壳聚糖的介绍--课程ppt

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关于壳聚糖的溶解性以及应用PPT讲稿

• 壳聚糖是一种阳离子型天然多糖，能与DNA形成聚电介质，因此壳聚
糖可用作基因转移工具。
• 3.1 在医药领域的应用
• 壳聚糖可以用来制备伤口覆盖膜，具有很
好的生物相容性和抗病毒性，并能促进创面的愈合。例如，用壳聚糖制成的口腔溃疡膜，疗效可靠，无不良反应。
• 壳聚糖及衍生物在人体内可生物降解，并
相类似，分子呈直链状，极性强，易结晶，但由于熔点高于其自身分解温度，故不易得到非晶态的壳聚糖。
• 在特定的条件下，壳聚糖能发生水解、烷
基化、酰基化、羧甲基化、磺化、硝化、卤化、氧化、还原、缩合和络合等化学反应，可生成各种具有不同性能的壳聚糖衍生物，从而扩大了壳聚糖的应用范围。
• 其结构为下图所示：
• 自1859年，法国人Rouget首先得到壳聚糖
后，这种天然高分子的生物官能性和相容性、血液相容性、安全性、微生物降解性等优良性能被各行各业广泛关注，在医药、
• 3.3 在生化领域的应用
• 壳聚糖具有生物降解的特性，可制成可降解的薄膜。壳聚糖的游离氨
基，对各种蛋白质的亲和力非常高，可用来作为固定化酶、抗原、抗体等的载体。改性甲壳素固定化酶不影响酶的活性，且有很高的催化能力，可重复使用。
• 壳聚糖的外观是白色或淡黄色半透明状固体，但壳聚糖不溶于水和碱
溶液，也不溶于硫酸和磷酸。溶于质量分数为1%的乙酸溶液后形成透明豁稠的壳聚糖胶体溶液是最重பைடு நூலகம்的性质之一。
• 壳聚糖无毒、无害，具有良好的保湿性、润湿性，但吸湿性较强，遇
水易分解。其吸湿性仅次于甘油，优于山梨醇和聚乙二醇。
• 壳聚糖的相对分子质量为10万到30万之间。壳聚糖分子结构与纤维素
• 方法：将壳聚糖用高温浓碱浸泡，然后洗

壳聚糖的介绍课程

表面处理、相纸、无碳复印纸
医学
绷带、海绵、人造血管、血液中胆固醇的控制、肿瘤抑制、治疗烧伤、人造皮肤、眼睛的玻
璃体、隐形眼镜、药物控制释放
P2a0gG2e1o▪o/11s/e41n2M. in Applications of Chitinand Chitosan. Technomic Publishing Inc, PA. 1997
壳聚糖的介绍课程
目录
I 定义、来源 II 结构特征 III 理化性质 IV 制备方法 Ⅴ 应用
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1.定义、来源
壳聚糖（chitosan），又名脱乙酰甲壳素，是由自然界广泛存在的几丁质(chitin)经过脱乙酰作用得到的, 属高分子直链型多糖，是自然界唯一的碱性多糖。壳聚糖作为一种天然、绿色的环保高分子物质，具有可生物降解性、可食用性及生物相容性等特点，且安全无毒，对环境无公害。
Franca E F, Leite F L, Cunha R A, Oliveira O N, Freitas L C G .Designing an enzyme-based nanobiosensor using
molecular modeling techniques. Physical Chemistry Chemical Physics. 2011，13: 8894-8899.
烷基化反应
羧基化反应是指用氯代烷酸或乙醛酸，在甲壳素或壳聚糖的6-羟基或胺基上引入羧烷基基团，研究最多的是羧甲基化反应
醚化反应
甲壳素与聚氧乙烯反应生成的醚化物具有良好的保水性能，几乎与透明质酸相当。
酯化反应
常见的酯化反应有硫酸酯化和磷酸酯化[22]。用含氧无机酸作酯化剂，使甲壳素或壳聚糖中的羟基形成有机酯类衍生物。

壳聚糖ppt课件

2019 13
四壳聚糖抑菌性能影响因素、机理及应用
1 壳聚糖的抑菌性能影响因素
（1）分子量对壳聚糖抑菌性能的影响：
壳聚糖分子量对其抑菌性能的影响初步认为与不同分子量壳聚糖的不同作用机理及细菌的不同结构与特性有关。
（2）浓度对壳聚糖抑菌活性的影响：
水溶性壳聚糖的抗菌活性随其浓度的增加而增加，且它的抗真菌活性强于抗细菌活性。
2019 9
3 水溶性甲壳素的热性质
水溶性甲壳素的玻璃化转变温度( Tg)是 219．6℃。而脱乙酰度为95．8l％的壳聚糖的玻璃化温度是202.6℃。水溶性甲壳素的玻璃化转变温度高于壳聚糖，主要是因为水溶性甲壳素含有较多的乙酰基，分子间的作用较壳聚糖强，分子运动更困难。从水溶性甲壳素和壳聚糖的热失重结果分析，二者在60℃附近开始脱水，水溶性壳聚糖脱去总重的4.61％，而壳聚糖脱去了3.69％，说明水溶性甲壳素的亲水性更好，在环境条件下样品含水量高，与水的作用更强。
（3）壳聚糖在农业中的应用
可做种子处理剂、生物农药
2019 17
（4）壳聚糖在医疗卫生中的应用
壳聚糖可用于伤口填料物质，具有杀菌、促进伤口愈合、吸收伤口渗出物、不易脱水收缩，减少疤痕的生成等作用。
（5）壳聚糖在环保中的应用
利用壳聚糖的抗菌性，可将壳聚糖用于生化水处理方面。
（6）壳聚糖在化妆品中的应用
2019
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6 金福生-壳聚糖抗菌成膜喷雾剂
简介：今福生是一种喷雾型分子级隐形敷料，喷洒在皮
肤、黏膜患处及损伤表面，通过全新的物理及生物双重抗菌机制，隔离、杀灭病原微生物，同时促进组织修复与再生。作用机理：物理及生物双重抗菌机理。使用范围：普通外科、皮肤科、妇产科、烧伤科、整形美容外科、肛肠科、褥疮的预防与治疗、预防医院内感染等。

环境友好型材料-壳聚糖

05 壳聚糖的未来研究方向
新应用领域探索
生物医学领域
壳聚糖在药物载体、组织工程和再生医学等领域具有广泛应用前景，未来可探索其在肿瘤治疗、细胞培养和基因治疗等方面的应用。
环保领域
壳聚糖具有较好的吸附性能和生物降解性，可应用于水处理、土壤修复和重金属离子吸附等方面，未来可进一步研究其在环保领域的应用潜力。
组织工程
壳聚糖可用于构建组织工程支架，支持细胞生长和分化，促进受损组织的再生。
生物材料
壳聚糖可作为生物材料用于制造医疗器械、人工器官等，提高医疗设备的生物相容性和安全性。
食品工业
食品添加剂
壳聚糖可作为食品添加剂用于改善食品的口感、质地和稳定性，如增稠剂、乳化剂等。
食品包装材料
壳聚糖可制成可降解的食品包装材料，减少塑料污染，提高食品安全性和环保性。
发现与历史
发现
壳聚糖最初是从蟹壳和虾壳中提取出来的。
历史
壳聚糖的研究始于19世纪，经过一个多世纪的发展，其应用领域不断扩大，成为一种重要的环境友好型材料。
生产与应用
生产
壳聚糖的生产主要通过甲壳素的脱乙酰化实现，通常采用化学法或酶法进行。
应用
壳聚糖在医药、环保、食品、化妆品等领域有广泛应用，如药物载体、生物材料、环保包装材料、食品保鲜剂等。
02 壳聚糖的环境友好性
可生物降解性
壳聚糖可在自然环境中被微生物分解为水和二氧化碳，这一特性使其成为一种理想的可降解材料。
与传统的塑料材料相比，壳聚糖在降解过程中不会释放有害物质，从而减少了对环境的污染。
低毒性
壳聚糖本身具有低毒性，对生物体无害，因此在接触过程中不会对生物造成伤害。
在使用壳聚糖作为包装材料、药物载体或其他与生物体接触的场合，其低毒性特性确保了安全性。

壳聚糖

•
生理活性
1、化妆品专用壳聚糖化妆品专用壳聚糖具有良好的吸湿、保湿、调理、抑菌等功能；适用于润肤霜、淋浴露、洗面奶、摩丝、高档膏霜、乳液、胶体化妆品等；有效的弥补了一般壳聚糖的缺陷。 2、絮凝剂专用壳聚糖壳聚糖及其衍生物都是具有良好的絮凝、澄清作用。作为饮料的澄清剂，可使悬浮物迅速絮凝，自然沉淀，提高原液的得率；在中药提取液中，大分子的蛋白质、鞣酸和果胶，可以用壳聚糖溶液方便地除去，精制出纯度较高的中药有效成份；利用壳聚糖的吸附性，在水质净化方面有良好的效果。
将甲壳素用浓碱加热处理，脱去乙酰基就得到壳聚糖。由虾、蟹壳制取甲壳素、壳聚糖的简要流程如下： 5%HCl 10%NaOH 40%～45%NaOH ↓ ↓ ↓ 虾或蟹壳→ 脱钙 → 脱蛋白→甲壳素 → 脱酰基→壳聚糖 ↓ ↓ ↓ CaCl2、CO2 蛋白质 CH3COONa
将虾、蟹壳洗净干燥后，以5％稀盐酸于室温浸泡2ｈ，除去原料中的碳酸钙，然后过滤水洗至中性，再置于10％的ＮａＯＨ溶液中煮沸2ｈ脱蛋白，过滤水洗至中性，干燥即得甲壳素。而后置于45％～50％ＮａＯＨ溶液中，在100～100水解4ｈ或用 40 ％ＮａＯＨ溶液，于（84±1）℃的烘箱中保温17ｈ，然后过滤，水洗至中性，干燥即得壳聚糖。为加快脱乙酰反应，可进行间断性水洗。
二、水溶性壳聚糖的制备
提出两种降解制备水溶性壳聚糖的新方法: (1)UV-H_2O_2联合制备水溶性低聚壳聚糖:
(2)在壳聚糖-水异相体系中,磷钨酸催化H_2O_2 制备水溶性低聚壳聚糖。
降解实验结果表明:两种方法均可以有效地制备水溶性低聚壳聚糖, 降解产物保持壳聚糖的基本结构特征。
壳聚糖的应用价值
⑥织物的整理剂。壳聚糖可作为织物的永久整理剂，使织物耐水洗，耐磨擦，具有固色和增强作用，提高织物的坚牢度，减少皱缩率，并使织物具有滑爽光洁和挺括的外观和手感。衬领和衣衬垫使用壳聚糖处理后既硬挺又不怕水洗。电线的绝缘包布用壳聚糖处理后可提高其绝缘性能及热老化性能。此外，甲壳素和壳聚糖也可制成具有特殊用途的纤维。 ⑦日用化学品。壳聚糖溶于稀的弱酸中即为阳离子型高分子电解质，它无色无味、无嗅、无毒副作用，有很高的吸湿和保湿作用，因其含有氨基，与毛、发、皮肤有很好的亲和、渗透作用，而且还有抗菌作用，因此是一种理想的化妆品用高分子化合物。可以用于固发剂、头发调理剂、洗发香波、护肤剂、口腔卫生剂等。此外，壳聚糖在生物大分子物质的回收，以及功能材料方面也有很好的应用。

关于壳聚糖的溶解性以及应用PPT课件

➢ 4.2 综上所述，可以看出壳聚糖的应用极为广泛而且前景非常诱人。自20世纪80 年代以来，在全世界范围内掀起开发甲壳素、壳聚糖的研究热潮后，世界各国都在加大甲壳素、壳聚糖的开发力度，日本当前处于各国的前列，是世界上第一个生产壳聚糖的大国。目前美国和日本年需壳聚糖已达3000t ,50 % 需进口。我国从20世纪80年代开始生产壳聚糖，目前年产量为400 t，主要生产厂家集中在沿海地区。
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➢ .3.2 在环保领域的应用
➢ 由于游离氨基的存在，壳聚糖类在酸性溶液中具有阳离子型聚电介质的性质，因此可作为凝聚剂用于水的澄清。还可用于工业废水的脱氯酚和造纸污水脱木质素处理等。
➢ 壳聚糖是高性能的重金属离子捕集剂，因此可用于含重金属离子的污水处理和贵金属的回收。将壳聚糖用于溶液中Cu2十、Cr3十、Ni'+金属离子的脱除和回收，最高回收率达95%一100%。例如，壳聚糖可速有效地吸附含Cr 废水中的Cr，除Cr率达90%以上。用D-半乳糖改性的壳聚糖能吸附 Ga,In,Nd,Eu,Cu,Ni,Co等金属离子，壳聚糖分子的氨基和经基起了鳌合配位体的作用。壳聚糖类也能用于放射性元素铀的捕集和核工业污水的处理。
第七页，共17页。
➢ 2.4外界环境Ｔ改变溶解性 ➢ 温度升高，分子(离子)的热运动加剧，使得分子间混台加快，壳聚糖的溶解性
能同样能受到温度的影响。 ➢ 原理：由于升高温度之后，氢离子的运动速率加快，使得氢离子对氨基和羟基
作用加强同时大分子链运动加快，从而加快了壳聚糖有序结构的破坏，促进了壳聚糖的溶解。 ➢ 但是升高温度对壳聚糖溶液也带来了不利的影响。由于壳聚糖的缩醛键结构，在氢离子的攻击下很容易发生水解，使壳聚糖降解。当温度升高时壳聚糖降解更为严重，所以溶解壳聚糖温度不宜过高，一般２０～３０度为宜，对于必须加热的才能溶解的溶剂，也要尽量采取最低温度下使其溶解。

壳聚糖、甲壳素应用PPT课件

涂依
戊二醛为交联剂，以涂覆的方法制备了壳聚糖 /羧甲基壳聚糖双层复合膜，羧甲基壳聚糖的分子量不同，研究对比不同分子量羧甲基壳聚糖双层复合膜的创伤修复效果。实验结果表明: 制备的双层复合膜对创伤都有一定的修复效果，但是羧甲基壳聚糖的分子量越小，创伤修复效果越好
余丕军
通过观察胶原蛋白－壳聚糖( 80: 20) 复合纳米纤维膜修复 SD 大鼠背部全层皮
营养药物载体针对壳聚糖微球作为药物载体的研究已经有很多，但其作为营养药物载体的研究则比较少。目前，
壳聚糖微球在营养物运送方面的研究主要是作为维生素载体。
8
甲壳素生物质转化为高附加值化合物
随着全球石油、天然气等传统化石资源逐渐枯竭，人们正在努力寻求新的替代能源。生物质是一种天然可再生资源，数量巨大，价格低廉，丰富的生物质资源有望成为未来获取燃料和高附加值化学品的主要来源。新加坡国立大学的颜宁教授等提出了甲壳素生物质精炼的概念，同时指出甲壳素生物质来源丰富，应该像纤维素生物质一样被充分利用，使其转化成为具有较高价值的化学品。
表面释放
壳聚糖微球溶蚀释放
扩散释放
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壳聚糖微球在药物载体中的应用
普通药物载体壳聚糖微球作为普通药物的载体，能提高药物稳定性，保持药物长期活性。目前已有多种药物可通
过壳聚糖微球缓释，如四环素、奈普生、阿司匹林等。药物经过壳聚糖微球负载后缓释作用十分明显，释放时间与原药相比都显著地延长。
生物大分子药物载体用壳聚糖微球作为多肽、蛋白质类药物的载体，不仅可以保护药物免受消化道酶的破坏及ｐＨ值的
肤缺损创面的作用，修复后14d 实验组创面已经基本对合; 而仅用油纱及干纱布
包扎并在创伤外缘打包固定的对照组创面对合不整齐，创面较实验组大。证实

甲壳素与壳聚糖简介课件

你现在学习的是第18页，课件共31页
甲壳素与壳聚糖的生产工艺：
制备甲壳素的主要操作是：脱钙和脱蛋白。
? 酸的作用即为脱钙，即用于浸泡虾蟹壳时使其中的碳酸钙
和无机盐变为水溶性溶液和二氧化碳等。碱的作用即为脱蛋白，因为蛋白质在碱液中比在酸液中溶
解得较快也较完全。这样剩余下来的就是甲壳素。
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甲壳素与壳聚糖的生产工艺：
壳聚糖
甲壳素
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甲壳素与壳聚糖的应用：
1.甲壳素与壳聚糖在食品工业上的应用：
国内外大量研究表明，甲壳素和壳聚糖是无毒的，美国食品与医药卫生管理局（FDA）已批准其为食品添加剂。
在日本，甲壳素或壳聚糖在食品工业中使用的数量，要占到总量的70%。
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甲壳素与壳聚糖的应用：
（4）抑菌和保鲜作用
（ba））抑保菌鲜作作用用：壳甲聚壳糖素以和壳其聚独糖特及的它结们构的，衍对生许物多对真果菌蔬具具有有抑明制显的作保用鲜。防已腐发作现用壳，
聚这糖些对作金用黄来色源葡于萄来球源菌于、它大们肠很杆好菌的、成小膜肠性结和炎耶抑尔菌森作菌用、，鼠甚伤至寒能沙门激菌发和一李些斯有特益单酶核的增作生用菌及这抑几制种一常些见有食害物酶中的毒菌作具用有。较强的抑制作用。壳聚糖具有很好的成膜性，将壳聚糖溶液喷涂到果蔬表面，干燥后即在果蔬在表日面本形已成有一将层壳无色聚透糖明作的为可食食品用防薄腐膜，剂由的于专壳利聚。糖膜的独特物理和生
（3）分离树脂可用来回收重金属、核酸、核苷酸、氨基酸，作高压液相色谱柱的载体
，薄层色谱的载体。
你现在学习的是第26页，课件共31页
甲壳素与壳聚糖的应用：

壳聚糖知识讲座

壳聚糖知识讲座1、壳聚糖与高血压壳聚糖是唯一带有正电荷（阳离子）的动物纤维素，可吸附带有负电荷的氯离子，防止由于氯离子增多而导致的血管收缩，血压升高；同时可有效清除血管壁表面的脂肪沉积物，将血管狭窄的根本原因祛除，从根本上调治高血压。

2、壳聚糖与高血脂及心脑血管病咨询qq1972548843壳聚糖中带正电荷碱性氨基，在负电荷脂肪周围构筑一层屏障，脂肪油滴不能被机体消化、吸收，而被排出体外；壳聚糖与胆汁酸有效结合，在肠道阻碍胆固醇的吸收；壳聚糖可利用其带有正电荷及本身的纤维性，来吸附、冲刷血管上的脂肪沉积物，起到降血脂及调理动脉硬化的作用。

对由于动脉粥状硬化引起的冠心病、心脑血管有较好的治疗效果！3、壳聚糖与骨关节病壳聚糖是制造蛋白多糖的主要元素，而蛋白多糖是构成骨关节软骨的主要成份，通过补充甲壳素，可促进蛋白多糖的合成，从而有效修复骨关节，促进关节润滑液的分泌，使骨膜液更浓且更有粘性，从而加强骨膜的保护功能，减轻关节间的摩擦及痛楚。

甲壳素能够沉积在骨表面，增强骨皮质的韧性，提高骨的弹性，使骨不易折断，同时有效防止骨钙的流失。

壳聚糖对关节炎、颈椎、腰椎、肱骨骨头疼痛、痛风有良好的疗效！4、壳聚糖与排毒（1）壳聚糖具有极强的吸附能力，其纤维状的结构使其内部有很多空隙,表面大,因而由分子间引力表现出的表面吸附能力也极强,加之带正电荷，因而能够包裹、吸附各种体内的垃圾、废物，如血脂、氯离子、胆汁酸、化学色素、农药等。

(2)壳聚糖带有的正电荷（氨基），可以结合金属离子形成复合物，将比重大于5的金属物质，如汞、砷、铅、铬等有效排出体外（3）由于其为纤维素,服用后,会有一部分未被分解的在肠道内起作用;其吸收水分后,会迅速膨胀,对肠道产生一定的压力,促进肠管蠕动加速有害物质的排出。

5、壳聚糖与胃肠道疾病壳聚糖迅速与胃酸结合,形成胶状物质,附在胃壁上形成保护膜,阻止胃损伤面的刺激、腐蚀,促进损伤面的修复，防止胃炎、胃溃疡的发生;壳聚糖是粪便的最佳稀释剂,１克甲壳素可增加粪便容量５－７克,增大的容积对肠壁产生压力,导致肠管蠕动增加而排便;壳聚糖可促进肠道双歧杆菌的生长，有利于维持肠道菌群的生态环境，减少肠道毒素对肠道的破坏作用，防止肠炎及肠癌的发生；甲壳素可吸附肠道毒素、农药、化学色素等，与重金属离子结合成为复合物壳聚糖对慢性胃肠炎、长期便秘、有痔疮的人有奇特效果！6.壳聚糖与美容壳聚糖能抑制脂质过氧化物（LPO）产生和脂褐素（LF）的形成，去除皮肤褐斑；诱导细胞产生大量的胶原纤维，使皮肤细腻。

甲壳素与壳聚糖 PPT

甲壳素与壳聚糖
甲壳素壳聚糖
水溶性壳聚糖甲壳素
成品壳聚糖
高密度壳聚糖
定义：
甲壳素：也称几丁质(chitin) ，壳多糖，学名为N—乙酰—2—氨基—2—脱氧—B—D—葡聚糖，分子式为 (C8HI3NO)是来源于海洋无脊椎动物的外壳，真菌细胞壁和昆虫的外角质层和内角质层的一类天然高分子聚合物，它属于氨基多糖。
催化活性，从而抑制氧化作用的形成。（4）果汁的澄清剂（5）保健食品添加剂（6）婴儿乳品添加剂（7）食物防腐剂
几丁质／几丁聚糖及其衍生物在食品中的应用
• 1减肥食品
2降血压食品
• 3心血管疾病防治食品 4糖尿病防治食品
• 5胃溃疡防治食品
6肝脏机能强化食品
• 7抗癌食品
8肠内菌群调节食品
• 9微量元素补充食品
大家有疑问的，可以询问和交流
可以互相讨论下，但要小声点
二、在化妆品原料中的应用
1）洗发香波、头发调理剂：甲壳素粉沫比表面积大，孔隙率高，吸收皮脂类油脂远大于淀粉或其他活性物质，是洗发剂理想的活性物质。 2）固发剂：壳聚糖分子中的氨基质子化带正电，能和头发的负电荷相互作用，有很强的亲合力，在头发表面形成薄层，是理想的固发剂原料。 3）牙膏添加剂：壳聚糖是良好的牙膏添加剂，它能够中和由口腔链球菌产生的有机酸，减弱非溶性葡萄糖在牙齿表面的附着能力，对抗腐蚀、洁齿起一定的作用。
壳聚糖：也称几丁聚糖(chitosan)，它是由几丁质在碱性条件下加热，脱去N—乙酰基后生成的。其学名为(1， 4)—2—氨基—2—脱氧—B—D—葡聚糖。几丁聚糖外观是白色或淡黄色半透明状固体，略有珍珠光泽。
甲壳素与壳聚糖的应用
• 一、在农业上的应用 • 二、在化妆品原料中的应用 • 三、在造纸化学品中的应用 • 四、在保健领域中的应用 • 五、在纺织印染业的应用 • 六、在食品工业中的应用 • 七、在医学领域中的应用 • 八、膜材料 • 九、吸附剂 • 十、在其他方面的应用

壳聚糖妇用抗菌栓敷料演示课件

[摘要] 为观察壳聚糖妇用抗菌栓（敷料）治疗细菌性阴道病和霉菌
性阴道炎的临床疗效及安全性，将产品（试验组）用于细菌性阴道病和霉菌性阴道炎患者120例的临床治疗，疗程7天，观察壳聚糖妇用抗菌栓（敷料）对细菌性阴道病和霉菌性阴道炎治疗效果及安全性，结果显示壳聚糖妇用抗菌栓（敷料）治疗效果显著，对人体无毒副作用，疗效明显好于对照组。
• 司诺药业拥有专业化的服务团队，提供高品质产品，并为客户提供优质的售后服务，指导客户进行市场操作，提高推广效率。公司建立了“稳定的价格体系”、“完善的市场管控体系”、“优质的后期服务体系”。实施独家代理制度，统一零售价格，并为客户提供便捷的物流服务，签约后快递免费送货上门。司诺药业视客户为合作伙伴，明确企业责任，愿做好客户的后勤保障，做好后勤服务才是企业发展的根本，只要是对销售有利的，就是我们要做的。司诺药业真诚希望与广大代理商精英们精诚合作、共创辉煌！
• 4、高脱乙酰度壳聚糖是天然阳离子高分子聚合物，具有吸附性、成膜性，进入女性阴道后，在阴道和宫颈部位形成一层保护膜，抑制致病微生物，阻断病原菌代谢。
• 5、高脱乙酰度壳聚糖在人体溶菌酶的作用下降解为低聚糖和单糖，可被人体吸收利用，低聚糖能促进阴道内乳酸杆菌等有益菌的生长，调整阴道菌群平衡，提高机体免疫力。
产品特点
• 1、抗菌活性高，有效治疗霉菌感染、细菌感染、真菌感染引起的阴道疾病； • 2、促进血液凝固，快速止血，改善重度阴道疾病和宫颈糜烂引起的出血症状； • 3、在人体溶菌酶的作用下降解为低聚糖和单糖，可被人体吸收利用，低聚糖能促进阴
道内乳酸杆菌等有益菌的生长，调整阴道菌群平衡，提高机体免疫力； • 4、具有吸附性、成膜性，能吸附分解阴道和宫颈内的有害分泌物，并在阴道和宫颈表
面形成保护膜，有隔离保护和修复作用； • 5、采用脂溶性基质，在阴道内可迅速溶解并发挥药效； • 6、阴道给药更科学，药物可直达病变部位，迅速止痒、止痛； • 7、大剂量、性价比高，1盒用6天，患者容易接受。

壳聚糖ppt

2 水溶性甲壳素的表征
甲壳素、水溶性甲壳素以及其它不同脱乙酰度样品在波数1650cm-1 和1550c-m1 附近的吸收峰是酰胺I带 (C=O)和酰胺II带(N-H和C-N的组合)的吸收峰，而脱乙酰度达到95.81％的壳聚糖在此处几乎没有吸收。水溶性甲壳素的酰胺I带吸收在166-15cm ，脱乙酰度为58.1％的壳聚糖的吸收在166-10cm ，甲壳素的吸收在 -1 1627cm ，谱带依次向低频移动，说明形成酰胺键中的羰基形成氢键依次增多，分子间作用逐渐增强。在波数34-51 5cm 、19-101cm 和6-165cm 3处红外吸收是壳聚糖的结晶敏感吸收，水溶性甲壳素在上述3处都无明显的吸收峰，说明水溶性甲壳素结晶性较差，而其它的有明显的红外吸收。水溶性甲壳素在1O℃处的衍射峰弱，在2O℃附近的衍射峰宽，说明非晶漫散射峰较弱。
2 壳聚糖的生产技术
1）脱乙酰化原理
壳聚糖是甲壳素N-脱乙酰基的产物，壳聚糖的制备过程，就是酰胺的水解过程。
2）资源化法
资源法包括有很多种方法，比如综合生产法、蝇蛆壳、蚕蛹壳等。综合生产法是利用虾、蟹壳资源化处理法。该项技术的关键，一是将虾、蟹壳中的中的成分转化为有用之物；二是尽量减少烧碱的消耗，在海边的生产厂家，尽量使用海水，减少淡水的消耗。蝇蛆壳又称蛆皮，干蛆皮中含有30%～54.8%的甲壳素。
（3）脱乙酰度对壳聚糖抑菌活性的影响：
随着壳聚糖脱乙酰度的增加，抑菌性能增强，氨基是壳聚糖的消毒因子。
（4）pH 值对抑菌性能的影响：
随着pH 值的降低，壳聚糖分子所带正增加，导致了抑菌活性的增加电荷。
（5）菌株本身的影响：
虽然壳聚糖的分子量、pH 值等因素都是壳聚糖抑菌活性的极显著影响因素，但菌株本身的内因才是壳聚糖抑菌活性大小的关键因素。壳聚糖对革兰氏阳性菌的抑制作用比对革兰氏阴性菌强。细菌容易受到壳聚糖的抑制，酵母菌次之，而壳聚糖对真菌的抑制作用则相对较弱。

《壳聚糖纤维介绍》课件

《壳聚糖纤维介绍》ppt 课件
CONTENTS
目录
• 壳聚糖纤维简介 • 壳聚糖纤维的应用 • 壳聚糖纤维的生产工艺 • 壳聚糖纤维的市场前景 • 总结与展望
CHAPTER
01
壳聚糖纤维简介
什么是壳聚糖纤维
定义
制备方法
壳聚糖纤维是一种由甲壳素脱乙酰化得到的天然高分子材料制成的纤维。
通常采用溶液纺丝或熔融纺丝的方法制备壳聚糖纤维。
壳聚糖纤维具有较好的吸附性能，能够有效地吸附水中的重金属离子、有机物和色素等污染物，为水处理提供了一种高效、环保的方法。
壳聚糖纤维在环保领域的应用具有可持续性和可降解性，符合绿色环保的理念。
纺织领域的应用
壳聚糖纤维在纺织领域的应用包括制作功能性纺织品和智能纺织品等。
壳聚糖纤维还可以与其他纤维混纺，制作出具有多种功能的纺织品，如防水透气的户外服装、智能调温的保暖内衣等。
CHAPTER
02
壳聚糖纤维的应用
医疗领域的应用
壳聚糖纤维在医疗领域的应用包括制作医疗敷料、止血材料、药物载体等。
输标02入题
由于壳聚糖纤维具有抗菌、消炎、促进伤口愈合等特性，因此被广泛应用于伤口护理和手术止血等方面。
01
03
壳聚糖纤维制成的医疗敷料和止血材料具有良好的透气性、吸水性和生物相容性，能够提供良好的伤口愈
壳聚糖纤维具有良好的抗菌、防臭、防霉等性能，可以用于制作内衣、袜子、床单等贴身纺织品，提高穿着的舒适度和卫生水平。
CHAPTER
03
壳聚糖纤维的生产工艺
壳聚糖的提取工艺
壳聚糖的提取
从虾蟹壳中提取甲壳素，经过脱乙酰基反应后得到壳聚糖。
提取条件控制

壳聚糖

Carbohydrate Polymers 117(2015)524–536Contents lists available at ScienceDirectCarbohydratePolymersj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /c a r b p olReviewGlycerophosphate-based chitosan thermosensitive hydrogels and their biomedical applicationsHui Yun Zhou a ,∗,Ling Juan Jiang a ,c ,Pei Pei Cao a ,Jun Bo Li a ,Xi Guang Chen b ,∗∗aChemical Engineering &Pharmaceutics College,Henan University of Science and Technology,263Kaiyuan Road,Luoyang,471023,PR China bCollege of Marine Life Science,Ocean University of China,5Yushan Road,Qingdao,266003,PR China cLiaoning Haisco Pharmaceutical Co.,Ltd.,PR Chinaa r t i c l ei n f oArticle history:Received 7May 2014Received in revised form 24September 2014Accepted 25September 2014Available online 19October 2014Chemical compounds studied in this article:Chitosan (PubChem CID:71853)␣-glycerophosphate (PubChem CID:14754)␤-glycerophosphate (PubChem CID:6101544)acetic acid (PubChem CID:176)lactic acid (PubChem CID:612)Keywords:Chitosan␤-Glycerophosphate ␣␤-Glycerophosphate Thermosensitive hydrogel Drug deliveryTissue engineeringa b s t r a c tChitosan is non-toxic,biocompatible and biodegradable polysaccharide composed of glucosamine and derived by deacetylation of chitin.Chitosan thermosensitive hydrogel has been developed to form a gel in situ,precluding the need for surgical implantation.In this review,the recent advances in chitosan ther-mosensitive hydrogels based on different glycerophosphate are summarized.The hydrogel is prepared with chitosan and ␤-glycerophosphate or ␣␤-glycerophosphate which is liquid at room temperature and transits into gel as temperature increases.The gelation mechanism may involve multiple interactions between chitosan,glycerophosphate,and water.The solution behavior,rheological and physicochemical properties,and gelation process of the hydrogel are affected not only by the molecule weight,deacetyla-tion degree,and concentration of chitosan,but also by the kind and concentration of glycerophosphate.The properties and the three-dimensional networks of the hydrogel offer them wide applications in biomedical ﬁeld including local drug delivery and tissue engineering.©2014Elsevier Ltd.All rights reserved.Contents 1.Introduction .........................................................................................................................................5252.Chitosan/␤-glycerophosphate hydrogels ...........................................................................................................5252.1.Development process and gelation mechanism ............................................................................................5252.2.Preparation and properties ..................................................................................................................5283.Chitosan/␣␤-glycerophosphate hydrogels .........................................................................................................5303.1.Development process and gelatinize mechanism...........................................................................................5303.2.Preparation and properties ..................................................................................................................5304.Biomedical applications of chitosan/glycerophosphate based hydrogels ..........................................................................5314.1.Local drug delivery ..........................................................................................................................5314.2.Tissue engineering applications .............................................................................................................5325.Conclusion ...........................................................................................................................................534Acknowledgments ..................................................................................................................................534References ...........................................................................................................................................534∗Corresponding author.Tel.:+86037964231914.∗∗Corresponding author.Tel.:+86053282032586;fax:+86053282032586.E-mail addresses:hyzhou@ (H.Y.Zhou),xgchen@ (X.G.Chen)./10.1016/j.carbpol.2014.09.0940144-8617/©2014Elsevier Ltd.All rights reserved.H.Y.Zhou et al./Carbohydrate Polymers117(2015)524–5365251.IntroductionHydrogels are composed of three-dimensional polymer networks that have a high number of hydrophilic groups.The hydrogels can absorb large quantities of water and will neither disintegrate nor dissolve.Fully swollen hydrogels are soft,pliable, and low interfacial tension with water or biologicalﬂuids.The high water content of hydrogel renders it compatible with most living tissue and the viscoelastic nature of hydrogel minimizes damage to the surrounding tissue when it is implanted in the host.These characteristics make hydrogel an ideal candidate in biomedical applications such as remedying injuries to living sys-tems(Bhattarai,Gunn,&Zhang,2010).In addition,hydrogels can serve as a supporting material for cells during tissue regeneration as well as drug delivery system because the hydrogel’s physico-chemical properties are similar to the native extracellular matrix both compositionally and mechanically(Lee&Mooney,2001; Tessmar&Gopferich,2007).The hydrogel will become responsive to environmental stimulation if the polymer network of hydrogel is endowed with functional groups(Buenger,Topuz,&Groll,2012). The stimulation may be temperature,pH,biomolecules,electric ﬁeld,magneticﬁeld,light rays and so on.When the environment stimulation is changed,the hydrogels undergo a volume-phase transition due to molecular interactions resulting in abrupt changes in the network such as swelling,collapse or sol-to-gel transition.Glycerophosphate is an organic compound naturally found in the body which is usually used as a source of phosphate in the treatment of unbalance of phosphate metabolism and its veinal administration has been approved by FDA.␤-Glycerophosphate has been shown as an osteogenic supplement when added to cultures of human bone marrow stem cells.␣␤-Glycerophosphate is the mixture of␣-glycerophosphate and␤-glycerophosphate,and␣-glycerophosphate has linear chain structure and shows less steric hindrance than␤-glycerophosphate.Glycerophosphate also has been used as a catalyst to cause a sol-to-gel transition in chitosan solutions at physiological pH and temperature.Chitosan,the cationic(1-4)-2-amino-2-deoxy-␤-D-glucan, partly acetylated to the typical extent close to0.25is industrially produced in medical/pharmaceutical grade from marine chitin (Jayakumar,Menon,Manzoor,Nair,&Tamura,2010;Jayakumar, Prabaharan,Nair,&Tamura,2010;Jayakumar et al.,2010; Muzzarelli,2009;Muzzarelli,2010;Muzzarelli,2012;Muzzarelli et al.,2012).The development of chitosan hydrogel has been an area drawing intensive investigation and a large amount of works have been reported on chitosan hydrogel and its potential use in various applications(Lee et al.,2009;Nagahama et al.,2009;Sung et al.,2010;Tang,Du,Hu,Shi,&Kennedy,2007;Zhou et al.,2012).Chitosan hydrogels have been prepared with a variety of differ-ent geometries and formulations including liquid gels,beads,ﬁlms, tablets,capsules,microspheres,microparticles,sponges,and textile ﬁbers(Denkbas,2006;Hamidi,Azadi,&Raﬁei,2008;Khan,Tare, Oreffo,&Bradley,2009;Ladet,David,&Domard,2008).In each preparation,the polymer binding is accomplished either by non-covalent physical association,such as secondary forces(hydrogen, ionic,or hydrophobic bonding)and physical entanglements,or by covalent cross-linked chemical association(Hoffman,2002).Physi-cal associated networks can often be obtained by simply mixing the components which make up the gel under the appropriate condi-tions.Furthermore,the gelation,requiring no toxic covalent linker molecules,is always safe for clinical applications.This review focuses on the hydrogel based on different glycerophosphate including the preparation and applications, which is a temperature-sensitive physical associated network. There are several excellent reviews of hydrogel or chitosan-based hydrogel(Bhattarai et al.,2010;Buenger et al.,2012; Hoffman,2002;Lee&Mooney,2001)and there is a review about thermosensitive chitosan/glycerophosphate-based hydrogel and its derivatives(Supper et al.,2014),but an in-depth review on chitosan/glycerophosphate hydrogel based on the different glyc-erophosphate cannot be found ever.In this review,we will summarize the various categories of chitosan/glycerophosphate hydrogels prepared with chitosan and␤-glycerophosphate or␣␤-glycerophosphate,describe the preparation methods,introduce the properties and gelation mechanism,and present recent advances in biomedical applications.2.Chitosan/␤-glycerophosphate hydrogels2.1.Development process and gelation mechanismChitosan dissolves in acidic environments via protonation of its amine groups.Once dissolved,chitosan remains in solution up to pH value in the vicinity of6.2.Neutralization of chitosan aqueous solutions to pH value exceeding6.2systematically leads to the for-mation of a hydrated gel-like precipitate.Effort on chitosan neutral solution isﬁrst proposed by Chenite et al.(2000).Theyﬁnd that chi-tosan solutions remain liquid below room temperature,even with pH values within a physiologically acceptable neutral range from 6.8to7.2,in the presence of␤-glycerophosphate salt.The system becomes thermally sensitive,which is liquid at room temperature and solidiﬁes into gel as temperature increasing to body tempera-ture(Fig.1)(Ruel-Gariépy et al.,2004).␤-glycerophosphate plays three essential roles in the system:(1)to increase the pH into the physiological range of7.0–7.4;(2)to prevent immediate precip-itation or gelation;and(3)to allow for controlled gel formation when an increase in temperature is imposed.The sol-to-gel tran-sition temperature is pH-sensitive and gelling time is shown to be temperature-dependent.The molecular mechanism of gelation may involve multiple interactions between chitosan,␤-glycerophosphate,and water (Crompton et al.,2005;Ruel-Gariépy,Chaput,Guirguis,&Leroux, 2000).The effective interactions responsible for the sol/gel tran-sition included:(1)the increase of chitosan interchain hydrogen bonding as a consequence of the reduction of electrostatic repulsion due to the basic action of the salt,(2)the chitosan-glycerol-phosphate electrostatic attractions via the ammonium and the phosphate groups,respectively,and(3)the chitosan–chitosan hydrophobic interactions which should be enhanced by the struc-turing action of glycerol on water.The solution behavior of chitosan/␤-glycerophosphate hydro-gel is affected by the concentration of chitosan and␤-glycerophosphate(Cho,Heuzey,Bégin,&Carreau,2006a).The pH of chitosan solution is slightly increased with increasing of ␤-glycerophosphate concentration due to the neutralizing effect of the phosphate groups.The pH increase with polymer concen-tration is due to the consumption of H+ions in solution by the protonation of the free amine groups.The relationship between gelation temperature and concentration of chitosan(C C)and␤-glycerophosphate(C GP)is shown in Fig.2.The region below the surface is the sol state,while that above is a gel.T gel is gradually decreased with increasing of C GP and C C.However,a synergetic effect at high C GP and C C results in a sudden drop of the gelation temperature and a phase transition which is on the edge between concentration-induced and heat-induced gelation.The rheological and physicochemical properties of the chitosan/␤-glycerophosphate system in terms of temperature are investigated sequentially(Chenite,Buschmann,Wang,Chaput, &Kandani,2001;Cho,AndréBégin,&Carreau,2005).Increasing temperature has no effect on the pH value of the chitosan/␤-glycerophosphate system,while conductivity is increased.The results indicate that the decrease of potential ionic interactions526H.Y.Zhou et al./Carbohydrate Polymers 117(2015)524–536Fig.1.The CS/GP formulation at room temperature (left)and at 37◦C (right).Figure was reprinted from Ruel-Gariépy et al.(2004).such as ionic bridging is resulted in by the reduction of the ratio of NH 3+in chitosan and OPO(O −)2in ␤-glycerophosphate at high temperature.On the other hand,the favorable conditions for gel formation resulted in by the increased ionic strength as a function of temperature involved which enhanced screening of electrostatic repulsion forces and hence more polymer–polymer hydrophobic interactions.Since it is generally assumed that hydrogen bonding interactions are not predominant at high temperature and hydrophobic effect is the main driving force for the chitosan/␤-glycerophosphate gelation at high temperature.To expand this standpoint,physicochemical and rheological properties of the chitosan/␤-glycerophosphate system is inves-tigated in the presence of urea,which is a hydrogen bonding disrupting agent and can also affect hydrophobic interaction (Cho,Heuzey,Bégin,&Carreau,2006b ).Heat-induced gelation of the chitosan system in the presence of urea shows higher gelation temperature in nonisothermal tests and longer gelation time in isothermal conditions.At low temperature,urea strongly affects polymer–polymer interactions by weakening hydrogen bonds.With temperature increasing,it hinders hydrophobic effect since the reduction of ionic strength results in less screening of elec-trostatic repulsion between protonated glucosamine groups.It is conﬁrmed that hydrophobic effect is the main driving force for the chitosan/␤-glycerophosphate heat-induced gelation.Aliaghaie,Mirzadeh,Dashtimoghadam,and Taranejoo (2012)have investigated the gelation mechanism of injectable thermosen-sitive hydrogels comprising chitosan and ␤-glycerophosphate by rheological measurements for a drug delivery.According totheFig.2.Phase diagram for T gel under various ␤-GP (C GP )and chitosan (C C )concen-trations.Figure was reprinted from Cho et al.(2006a).gelation behavior,three regions are deﬁned:(1)a liquid-like behav-ior at low temperature,(2)a fast gelation process near the gel point,and (3)a slow gelation process at higher temperatures (seen in Fig.3).The theory initially worked out by Fredrickson and Larson for block copolymers near their order–disorder transition is extended and proposed to precisely determine the gel point in such systems by considering the aggregation of hydrophobic acetylated blocks of chitosan chains and gelation in chitosan/glycerophosphate systems as an order–disorder transition of block copolymers.Upon heat-ing,the water sheaths around chitosan chains are removed and the heat induced transfer of protons from protonated amino groups to glycerophosphate occurs,and consequently the formation of hydrophobic interactions among chitosan chains is facilitated.Then the gelation process beyond the crossover point goes through a nucleation and growth mechanism and the growth of hydrophobic domains could happen through the reaction limited cluster aggre-gation.In the third region,the observed rheological behavior could be associated with the tendency of system to minimize its interfa-cial area through the Ostwald ripening process.In addition,the effect of molecular weight and deacetylation degree of chitosan on gelation process is researched.The results of the temperature sweep measurement (Aliaghaie,Mirzadeh,Dashtimoghadam,&Taranejoo,2012)have been shown that the G and G crossover point for lower molecular weight chitosan sample have been shifted to 33◦C,which is 2◦C higher than that for high molecular weight chitosan sample.This implies that the hydropho-bic interactions in lower molecular weight chitosan sample have been formed at a higher temperature,which might be a result of lower entanglement and shorter hydrophobic domains.Such an observation could be attributed to the lower molecular weight and consequently lower viscosity of the sample,which provides more possibility for aggregation and percolation of hydrophobic domains through reaction limited cluster aggregation theory.ItFig.3.The evolution of the storage (G )and loss (G )moduli of the chitosan hydrogel during heating from 25to 65◦C.Figure was reprinted from Aliaghaie et al.(2012).H.Y.Zhou et al./Carbohydrate Polymers117(2015)524–536527 Table1Parameters,gel temperature and gel time of chitosan/glycerophosphate hydrogels:some examples..Chitosan C GP(w/v)T gel/◦C Gel time ReferenceMw/kD DD C(w/v)␤-GP␣␤-GP700/200–30074%/99%1%(1/1)23%31–33120–280s Aliaghaie et al.(2012) 35091%1–2%0–8%32–4213–2min Chenite et al.(2001)552–80870–91%2% 5.6%37–66quickly Chenite et al.(2000) 85093%0.05–0.20M0.33–0.83M58–797–11s Cho et al.(2006a,b)140cps96.5%0.1512–0.1728%2–8%30.1–45.71–3min Dang et al.(2011)140cps96.5%0.1512–0.162%5–8%21–3530–90s Dang et al.(2012a,b)463–86281.8–83.4% 2.05%9.09%371400–2400s Douglas et al.(2013)455.295%2% 5.6%,7%33,37/Hastings et al.(2012)20–525cps91%2%8%374–10min Huang et al.(2009) 108086%2%8.33–9.09%25–3720–3min Ji et al.(2010)/95% 2.5%6–16%50–37Kempe et al.(2008) 31075% 1.5%0.045–1.155M3760–330s Kim et al.(2010)200–800cps75–80% 1.6%30%37/Kwon et al.(2012)/75–85%0.9% 5.8%376min Niranjan et al.(2013)/95% 1.4–2.2%w/w8–16%w/w37/Peng et al.(2013a,b)421.8/455.284%/95% 1.5%w/w7.27%w/w7.27%w/w375/140min Ruel-Gariépy et al.(2000) 113–90065–88%2%2–8%24.3–91.7/Tsai et al.(2011)300–40081.0–94.8% 1.8%5%372–60min Zan et al.(2006)5095%2%10%376min Zhang et al.(2013) 136075% 1.7–1.9% 2.5–7.5%3710min Zhou et al.(2009)88–136056.5–90.3% 1.0–3.0%5%3710min Zhou et al.(2008)␤-GP:␤-glycerophosphate;␣␤-GP:␣␤-glycerophosphate;T gel:gel temperature.could be suggested that the lower molecular weight has facilitated the aggregation and percolation of hydrophobic domains,which is consistent with the lower percolation temperature obtained from temperature sweep measurements.Furthermore,it is under-stood that the deacetylation of chitin chains to achieve chitosan preferably occurs at the amorphous zones,and hence blocktype distribution of hydrophobic and hydrophilic segments are the result.So deacetylation affects the gelation process by affecting the hydrophobic and hydrophilic properties of chitosan.Chitosan could be considered as a block copolymer of acetylated and deacetylated units and the thermo-gelation of the chitosan/glycerophosphate system happens due to aggregation of hydrophobic acetylated blocks,and could be considered as an order–disorder transition or phase separation.It is the same result as Ruel-Gariépy et al. (2000)that gelation could occur at relatively low temperatures depending on the deacetylation degree of chitosan.The increase in gelation rate observed with chitosans of higher deacetylation degree might be attributed to the increase in cross-link density between the phosphate groups of glycerophosphate and the ammo-nium groups of chitosan.The parameters,gel temperature and gel time of chitosan/glycerophosphate hydrogels from some ref-erences are shown in Table1.Tsai,Chang,Yu,Lin,and Tsai(2011)has explored the effect of nanosilver,chitosan characteristics,and solution conditions on gelation temperature of chitosan/␤-glycerophosphate thermosen-sitive hydrogel.The gelation temperature of hydrogel is decreased with the increasing of deacetylation degree of chitosan,concen-tration of␤-glycerophosphate,and pH value(6.5–6.8).It is also decreased with the decreasing of chitosan molecular weight.The present of12ppm nanosilver has no effect on gelation temperature. Then,effects of chitosan characteristics on the physicochemical properties are also studied by Chang,Lin,Tsai,and Tsai(2013). It is concluded that the gelation temperatures for the hydro-gels are measured in the range of32–37◦C by manipulating the molecular weight and deacetylation degree of chitosan and the glycerophosphate concentration.The structure of hydrogel with 88%deacetylation degree of chitosan is more porous,uniform,and connective than that of the hydrogel with80%deacetylation degree of chitosan.Li,Fan,Ma,et al.(2014)and Li,Fan,Zhu,and Ma(2014) have prepared the chitosan/␤-glycerophosphate hydrogel included human-like collagen and studied the gelation mechanism and its properties.The results show that an amide bond(CONH) is formed between the carbonyl(C O)of human-like collagen and the amino of chitosan and NRH2+is formed between the amide bond and␤-glycerophosphate.The temperature sensitivity depends on the hydrophobic–hydrophilic interaction of molecular chains,and the pH sensitivity depends on the electrostatic inter-action of ionic groups(NRH2+and OPO32−).In addition,the chitosan/human-like-collagen/␤-glycerophosphate hydrogel with crosslinking agent of carbodiimide is prepared and the proper-ties are also examined(Li et al.,2013).The results show that the gelation time,structure,equilibrium swelling and degradation in vitro and in vivo are dependent upon crosslinking and struc-ture of composite hydrogels.The hydrogel shows desirable gelling time,swelling ratio,smooth surface,regular porous networks and biodegradability.Furthermore,Li,Fan,Ma,et al.(2014) and Li,Fan,Zhu,et al.(2014)have prepared chitosan/human-like collagen/hyaluronic acid/␤-glycerophosphate hydrogels based on the self-assembly of chitosan/human-like collagen/hyaluronic acidﬁbers.The results indicate that a new amide bond (CONH)and NRH2+are formed.The gelling time and swelling behaviors are dependent on the intertwining,overlap and adsorp-tion of the polymer chains at various temperatures and pH values.Furthermore,the biological properties of the chitosan/␤-glycerophosphate system are investigated and the effects of different factors are analyzed.The effects of chitosan characteristics on the antibacterial activity,and cytotoxicity of chitosan/␤-glycerophosphate/nanosilver hydrogels are studied(Chang et al., 2013).It is concluded that the hydrogel could be prepared with lower molecular weight chitosan and lower concentration of nanosilver in order to reduce the cytotoxicity of nanosilver, while maintaining similar antibacterial activity with the hydro-gel prepared with higher concentration nanosilver and higher molecular weight chitosan.Then the effect of the self-assembly of chitosan/human-like collagen/hyaluronic acidﬁbers on the histo-compatibility of the hydrogels is studied(Li,Fan,Ma,et al.,2014; Li,Fan,Zhu,et al.,2014)and the result reveals that theﬁbers inside the hydrogel pores reduce the quantity of macrophages,decrease the degree of inﬂammation,and improve the anti-degradation of the modiﬁed hydrogels.528H.Y.Zhou et al./Carbohydrate Polymers117(2015)524–5362.2.Preparation and propertiesA novel injectable in situ gelling thermosensitive chitosan/␤-glycerophosphate formulation has been proposed in recent years (Chenite et al.,2000,2001;Ruel-Gariépy,Hildgen,Gupta,&Leroux, 2002).First,chitosan and␤-glycerophosphate solutions are pre-pared in deionized water.Second,the two solutions are chilled in an ice bath for15min.Then the␤-glycerophosphate solution is added dropwise to the chitosan solution under stirring and the resulting mixture is stirred for another10min.The release of macromolecules from the system could sustain over a period of sev-eral hours to a few days while the release of low-molecular-weight hydrophilic compounds is generally completely within24h.The gelation rate and gel strength is slightly increased by the adding of liposome to the chitosan/␤-glycerophosphate solution,and the liposome-chitosan/␤-glycerophosphate system rapidly gels at body temperature(Ruel-Gariépy et al.,2002).The similar prepara-tive method has been used to control the release of different model compounds(Ruel-Gariépy et al.,2000).Ruel-Gariepy et al.(2004) have proposed to use the chitosan thermosensitive hydrogel for the sustained release of paclitaxel at tumor resection sites in order to prevent local tumor recurrence.The macro-and microstructure of chitosan/␤-glycerophosphate systems is exosyndromed by rheology and electron paramagnetic resonance spectroscopy(Kempe et al.,2008).Increasing␤-glycerophosphate concentration leads to a lowering of the gelation temperature from about50◦C to37◦C,and higher␤-glycerophosphate concentrations lead to faster gelation.The results indicate that the insulin is incorporated into the aqueous environ-ment of the gel and released in its native form.The viscosity of the gelled system is much higher compared to the sol systems of the same composition.The pH of chitosan/␤-glycerophosphate solu-tion is between6.6and6.8which do not change during gelation irrespective of the proportion of␤-glycerophosphate.The gela-tion formation process does not change the microacidity inside the sample.Sharma,Italia,Sonaje,Tikoo,and Ravi Kumar(2007)have devel-oped a chitosan-based in situ gelling system for subcutaneous administration of ellagic acid.The ellagic acid/chitosan/␤-glycerophosphate hydrogel system shows an initial burst release in vitro with about85%drug releasing in12h followed by a steady release till160h.The data indicate that formulations are effec-tive against cyclosporine induced nephrotoxicity,where the ellagic acid/chitosan/␤-glycerophosphate hydrogel shows activity at10 times lower dose compared to orally given ellagic acid.So the bioavailability of ellagic acid can be improved by subcutaneous formulations administered as simple ellagic acid hydrogel.Kim et al.(2010)have reported a thermosensitive chitosan hydrogel for the delivery of ellagic acid for the treatment of brain cancer. The gelation temperature and time are affected by theﬁnal pH of the chitosan/␤-glycerophosphate solution.Dialyzed chitosan solu-tion withﬁnal pH6.3greatly reduces␤-glycerophosphate needed for gelation,thereby signiﬁcantly improves the biocompatibility of gel.The chitosan gels containing1%(w/v)of ellagic acid signiﬁ-cantly reduces viability of U87cells and C6cells compared with the chitosan gels at3days incubation.Cui et al.(2011)have fabricated bioabsorbable chitosan/␤-glycerophosphate composite membranes through a relatively pH neutral and mild sol-to-gel process for guided bone regeneration. The results show that the chitosan/␤-glycerophosphate compos-ite membranes have a porous structure both at the surface and in sub-layers and the incorporation of␤-glycerophosphate in the chitosan matrix decreases the initial tensile strength of the mem-brane.The concentration of␤-glycerophosphate is proportional to the pore size and thickness but is inversely proportional to the tensile strength of the chitosan/␤-glycerophosphate membrane.Hydrogel beads are proposed with two sequential gelation steps based on chitosan/␤-glycerophosphate system and the model drug/cell(dexamethasone and L929cells)are immobilized inside (Lima,Correia,Oliveira,&Mano,2014).Superhydrophobic surfaces are used to produce the spherical hydrogel particles that provided favorable conditions to encapsulate cells or bioactive agents.First, the chitosan acidic solution is neutralized with␤-glycerophosphate at room temperature to pH6.2.Suspended cells(or dexametha-sone)in the formulation are dispensed in controlled volumes onto biomimetic polystyrene superhydrophobic surfaces,to form spher-ical shapes.The addition of sodium tripolyphosphate on the top of each sphere induces an ionic gelation process of the chitosan through electrostatic interactions.At37◦C,the hydrophobicity of the chitosan/␤-glycerophosphate system increases and a second gelation step occurs,which increase the elastic modulus.The soft-ness andﬂexibility of the system can potentially be utilized to implant cells and therapeutic molecules using less invasive pro-cedures.Recent studies have been reported that the physical proper-ties includingﬂexibility and mechanical properties of CS/␤-GP hydrogel can be improved by blending chitosan with other mate-rials.Ngoenkam,Faikrua,Yasothornsrikul,and Viyoch(2010)have developed a thermosensitive hydrogel which forms gel rapidly by blending chitosan/␤-glycerophosphate solution with the pregela-tinized starch.The presence of starch in the system could increase the water absorption and average pore size of the hydrogels.The hydrogel could degrade in lysozyme slowly during56days of incubation.In vivo studies indicate that the hydrogel shows rapid formation and localization at the injection site(shown as Fig.4)and has a potential to stabilize chondrocytes which is characterized by the expression of type II collagen mRNA and protein.Sun,Jiang, Wang,and Ding(2012)have reported that hydrophilic polymer poly(vinyl alcohol)is blended into the thermosensitive hydro-gel composed of chitosan and glycerophosphate to mitigate the body responses and promote the drug bioavailability.The results show that the presence of poly(vinyl alcohol)improves the sur-face hydrophilicity of the hydrogel and inhibits the cell attachment on the hydrogel,which alleviates the further cell inﬁltration and tissue integration in body.In addition,the presence of poly(vinyl alcohol)leads to the more rapid gel formation and more compact network,which resisted the dehydration and survived the hydrogel from cell division.These advantages beneﬁt the controlled release and absorption of cyclosporine A,and contribute to the higher drug bioavailability.Fatimi et al.(2012)have developed the chitosan/␤-glycerophosphate hydrogel which is injectable,radiopaque and contains sodium tetradecyl sulfate,a well-known sclerosing agent,in order to combine bloodﬂow occlusion and endothelium ablation properties.The hydrogel is shown to exhibit rapid gelation and good mechanical properties,as well as sclerosing properties. The preliminary animal study shows that no endoleak is detected in any of the three aneurysms treated with chitosan/sodium tetrade-cyl sulfate/␤-glycerophosphate hydrogel at3months.Generally, the prepared hydrogels have great potential as embolizing and sclerosing agents for endovascular aneurysm repair and possibly other endovascular therapies.Then chitosan radiopaque hydrogels are prepared using chitosan,␤-glycerophosphate,iopamidol,and different sodium tetradecyl sulfate concentrations to investigate whether embolization with chitosan/␤-glycerophosphate hydro-gel with or without a sclerosant can induce chemical endothelial ablation and prevent endothelial recanalization in a rabbit model (Chabrot et al.,2012).It is concluded that the viscosity obtained with chitosan,␤-glycerophosphate,and3%sodium tetradecyl sulfate permits better control during injection and longer vascular occlusion.Theseﬁndings,combined with the intravascular neo-vascularization observed with the chitosan/␤-glycerophosphate。

壳聚糖知识讲座

对全部高中资料试卷电气设备，在安装过程中以及安装结束后进行高中资料试卷调整试验；通电检查所有设备高中资料电试力卷保相护互装作置用调与试相技互术关，系电，力根通保据过护生管高产线中工敷资艺设料高技试中术卷资0配不料置仅试技可卷术以要是解求指决，机吊对组顶电在层气进配设行置备继不进电规行保范空护高载高中与中资带资料负料试荷试卷下卷问高总题中体2资2配，料置而试时且卷，可调需保控要障试在各验最类；大管对限路设度习备内题进来到行确位调保。整机在使组管其高路在中敷正资设常料过工试程况卷中下安，与全要过，加度并强工且看作尽护下可关都能于可地管以缩路正小高常故中工障资作高料；中试对资卷于料连继试接电卷管保破口护坏处进范理行围高整，中核或资对者料定对试值某卷，些弯审异扁核常度与高固校中定对资盒图料位纸试置，卷.编保工写护况复层进杂防行设腐自备跨动与接处装地理置线，高弯尤中曲其资半要料径避试标免卷高错调等误试，高方要中案求资，技料编术试写5交、卷重底电保要。气护设管设装备线备置4高敷、调动中设电试作资技气高，料术课中并3试中、件资且卷包管中料拒试含路调试绝验线敷试卷动方槽设技作案、技术，以管术来及架避系等免统多不启项必动方要方式高案，中；为资对解料整决试套高卷启中突动语然过文停程电机中气。高课因中件此资中，料管电试壁力卷薄高电、中气接资设口料备不试进严卷行等保调问护试题装工，置作合调并理试且利技进用术行管，过线要关敷求运设电行技力高术保中。护资线装料缆置试敷做卷设到技原准术则确指：灵导在活。分。对线对于盒于调处差试，动过当保程不护中同装高电置中压高资回中料路资试交料卷叉试技时卷术，调问应试题采技，用术作金是为属指调隔发试板电人进机员行一，隔变需开压要处器在理组事；在前同发掌一生握线内图槽部纸内故资，障料强时、电，设回需备路要制须进造同行厂时外家切部出断电具习源高题高中电中资源资料，料试线试卷缆卷试敷切验设除报完从告毕而与，采相要用关进高技行中术检资资查料料和试，检卷并测主且处要了理保解。护现装场置设。备高中资料试卷布置情况与有关高中资料试卷电气系统接线等情况，然后根据规范与规程规定，制糖尿病壳聚糖可调整体液酸碱度，使体液由酸性向碱性转化，提高胰岛素的活性及受体的敏感性，从而使糖分解量增加，使血糖下降；壳聚糖可直接活化、修复及再生胰岛 β 细胞，提高胰岛 β 细胞的数量及活性，使血糖下降；壳聚糖可限制胃肠道中糖分的摄入，从而减轻胰腺工作的负荷，减轻对胰腺的损害，促进胰腺恢复。 10、壳聚糖与肝病壳聚糖能够有效清除胃肠道及血液中的油脂成分，防止脂肪肝，减轻肝脏负担；壳聚糖能促进肝炎病毒抗体生成，抗肝炎；壳聚糖能够修复受损肝细胞，同时具有强大的活化作用；壳聚糖可与洒精的毒性分解产物乙醛有效结合、减轻乙醛对神经的毒害作用，有效防止酒后头疼、头晕、呕吐（解酒）。 11、壳聚糖与抗肿瘤（1）清除肿瘤毒素。清除由毒性激素 l 带来的食欲不振、贫血、乏力等症状。（2）活化杀伤肿瘤的淋巴细胞。增强巨噬细胞的吞噬功能，刺激巨噬细胞产生淋巴因子，启动免疫系统，有效提高机体抗肿瘤免疫等功能（3）抑制肿瘤转移。与接着分子有效结合，降低肿瘤细胞