血液相容材料的合成研究Ⅷ.磺铵两性离子单体在聚醚氨酯表面的臭氧活化接枝

生物相容性 ,特别是血液相容性是生物医用材料极其重要的性能[1] .提高不凝血性一直是生物材料研究与发展 (Ｒ Ｄ)的主要内容之一 ,半个多世纪来 ,不凝血材料的Ｒ Ｄ已取得了很大的发展[2 ] .但还不能满足心血管植入物 (Ｃａｒｄｉｏｖａｓｃｕｌａｒｉｍｐｌａｎｔｓ)及心血管医物 (Ｃａｒｄｉｏｖａｓｃｕｌａｒｄｅｖｉｃｅｓ)对不凝血性的需要 .Ｒａｔｎｅｒ[3 ] 在最近一次的血液相容性问题研讨会上再次强调了不凝血材料研究的紧迫性 .会议的报告也反映了该领域的研究现状 ,并提出了今后要研究的问题等 .目前不凝血性较好的材料仅有聚…     

PDMS微芯片吸附牛血清白蛋白的研究

材料表面的物理和化学性质对蛋白质的吸附具有很大的影响[1].对蛋白质吸附的研究是研制生物传感器、生物芯片和生物材料的基础.     

Synthesis and Crystal Structure of Cu2（pba）（bpy）2Cl2.4H2O

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｃｏｏｒｄｉｎａｔｉｏｎｃｈｅｍｉｓｔｒｙｏｆｍｕｌｔｉ ｓｕｂｓｔｉｔｕｔｅｄｏｘａｍｉｄｅｓｉｓｏｆｉｍｐｏｒｔａｎｃｅｔｏａｗｉｄｅｖａｒｉｅｔｙｏｆｃｈｅｍｉｃａｌ[1 ] ,ｂｉｏｌｏｇｉｃａｌ[1 ] ａｎｄａｐｐｌｉｅｄｓｙｓｔｅｍｓ[2 ,3] .Ｔｈｅｍａｇｎｅｔｉｃ[4,5]ａｎｄｓｐｅｃｔｒｏｓｃｏｐｉｃ[6 ,7] ｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｏｘａｍｉｄｅｃｏｍｐｌｅｘｅｓａｒｅｖｅｒｙｉｎｔｅｒｅｓｔｉｎｇ .Ａｌｏｔｏｆｍｏｎｏｎｕｃｌｅａｒａｎｄｂｉｍｅｔａｌｌ…     

聚合物材料表面纳米条纹对生物细胞生长的影响

20世纪 80年代后期 ,工程学科与生命学科的交叉融合产生了组织工程学 [1,2 ] ,细胞与生物材料之间的相互作用是组织工程学的一个主要领域 .细胞必须与材料发生适当的粘附 ,才能进行迁移、分化和增殖 ,细胞与材料粘附及随后的扩散能力的大小主要由材料表面的物理和化学性质所决定 [3,4 ] .目前 ,材料表面改性以提高细胞粘附力是组织工程学的一大难题 .聚苯乙烯 (PS)以其无毒、高透明度、低成本以及易加工等性能 ,被广泛应用于基础医学研究及临床医学实验 [5,6 ] .未改性 PS的生物相容性较差 ,只有表面改性后才能用于细胞培养 .目前文献报道…     

《化学通报》网络版(Chemistry Online)2001年11月论文摘要

[Ｗ 0 1 0 98]聚羟基酯与骨组织工程Ｐｏｌｙ(α ｈｙｄｒｏｘｙｅｓｔｅｒ)ａｎｄＢｏｎｅＴｉｓｓｕｅＥｎｇｉｎｅｅｒｉｎｇ毛津淑　姚康德 (天津大学材料科学与工程学院　天津　 30 0 0 72 )组织工程的发展 ,对作为人工细胞外基质 (ＥＣＭ)的生物材料提出了挑战。本文阐述了理想骨再生组织工程用生物可降解支架的研制要求 ,重点介绍了聚羟基酯类聚合物 ,作为生物可降解支架原材料的优缺点和加工方法 ,强调了在其表面进行相应的仿生修饰 ,从而实现人工ＥＣＭ智能化。因此 ,以聚乳酸类可降解生物材料为主要成分的 ,有利于成骨细胞粘附 …     

Surface Activities of Calix[4] resorcinarenes Bearing Four Hydrophobic Chains and Its Sol ubilization for Organic Compounds

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｃｌｕｓｉｏｎｃｏｍｐｏｕｎｄｓｈａｖｅｂｅｅｎｎｏｔｅｄｉｎｒｅｃｅｎｔｙｅａｒｓａｎｄｒｅｓｏｒｃｉｎｏｌ ｔｙｐｅｃａｌｉｘ [4 ]ａｒｅｎｅｈａｓｂｅｅｎｓｔｕｄｉｅｄｆｏｒｔｈｅｉｒｉｎｃｌｕｓｉｏｎａｂｉｌｉｔｉｅｓｂｙＳｃｈｅｉｄｅｒａｎｄＢｕｇｌｅｒｅｔａｌ[1— 3] .Ｔｈｅｐｏｌｙｏｌｍｏｉｅｔｉｅｓｉｎｃａｌｉｘ[4 ]ｒｅ ｓｏｒｃｉｎａｒｅｎｅｆｏｒｍｒｉｇｉｄｈｙｄｒｏｇｅｎ ｂｏｎｄｉｎｇｎｅｔｗｏｒｋｓ[4 ] ,ａｎｄｃａｌｉｘ [4 ]ｒｅｓｏｒｃｉｎａｒｅ…     

含偶氮苯生色团的环氧树脂型光动力高分子的合成

1995年 ,Ｎａｔａｎｓｏｈｎ等和Ｔｒｉｐａｔｈｙ等分别同时报道了在干涉的偏振激光照射下 ,聚合物膜表面分子可发生宏观质量迁移的现象[1 ,2 ] .这种现象一经发现就得到了科技界和工业部门的广泛关注 .利用此效应可以在聚合物表面形成表面起伏光栅 (Ｓｕｒｆａｃｅｒｅｌｉｅｆｇｒａｔｉｎｇｓ)等复杂结构 ,并可用热或光的方法不留痕迹地进行擦除[3 ,4] .这类新型材料和有关的表面可逆光加工技术在光电子通讯和信息存储等领域具有很大的发展潜力和应用价值[5 ,6] .具有上述特性的聚合物也被称为光动力高分子 (Ｐｈｏｔｏｄｙｎａｍｉｃｐ…     

以数字处理对魔芋葡甘聚糖膜面特征的初步研究

以天然生物材料为原料的绿色环保型膜材料取代塑料薄膜将是今后膜材料的发展趋势[1 4 ] 。从魔芋 (ＡｍｏｒｐｈｏｐａｌｌｕｓＫｏｎｊａｃＫ .ＫｏＣｈ)中提取出的魔芋精粉 ,其主要成分为葡甘聚糖 ,其优良的成膜性已引起人们的重视[4 5] 。分形维数在材料研究中得到了广泛的应用[6 ] ,本文以魔芋葡甘聚糖为主要原料制成膜 ,对膜的扫描电镜图象进行数字化处理 ,探讨膜面的微观形貌特征及制膜条件对膜面的影响。1　实验部分1 1　膜的制备以魔芋精粉 (四川安县魔芋精粉厂 )为主要原料 ,并添加明胶增强剂、甘油 (食品级 )增塑剂 (质量比为 1…     

Synthesis and Characterization of Heteropoly Coordination Compounds Containing Optical Ligands

ＴｈｅｈｅｔｅｒｏｐｏｌｙａｎｉｏｎｐｈａｓｅｔｒａｎｓｆｅｒｃｈｅｍｉｓｔｒｙｃｒｅａｔｅｄｂｙＰｏｐｅＭ .Ｔ .ｉｎ 1 984ｈａｓｏｐｅｎｅｄｕｐａｎｅｗｆｉｅｌｄｆｏｒｈｅｔｅｒｏｐｏｌｙｃｏｍｐｏｕｎｄｒｅｓｅａｒｃｈ[1— 3] .Ｂｕｔｓｕｂｓｔｉｔｕｔｉｎｇｃｏｏｒｄｉｎａｔｉｏｎｗａｔｅｒｍｏｌｅｃｕｌｅｓｂｙｏｒｇａｎｉｃｏｐｔｉｃａｌｌｙａｃｔｉｖｅｌｉｇａｎｄｈａｓｎｏｔｂｅｅｎｒｅｐｏｒｔｅｄｉｎｌｉｔｅｒａｔｕｒｅｓｕｎｔｉｌ 1 997[4] .Ｔｈｉｓ ｐａｐｅｒｃｏｖｅｒｓｓｉｘｈｅｔ…     

生物材料与细胞相互作用及表面修饰

生物材料用作人工细胞外基质(ECMs)在组织工程中起重要作用。生物材料表面的拓扑结构、亲水／疏水平衡、自由能、电荷状况、化学基团和生物特异性识别对材料／细胞相互作用有较大影响。生物材料表面与细胞的相互作用主要是细胞膜表面受体与生物材料表面配体间的相互分子识别,因此采用仿生修饰生物材料表面以提高细胞亲和性和特异性识别。本文对生物材料与细胞相互作用及表面修饰的技术方法进行了介绍。     

壳聚糖微球负载的己二胺型聚酰胺-胺树状大分子的制备及对胆红素的吸附

通过反相悬浮反应制备了戊二醛交联的壳聚糖微球。以所制备的壳聚糖微球为载体,合成了己二胺型低代数聚酰胺-胺（Polyamidoamine,简称PAMAM）树枝状大分子（Genaration≤3）。考察了该微球在生理条件下对水溶液中胆红素的吸附行为,以及溶液的pH值,离子强度,温度,胆红素初始浓度,牛血清白蛋白等因素对吸附的影响。结果表明,吸附剂对胆红素具有良好的吸附性能,CS-G2.0,CS-G3.0,CS-G1.0,CS-G0和CS微球的平衡吸附率分别为94.61%,93.44%,92.97%,86.47%,52.38%,CS-G1.0-G3.0微球在0.5h吸附率已经超过70%,1h基本接近平衡,对胆红素的吸附量高达42.78mg/g。     

Macroporous chitosan layer coated on non-porous silica gel as a support for metal chelate affinity chromatographic adsorbent

A new immobilized metal affinity chromatography (IMAC) matrix was prepared by coordinating Cu2+ with cross-linked chitosan coated on non-porous silica gel (Cu-CTS-SiO2). Macroporous structure could be formed on the coated layer by imprinting polyethylene glycol (PEG) in chitosan film. The surface morphology changes on Cu-CTS-SiO2 bead prepared in different condition were confirmed by scanning electron microscopy (SEM). Effects of chitosan and PEG content in coating solution, the molecular mass of PEG on the surface macropore formation and adsorption capacity of bovine serum albumin (BSA) were investigated. Results indicated that coating solution with 2% chitosan and 10% PEG 20000 was optimal. Batch experiments were also conducted for elucidating the optimal pH, the adsorption isotherm and adsorption kinetics of BSA. Adsorption isotherm of trypsin on the same adsorbent was also performed. Results showed that the support itself had low non-specific interaction with both BSA and trypsin. The maximum adsorption capacity for BSA and trypsin on the prepared IMAC adsorbent could reach 192 mg and 5000 IU, respectively calculated by every gram of chitosan. The binding and eluting condition for BSA were tested on column filled with the adsorbent. Crude BSA sample could be purified on the IMAC column.     

Biodegradable hyaluronic acid/n-carboxyethyl chitosan/protein ternary complexes as implantable carriers for controlled protein release

An ampholytic N-carboxyethyl chitosan (CEC), with various isoelectric points (IPs), was synthesized by grafting acrylic acid on chitosan utilizing Michael's reaction. Compared to native chitosan, CEC has enhanced water solubility and dramatically accelerated enzymatic degradation; the rate of degradation is proportional to the degree of substitution (DS). The results from turbidimetric titration and fluorescence studies revealed that CEC formed complexes with either hyaluronic acid (HA) or bovine serum albumin (BSA) within a certain pH range. The HA/CEC/BSA ternary complexes could be prepared by colloid titration with quantitative yield and BSA entrapment. The rate of BSA release from the complexes was affected by pH, ionic strength, DS of CEC, and the molecular weight (MW) of HA. The endurance of BSA release from the complexes could be extended up to 20 d by formulating them with high-MW HA and CEC with low DS.BSA release profiles from HA/CEC-2/BSA complexes.     

Influence of pH of the BSA solutions on velocity of the rising bubbles and stability of the thin liquid films and foams

Influence of pH of the BSA solutions on velocity of the rising bubbles, stability of foams, and properties of single foam and wetting films was studied. It was found that the solution pH affected significantly the BSA surface activity and properties of the protein adsorption layer under dynamic and static conditions. At pH close to the isoelectric point (pH_IEP=4.8) the BSA showed the highest surface activity. The equilibrium microscopic foam films of thicknesses of 64–80 nm, depending on the BSA concentration, were obtained at pH=5.8. Under dynamic conditions the bubble rising velocity was reduced in a highest degree and the foam formed were most stable at the solutions pH-5.8 and 4.8. Lowering the bubble velocity shows that the BSA adsorption layer was formed, which retarded fluidity of the bubble surface. When the solution pH was significantly lower (pH=3.9) or much higher (pH=10) than the pH_IEP then the BSA practically had no influence on the bubble velocity and the foam stability was drastically reduced. Moreover, the pH variations affected also the time of the three-phase contact (TPC) formation on mica surface covered by the BSA adsorption layers. These pH dependent changes in the BSA surface activity indicate that the BSA linear conformers, existing at pH far away from the pH_IEP, have much higher affinity to aqueous phase resulting from higher net electrical charge present over the extended BSA molecule conformers.     

Nanofibrillar Cellulose‐Chitosan Composite Film Electrodes: Competitive Binding of Triclosan,Fe(CN)63−/4−, and SDS Surfactant

Glassy carbon electrodes are modified with a thin film of a cellulose‐chitosan nanocomposite. Cellulose nanofibrils (of ca. 4 nm diameter and 250 nm length) are employed as an inert backbone and chitosan (poly‐D ‐glucosamine, low molecular weight, 75–85% deacetylated) is introduced as a structural binder and “receptor” or molecular binding site. The composite films are formed in a solvent evaporation method and prepared in approximately 0.8 μm thickness. The adsorption of three molecular systems into the cellulose‐chitosan films is investigated and approximate Langmuirian binding constants are evaluated: i) Fe(CN)₆^4? (K_Ferrocyanide=2.2×10³ mol^?1 dm³ in 0.1 M phosphate buffer at pH 6) is observed to bind to ammonium chitosan functionalities (present at pH<7), ii) triclosan (K_Triclosan=2.6×10³ mol^?1 dm³ in 0.1 M phosphate buffer pH 9.5) is shown to bind only weakly and under alkaline conditions, and iii) the anionic surfactant dodecylsulfate (K_SDS=3.3×10⁴ mol^?1 dm³ in 0.1 M phosphate buffer pH 6) is shown to bind relatively more strongly in acidic media. The competitive binding of Fe(CN)₆^4? and dodecylsulfate anions is proposed as a way to accumulate and indirectly determine the anionic surfactant.     

γ-irradiated chitosan-polyvinyl pyrrolidone hydrogels as pH-sensitive protein delivery system

The effects of pH of the buffer solution and the composition of the hydrogel system on the bovine serum albumin (BSA) adsorption capacity of chitosan (CS)–polyvinyl pyrrolidone (PVP) (CSPVP) hydrogels and release of BSA were investigated. Poly-electrolyte CSPVP hydrogels with different compositions were prepared by irradiating CS/PVP/water mixtures with γ-rays at ambient temperature. The adsorption capacity of hydrogels was found to increase from 0 to 350 mg BSA/g dry gel, by changing external stimuli and hydrogel composition. The adsorption of BSA within CSPVP hydrogels increased with increase in CS content in the hydrogels. When the irradiation doses of hydrogel increased, the adsorption of BSA decreased. The maximum adsorption of BSA was observed at pH 5. A significant amount of the adsorbed BSA (up to 95%) was eluted in the phosphate medium containing 0.1 M NaCl at pH 7.4.     

Albumin separation with Cibacron Blue carrying macroporous chitosan and chitin affinity membranes

Cibacron Blue F3GA, Procion Red HE-3B and Procion Blue MX-R were immobilized on macroporous chitosan and chitin membranes with concentrations as high as 10–200 μmol/ml membrane. These dyed membranes were chemically and mechanically stable, could be reproducibly prepared, and operated at high flow rates. Human serum albumin (HSA) and bovine serum albumin (BSA) were selected as model proteins, and their adsorption on and desorption from the dyed chitosan membranes investigated. The Cibacron Blue F3GA membranes had a higher protein adsorption capacity, much greater for HSA than BSA, than the other dyed membranes. About 8.4 mg HSA/ml membrane were adsorbed at saturation by Cibacron Blue F3GA–chitosan membranes from a 0.05 M Tris–HCl/0.05 M NaCl, pH 8 solution. The chitin membranes had a lower dye content and hence a lower protein adsorption capacity than the chitosan membranes. The effects of important operation parameters (flow rate, protein concentration and loading) were also investigated. Cibacron Blue F3GA–chitosan membranes were employed for the separation of HSA from human plasma and high purity HSA thus obtained. This suggests that these membranes could be used for large-scale plasma fractionation.     

Fabrication,structure and surface charges of albumin-chitosan hybrids

Protein-polymer hybrids consisting of protein and natural polymers or synthetic polymers exhibit superior properties to unmodified proteins,generating a high demand for these materials in the fields of medicine,biotechnology,and nanotechnology.Herein,protein-polysaccharide hybrids were fabricated via the formation of an amide bond between bovine serum albumin(BSA) and chitosan(CS) using N-ethyl-N-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC) as the couple reagent.FTIR spectrum reveals that the carboxyl group of BSA conjugated with the amino group of chitosan backbone.The molecular weight of BSA-CS hybrids was identified by matrix-associated laser desorption ionization time of flight mass spectra(MALDI-TOF MS) and sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).The maximum number of chitosan chains binding to each BSA molecule was estimated as 6,and the optimal number was estimated as 2.In addition,the secondary structure and surface property of BSA were dependent upon the number of polymer conjugating on protein.The secondary structure of BSA was not significantly changed,if a few chitosans were coupled with BSA.By further increasing the molar ratio of chitosan to BSA,the secondary structure of BSA was markedly damaged.The surface’s negative charges of modified BSA also decreased.The result of native polyacrylamide gel electrophoresis(native-PAGE) also demonstrated the changes in surface charges and molecular weight of BSA-CS hybrids.     

3-Diethylaminopropyl-bearing glycol chitosan as a protein drug carrier

Polysaccharidic nanogels were fabricated with bovine serum albumin (BSA) and a glycol chitosan (GCS) grafted with functional 3-diethylaminopropyl (DEAP) groups. These nanogels were investigated to evaluate their cellular uptake in HeLa cells and in vivo fate in nude mice tumor model. Unlike free BSA, GCS-g-DEAP/BSA nanogels improved cellular uptake of BSA. Furthermore, this system led to an enhanced blood circulation and a high accumulation of BSA in the tumor site. Our collective results strongly support that GCS-g-DEAP/BSA nanogel is a potential carrier system for high molecular weight proteins.     

染料壳聚糖微球的制备及其对牛血清白蛋白(BSA)吸附性能的研究

采用反相悬浮交联法制备壳聚糖微球,对微球进行羟丙基氯化及氨基化,并偶联色素配体Cibacron Blue F3GA,得到一种新型染料亲和吸附剂.以牛血清白蛋白(BSA)为目标蛋白,考察了该染料亲和吸附剂的吸附性能,发现其对BSA有较高的吸附量(95.2mg/g),吸附行为满足Langmuir吸附等温式.负载牛血清白蛋白的微球容易洗脱,洗脱率高达99％.