, sulfobetaine was grafted copolymerization on the surface using AIBN as an initiator. The reaction process was monitored with ATR-IR spectra and X-ray photoelectron spectroscopy (XPS) spectra. The wettability of films was investigated by water contact angle measurement. The blood compatibility of the grafted films was evaluated by platelet adhesion in platelet rich plasma (PRP) and protein absorption in bovine fibrinogen (BFG). Low platelet adhesion was observed on the grafted films incubated in PRP for 1 and 3 h, respectively. The protein absorption was reduced on the grafted films after incubated in bovine fibrinogen for 2 h. All of these results revealed that the improved blood compatibility was obtained by grafting copolymerization with zwitterionic monomer of sulfobetaine onto polyurethane film. In addition, introducing vinyl groups onto surface through DCC and AA is a novel method to functionalize polyurethane for further modification.     

Chemical graft polymerization of sulfobetaine monomer on polyurethane surface for reduction in platelet adhesion

Surface modification is an effective way to improve the hemocompatibility and remain bulk properties of biomaterials. Recently, polymer tailored with zwitterions was found having good blood compatibility. In this study, the zwitterionic monomer of sulfobetaine was graft polymerized onto polyurethane (PU) surface in a three-step heterogenous system through the vinyl bonds of acrylic acid (AA) or hydroxyethyl methacrylate (HEMA), which was immobilized with hexamethylene diisocyanate (HDI) beforehand. First, PU was activated with isocyanate groups using HDI as coupling agent. Second, AA or HEMA was introduced through reaction of AA or HEMA with NCO groups bonded on PU surface. Last, zwitterionic monomer of sulfobetain was graft polymerized with vinyl group of AA or HEMA using AIBN as polymerization initiator. The reaction process was monitored with ATR-IR spectra and XPS spectra. Variation of graft yield with temperature and monomer feed concentration was investigated and feasible conditions were optimized. The wettability of films was investigated by water contact angle measurement and water absorbance. Platelet adhesion experiment was conducted as a preliminary test to confirm the improved blood compatibility of PU. The number of platelets adhering to PU decreased greatly comparing with the originals after 1 and 3 h of contact with human plate-rich plasma (PRP).     

结构可切换型聚合物刷的构建及表面性能

合成了结构可切换型甲基丙烯酸酯季铵盐(CBMA-1C2). 在聚丙烯(PP)片基表面光接枝构建CBMA-1C2聚合物刷, 其在碱性水溶液中可水解形成两性离子聚合物刷PCBMA. 用蛋白质吸附及血小板黏附实验评价改性表面亲/疏水性及表面电荷对生物分子与材料表面之间相互作用的影响. 结果发现, 与未改性PP片基相比, 聚合物PCBMA-1C2改性表面水解前后均具有优异的亲水性能, 由于聚合物PCBMA-1C2水解前后表面电荷不同, 对生物分子与改性PP表面的相互作用表现出明显差异. 亲水性好、 两性离子结构的聚合物PCBMA表面表现出对蛋白吸附和血小板黏附的良好抑制作用.     

D-penicillamine adsorption on gold: an in situ ATR-IR spectroscopic and QCM study

The adsorption of penicillamine from ethanol on gold was studied in situ by attenuated total reflection infrared (ATR-IR) and quartz crystal microbalance (QCM) experiments. Both ATR-IR and QCM reveal a fast mass uptake. In ethanol, the molecule adopts a zwitterionic form. Upon adsorption, part of the molecules deprotonate at the amine group, which is a relatively slow process that goes along with a strong shift of the nu(as)(COO(-)) mode. Both ATR-IR and QCM confirm a physisorbed layer. ATR-IR furthermore shows that the latter consists of zwitterionic molecules only, whereas both zwitterionic and anionic species are found in the chemisorbed layer. The infrared spectra of the physisorbed and chemisorbed layers are rather different, and the molecules within both layers seem to be oriented with respect to the surface. The ATR-IR spectra furthermore indicate that all three functional groups of penicillamine (i.e., thiol, carboxylate, and amine) interact with the surface, and density functional theory calculations support this finding. QCM also shows that the molecule uses considerably more space on the surface than molecules of similar size, which supports a three-point interaction. The latter leads to a strong anchoring of the molecule to the metal, which may explain the exceptional capability of penicillamine to bind metals.     

Surface modification of SPEU films by ozone induced graft copolymerization to improve hemocompatibility

Surface modification of segmented poly(ether urethane) (SPEU) by graft copolymerization with N,N′-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium (DMMSA), a zwitterionic sulfobetaine structure, was conducted. A simple two-step procedure for grafting of DMMSA onto the surface of SPEU film was used. The surface was first treated with ozone to introduce active hydroperoxide groups. The active surface was then exposed to the DMMSA solution in the sealed tube. Grafted SPEU film was characterized by ATR–FTIR, XPS and contact angle measurement. ATR–FTIR and XPS investigations confirmed the graft copolymerization. The monomer concentration, copolymerization temperature and time were varied to maximize the efficiency of DMMSA grafting. The equilibrium water content (EWC) and contact angle measurements showed that the hydrophilicity of the film had been greatly improved. The blood compatibility of the grafted films was evaluated by platelet adhesion in platelet rich plasma (PRP), deposits in blood control and protein adsorption in bovine fibrinogen using SPEU film as the control. No platelet adhesion and no thrombus were observed for the grafted films incubated in PRP for 300 min and in blood for 120 min, respectively. The protein adsorption was reduced on the grafted films after incubation in bovine fibrinogen for 120 min. These results proved that improved blood compatibility was obtained by grafting this new zwitterionic sulfobetaine structure monomer onto SPEU film.     

Formation, structure, and reactivity of amino-terminated organic films on silicon substrates

Amino-functionalized organic films were prepared by self-assembling 3-aminopropyltriethoxysilane (APTES) on silicon wafers in either anhydrous toluene or phosphate-buffered saline (PBS) for varied deposition times. Fourier transform infrared spectroscopy (FTIR) and ellipsometry have shown that the structure and thickness of APTES films are governed by the deposition time and reaction solution. Deposition from an anhydrous toluene solution produces APTES films ranging from 10 to 144 A in thickness, depending on the reaction time. FTIR spectra indicate that film growth initially proceeds by adsorption of APTES to the silicon surface followed by siloxane condensation, and after an extended period of time APTES molecules accumulate on the underlying APTES film by either covalent or noncovalent interactions. In contrast, spectroscopically indistinguishable APTES films in thickness ranging from 8 to 13 A were formed when deposition was conducted in aqueous solutions. Measured water contact angles indicate that APTES films deposited in aqueous solutions are more hydrophilic compared to those prepared in toluene solutions. Fluorescence measurements revealed that APTES films prepared in toluene solutions contain more reactive surface amino groups by ca. 3 to 10 times than those prepared in aqueous solutions for the identical reaction time.     

Structure of water incorporated in sulfobetaine polymer films as studied by ATR-FTIR

The structure and hydrogen bonding of water in the vicinity of a thin film of a sulfobetaine copolymer (poly[(N,N-dimethyl-N-(3-sulfopropyl)-3'-methacrylamidopropanaminium inner salt)-ran-(butyl methacrylate)], poly(SPB-r-BMA)), were analyzed with band shapes of O-H stretching of attenuated total reflection infrared (ATR-IR) spectra. The copolymer could be cast as a thin film, of approximate thickness 10 microm, on a ZnSe crystal for the ATR-IR spectroscopy. At an early stage of sorption of water into the polymer film, the O-H stretching band of the IR spectra for the water incorporated in the film was similar to that for free water. This is consistent with the tendency for another zwitterionic polymeric material, poly[(2-methacryloyloxyethylphosphorylcholine)-ran-(butyl methacrylate)] (poly(MPC-r-BMA). It is, however, contradictory to the drastic change in the O-H stretching band for water incorporated into films of polymers such as poly(2-hydroxyethyl methacrylate), poly(methyl methacrylate) and poly(butyl methacrylate). These results suggest that polymers with a zwitterionic structure do not significantly disturb the hydrogen bonding between water molecules incorporated in the thin films. The investigation into the blood-compatibility of both the poly(SPB-r-BMA) and the poly(MPC-r-BMA) films indicate a definite correlation between the blood-compatibility of the polymers and the lack of effect of the polymeric materials on the structure of the incorporated water.     

两性离子自组装仿生表面的制备、 表征及抗黏附性能

设计与合成了磺酸甜菜碱型的两性离子化合物: N,N-二甲基氨甲酸乙酯基丙基三乙氧基硅烷磺酸内盐(SiNNS), 利用红外光谱(FTIR)和氢核磁共振波谱(¹H NMR)对其分子组成与结构进行了表征. 通过自组装技术将SiNNS分子构筑在玻璃基材表面, 形成了模拟细胞外层膜的仿生表面. 利用原子力显微镜(AFM)、 X光电子能谱(XPS)和接触角测量仪对表面的形貌特征、 化学组成和润湿性进行了表征. 以空白玻璃为对照样品, 研究了这一表面的防雾性能和抗细菌黏附性能. 结果表明, 所制备的两性离子自组装仿生表面具有超亲水性和水下超疏油特性, 其水滴接触角为9.2°, 水下油滴接触角接近180°; 与对照样品相比, 两性离子自组装表面具有优异的防雾性与抗细菌黏附性.