壳聚糖及其衍生物在药物载体中的应用

摘 要壳聚糖及其衍生物具有无毒、良好的生物相容性和可降解性、黏膜黏附性和促渗性等优点,在药物载体领域具有较为广阔的研究及应用前景。本文结合国内外最新发表的相关文献,对壳聚糖及其衍生物作为相关药物载体的应用以及作用机制进行分析讨论,并对其作为抗肿瘤药物靶向载体、缓控释药物载体、眼用药物载体、基因载体和凝胶基质的应用及研究进展进行综述。     

壳聚糖及其衍生物纳米粒的制备以及在疫苗中的应用

壳聚糖是一种高分子线性阳离子多糖。由壳聚糖及其化学改性衍生物制备的纳米粒具有生物相容性好、细胞毒性低以及可降解等特点,人们对其作为佐剂或递送系统在疫苗中的应用已开展了广泛研究。此文对壳聚糖及其衍生物纳米粒的制备方法以及在疫苗中的应用进行综述。     

两亲性壳聚糖衍生物在药物递送中的研究进展

壳聚糖是一种来源丰富的碱性多糖,具有良好的生物相容性和生物可降解性,但是其差的溶解性限制了壳聚糖在医药领域的应用。为了提高壳聚糖的溶解性,研究者对壳聚糖进行两亲性改性,通过选择不同的亲水、疏水基团,设计合成了两亲性壳聚糖衍生物。并利用其在水溶液中的自组装性能,形成两亲性壳聚糖纳米粒,用于多种药物的递送,以达到增加药物溶解性、稳定性、降低药物毒性和提高生物利用度等目的。本文综述了两亲性壳聚糖衍生物的合成方法,以及其在药物递送系统中的应用。     

壳聚糖在靶向制剂中的应用进展

壳聚糖是一种天然高分子化合物，壳聚糖及其衍生物具有优良的生物相容性和生物可降解性，在制药业有广阔的应用前景。综述了近几年来壳聚糖及其衍生物在靶向制剂中的应用。     

壳聚糖在药物剂型中的应用

壳聚糖具有良好的生物可降解性、生物相容性、成膜性、无毒性与可塑性,已经成为当前药物剂型中应用最为广泛的高分子材料。有文献报道,壳聚糖制成的缓释制剂有助于提升药物有效性、安全性与可靠性,它可以提升药物缓释速度,降低给药频率。现阶段,壳聚糖及其衍生物作为靶向制剂载体,以其显著优势被广泛应用于靶向给药系统研究中,但是其应用多结合戊二醛作为化学交联剂,具有一定毒副作用及其它不足。因此,关于壳聚糖改性研究不断开展,为其载药能力的提升具有一定的指导作用。     

喷雾干燥法制备斑蝥素壳聚糖生物黏附微球的处方工艺研究

摘 要 目的：优选斑蝥素壳聚糖生物黏附微球的最佳处方工艺。方法: 采用喷雾干燥法制备微球,运用单因素试验考察不同壳聚糖分子量对微球胃黏膜黏附率的影响,不同药载比、壳聚糖醋酸溶液浓度和蠕动泵速度对斑蝥素包封率的影响。采用效应面法,以斑蝥素的包封率为考察指标,进一步优化药载比、壳聚糖醋酸溶液浓度和蠕动泵流速3个因素。结果: 斑蝥素壳聚糖生物黏附微球的最佳处方工艺为：斑蝥素和壳聚糖的重量比为19.83%,壳聚糖醋酸溶液浓度为0.77%,蠕动泵流速为9.225 ml·min-1。以最佳处方工艺制得的斑蝥素壳聚糖生物黏附微球包封率为90.14%。结论: 采用喷雾干燥法制备微球,具有工艺稳定、可重复等优点,制备的斑蝥素壳聚糖生物黏附微球具备较好的包封率和生物黏附性能。     

对香豆酸壳聚糖生物黏附微球的制备与体内外评价

摘 要 目的：以壳聚糖为生物黏附材料制备对香豆酸微球,延长药物在体内吸收时间并提高其口服生物利用度。方法: 采用喷雾干燥技术制备对香豆酸壳聚糖生物黏附微球,采用激光粒度仪和扫描电镜考察微球的粒径及外观形态,并考察其体外释放度;以大鼠为动物模型进行生物利用度评价。结果: 所制备的黏附微球粒径在4 μm左右,形态圆整,90 min内释放完全;在体内显示出较好的缓释和促吸收效果,大鼠口服后,相对生物利用度为222%。结论:制备的对香豆酸生物黏附微球具有较好的体内缓释效果,并显著提高了口服生物利用度,可为对香豆酸的制剂开发提供参考依据。     

壳聚糖及其衍生物作为促渗剂在经皮给药系统中的研究进展

壳聚糖及其衍生物具有良好的生物特性,广泛应用于医药领域中。近些年,越来越多的研究发现其应用于经皮给药系统中具有一定的促渗作用,因此本文对壳聚糖及其衍生物在经皮给药系统中的透皮促渗机制、应用及前景进行综述。     

壳聚糖及其衍生物在固定化酶中的应用进展

综述了壳聚糖及其衍生物在固定化酶中的应用进展，重点介绍了以各种形态的壳聚糖及其衍生物作栽体通过多种固定化方法制备固定化酶的研究及应用；指出了壳聚糖及其衍生物作为固定化酶的载体具有固定化方法多样、简单易行、生物相容性好、来源丰富等优点。     

卟啉修饰的壳聚糖光敏新材料的制备与表征

目的 合成卟啉修饰的壳聚糖光敏新材料,对其进行表征,并优化其合成工艺。方法 以溴己烷苯基卟啉衍生物和壳聚糖为原料,以K₂CO₃为碱,采用四丁基溴化铵为相转移催化剂,合成卟啉-壳聚糖复合物,采用茚三酮法测定卟啉接枝率。通过单因素实验研究反应温度、反应时间、混合溶剂比例、催化剂当量等对接枝率的影响,采用正交实验法优化获得最佳制备工艺条件。结果 最佳合成条件为温度55℃、反应时间为5.5 h、混合溶剂中水和氯仿的比例为1：2、催化剂为1当量、无机碱使用K₂CO₃,卟啉的平均接枝率为41.30%。结论 通过共价偶联合成卟啉修饰壳聚糖光敏新材料的方法可行。     

Chitosan as a starting material for wound healing applications

Chitosan and its derivatives have attracted great attention due to their properties beneficial for application to wound healing. The main focus of the present review is to summarize studies involving chitosan and its derivatives, especially N,N,N-trimethyl-chitosan (TMC), N,O-carboxymethyl-chitosan (CMC) and O-carboxymethyl-N,N,N-trimethyl-chitosan (CMTMC), used to accelerate wound healing. Moreover, formulation strategies for chitosan and its derivatives, as well as their in vitro, in vivo and clinical applications in wound healing are described.     

叶酸修饰壳聚糖在肿瘤靶向制剂中的研究进展

壳聚糖及其衍生物具有无毒、生物可降解性和良好的生物相容性等特点,在药物递送系统中有良好的应用前景。叶酸受体在肿瘤细胞过表达,利用叶酸与其受体的特异性结合,可实现靶向肿瘤效应。该文综述叶酸修饰壳聚糖及其在肿瘤靶向制剂方面的研究。     

Chitosan and its derivatives as vehicles for drug delivery

Abstract

Chitosan and its derivatives as vehicles for drug delivery can achieve the purpose of sustained release and controlled release for drugs, improve the stability of drugs, and reduce adverse drug reactions. So, the bioavailability of drugs can be enhanced. Therefore, chitosan and its derivatives have become a hotspot in the field of drug delivery. Their characteristics as drug delivery vectors were introduced, the types and applications were summarized. The development direction of chitosan and its derivatives in this field was also forecasted.     

壳聚糖衍生物在口鼻黏膜疫苗中的应用

壳聚糖是一种有效的黏膜疫苗佐剂和递送载体,但因其水溶性差,应用受到一定限制.通过对壳聚糖进行不同的化学修饰可得到各类壳聚糖衍生物,这些衍生物不仅溶解性较好,而且保持了壳聚糖良好的生物相容性、生物降解性、免疫刺激活性等优势,为黏膜疫苗,尤其是经口、鼻途径递送的疫苗提供了新型候选佐剂和递送载体.此文对修饰壳聚糖的主要方法以及其衍生物在口鼻黏膜疫苗中的应用做一综述.     

Chitosan-based nanoparticles as drug delivery systems: a review on two decades of research

Abstract

Chitosan (CS) is one of the most functional natural biopolymer widely used in the pharmaceutical field due to its biocompatibility and biodegradability. These privileges lead to its application in the synthesis of nanoparticles for the drug during the last two decades. This article gives rise to a general review of the different chitosan nanoparticles (CSNPs) preparation techniques: Ionic gelation, emulsion cross-linking, spray-drying, emulsion-droplet coalescence method, nanoprecipitation, reverse micellar method, desolvation method, modified ionic gelation with radial polymerisation and emulsion solvent diffusion, from the point of view of the methodological and mechanistic aspects involved. The physicochemical behaviour of CSNPs including drug loading, drug release, particles size, zeta potential and stability are briefly discussed. This review also directs to bring an outline of the major applications of CSNPs in drug delivery according to drug and route of administration. Finally, derivatives of CSNPs and CS nano-complexes are also discussed.     

Chitosan-Based Particles as Controlled Drug Delivery Systems

Chitosan, a natural-based polymer obtained by alkaline deacetylation of chitin, is nontoxic, biocompatible, and biodegradable. These properties make chitosan a good candidate for conventional and novel drug delivery systems. This article reviews the approaches aimed to associate bioactive molecules to chitosan in the form of colloidal structures and analyzes the evidence of their efficacy in improving the transport of the associated molecule through mucosae and epithelia. Chitosan forms colloidal particles and entraps bioactive molecules through a number of mechanisms, including chemical crosslinking, ionic crosslinking, and ionic complexation. A possible alternative of chitosan by the chemical modification also has been useful for the association of bioactive molecules to polymer and controlling the drug release profile. Because of the high affinity of chitosan for cell membranes, it has been used as a coating agent for liposome formulations. This review also examines the advances in the application of chitosan and its derivatives to nonviral gene delivery and gives an overview of transfection studies that use chitosan as a transfection agent. From the studies reviewed, we concluded that chitosan and its derivatives are promising materials for controlled drug and nonviral gene delivery.     

Chitosan derivatives with antimicrobial, antitumour and antioxidant activities--a review

Chitosan is a linear polysaccharide with a good biodegradability, biocompatibility, and no toxicity, which provide it with huge potential for future development. The chitosan molecule appears to be a suitable polymeric complex for many biomedical applications. This review gathers current findings on the antibacterial, antifungal, antitumour and antioxidant activities of chitosan derivatives and concurs with our previous review presenting data collected up to 2008. Antibacterial activity is based on molecular weight, the degree of deacetylation, the type of substitutents, which can be cationic or easily form cations, and the type of bacterium. In general, high molecular weight chitosan cannot pass through cell membranes and forms a film that protects cells against nutrient transport through the microbial cell membrane. Low molecular weight chitosan derivatives are water soluble and can better incorporate the active molecule into the cell. Gram-negative bacteria, often represented by Escherichia coli, have an anionic bacterial surface on which cationic chitosan derivatives interact electrostatically. Thus, many chitosan conjugates have cationic components such as ammonium, pyridinium or piperazinium substituents introduced into their molecules to increase their positive charge. Gram-positive bacteria like Staphylococcus aureus are inhibited by the binding of lower molecular weight chitosan derivatives to DNA or RNA. Chitosan nanoparticles exhibit an increase in loading capacity and efficacy. Antitumour active compounds such as doxorubicin, paclitaxel, docetaxel and norcantharidin are used as drug carriers. It is evident that chitosan, with its low molecular weight, is a useful carrier for molecular drugs requiring targeted delivery. The antioxidant scavenging activity of chitosan has been established by the strong hydrogen-donating ability of chitosan. The low molecular weight and greater degree of quarternization have a positive influence on the antioxidant activity of chitosan. Phenolic and polyphenolic compounds with antioxidant effects are condensed with chitosan to form mutual prodrugs.