智能药物传输系统的研究进展

智能药物传输系统是指系统自身具有传感、处理及响应释药、停止释药的"自动"药物传输体系。各种智能药物传输系统实现了药物的定点、定时及定量释放。简要介绍了智能药物传输系统的发展近况,并从pH值敏感型、温度敏感型、葡萄糖敏感型以及其他敏感型给药系统角度阐述了智能药物传输系统的研究现状及未来展望。     

靶向释放智能纳米载体的研究进展

随着材料科学的进步,智能纳米载体在药物和基因靶向治疗方面取得了巨大的研究进展。智能纳米载体被化学信号、温度、pH等"触发器"激发后,能在特定部位响应性地释放药物或基因。该文从智能纳米载体的定义,不同类型靶向释放的智能纳米载体在药物和基因中的研究进展,靶向释放的智能纳米载体的不足及发展前景等方面进行综述。     

还原响应型药物载体的研究进展

还原响应型药物载体以其高效快速释放药物、毒副作用小、可生物降解的优良特性,逐渐成为药物载体领域研究的热点,也是最具临床应用潜力的智能药物载体之一。本文综述了还原响应型药物载体研究的最新进展,包括还原响应的药物、基因与载体的偶联物及还原响应的纳米聚合物胶束、纳米囊泡、纳米中空微球、纳米脂质体等的合成和药物释放的机制以及各类载体的优缺点,为其在药剂学中的进一步应用提供理论依据。     

还原响应型介孔二氧化硅-巯基嘌呤共价载药系统的构建与初步评价

目的为控制药物在到达作用部位前于载药系统的提前释放,提高疗效和降低毒副作用,研究制备了还原响应型介孔二氧化硅载药系统。方法采用后修饰法制备不同巯基化的介孔二氧化硅载体,通过扫描电镜、透射电镜及氮气吸附-脱附等手段对载体的外观形貌、比表面积及孔径分布进行表征,并选取具有巯基的抗癌药物6-巯基嘌呤作为模型药物,将药物通过二硫键共价装载到载体上。结果当巯基化试剂加入量为1 m L时,载药体系有最大的载药量为5.02%。研究所构建的还原响应型介孔二氧化硅载药系统,在没有谷胱甘肽(glutathione,GSH)存在的条件下,药物"零"释放,而当GSH的浓度为3 mmol·L~(-1)时,2 h累计释放量超过70%。结论研究构建的共价载药系统具有明显的还原响应型释药特征,为控制药物的释放提供了一个新的探索思路。     

智能响应型介孔二氧化硅抗肿瘤纳米递药系统的设计策略与研究应用

恶性肿瘤是危害人类健康的重大疾病,由于其微环境复杂多变,导致大多数抗肿瘤药物不能精准地到达病灶组织并可控释放。智能响应型纳米载体已成为抗肿瘤递药系统研究领域的热点。介孔二氧化硅作为一种优良的纳米材料,具有无毒、稳定、孔容孔径可调及表面易于功能化修饰等优势,凭借其对机体肿瘤微环境或生理变化的感知响应、实现递药系统在病灶组织定位释药或控制释药,使其成为智能响应型递药系统的理想载体。本文基于介孔二氧化硅的智能响应型递药系统的设计策略及研究应用展开综述,以期为抗肿瘤药物纳米制剂的研发提供参考。     

炎症反应过程中药物转运体调控的研究进展

炎症状态下机体对药物的处置过程会发生显著改变,众多药物代谢酶及转运体的表达和功能发生下调。研究表明机体在该状态下会释放一系列炎症细胞因子对药物代谢酶的表达和功能产生调控,而近年来的研究表明在炎症状态下药物转运体也受到这些细胞因子的调控,且部分转运体的调控呈现明显的种属差异性。进一步的机制研究表明,一些转录因子在调控的信号通路中发挥了重要的作用。本文对炎症状态下药物转运体的调控研究进展进行综述。     

头孢唑酮在Triton X-100体系中的释放机制初探

目的 探讨抗生素药物头孢唑酮在表面活性剂体系中的释放机制.方法 测定了头孢唑酮在表面活性剂体系中的释放曲线,用数学模型对药物的释放曲线进行拟合.结果 头孢唑酮在TritonX,100体系的释放为非菲克扩散控制过程.结论 为表面活性剂体系中药物控制释放的深入研究提供了科学依据.     

基于纳米发电机的自驱动技术控制药物释放的研究进展

基于纳米发电机的自驱动技术自被提出以来得到了迅速发展,该技术可将人体生命活动中的机械能转化为电能,可用于自驱动的生理信号监测、电子医疗器件和药物可控释放等.综述自驱动技术在微针药物释放、膜控型药物释放、电穿孔药物释放、微流控药物释放及电化学药物释放等方面的研究成果,并探讨自驱动的药物控制释放技术应用于临床治疗面临的挑战...     

智能给药系统的研究概况

目的:介绍智能给药系统的研究概况。方法:依据近年来国内外相关文献资料,进行分析、归纳和总结。结果:从生物传感器、物理刺激响应型、化学刺激响应型和生物分子识别响应型智能给药系统四个方面,综述了智能给药系统的研究概况。结论:智能给药系统作为一种新型给药系统,具有良好的潜在应用前景,值得深一步研究。     

胃内滞留漂浮型缓释制剂技术研究进展及其在中药制剂中的应用

胃内滞留漂浮型缓释制剂是根据流体动力学平衡控制系统(The Hydronamically Balanced Controlled Drug Delivery System,HBS)原理设计制备,口服后可以漂浮于胃液之上持续释放药物的一种特殊制剂.这种制剂由于自身密度小于胃内容物密度,通常在胃液中呈漂浮状态滞留5～6 h,达到延长药物在胃内的释放时间,改善药物吸收,提高生物利用度的目的.     

Smart linkers in polymer–drug conjugates for tumor-targeted delivery

To achieve effective chemotherapy, many types of drug delivery systems have been developed for the specific environments in tumor tissues. Polymer–drug conjugates are increasingly used in tumor therapy due to several significant advantages over traditional delivery systems. In the fabrication of polymer–drug conjugates, a smart linker is an important component that joins two fragments or molecules together and can be cleared by a specific stimulus, which results in targeted drug delivery and controlled release. By regulating the conjugation between the drug and the nanocarriers, stimulus-sensitive systems based on smart linkers can offer high payloads, certified stability, controlled release and targeted delivery. In this review, we summarize the current state of smart linkers (e.g. disulfide, hydrazone, peptide, azo) used recently in various polymer–drug conjugate-based delivery systems with a primary focus on their sophisticated design principles and drug delivery mechanisms as well as in vivo processes.     

Biodegradable polymeric drug delivery systems

The use of biodegradable polymeric materials as drug carriers is a relatively new dimension in polymeric drug delivery systems. A number of biodegradable or bioerodible polymers, such as poly (lactic/glycolic acid) copolymer, poly(α-amino acid), polyanhydride, and poly (ortho ester) are currently being investigated for this purpose. These polymers are useful for matrix and reservoir-type delivery devices. In addition, when chemical functional groups are introduced to the biodegradable polymer backbone, such as poly (N-(2-hydroxypropy) methacrylamide), the therapeutic agent can be covalently bound directly orvia spacer to the backbone polymer. These polymer/drug conjugates represent another new dimension in biodegradable polymeric drug delivery systems. In this paper, major emphasis is placed on clinical applications of biodegradable polymeric delivery systems. In addition, examples of biodegradable polymeric durg delivery systems currently being investigated will be discussed for the purpose of demonstrating the potential importance of this new field.     

Recent advances in chitosan films for controlled release of drugs

Chitosan is a versatile carrier for biologically active agent from a small molecule such as an antibiotic to macromolecules such as proteins and nucleic acids. In addition, drug delivery devices based on chitosan can be available in a variety of morphologies including films, fibers, nanoparticles and microspheres. Otherwise the inherent advantages of this polymer such as biocompatibility, tissue adhesions and hydrophilic nature, chitosan can be modified to accomplish a specific purpose, for example improves release kinetics. In this review, recent patents of chitosan-based film systems for drug delivery are presented and discussed. This review include matrix type systems, membrane coated systems and film forming solution. For each one of these systems, several examples of manufacture processes, bioactive agents to be delivered and specifics applications are considered. This work highlights the use of chitosan in the film technology for drug delivery, presenting examples of chitosan used in an unmodified state and examples of modifications of the polymer backbone.     

Non-degradable polymer nanocomposites for drug delivery

INTRODUCTION: The need to optimize therapeutic outcomes while minimizing side effects is a major driving force for research and development in the controlled drug delivery field. Polymer nanocomposites (NCs) are an emerging class of materials with remarkable potential for controlled drug delivery. There are a range of release mechanisms that characterize polymer NC systems, and these may be perturbed not only by the addition of nanofillers, but also by the type of drug and the interactions of the drug with the components of the system. AREAS COVERED: The focus of this review is on non-degradable polymer NC systems. In particular, the types of drug delivery approach from these polymer NCs and the theoretical models developed to describe those approaches are discussed. The importance of component interactions and factors affecting drug delivery from polymer NCs is also addressed. EXPERT OPINION: Despite the remarkable potential and extensive research being conducted on polymer NCs for use in drug delivery, commercialization and large-scale production are limited by the cost and difficulty in consistently producing fully exfoliated NCs. A continuing challenge for the field is to understand better the key interactions and structure-property relationships arising from different polymer, filler and drug combinations.     

Affinity-Based Polymers Provide Long-Term Immunotherapeutic Drug Delivery Across Particle Size Ranges Optimal for Macrophage Targeting

Drug delivery to specific arms of the immune system can be technically challenging to provide prolonged drug release while limiting off-target toxicity given the limitations of current drug delivery systems. In this work, we test the design of a cyclodextrin (CD) polymer platform to extend immunomodulatory drug delivery via affinity interactions for sustained release at multiple size scales. The parameter space of synthesis variables influencing particle nucleation and growth (pre-incubation time and stirring speed) and post-synthesis grinding effects on resulting particle diameter were characterized. We demonstrate that polymerized CD forms exhibit size-independent release profiles of the small molecule drug lenalidomide (LND) and can provide improved drug delivery profiles versus macro-scale CD polymer disks in part due to increased loading efficiency. CD polymer microparticles and smaller, ground particles demonstrated no significant cytotoxicity as compared to the base CD monomer when co-incubated with fibroblasts. Uptake of ground CD particles was significantly higher following incubation with RAW 264.7 macrophages in culture over standard CD microparticles. Thus, the affinity/structure properties afforded by polymerized CD allow particle size to be modified to affect cellular uptake profiles independently of drug release rate for applications in cell-targeted drug delivery.     

Recent advances in PLGA particulate systems for drug delivery

PLGA is a FDA-approved biocompatible and biodegradable polymer that is widely used in biomedical fields including drug delivery. Micro and nanoparticles based on PLGA have been extensively studied as drug delivery systems. Numerous studies proved that PLGA particulate systems are highly promising drug carriers for tumor targeting as well as pulmonary, oral, ophthalmic and vaginal delivery. PLGA particles can load a variety of classes of drugs including peptides, proteins and siRNA, protect unstable drugs in the body and have an ability to adapt versatile surface functionalities. PLGA particle systems have evolved with advancement of nano and biotechnology in the past decade. This review focuses on novel and innovative PLGA-based particulate drug delivery carriers in recent years.     

偶氮聚合物作为结肠靶向给药载体的研究进展

偶氮聚合物中的偶氮键可被结肠菌丛产生的偶氮还原酶催化还原，可用作高定位性的结肠靶向给药药物载体。偶氮聚合物药物释放体系可分为水凝胶骨架制剂、包衣制剂和聚合物前药体系。本文综述了这几方面的偶氮聚合物的研究进展。     

Effects of surfactants on gel behavior

The recent advances in the design and synthesis of new polymeric systems have opened a wide range of possibilities for the use of gels as drug dosage forms. These systems are able to act not only as simple reservoirs, but also as controlled-release systems and/or targeting agents for site-specific delivery. Applications of gels are determined by their drug-loading capability, rheological properties, and the mechanisms and kinetics of drug release. The incorporation of small proportions of surfactants, which are able to promote or hinder intra- or interchain polymeric bonds, may modify these properties and be a useful tool for developing gel-based dosage forms. Polymers and surfactants may interact, depending on their chemical structure, through ionic, hydrophobic and hydrogen-bonding mechanisms. The strength of the interaction is strongly affected by pH, ionic strength and presence of other substances, and physiological changes in these variables. These physiologic parameters affect the performance of polymer/surfactant gels as drug delivery systems. Surfactants may also promote cutaneous or mucosal drug penetration. Drug release processes from polymer/surfactant gels depend on the microstructure of the gel and the drug ‘state’ in the system. The drug can be: solubilized in water without interacting with any of the components; electrostatically or hydrophobically bound to the polymer; or solubilized inside micelles or polymer/surfactant aggregates. Interactions between surface-active drugs and polymers should also be taken into account because of their important repercussions on gel behavior. Finally, polymer/surfactant systems have a great potential for gene therapy, and some polymers that are able to interact with natural surfactants can be used as trap systems of bile salts for controlling the physiological levels of cholesterol.     

Silk fibroin biomaterials for controlled release drug delivery

INTRODUCTION: Given the benefits of polymer drug delivery implants over traditional periodic systemic administration, the development of biomaterial systems with the necessary properties (biocompatibility, degradation, stabilization, controllability) is paramount. Silk fibroin represents a promising, naturally derived polymer for local, controlled, sustained drug release from fully degrading implants and the polymer can be processed into a broad array of material formats. AREAS COVERED: This review provides an overview of silk biomaterials for drug delivery, especially those that can function as long-term depots. Fundamentals of structure and assembly, processing options, control points and specific examples of implantable silk drug delivery systems (sponges, films) and injectable systems (microspheres, hydrogels) from the 1990s and onwards are reviewed. EXPERT OPINION: Owing to its unique material properties, stabilization effects and tight controllability, silk fibroin is a promising biomaterial for implantable and injectable drug delivery applications. Many promising control points have been identified, and characterization of the relationships between silk processing and/or material properties and the resulting drug loading and release kinetics will ultimately enhance the overall utility of this unique biomaterial. The ever-expanding biomaterial 'tool kit' that silk provides will eventually allow the simultaneous optimization of implant structure, material properties and drug release behavior that is needed to maximize the cost-efficiency, convenience, efficacy and safety of many new and existing therapeutics, especially those that cannot be delivered by means of traditional administration approaches.     

新型胃滞留给药系统的研究进展

目的介绍新型胃滞留给药系统近年来的研究进展,为研究开发胃滞留制剂提供参考。方法通过查阅近年国内外相关文献,进行分析、整理和归纳。结果胃滞留给药系统能改善药物吸收,有效提高生物利用度,其中,以漂浮型、生物黏附型、膨胀型等三类胃滞留给药系统的研究较多。结论随着对胃滞留给药系统的深入研究,以及新型药用高分子材料的开发和制剂新技术的发展,胃滞留制剂具有广阔的应用前景。