戊二醛交联壳聚糖树脂的制备及其血液相容性研究

以戊二醛为交联剂制备了交联壳聚糖树脂,讨论了合成过程中的诸多影响因素,得到了制备的最佳条件。对交联树脂的血要容性进行了研究。结果表明,树脂对人血清白蛋白的吸附量较低;经过处理后,其血液相容性得到一定程度的改善。     

负载壳聚糖及其衍生物的材料表面血液相容性研究进展

壳聚糖及其衍生物具有多种生物活性,基于壳聚糖及其衍生物的材料表面改性是获取各种生物活性表面的重要手段,在生物材料领域显示出广阔的应用前景。为了获得血液相容性良好的壳聚糖改性生物材料表面,可通过引入具备抗凝活性的壳聚糖衍生物或壳聚糖/抗凝剂复合物来抑制壳聚糖固有的促凝作用。本文综述了负载有壳聚糖或其衍生物的材料表面的血液相容性改性方法方面的进展,并根据表面改性方法的不同按照物理改性和化学改性分别对其进行了阐述。     

甲壳素／壳聚糖的化学修饰

详述了甲壳素／壳聚糖的主要化学反应所得衍生物的一些性质和应用。     

血液接触生物材料的血液相容性评价研究进展

生物材料的血液相容性是决定该材料能否在临床成功应用的重要标准之一.当材料与血液接触后,会引起溶血、凝血和免疫等一系列反应,机制复杂且受多种因素影响.因此,在材料临床应用前需根据ISO 10993-4进行生物相容性评价,血液相容性评价是其中重要部分,但目前尚未形成统一的评价标准与评价体系.本文总结了近年对血液相容性评价的...     

血液相容性改善策略与研究进展

血液接触类医疗器械已被广泛应用于临床诊治居人类病死率首位的心血管病.血液相容性是血液接触类生物材料最为重要的评价指标.改善和提高血液相容性仍是血液接触类生物材料研发的主要任务和中心内容,对经济建设、社会进步和人类健康意义重大.本文系统综述了血液相容性研究的理论基础,重点阐述了血液相容性的改善策略(生物仿生、生物惰性和生...     

医用高分子表面及其血液相容性

本文首先概述了医用高分子表面的表征方法。接着着力讨论材料和血液的相互作用,其中主要阐述目前血液相容性研究所涉及的内容和各种抗凝假设。最后具体介绍了几种常见医用高分子材料的表面特性。     

羟乙基壳聚糖的合成及其与聚乳酸的相容性

本文以异丙醇为溶剂,碱化壳聚糖与2-氯乙醇反应制备了羟乙基壳聚糖,对产物的结构与性能进行了分析表征;然后以二甲基亚砜为溶剂,采用溶液共混法制备了一系列不同组成的壳聚糖/聚乳酸和羟乙基壳聚糖/聚乳酸复合膜,对两组分间的相容性进行了研究。结果表明,羟乙基化反应在-OH和-NH2上均有发生,壳聚糖单元糖环上的羟乙基取代度为2.46;改性后,壳聚糖结晶性能和起始热分解温度下降,溶解性能得到改善。复合膜的电镜结果显示,在壳聚糖/聚乳酸复合膜中,相分离现象显著存在,壳聚糖在聚乳酸基体中的分散不均匀,有团聚现象,随着壳聚糖含量增加,两组分间的相分离程度增大,团聚现象更为严重,当壳聚糖含量达到50%时,已难以制备完整的复合膜;与之相反,羟乙基壳聚糖/聚乳酸复合膜中两种组分之间的相容性有所改善,相分离现象不明显,并且,当羟乙基壳聚糖含量从10%增加到50%,复合膜中两种组分之间的相容性变化不大。     

壳聚糖共价键合化学修饰电极测定亚硝酸根

用共价键合法把壳聚糖修饰在玻碳电极表面,研究了NO-2在修饰电极上的阳极溶出伏安特性.实验结果表明:修饰电极在0.1 mol/L NaNO3(pH 2.60)底液中对NO-2有良好的吸附性和选择性,其峰电流与NO-2的浓度在1.5×10-6～1.0×10-3 mol/L范围内呈较好的线性关系;检测限可达2.0×10-7 mol/L.将壳聚糖修饰电极应用于雨水、湖水中NO-2的测定,结果满意.     

羧基化氧化石墨烯的血液相容性

氧化石墨烯的官能团修饰可促进氧化石墨烯与生物体液、聚合物基体等不同环境的融合. 通过超声法制备了氧化石墨烯, 并利用化学改性的方法, 将氧化石墨烯表面的羟基和环氧基转变为羧基. 红外图谱上羧基化氧化石墨烯(GeneO-COOH)的羧基振动明显, 峰强增大. GeneO-COOH的主要失重表现为羧基官能团缩合以一个水分子的形态释放失去结构水[OH2]. 复钙动力学曲线随着GeneO-COOH的浓度增加, 曲线上升趋势由陡峭趋于平缓, 当浓度为1.25 μg/mL时复钙时间延长了11 min, 平台期OD值降低了8.14 %; 在0.5~100 μg/mL浓度范围内溶血率均<5 %. GeneO-COOH比GeneO在同等低浓度下的抗凝血性能有一定程度的改善, 主要是因为带负电的羧基可直接络合凝血因子. 因此, 羧基修饰氧化石墨烯是提高血液相容性的有效手段, 羧基化氧化石墨烯可作为潜在的生物医用材料的填料.     

血液相容性及表面改性的研究

血液相容性是生物材料的必要条件 ,本文结合血栓形成的机理 ,综述了改善生物材料血液相容性的主要的几种表面改性方法     

应用于生物医学领域的化学改性壳聚糖

简述了壳聚糖的化学改性方法,改性壳聚糖的特殊功能及其在生物医学领域中的应用研究进展。     

Chemical Modification of Chitosan for Gene Delivery

Abstract

Chitosan has been investigated as a non‐viral vector because it has several advantages such as biocompatibility, biodegradability, and low toxicity. However, low specificity and low transfection efficiency of chitosan as a DNA carrier need to be overcome prior to clinical trial. In this review paper, chemical modification of chitosan was tried in order to enhance cell specificity and transfection efficiency. Also, chemical modification of chitosan was performed to increase stability of chitosan/DNA complexes.     

Preparation and Blood Compatibility of Oxidized-chitosan Films

Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of -COOH and -COO groups on the modified membrane surface. The SEM study showed the modified membrane surface was rough rather than smooth as chitosan membrane. All antithrombosis test, hemolysis test and blood cell morphology observation with SEM revealed that modified chitosan membranes have superior blood compatibility to chitosan.     

Chemical Modification and some Aligned Composites of Chitosan in a Filament State

The mono‐filaments (> 10 m in length) of chitosan and the blends of chitosan‐collagen, chitin‐collagen and chitin‐silk fibroin were wet‐spun. The mono‐filaments were chemically N‐modified with each of n‐fatty acid anhydrides, intra‐molecular carboxylic anhydrides, fragrant aldehydes and transition metal ions. The mono‐filament was aligned on a straight line with the mono‐filament of silk fibroin or poly(ethylene terephthalate) (PET), and a bundle of one to three mono‐filaments was coated with a medium of sericin (Se), chitosan or N‐acylchitosan to give rise to novel silk‐mimic filament composites. The filaments coated with a medium of sericin exhibited 26–27 denier for the titer, 2.46–3.36 gf · denier^?1 for the tenacity and 11.8–25.0% for the elongation. The apparent density (denier · μm^?1 in the filament diameter) of the filament composites was about 3–4 times higher than that of the mono‐filaments. Portion of fragrant aldehydes in Schiff's base was slowly hydrolyzed at room temperature by contacting with atmospheric moisture in the open air, and released from the fragrant filaments and composites. The filament composites coated with a chitosan medium were thrombogenic, and those coated with N‐acylchitosans were antithrombogenic.

An illustrated model for a silk‐mimic filament composite, N₀(N₂I‐FI).     

半纤维素化学改性

对近十年半纤维素的化学改性如:醚化改性、酯化改性进行了综述,主要从多相反应和均相反应两个方面进行了归纳说明,最后提出了半纤维素改性的前景。     

Chemical modification of Chitosan for metal ion removal

In the current work some modification reactions have been conducted to modify Chitosan with some organic compounds, such as aldehydes and organic acids. On the other hand, different blends of Chitosan with some carbohydrates were prepared to obtain Chitosan derivatives of certain physical and chemical properties. The obtained products have been characterized with the necessary chemical and spectroscopic techniques. The efficiency of the obtained modified materials has been investigated for separation of metal ions and for water uptake.     

Chemical Modification of Chitosan, 17

The Michael reaction of chitosan with acrylic acid was carried out successfully, even in water alone as the reaction medium. As a consequence of its good solubility in water, the reaction product, N‐carboxyethylchitosan, showed excellent biodegradable properties with standard activated sludge.

     

低聚氨基葡萄糖的化学合成及修饰研究进展

低聚氨基葡萄糖是一种天然多糖,已在医药、农药等领域得到了应用。由于它具有良好的生物活性,因此,低聚氨基葡萄糖的化学合成和修饰成为该研究领域的重要方向之一。本文综述了近年来低聚氨基葡萄糖的化学合成和结构修饰方面的研究进展,着重介绍了化学修饰方法。     

球壳烯类的化学修饰

自从Kratschmer和Huffman发表了较为简便的制备和分离碳-60,碳-70的方法以来,对于球壳烯类,特别是碳-60的表征和物化性质已进行了较为翔实的研究。关于球壳烯类的化学修饰,尽管起步较晚,对其兴趣也日益高涨。本文综述了球壳烯类的化学修饰,特别在球壳烯外壳的化学反应方面。