靶向性纳米载药系统对中枢神经系统疾病作用的研究进展

目的由于血脑屏障的存在,大多数常规制剂中的药物难以进入脑部,影响脑部疾病的诊疗效果,利用纳米微粒作为载药系统可以使药物穿透血脑屏障。方法将大分子药物制成纳米粒,可增大中枢神经系统中药物浓度及延长药效,增加了对脑内病灶的靶向性。结果与结论尽管纳米给药系统用于脑部疾病靶向的治疗距临床应用仍有相当多的工作尚待完成,但目前的研究已展现其重要的意义。     

纳米粒技术在转运药物通过血脑屏障中的应用

纳米粒（nanoparticles）是一类粒径为1－1000nm的固体胶粒，现已被用作传递药物的载体。利用纳米粒将药物转运通过血脑屏障可能会提供更具有显著优势的脑内给药方法。纳米粒载体技术的主要优势在于纳米粒能克服血脑屏障限制治疗药物通过的特性，此外，这类给药系统还能延缓药物在脑内的释放，降低外周毒性。本文评价了以往的脑内给药方法，讲座了纳米粒通过血脑屏障的转运机制，描述了纳米粒的主要制备方法和特性。此外，对与药物转运通过血脑屏障有关的影响纳米粒制备的因素（聚合物和表面活性剂的类型、纳米粒的粒径和药物分子）也作了详细阐述。目前，评价纳米粒脑内给药的报道主要是针对麻醉药和化疗药。本文对这类报道中转运的机制和效果作了叙述。同时讨论了突破网状内皮系统的吞噬作用等生理因素对药物转运进入大脑的限制的方法。     

功能化纳米粒在脑靶向递药中应用的研究进展

血脑屏障的存在,导致药物不能有效到达靶部位发挥作用,极大的影响神经系统药物的发展和进步。纳米技术已被证明是用于脑靶向治疗的一种有效工具,尤其在脑肿瘤和神经退行性疾病中应用甚广。功能化纳米粒通过表面修饰等提高药物的顺应性,在药物原来的治疗基础上,达到更加精准的靶向性,高效率在靶部位聚集,起到治疗作用。本文主要综述功能化纳米粒及其功能化策略,总结了影响功能化纳米粒脑靶向运输的因素,同时对功能化的纳米粒在脑部疾病治疗中的优势和应用进行阐述,为其相关研究提供参考。     

载药纳米粒透过血脑屏障机制的研究进展

血脑屏障是维持中枢神经系统内环境稳定的结构基础,有效保护脑组织避免外源性有害物质侵害,但也阻碍许多治疗药物进入脑内,限制了中枢神经系统药物的临床应用。如何有效透过血脑屏障成为此类药物发挥治疗作用的关键环节。纳米粒作为一种新型药物载体,能携载药物透过血脑屏障进入脑组织,提高脑内药物浓度,实现脑内靶向给药。本文对载药纳米粒及其透过血脑屏障机制的研究进展作一综述。     

纳米粒作为脑靶向给药系统的研究进展

中枢神经系统(Central nervous system,CNS)疾病,如脑肿瘤、老年痴呆、帕金森综合征、病毒感染等是威胁人类健康的一大类疾病。但血脑屏障(Blood brain barrier,BBB)的存在限制了许多有效的治疗药物从血液进入脑部而发挥作用。因此,解决通过BBB的药物传递问题已成为脑部疾病药物治疗的关键。纳米粒(Nanoparticle,NP)又称毫微粒,是粒径大小在10～1000nm的固态胶体颗粒,可作为传导或输送药物的载体[1]。广义的NP给药系统包括脂质体(Liopsomes)、固体脂质纳米粒(Solidlipid nanoparticles,SLN)、纳米囊(Nanocapsules)和纳米球(Nanospheres)以及聚合物胶束(Polymeric micelles),本文所述的NP特指纳米球和纳米囊。NP在体内具有长循环、隐形和立体稳定等特点,有利于靶向给药。对其进行表面修饰,能显著提高药物在脑内的浓度,改善药物对脑部疾病治疗的有效性。本文着重对NP的最新研究进展作如下综述。1BBB的主要生理特征CNS与体循环之间主要存在二重屏障:BBB与血-脑脊液屏障(B-CSF-B)。B...     

脑靶向纳米载体材料研究进展

血脑屏障的存在使许多药物难以入脑,促进药物跨血脑屏障成为关键。纳米粒具有小粒子特征,能携载药物跨血脑屏障实现脑靶向,并提高脑内药物浓度。本文综述了PLA、PLGA、PCL、PBCA、PAMAM、CS等作为载体材料制备的纳米粒入脑的情况,并重点探讨纳米粒粒径大小、表面修饰等对入脑的影响。     

纳米粒穿透血脑屏障机制的研究进展

血脑屏障(blood-brain barrier,BBB)的存在使98%的药物无法进入脑组织,是制约神经系统药物发展的重要因素.纳米粒载药系统能够透过BBB,并提高脑内药物浓度,是实现脑内靶向给药的良好载体,但其透过BBB的机制至今尚未完全明白.自从2001年Kreuter提出关于纳米粒(nanoparticles,NP)透过BBB的6点可能机制后,针对此机制并进而提高载药NP入脑效率的探讨已成为热点之一,文中就目前NP穿透BBB机制研究进展做一综述.     

跨血脑屏障纳米给药系统载体的研究进展

目的:为深入研究和开发治疗脑部疾病的药物提供参考。方法:以"血脑屏障""纳米给药系统""脑靶向""纳米药物""载体""Blood brain barrier""Brain targeting""Drug delivery system""Nanomedicine""Carrier"等为关键词,组合查询2001-2016年在Pub Med、Elsevier、中国知网、万方、维普等数据库中的相关文献,对跨血脑屏障(BBB)纳米给药系统载体的研究成果进行综述。结果与结论:共检索到相关文献242篇,其中有效文献26篇。脑靶向纳米给药系统的常用载体有脂质体、聚合物胶束、聚合物纳米粒、树枝状聚合物及固体脂质纳米粒。将脑靶向纳米载体系统用于脑部疾病对于诊断和治疗疾病意义重大,其能在一定程度上克服BBB阻碍作用,有很好的应用前景。但脑靶向纳米给药系统大多数仍停留在基础研究层面,在研究中仍存在着多种问题。今后应寻找BBB选择性更高的作用靶点,研发高效、低毒的跨BBB纳米药物。     

替莫唑胺白蛋白纳米粒的制备及其脑内递药特性研究

以牛血清白蛋白为载体,采用高压均质法制备替莫唑胺白蛋白纳米粒,并运用脑微透析技术,考察该纳米粒经大鼠尾静脉注射给药后的脑内递药特性.结果表明,白蛋白纳米粒形态圆整,平均粒径为(117.60±3.40) nm,ξ电位为(14.70±3.51)mV,包封率与载药量分别为(52.16±2.23)％和(5.33±0.10)％.替莫唑胺白蛋白纳米粒组的tmax和AUC0→1比其溶液剂组显著提高,但Cmax无显著差异.结果提示本品可延长药物在脑内的持续时间,促进药物的脑内吸收,有望成为替莫唑胺脑部递药的有效载体.     

纳米结构脂质载体在脑靶向传递体系的研究进展

随着全球环境不断恶化以及社会老龄化程度不断加深,中枢神经系统疾病已经成为社会关注的热点话题,而血脑屏障是治疗多种中枢神经系统疾病的主要障碍。纳米技术已被证明有效用于脑靶向的治疗,而纳米结构脂质载体是一种极具发展前景的新型纳米载体给药系统。通过查阅近年来的相关文献,本文介绍了纳米结构脂质载体和血脑屏障的结构特点,总结了药物透过血脑屏障的评价方法,并对纳米结构脂质载体在治疗中枢神经系统疾病中的应用进行综述。笔者对近年来纳米结构脂质载体在脑靶向传递体系的研究进展进行归纳和总结,同时对其发展前景进行展望,以期为今后纳米结构脂质载体用于中枢神经系统疾病的临床治疗提供更理想的治疗方案,为更深层次的理论研究和机制探索开拓思路。     

脑靶向性鼻腔给药的研究进展

鼻腔给药作为脑靶向给药的途径之一,可有效地使通过其他给药途径不易透过血脑屏障的药物绕过血脑屏障,靶向递送到脑部,为中枢神经系统疾病的治疗提供一种极有发展前景的给药途径.现从药物由鼻腔到脑的转运方式、影响因素、剂型、评价方法以及增强脑靶向性的方法等方面,对近年来鼻腔给药脑靶向性的研究进展进行综述.     

Evaluation of brain-targeted chitosan nanoparticles through blood–brain barrier cerebral microvessel endothelial cells

The blood–brain barrier (BBB) is the major problem for the treatment of central nervous system diseases. A previous study from our group showed that the brain-targeted chitosan nanoparticles-loaded with large peptide moieties can rapidly cross the barrier and provide neuroprotection. The present study aims to determine the efficacy of the brain-targeted chitosan nanoparticles’ uptake by the human BBB cerebral microvessel endothelial cells (hCMECs) and to investigate the underlying mechanisms for enhanced cellular entry. Fluorescently labelled nanoparticles either conjugated with antibodies recognising human transferrin receptor (anti-TfR mAb) or not were prepared, characterised and their interaction with cerebral endothelial cells was evaluated. The antibody decoration of chitosan nanoparticles significantly increased their entry into hCMEC/D3 cell line. Inhibition of cellular uptake by chlorpromazine indicated that the anti-TfR mAb-conjugated nanoparticles were preferentially cell internalised through receptor-mediated endocytosis pathway. Alternatively, as primarily observed with control chitosan nanoparticles, aggregation of nanoparticles may also have induced macropinocytosis.     

经鼻脑靶向递药系统的研究进展

鼻腔与脑在解剖生理上的独特联系使得鼻腔给药作为脑内递药途径成为可能.鼻腔给药作为脑靶向的途径之一,可有效地使通过其他给药途径不易透过血脑屏障的药物绕过血脑屏障到达脑部,为中枢神经系统疾病的治疗提供了一种极有发展前景的脑内递药途径.就鼻腔给药脑靶向的依据、影响因素、评价方法、剂型等方面对经鼻脑靶向递药系统的研究现状进行总结.     

Targeted Delivery of Nano-Therapeutics for Major Disorders of the Central Nervous System

Major central nervous system (CNS) disorders, including brain tumors, Alzheimer’s disease, Parkinson’s disease, and stroke, are significant threats to human health. Although impressive advances in the treatment of CNS disorders have been made during the past few decades, the success rates are still moderate if not poor. The blood–brain barrier (BBB) hampers the access of systemically administered drugs to the brain. The development of nanotechnology provides powerful tools to deliver therapeutics to target sites. Anchoring them with specific ligands can endow the nano-therapeutics with the appropriate properties to circumvent the BBB. In this review, the potential nanotechnology-based targeted drug delivery strategies for different CNS disorders are described. The limitations and future directions of brain-targeted delivery systems are also discussed.     

Differential receptor-mediated drug targeting to the diseased brain

The brain is not directly accessible for intravenously administered macro- and most small molecular drugs because of the presence of the blood–brain barrier (BBB). In this respect the BBB functions as a physical and metabolic barrier which is presented by the endothelial cells in brain capillaries. In order to overcome the BBB, therapeutic compounds have been targeted to internalizing receptors at the BBB. In this review we summarize the different approaches that have been described in current literature, including the possible difficulties for clinical application. Particularly, we focus on the possible impact of brain diseases on receptor-mediated transport to the BBB/brain and how this may affect various targeting strategies. Moreover, it is our opinion that a differential drug targeting/delivery approach should be applied to treat central nervous system (CNS) diseases that are related to the BBB alone, and for CNS diseases that are related to both the brain and the BBB.     

泊洛沙姆在药物穿越血脑屏障中的重要作用

泊洛沙姆是一种具有药理活性的多功能药用辅料，在药剂学中应用广泛。近年来，研究发现泊洛沙姆可以通过多种作用机制帮助药物穿越血脑屏障，抑制血脑屏障上的P-糖蛋白、多药耐药相关蛋白等外排泵系统；吸附血浆中的不同载脂蛋白后，通过与血脑屏障上相应受体的结合，使泊洛沙姆包被的纳米粒主动转运入脑；连接各种配体及单克隆抗体等导向性分子，使其通过受体介导的转运进入脑部。本文综述了泊洛沙姆在促进药物穿越血脑屏障的重要作用，对设计脑靶向药物传递系统具有重要意义。     

Nano-enabled delivery systems across the blood–brain barrier

The development of drugs to treat disorders of the central nervous system (CNS) faces difficulties in achieving penetration of a drug through the blood–brain barrier (BBB) and allowing the drug to reach its intended target in the brain. There have been strategies to improve drug delivery to the brain through endogenous transport pathways such as passive diffusion, endocytosis, and active transport. Among various strategies, nano-enabled delivery systems offer a promising solution to improve the uptake and targeted delivery of drugs into the brain. Various nanocarriers including liposomes, bolaamphiphiles and nanoparticles can be used as a means to encapsulate drugs, either alone or in combination with targeting ligands. Moreover, most of materials used in nanocarrier fabrication are both biodegradable and biocompatible, thereby increasing the clinical utility of them. Here, we review the possibility to employ nano-enabled materials for delivery of drug across the BBB and the recent advances in nanotechnologies for therapy of the CNS diseases.     

Nanotechnological advances for the delivery of CNS therapeutics

Effective non-invasive treatment of neurological diseases is often limited by the poor access of therapeutic agents into the central nervous system (CNS). The majority of drugs and biotechnological agents do not readily permeate into brain parenchyma due to the presence of two anatomical and biochemical dynamic barriers: the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB). Therefore, one of the most significant challenges facing CNS drug development is the availability of effective brain targeting technology. Recent advances in nanotechnology have provided promising solutions to this challenge. Several nanocarriers ranging from the more established systems, e.g. polymeric nanoparticles, solid lipid nanoparticles, liposomes, micelles to the newer systems, e.g. dendrimers, nanogels, nanoemulsions and nanosuspensions have been studied for the delivery of CNS therapeutics. Many of these nanomedicines can be effectively transported across various in vitro and in vivo BBB models by endocytosis and/or transcytosis, and demonstrated early preclinical success for the management of CNS conditions such as brain tumors, HIV encephalopathy, Alzheimer's disease and acute ischemic stroke. Future development of CNS nanomedicines need to focus on increasing their drug-trafficking performance and specificity for brain tissue using novel targeting moieties, improving their BBB permeability and reducing their neurotoxicity.