口服多糖靶向药物递送体系在结肠疾病治疗中的应用研究进展

多糖(polysaccharide)作为常见的药物递送材料,具有来源广泛、生物安全性好及功能丰富等优点,在医药及食品领域应用广泛,特别是在结肠疾病的口服靶向药物递送中具有重要的研究和应用价值。利用多糖的结构与理化特性优势,目前研究已构建出基于pH响应、微生物酶响应、活性氧响应、肠黏膜吸附和受体分子靶向等递送策略的交联型纳米粒、自组装型纳米粒及水凝胶,并在结肠炎与结肠癌等消化道疾病治疗中展现出优异效果。本文综述了基于多糖的口服靶向型药物递送体系在结肠疾病治疗中的研究进展,并对其研究和应用前景进行深入讨论。     

基于水凝胶的核酸药物负载策略的研究进展

基因治疗在癌症以及遗传疾病的治疗中具有广阔的应用前景,基因治疗的关键在于如何实现将核酸药物精准递送至靶部位。近年来,研究人员致力于将核酸药物负载于水凝胶中,以实现全身或局部的基因递送。水凝胶系统由于其良好的生物相容性、高效的核酸药物负载能力和局部定位控制释放等优势,为核酸药物的递送提供了有效的工具,在实体瘤和再生医学领域具有巨大的潜力。本文综述了近年来水凝胶系统作为核酸药物载体的研究,并重点探讨基于水凝胶的核酸药物负载策略,以期为基于水凝胶的核酸药物递送系统的研究提供参考。     

基于丝素蛋白的纳米粒药物递送系统研究进展

丝素蛋白(silk fibroin, SF)是一种天然高分子,具有一定的水溶性、结构修饰性、良好的生物相容性和生物降解性,可作为药物递送的载体材料。SF载药纳米粒可控制药物释放、减少不良反应、提高治疗效果,是一种有前景的药物递送系统。本综述介绍了SF的基本特征、SF载药纳米粒的制备方法和SF在纳米粒药物递送系统的应用,在此基础上,对SF载药纳米粒的进一步发展进行了展望。     

海藻酸盐复合水凝胶在癌症治疗中的应用进展

海藻酸盐复合水凝胶是目前肿瘤药物递送系统材料的研究热点之一。海藻酸盐水凝胶具有良好的生物相容性、可再生的特点,然而天然海藻酸盐水凝胶因降解缓慢、凝胶不稳定等缺点使其在机体环境下可能无法实现预期的结果。海藻酸盐通过结合其他材料,并用离子交联、共价交联和自由基聚合等方法形成水凝胶,使其在癌症治疗中得到广泛应用。本文基于海藻酸盐水凝胶复合体系,综述了海藻酸盐水凝胶结构及其基本性质,重点阐述了近几年来海藻酸盐复合水凝胶在常见癌症治疗应用的研究状况,总结当前研究重点方向并讨论了海藻酸盐复合水凝目前存在问题,为进一步拓展海藻酸盐复合水凝胶在临床癌症治疗的研究提供参考。     

水凝胶递药系统的研究进展及应用

水凝胶是一种具有优异亲水性、柔韧性、溶胀特性的三维网状空间结构聚合物。由于良好的载药特性，水凝胶在药物递送、诊断、治疗、组织工程等领域应用广泛。该研究总结了国内外有关水凝胶的近期文献，就水凝胶的分类、材料及性能改进、水凝胶的形成机制与交联剂等方面进行了综述，并展望水凝胶递药系统的发展前景，以期为相关研究提供参考。     

壳聚糖与葡聚糖在基因递送应用中的研究进展

在基因疗法中,天然高分子多聚糖因其高生物相容性和可修饰性而成为良好的基因递送材料。壳聚糖和葡聚糖是2种重要的天然高分子多聚糖,它们本身及其衍生物都可以用做基因药物载体材料。研究者采用多种方法对壳聚糖和葡聚糖进行改良,拓宽它们在基因递送中的应用范围。本综述介绍了两者的结构和性质特点以及近年来两者及其衍生物在基因递送应用中的研究进展,最后对它们的发展前景进行了展望。     

海藻酸钠与天然聚合物复合的多功能止血水凝胶研究进展

水凝胶是一种具有贯通三维网状结构的可降解天然亲水性聚合物,这些特性使得水凝胶具有优异的吸水特性和生物相容性从而被广泛地用于止血材料的制备。随着研究不断的发展,传统的止血水凝胶逐渐发展成具有促进组织再生、载药与修复骨缺失的多功能水凝胶。在几种常用的水凝胶材料中,海藻酸钠除了具有水凝胶的固有特性外,还具有来源广泛价格低廉,且粘附性能强的优势,被越来越多地用于多功能水凝胶的制备。本文对海藻酸钠与天然聚合物复合制备的水凝胶在止血、抗菌、促进组织再生等方面的研究进展进行介绍,为后续的研究应用提供理论基础。     

水凝胶材料在骨骼肌组织再生的研究进展

骨骼肌约占成人体重的40%,它能够对人体呼吸、运动等基本生命活动发挥重要调控作用。目前,由于严重创伤导致的骨骼肌大体积缺失,骨骼肌修复能力会严重受损,并可导致肌肉功能障碍或功能丧失,而临床采用自体组织移植治疗的方式也存在成本高、风险大、效果不稳定的问题。在生物医学领域,已经尝试将多种天然和人工合成材料用于骨骼肌的再生。水凝胶作为一种以水为分散介质的高分子网络体系,具有生物相容性好、可模仿天然细胞外基质等特点,已广泛用于肌肉组织工程中细胞及生长因子的递送。本文对水凝胶材料的分类、制备及其在骨骼肌组织再生的应用作一综述,重点探讨不同来源水凝胶材料在骨骼肌再生的研究情况,期望为骨骼肌再生材料的设计应用提供一定参考。     

白芨多糖在药剂领域的应用

寻找理想的新型药物递送载体材料一直是药学领域的研究热点。白芨多糖是一种新型的天然高分子材料,作为制剂材料在药剂领域有着广泛的应用前景。本文对近十余年来国内外以白芨多糖及白芨多糖衍生物为制剂材料、药物载体,尤其是作为血管栓塞材料、基因载体和聚合物胶束材料在抗肿瘤药物递送领域的文章进行综述,以期为白芨多糖相关领域的科研工作者提供参考。     

固体自微乳药物递送系统的研究进展

作为一种新型的药物递送系统,固体自微乳药物递送系统可以显著提高水难溶性药物的口服生物利用度,且具有液态自微乳和固体制剂二者的优势。通过设计不同的辅料处方和包衣技术,可以控制药物释放使其具有靶向性,来达到不同的给药目的。固体自微乳药物递送系统的应用前景广阔,具有研究意义。本文对固体自微乳载体、固化技术、固体自微乳新制剂的应用进行了总结归纳,为提高水难溶性药物释放的固体自微乳化技术的研究提供了参考。     

Thermosensitive hydrogels for drug delivery

INTRODUCTION: Controlled drug delivery has been widely applied in areas such as cancer therapy and tissue regeneration. Thermosensitive hydrogel-based drug delivery systems have increasingly attracted the attention of the drug delivery community, as the drugs can be readily encapsulated and released by the hydrogels. AREAS COVERED: Thermosensitive hydrogels that can serve as drug carriers are discussed in this paper. Strategies used to control hydrogel properties, in order to tailor drug release kinetics, are also reviewed. This paper also introduces applications of the thermosensitive hydrogel-based drug delivery systems in cancer therapy and tissue regeneration. EXPERT OPINION: When designing a drug delivery system using thermosensitive hydrogels, one needs to consider what type of thermosensitive hydrogel needs to be used, and how to manipulate its properties to meet the desired drug release kinetics. For material selection, both naturally derived and synthetic thermosensitive polymers can be used. Various methods can be used to tailor thermosensitive hydrogel properties in order to achieve the desired drug release profile.     

In situ forming hydrogels based on chitosan for drug delivery and tissue regeneration

In situ forming hydrogels with simple sol–gel transition are more practicable as injectable hydrogels for drug delivery and tissue regeneration. State-of-the-art in situ gelling systems can easily and efficiently be formed by different mechanisms in situ. Chitosan is a kind of natural polysaccharide that is widely exploited for biomedical applications due to its good biocompatibility, low immunogenicity and specific biological activities. Chitosan-based in situ gelling systems have already gained much attention as smart biomaterials in the development of several biomedical applications, such as for drug delivery systems and regeneration medicine. Herein, we review the typical in situ gelling systems based on chitosan and mechanisms involved in hydrogel forming, and report advances of chitosan-based in situ gels for the applications in drug delivery and tissue regeneration. Finally, development prospects of in situ forming hydrogels based on chitosan are also discussed in brief.     

Thermosensitive hydrogels for drug delivery

Introduction: Controlled drug delivery has been widely applied in areas such as cancer therapy and tissue regeneration. Thermosensitive hydrogel-based drug delivery systems have increasingly attracted the attention of the drug delivery community, as the drugs can be readily encapsulated and released by the hydrogels.

Areas covered: Thermosensitive hydrogels that can serve as drug carriers are discussed in this paper. Strategies used to control hydrogel properties, in order to tailor drug release kinetics, are also reviewed. This paper also introduces applications of the thermosensitive hydrogel-based drug delivery systems in cancer therapy and tissue regeneration.

Expert opinion: When designing a drug delivery system using thermosensitive hydrogels, one needs to consider what type of thermosensitive hydrogel needs to be used, and how to manipulate its properties to meet the desired drug release kinetics. For material selection, both naturally derived and synthetic thermosensitive polymers can be used. Various methods can be used to tailor thermosensitive hydrogel properties in order to achieve the desired drug release profile.     

Chitosan-based hydrogels for controlled, localized drug delivery

Hydrogels are high-water content materials prepared from cross-linked polymers that are able to provide sustained, local delivery of a variety of therapeutic agents. Use of the natural polymer, chitosan, as the scaffold material in hydrogels has been highly pursued thanks to the polymer's biocompatibility, low toxicity, and biodegradability. The advanced development of chitosan hydrogels has led to new drug delivery systems that release their payloads under varying environmental stimuli. In addition, thermosensitive hydrogel variants have been developed to form a chitosan hydrogel in situ, precluding the need for surgical implantation. The development of these intelligent drug delivery devices requires a foundation in the chemical and physical characteristics of chitosan-based hydrogels, as well as the therapeutics to be delivered. In this review, we investigate the newest developments in chitosan hydrogel preparation and define the design parameters in the development of physically and chemically cross-linked hydrogels.     

Interpenetrating Polymer Networks polysaccharide hydrogels for drug delivery and tissue engineering

The ever increasing improvements of pharmaceutical formulations have been often obtained by means of the use of hydrogels. In particular, environmentally sensitive hydrogels have been investigated as “smart” delivery systems capable to release, at the appropriate time and site of action, entrapped drugs in response to specific physiological triggers. At the same time the progress in the tissue engineering research area was possible because of significant innovations in the field of hydrogels. In recent years multicomponent hydrogels, such as semi-Interpenetrating Polymer Networks (semi-IPNs) and Interpenetrating Polymer Networks (IPNs) have emerged as innovative biomaterials for drug delivery and as scaffolds for tissue engineering. These interpenetrated hydrogel networks, which can be obtained by either chemical or physical crosslinking, in most cases show physico-chemical properties that can remarkably differ from those of the macromolecular constituents. Among the synthetic and natural polymers that have been used for the preparation of semi-IPNs and IPNs, polysaccharides represent a class of macromolecules of particular interest because they are usually abundant, available from renewable sources and have a large variety of composition and properties that may allow appropriately tailored chemical modifications. Sometimes both macromolecular systems are based on polysaccharides but often also synthetic polymers are present together with polysaccharide chains.     

Environment-sensitive hydrogels for drug delivery.

Environmentally sensitive hydrogels have enormous potential in various applications. Some environmental variables, such as low pH and elevated temperatures, are found in the body. For this reason, either pH-sensitive and/or temperature-sensitive hydrogels can be used for site-specific controlled drug delivery. Hydrogels that are responsive to specific molecules, such as glucose or antigens, can be used as biosensors as well as drug delivery systems. Light-sensitive, pressure-responsive and electro-sensitive hydrogels also have the potential to be used in drug delivery and bioseparation. While the concepts of these environment-sensitive hydrogels are sound, the practical applications require significant improvements in the hydrogel properties. The most significant weakness of all these external stimuli-sensitive hydrogels is that their response time is too slow. Thus, fast-acting hydrogels are necessary, and the easiest way of achieving that goal is to make thinner and smaller hydrogels. This usually makes the hydrogel systems too fragile and they do not have mechanical strength necessary in many applications. Environmentally sensitive hydrogels for drug delivery applications also require biocompatibility. Synthesis of new polymers and crosslinkers with more biocompatibility and better biodegradability would be essential for successful applications. Development of environmentally sensitive hydrogels with such properties is a formidable challenge. If the achievements of the past can be extrapolated into the future, however, it is highly likely that responsive hydrogels with a wide array of desirable properties can be made.     

Environment-sensitive hydrogels for drug delivery

Environmentally sensitive hydrogels have enormous potential in various applications. Some environmental variables, such as low pH and elevated temperatures, are found in the body. For this reason, either pH-sensitive and/or temperature-sensitive hydrogels can be used for site-specific controlled drug delivery. Hydrogels that are responsive to specific molecules, such as glucose or antigens, can be used as biosensors as well as drug delivery systems. Light-sensitive, pressure-responsive and electro-sensitive hydrogels also have the potential to be used in drug delivery and bioseparation. While the concepts of these environment-sensitive hydrogels are sound, the practical applications require significant improvements in the hydrogel properties. The most significant weakness of all these external stimuli-sensitive hydrogels is that their response time is too slow. Thus, fast-acting hydrogels are necessary, and the easiest way of achieving that goal is to make thinner and smaller hydrogels. This usually makes the hydrogel systems too fragile and they do not have mechanical strength necessary in many applications. Environmentally sensitive hydrogels for drug delivery applications also require biocompatibility. Synthesis of new polymers and crosslinkers with more biocompatibility and better biodegradability would be essential for successful applications. Development of environmentally sensitive hydrogels with such properties is a formidable challenge. If the achievements of the past can be extrapolated into the future, however, it is highly likely that responsive hydrogels with a wide array of desirable properties can be made.     

Intelligent hydrogels for drug delivery system

Intelligent hydrogel, also known as smart hydrogels, are materials with great potential for development in drug delivery system. Intelligent hydrogel also has the ability to perceive as a signal structure change and stimulation. The review introduces the temperature-, pH-, electric signal-, biochemical molecule-, light- and pressure- sensitive hydrogels. Finally, we described the application of intelligent hydrogel in drug delivery system and the recent patents involved for hydrogel in drug delivery.     

一种pH敏感水凝胶的性质及用于胰岛素口服给药的研究

目的研究pH敏感水凝胶的性质及其用于胰岛素口服给药的降血糖作用。方法制备了聚(甲基丙烯酸 泊洛沙姆 )共聚物水凝胶 ;在不同pH值的介质中研究凝胶溶胀、药物扩散和药物释放性质 ;含胰岛素的凝胶经口服给予糖尿病大鼠。结果水凝胶具有 pH敏感的性质 ;糖尿病大鼠口服给予含胰岛素的聚合物后有明显的剂量依赖的降血糖作用。结论这种水凝胶有望用作药物传递的载体。     

Hydrogels: Swelling,Drug Loading,and Release

Hydrogels have been used by many investigators in controlled-release drug delivery systems because of their good tissue compatibility and easy manipulation of swelling level and, thereby, solute permeability. The desired kinetics, duration, and rate of solute release from hydrogels are limited to specific conditions, such as hydrogel properties, amount of incorporated drug, drug solubility, and drug–polymer interactions. This review summarizes the compositional and structural effects of polymers on swelling, loading, and release and approaches to characterize solute release behavior in a dynamic state. A new approach is introduced to compensate drug effects (solubility and loading) with the release kinetics by varying the structure of heterogeneous polymers. Modulated or pulsatile drug delivery using functional hydrogels is a recent trend in hydrogel drug delivery.