壳聚糖及其衍生物抗菌性质的研究进展

壳聚糖对多种细菌、真菌具有广谱抗菌的功能,因此它被广泛地应用于广泛地用于口腔疾病、皮肤炎症、伤口感染、胃肠道疾病等各种疾病的治疗。本文综述了壳聚糖及其衍生物对常见的口腔致病菌、皮肤癣菌、伤口感染菌以及胃肠道疾病的致病菌的抗菌作用和壳聚糖及其衍生物的抗菌机理。     

壳聚糖衍生物及其胶束：特性、功能化修饰和在药物传递系统中的应用

壳聚糖是一种天然多糖,具有无毒、可生物降解、生物相容性等诸多优点,但水溶性差的自身特点限制了其在药剂学中的应用,而其经合理的结构设计、修饰和优化,可获得性能良好的两亲性壳聚糖衍生物,这些衍生物在水溶液中能自组装成具有良好药物传输性能（如载药量、稳定性、刺激敏感性、靶向性等）的胶束,并被广泛应用于构建药物传递系统,以改善药物的溶解性、靶向性、生物利用度及耐药性,降低药物的毒副作用。综述壳聚糖衍生物结构对其胶束药物传输性能的影响以及壳聚糖衍生物及其胶束的功能化修饰和在药物传递系统中的应用。     

壳聚糖的结构修饰及其应用

壳聚糖是甲壳素的衍生物,其水溶性较差。为了改善其溶解性,拓宽其应用范围,根据其结构特点对其进行化学修饰,制得多种衍生物。该就其在羧基化、酰基化、烷基化、醚化等方面的修饰及其应用进行综述。     

低聚壳聚糖美拉德衍生物抑菌性能研究

本文研究了基于与葡萄糖、麦芽糖和木糖进行美拉德反应的低聚壳聚糖衍生物的抑菌性.测定低聚壳聚糖及其衍生物对大肠杆菌和金黄色葡萄球菌的抑制效果.结果显示:壳聚糖及其衍生物对金黄色葡萄球菌的抑制作用强于对大肠杆菌的抑制作用,且随着浓度增加,对两种菌的抑菌效果增强.大多数壳聚糖衍生物的抑菌效果优于壳聚糖本身,其中CG 1∶1 8 h(低聚壳聚糖的氨基与葡萄糖的羰基的物质量比为1∶1,反应8h)的抑菌效果最好,CM 1∶3 8 h(低聚壳聚糖的氨基与麦芽糖的羰基的物质量比为1∶3,反应8 h)抑菌性最差,这可能与参加反应的还原糖种类、反应物比例以及反应时间相关.     

壳聚糖及其衍生物在生物医药中的应用与研究进展

随着科学、医疗技术的不断发展,自然界中很多有用的化学物质都被提炼出来,并广泛运用于生物、医疗、美容、化学等方面,壳聚糖就是其中的一种,壳聚糖具有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,这些特性使得其被各行各业广泛关注并应用。本文系统地介绍了壳聚糖极其衍生物发展史、性质、以及其生物医药中的具体应用。     

壳聚糖及其衍生物抗肿瘤作用研究进展

壳聚糖为天然多糖甲壳素脱除部分乙酰基的产物,是自然界存在的唯一碱性多糖,无毒,可生物降解,具有免疫功能和良好的生物相容性。近年发现,壳聚糖具有抗肿瘤作用,却因其难溶于水及中性溶剂而影响其应用,壳聚糖衍生物改善了壳聚糖的这个缺点,也具有更广泛的药理作用。本文对壳聚糖及其壳聚糖衍生物在抗肿瘤方面的研究情况做了综述。     

壳聚糖及其衍生物在医药上的应用

本文着重对壳聚糖及其衍生物的抗菌特性,降低血清胆甾醇和抑制高血压的特性及其作为肝素材料在医药上的应用进行综述,并展望了其在医药上的发展前景。     

甲壳素及其应用

概述了甲壳素的来源,甲壳素、壳聚糖的化学组成及性质。讨论了甲壳素及其衍生物在医学、工业、农业及环保等领域的应用。     

壳聚糖及其衍生物作为药物载体研究进展

壳聚糖是甲壳素脱乙酰化的衍生物,是自然界中唯一的碱性多糖.壳聚糖及其衍生物是一类资源丰富、可生物降解的天然聚合物,具有生物相容性、高电荷密度、无毒性和粘膜粘附性,广泛应用于生物医学和药物制剂领域.壳聚糖作为药物载体可以控制药物释放、提高药物疗效、降低药物毒副作用,可以提高疏水性药物对细胞膜的通透性和药物稳定性及改变给药途径,还可以加强制刑的靶向给药能力.本文分别从壳聚糖及其衍生物在大分子药物载体、缓控释系统及不同部位给药系统中的应用进行了综述,以说明壳聚糖及其衍生物是一种优良的药物传递载体和新型药用辅料.     

壳聚糖作为基因药物载体的研究进展

以壳聚糖及其衍生物作为基因的载体的转染效率受到许多因素的影响, 如复合物粒子大小、壳聚糖/DNA的比值、壳聚糖的分子量、脱乙酰度、转染过程中血清的浓度、介质的pH值等。对壳聚糖进行一定程度的修饰, 可以改变壳聚糖的转染效率。介绍了壳聚糖作为基因转移载体的转染条件, 转染效率和转染机制的研究情况及研究进展。     

壳聚糖作为药物缓释控释载体的研究进展

壳聚糖因其具有良好的生物学特性而成为多种药物载体研究的热点。药物经过壳聚糖负载后,不仅能够达到缓释控释的目的,还能够改变药物的给药方式,以此减少给药次数,降低药物不良反应,提高药物生物利用度。本文就壳聚糖和改性壳聚糖作为普通药物和生物大分子药物载体的研究进展作一综述。     

Growth of human mesenchymal stem cells (MSCs) on films of enzymatically modified chitosan

Mesenchymal stem cells (MSCs) are known to be an attractive cell source for tissue engineering and regenerative medicine. One of the main limiting steps for clinical use or biotechnological purposes is the expansion step. The research of compatible biomaterials for MSCs expansion is recently regarded as an attractive topic. The aim of this study was to create new functional biomaterial for MSCs expansion by evaluating the impact of chitosan derivative films modified by enzymatic approach. First, chitosan particles were enzymatically modified with ferulic acid (FA) or ethyl ferulate (EF) under an eco‐friendly procedure. Then, films of chitosan and its modified derivatives were prepared and evaluated by physicochemical and biological properties. Results showed that the enzymatic grafting of FA or EF onto chitosan significantly increased hydrophobic and antioxidant properties of chitosan films. The MSCs cell viability on chitosan derivative films also increased depending on the film thickness and the quantity of grafted phenols. Furthermore, the cytotoxicity test showed the absence of toxic effect of chitosan derivative films towards MSCs cells. Cell morphology showed a well attached and spread phenotype of MSCs cells on chitosan derivative films. On the other hand, due to the higher phenol content of FA‐chitosan films, their hydrophobic, antioxidant properties and cell adhesion were improved in comparison with those of EF‐chitosan films. Finally, this enzymatic process can be considered as a promising process to favor MSCs cell growth as well as to create useful biomaterials for biomedical applications especially for tissue engineering. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:491–500, 2016     

Recent Advancement of Chitosan-Based Nanoparticles for Oral Controlled Delivery of Insulin and Other Therapeutic Agents

Nanoparticles composed of naturally occurring biodegradable polymers have emerged as potential carriers of various therapeutic agents for controlled drug delivery through the oral route. Chitosan, a cationic polysaccharide, is one of such biodegradable polymers, which has been extensively exploited for the preparation of nanoparticles for oral controlled delivery of several therapeutic agents. In recent years, the area of focus has shifted from chitosan to chitosan derivatized polymers for the preparation of oral nanoparticles due to its vastly improved properties, such as better drug retention capability, improved permeation, enhanced mucoadhesion and sustained release of therapeutic agents. Chitosan derivatized polymers are primarily the quaternized chitosan derivatives, chitosan cyclodextrin complexes, thiolated chitosan, pegylated chitosan and chitosan combined with other peptides. The current review focuses on the recent advancements in the field of oral controlled release via chitosan nanoparticles and discusses about its in vitro and in vivo implications.     

Preparative methods of phosphorylated chitin and chitosan--an overview

Biomaterials such as chitin, chitosan and their derivatives have a significant and rapid development in recent years. Chitin and chitosan have become cynosure of all party because of an unusual combination of biological activities plus mechanical and physical properties. However, the applications of chitin and chitosan are limited due to its insolubility in most of the solvents. The chemical modification of chitin and chitosan are keen interest because of these modifications would not change the fundamental skeleton of chitin and chitosan but would keep the original physicochemical and biochemical properties. They would also bring new or improved properties. The chemical modification of chitin and chitosan by phosphorylation is expected to be biocompatible and is able to promote tissue regeneration. In view of rapidly growing interest in chitin and chitosan and their chemical modified derivatives, we are here focusing the recent developments on preparation of phosphorylated chitin and chitosan in different methods.     

Chitosan: An option for development of essential oil delivery systems for oral cavity care?

Microencapsulation of bioactive compounds has received increased attention in the last decade. Among the polymers used for developing microparticulated systems, chitosan has been widely cited. Obtained by deacetylation of chitin, chitosan is a natural, biodegradable, biocompatible and mucoadhesive polymer with permeability enhancement properties. These data justify its use for overcoming the reduced efficacy of conventional treatments of oral diseases. Various tests simulating the buccal environment have described controlled drug release profile and significant activity against buccal pathogens by chitosan microparticles entrapping antimicrobial agents. Considering the increasing microbial resistance to conventional antibiotics, essential oils have shown to be an important option against these pathogens. For sustained stability and prolonged release of essential oils from pharmaceutical formulations, some authors have studied the association of chitosan to them. This review disserts about the application of chitosan and essential oils on oral cavity care pointing out their association may be an interesting option.     

甲壳素/壳聚糖在酶固定化中的应用

作为功能性材料,甲壳素与壳聚糖分布广泛,且具有一系列独特的性质:无毒性、凝胶性、生物适应性、降解产物的无毒性、显著的蛋白质亲和性等。正是由于这些特性,虽然甲壳素/壳聚糖材料目前尚未得到充分的开发利用,但是与其它一些酶的固定化载体相比,具有广泛的开发前景。该文综述了近年来甲壳素/壳聚糖在酶的固定化方面的一些研究成果。主要包括:甲壳素/壳聚糖的理化性质、载体不同制备方法的特色和差异、在食品工业、非食品工业、环保、酶的分离纯化以及医疗应用方面的研究进展。     

甲壳素及其衍生物在防病抗衰中的应用研究

甲壳素及其衍生物具有独特的生物学特性和生物保健功能,现已作为辅助药物,被广泛应用于肿瘤、糖尿病、骨关节炎和心脑血管等老年相关性疾病的治疗,也具有增强机体免疫、清除自由基、延缓机体衰老等功能.现逐渐被用作为继蛋白质、脂肪、碳水化合物、维生素和矿物质之后人体的第6生命要素.     

A biomimetic chitosan composite with improved mechanical properties in wet conditions

Chitosan is one of the most widely used structural polymers for biomedical applications because it has many favorable properties. However, one of the most critical drawbacks regarding the use of chitosan as a biomedical material is its poor mechanical properties in wet conditions. Here, we designed a method to improve the mechanical properties of chitosan in wet conditions and minimized the swelling behavior of chitosan film due to water adsorption by mimicking the sclerotization of insect cuticles and squid beaks, that is, catechol‐meditated crosslinking. The biomimetic chitosan composite film was prepared by mixing chitosan with l ‐3,4‐dihydroxyphenylalanine (DOPA) as a catecholic crosslinker and sodium periodate as an oxidant. The catechol‐meditated crosslinking provided a sevenfold enhancement in the stiffness in wet conditions compared to pure chitosan films and reduced the swelling behavior of the chitosan film. This strategy expands the possible applications for the use of chitosan composites as load‐bearing biomaterials. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 505–512, 2013     

Synthesis, characterization, cytotoxicity and antibacterial studies of chitosan, O-carboxymethyl and N,O-carboxymethyl chitosan nanoparticles

Chitosan (CS) is a naturally occurring biopolymer. It has important biological properties such as biocompatibility, antifungal and antibacterial activity, wound healing ability, anticancerous property, anticholesteremic properties, and immunoenhancing effect. Recently, CS nanoparticles have been used for biomedical applications. However, due to the limited solubility of CS in water its water-soluble derivatives are preferred for the above said applications. In this work, the nanoparticles of CS and its water-soluble derivatives such as O-carboxymethyl chitosan (O-CMC) and N,O-carboxymethyl chitosan (N,O-CMC) was synthesized and characterized. In addition, cytotoxicity and antibacterial activity of the prepared nanoparticles was also evaluated for biomedical applications.