褐藻多糖及其衍生物的抗肿瘤作用

海洋植物作为一类有益健康的天然产品受到诸多关注。其中,褐藻科植物和褐藻的粗提取物在抗肿瘤活性方面显示出极大优势。鉴于此,褐藻粗提取物的活性成分褐藻多糖的抗肿瘤作用引起制药领域的极大兴趣。褐藻多糖包括褐藻胶、岩藻聚糖和褐藻淀粉等,主要来自海带、巨藻、泡叶藻、墨角藻等海藻植物。研究发现,褐藻糖胶的衍生物及海藻酸钠的衍生物具有降血压、调节免疫、抗炎抗病毒、抗氧化以及抗肿瘤的作用。本文介绍了褐藻多糖及其衍生物在抗肿瘤活性方面的研究现状。     

壳聚糖及其衍生物在口腔疾病防治中的研究进展

壳聚糖是一种天然高分子多糖,在食品、纺织、美容、医疗等行业被广泛应用。在口腔医学领域,壳聚糖及其衍生物因多种优良的生物学性能,如抗菌性能、载药功能、再矿化性能和成骨作用等,被广泛应用于多种口腔常见疾病的预防和治疗。文中介绍了壳聚糖的生物学性能、壳聚糖常见衍生物,与壳聚糖及其衍生物在口腔疾病防治方面的最新应用研究进展。     

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.     

多糖硫酸化修饰和多糖硫酸酯的研究进展

硫酸多糖是一类糖羟基上带有硫酸根的多糖,包括从植物中提取的各种硫酸多糖、肝素、天然多糖的硫酸衍生物及人工合成的各种硫酸多糖。硫酸多糖具有抗病毒、抗肿瘤、抗凝血和增强免疫等生物活性,为提高中药多糖的生物活性,可通过硫酸化修饰的方法进行结构改造,获取多糖硫酸酯。本文就多糖的硫酸化修饰方法、多糖硫酸酯的生物学活性及其影响因素、作用机制和临床应用进行了综述。     

壳聚糖絮凝纯化香菇多糖的研究

研究了壳聚糖对香菇多糖提取液的沉降作用,考察了壳聚糖用量、沉降时间、溶液酸度对吸附色素、沉降蛋白质和多糖损失的影响,同时考察了壳聚糖对超滤膜分离初始膜通量的影响。实验结果表明壳聚糖对香菇多糖提取液中色素和蛋白质具有较好的絮凝沉降效果,当壳聚糖的用量为5.0mg/mL,絮凝沉降时间为40min,溶液pH为5.0时,60r/min的转速搅拌条件下,色素含量降低了约28%,蛋白质含量降低了42%左右,而多糖含量只损失8.9%左右,溶液粘度降低了11.8%,采用超滤分离时,经壳聚糖沉降的多糖溶液初始膜通量增加了14%左右。     

海洋寡糖及其衍生物活性的研究进展

海洋寡糖由海洋多糖经弱酸或糖苷酶等方法降解制备,具有来源丰富、结构新颖、分子量小、类型多样等特点,表现出抗肿瘤、抗氧化、免疫调节、抗病毒等多种生物活性,在食品、医药、保健品及化妆品等领域有着广泛的应用,具有巨大的开发潜力。为了及时了解海洋寡糖的研究进展,促进海洋寡糖的应用与开发,就海洋寡糖及其衍生物的免疫调节、抗肿瘤、抑菌、抗病毒、抗氧化、抗辐射、抗凝血、抗糖尿病以及调节肠道微生物等方面的活性研究进展进行了简要总结,以期为海洋寡糖及其衍生物的深入研究和深度开发提供参考。     

复合药用真菌多糖抗肿瘤活性的研究进展

复合药用真菌多糖中各单一多糖的结构与活性之间具有互效性,在营养和药理作用方面呈现互补性、协调性和增效性,且复合药用真菌多糖具有全面的免疫调节、抗肿瘤等生理活性和保健功能。我们以单一药用真菌多糖抗肿瘤研究结果为对象,对比分析了复合药用真菌多糖抗肿瘤的机制与功效,揭示了复合药用真菌多糖在生命科学、食品科学和医药科学等领域的应用价值。     

两种不同方法制备的黑木耳多糖性质比较

本研究以黑木耳子实体为材料,对比了壳聚糖絮凝法制备的絮凝多糖HJD-1和传统水提醇沉法制备的醇沉多糖HJD-2的表观结构、α-葡萄糖甘酶抑制活性以及体外抑制肿瘤细胞增殖的活性。结果表明：（1）壳聚糖絮凝法制备粗多糖得率均值为4.76%,是醇沉法的2.17倍;醇沉法制备多糖的损失率为33.87%,是絮凝法的1.36倍;（2）絮凝多糖HJD-1和醇沉多糖HJD-2的表观评估及复溶性结果分析显示：絮凝多糖HJD-1为亮白色透明晶体,色泽均匀,颗粒规整;醇沉多糖HJD-2为棕褐色,颗粒状,有砂质感,前者相较后者的复溶性更好;（3）对α-葡萄糖甘酶抑制活性以及体外抗肿瘤能力结果分析表明：在相同浓度下,壳聚糖絮凝法制备黑木耳多糖对α-葡萄糖苷酶活性的抑制效果优于醇提法;絮凝多糖HJD-1对HepG2细胞的增殖抑制作用强于醇沉多糖HJD-2。     

灵芝多糖抗肿瘤作用的免疫分子机制研究

灵芝多糖是一种从灵芝实体中被提取出来的多糖组份,灵芝多糖极易溶于水。很多科学研究表明,灵芝多糖具有一定的免疫调节功能以及一定的抗肿瘤等作用,并且认为在体外灵芝多糖并没有直接的对肿瘤细胞有抑制作用或者杀伤作用,反而在体内灵芝多糖则具有很好的抗肿瘤作用。所以,通常情况下,对灵芝多糖的抗肿瘤作用的研究主要就是通过增加免疫功能,尽管我国很多科学家已经从免疫功能的角度对灵芝多糖的抗肿瘤作用进行研究,但确切的机制并没有明确。因此文章结合具体实验对灵芝多糖的抗肿瘤作用的免疫分子机制进行深入研究。     

In vivo antitumor activity of chitosan nanoparticles

Chitosan nanoparticles have been synthesized as potential anticancer agents, and evaluated, in vitro, against various cancer cell lines. In this study, in vivo antitumor activity of chitosan nanoparticles against Sarcoma-180 and mouse hepatoma H22 was investigated. Chitosan nanoparticles showed significant antitumor activity in vivo. The doses and particle size made a great effect on their efficacy.     

Cytotoxic activity of aminoderivatized cationic chitosan derivatives

Chitosan derivatives were prepared by dialkylaminoalkylation and reductive amination followed by quaternization. In this study, the cytotoxic activity of the chitosan derivatives was investigated and a relationship between structure and activity is suggested. The cationic chitosan derivatives elicited dose-dependent inhibitory effects on the proliferation of tumor cell lines.     

Obtaining and study of monosaccharide derivatives of low-molecular-weight chitosan

The possibility of obtaining monosaccharide derivatives of low-molecular-weight chitosan with the use of the Maillard reaction was studied. Chitosan derivatives (molecular weight, 24 and 5 kDa) obtained with glucosamine, N-acetyl galactosamine, galactose, and mannose with a substitution degree of 4-14% and a yield of 60-80% were obtained. Some physicochemical and biological properties of these derivatives were studied. We showed that monosaccharide derivatives of low-molecular-weight chitosan exhibited antibacterial activity. Chitosan at a concentration of 0.01% caused 100% death of bacteria B. subtilis and E. coil. The strongest antibacterial effect was exhibited by 24-kDa derivatives: only 0.02-0.08% of cells survived. These derivatives were two orders of magnitude more effective than the 5-kDa chitosan modified with galactose.     

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。     

Obtaining and study of monosaccharide derivatives of low-molecular-weight chitosan

The possibility of obtaining monosaccharide derivatives of low-molecular-weight chitosan with the use of the Maillard reaction was studied. Chitosan derivatives (molecular weight, 24 and 5 kDa) obtained with glucosamine, N-acetyl galactosamine, galactose, and mannose with a substitution degree of 4–14% and a yield of 60–80% were obtained. Some physicochemical and biological properties of these derivatives were studied. We showed that monosaccharide derivatives of low-molecular-weight chitosan exhibited antibacterial activity. Chitosan at a concentration of 0.01% caused 100% death of bacteria B. subtilis and E. coli. The strongest antibacterial effect was exhibited by 24-kDa derivatives: only 0.02–0.08% of cells survived. These derivatives were two orders of magnitude more effective than the 5-kDa chitosan modified with galactose.     

A new method for the quantification of chitin and chitosan in edible mushrooms

Along with β-glucans, chitin is the dominant component of the fungal cell wall. Chitosan, the deacetylated form of chitin, has found quite a number of biomedical and biotechnological applications recently. Mushroom chitin could be an important source for chitosan production. A direct determination of chitin and chitosan in mushrooms is of expedient interest. In this paper, a new method for the quantification of chitin and chitosan is described. This method is based on the specific reaction between polyiodide anions and chitosan and on measuring the optical density of the insoluble polyiodide–chitosan complex. After deacetylation, chitin can also be quantified. The specificity of the reaction is used to quantify the polymers in the presence of complex matrices. With this new spot assay, the chitin content of mycelia and fruiting bodies from several basidiomycetes and an ascomycete were analysed. The presented method could also be used for the determination in other samples as well. The chitin content of the analysed species varies between 0.4 and 9.8 g chitin per 100 g of dry mass. Chitosan could not be detected in our mushroom samples, indicating that the glucosamine units are mostly acetylated.     

Analysis of toxicity and biocompatibility of chitosan derivatives with different physico-chemical properties

A comparative study of the toxicity and hemocompatibility of chitosan and its derivatives with different acetylation degrees, molecular masses, charges, and hydrophobicity has been performed. It has been shown that only positively charged chitosan derivatives activate platelets and suppress cell proliferation, regardless of the acetylation degree, molecular mass, and hydrophobicity. Chitosan quaternization decreases toxicity at a low degree of substitution and abruptly increases it at a high one. Negatively charged chitosan derivatives were nontoxic and compatible with blood components. It was concluded that the toxicity of chitosan and its derivatives is defined by their charge and solubility at a neutral pH.     

Effect of chitosan derivatives on the reproduction of Coliphages T2 and T7

The effect of chitosan derivatives with different degrees of polymerization and deamination, as well as of chitosan 6-O-sulfate and chitosan N-succinate-6-O-sulfate, on the reproduction of coliphages T2 and T7 in Escherichia coli and on the growth of this bacterium was studied. Chitosan derivatives decreased the yield of coliphages and exhibited bactericidal activity. The efficiency of inhibition of viral infection and the bactericidal activity of chitosan were found to be dependent on the degree of its polymerization. At the same time, there was no correlation between the degree of chitosan deamination and the extent of inhibition of viral infection. Anionic chitosan derivatives virtually did not possess antiviral or bactericidal activity. It is assumed that chitosan blocks some stages of phage reproduction. The decrease in the phage-producing ability of E. coli may also be due to the bactericidal effect of chitosan.     

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.     

A review of the antiviral activity of Chitosan,including patented applications and its potential use against COVID-19

Chitosan is an abundant organic polysaccharide, which can be relatively easily obtained by chemical modification of animal or fungal source materials. Chitosan and its derivatives have been shown to exhibit direct antiviral activity, to be useful vaccine adjuvants and to have potential anti-SARS-CoV-2 activity. This thorough and timely review looks at the recent history of investigations into the role of chitosan and its derivatives as an antiviral agent and proposes a future application in the treatment of endemic SARS-CoV-2.