大内径多壁碳纳米管基靶向缓释载药系统的制备及性能

目的制备大内径多壁碳纳米管（LID-MWCNT）基靶向抗肿瘤药物缓释系统,分析其功能特性并检测其对肿瘤细胞的增殖抑制作用。方法纯化、切割LID-MWCNT,制备碳管载体及同源封堵物超短LID-MWCNT （UST）。碳管表面负载靶向分子叶酸（FA）及荧光标记分子;管内负载抗肿瘤药物顺铂（CDDP）,并以UST 封堵药物通道。观察载药系统显微形态;测定载药率及药物释放曲线;观察载药系统对肿瘤细胞的靶向趋化状况及增殖抑制效应。结果成功制备大内径多壁碳纳米管基靶向抗肿瘤药物缓释系统（CDDP@UST-FA-LID-MWCNT）,其载药率为70.97%。体外释放呈双相缓释模式,持续释放时间约18 h。载体系统具备了一定靶向趋化能力;较低载药浓度的 CDDP@UST-FA-LID-MWCNT 即对肿瘤细胞具有增殖抑制作用,且随着药物浓度的增加,抑制作用增强。结论载药系统CDDP@UST-FA-LID-MWCNT 具有较高的载药率及良好的药物缓释效果,能够靶向作用于肿瘤细胞,具有较强的抗肿瘤作用。     

碳纳米管作为药物载体的研究进展

新型药物载体的开发对药物的研究具有举足轻重的作用。碳纳米管具有独特的中空结构和纳米管径，可用作药物载体。采用肽、蛋白、核酸及药物分子修饰的碳纳米管作为载体，可运载生物活性分子进入细胞且不产生毒性。本文综述了近年来修饰碳纳米管作为药物载体的研究进展，评述了碳纳米管的细胞穿透性能和细胞毒性，概述了碳纳米管功能化修饰的方法。随着碳纳米管在药物载体领域研究日趋深入，碳纳米管修饰方式与其细胞穿透性能的相互关系、尺寸效应将会深入研究。制备溶解性好、低毒性的修饰碳纳米管作为药物载体，将是今后研究的主要方向。     

顺铂载入碳纳米管内增加其抗肿瘤性的研究

目的 观察大孔径碳纳米管(SWNTs)做为载体以增加顺铂抗肿瘤活性的模式及机制.方法 用毛细现象,将碘化丙啶(PI)和顺铂装载进入纳米管管腔,内载顺铂进入宫颈癌细胞,并在细胞内释放顺铂;用荧光分光光度计及紫外分光光度计,观察PI及顺铂在细胞外和细胞内释放模式,并通过流式细胞技术及MTT法,检测顺铂对宫颈癌细胞增殖活性的抑制.结果 顺铂在碳纳米管的运载下,可较易进入细胞内,从而使细胞内药物浓度增加,其模式与PI的转载模式相同,且在顺铂浓度较低时,就可对Hela细胞产生明显的抑制作用.结论 SWNTs内载抗癌药物可逆转肿瘤耐药,增加药物抗肿瘤作用.     

碳纳米管靶向抗肿瘤药物载体的制备及初步分析

目的 制备单壁碳纳米管(SWNTs)靶向抗肿瘤药物载体,初步分析其药学特性和细胞学特性.方法 功能化处理SWNTs后,在其表面负载各种生物活性分子,包括表面改性分子叶酸-聚乙二醇(PEG-FA)、抗肿瘤化疗药物阿霉素(DOX)以及荧光标记分子异硫氰酸荧光素(FITC),考察各生物分子负载情况及该药物载体的体外细胞学特性.结果 酸处理及PEG-FA功能化后的SWNT能稳定分散于水中,长度为200～500nm,浓度最高可达50μg·mL-1;DOX及FITC能在SWNTs表面稳定结合,最佳结合值pH7;药物载体能通过叶酸分子的靶向介导进入肿瘤细胞,较游离DOX有更强的体外抑癌效能.结论 碳纳米管靶向抗肿瘤药物载体能靶向作用于肿瘤细胞,性状稳定,载药量可控,增加了化疗药物的抗癌活性.     

多壁碳纳米管与甘草苷和异甘草苷的选择性吸附作用

碳纳米管作为一种特殊的纳米材料,具有中空结构,高强度韧性及良好的化学和热力学稳定性。对人体毒性小,有良好的生物相容性,一直被期望作为药物传送系统的运输载体[1~4]。在碳纳米管与生物体系相互作用研究中发现碳纳米管是一种高效地向细胞内输送药物的载体。沈海军[5]利用MM     

载阿霉素的单壁碳纳米管的制备及体外抗肿瘤初步评价

目的 为了开发一种新型的多功能药物递送载体平台，引入了具有较强细胞摄取能力和较高载药效率的碳纳米管，通过功能化修饰可能降低碳纳米管细胞毒性的同时提高肿瘤细胞对其的摄取能力。方法 选取单壁碳纳米管(single-walled carbon nanotubes, SWCNTs),通过混酸处理、活性基团以及靶向基团的修饰降低载体材料的毒性，提升其生物相容性，并且为载体材料增加了对肿瘤细胞的靶向性，以X-射线光电子能谱(X-ray photoelectron spectroscopy, XPS),X射线衍射(X-ray diffraction, XRD)等分析手段验证了修饰基团的成功连接。借助MTT实验以及荧光图像检测了载体的细胞毒性，摄取能力和活性氧水平。结果 经聚乙二醇(polyethylene glycol, PEG),聚乙烯亚胺(polyetherimide, PEI),叶酸(folicacid, FA)等活性基团修饰后的SWCNTs细胞毒性明显下降，且增加了MCF-7细胞对阿霉素(doxorubicin, DOX)的有效摄取和ROS水平，提高了机体抗肿瘤免疫能力。结论 表明修饰后的S...     

脑肿瘤靶向纳米递药系统的研究进展

脑肿瘤中恶性肿瘤较为常见,脑瘤发展快、治疗难导致了较高的死亡率。采用化学药物治疗时,药物进入脑肿瘤组织必须通过血脑屏障和血- 脑瘤屏障。一些有潜力的抗肿瘤药物由于自身物理化学性质的限制,不能有效到达肿瘤。针对脑肿瘤形成和发展不同阶段的特点,目前脑肿瘤靶向递药有3 种策略：跨血脑屏障（BBB）转运递药、跨血- 脑瘤屏障（BBTB）转运递药和利用实体瘤的高通透性和滞留效应（EPR 效应）递药,已被广泛研究的纳米递药载体有脂质体、固体脂质纳米粒、聚合物胶束、树枝状聚合物、碳纳米管、聚合物纳米粒、磁性纳米粒等。控制载药纳米微粒粒径大小以及对其表面进行修饰可改善药物在体内的分布与滞留,提高化疗药物的疗效,降低毒副作用。多级靶向纳米递药系统有潜力成为治疗脑肿瘤的重要辅助方式。     

载药纳米微粒的应用及研究进展

目的：对纳米、纳米科反及其在药物研究中的应用进行介绍。方法：通过对国内外文献的总结。概述了载药纳米微粒中的普通载药微粒,控释载药微粒、靶向定位载药微粒、载药磁性微粒等类别,介绍了复乳化法技术、超声乳化法、等电临界法、氧化还原法等制备载药纳米微粒的方法。结果：纳米技术与现代医药学结合的产物-载药纳米微粒具有易吸收、定向性强等优点。结论：载药纳米微粒的研究开发可解决口服易水解药物的给药途径,延长药物的体内半衰期,更精确的靶向定位给药。减少药物不良反应,消除生物屏障对药物作用的影响。     

碳纳米管在生物医药领域的应用及其安全性

碳纳米管包括单壁碳纳米管和多壁碳纳米管,是目前最有应用前景的纳米材料之一.作为载体,其具有的独特中空结构和纳米管径,可运送生物活性分子及药物进入细胞或组织.作为一种新型生物材料,能促进骨组织修复生长、神经再生,减少神经组织瘢痕产生.然而,碳纳米管对人体也有一定的毒性作用,目前研究主要集中在肺脏毒性和细胞毒性,表现为可引起肺脏炎症、内芽肿和细胞凋亡、活力下降、细胞周期改变等.其毒力大小与碳纳米管的特性有关,如结构、长度、表面积、制备方法、浓度、剂量等,毒性作用机制可能与氧化应激有关.     

碳纳米管的生物相容性

碳纳米管（CNT）是一种非常有序、高纵横比的碳同素异形体，包括单壁碳纳米管（SWCNT）和多壁碳纳米管（MWCNT）。它的特性使其在生物医学领域得到广泛应用，包括生物传感器、药物和疫苗传递，以及特殊生物材料的制备。本文总结了现有碳生物材料性能，概述了纳米毒理学研究内容，探讨了CNT细胞毒性和生物相容性。     

硅纳米管药物传递系统研究进展

综述了近年来国内外硅纳米管药物传递系统的研究进展,包括硅纳米管的特点、制备工艺、功能化及用作药物传递系统的研究情况。硅纳米管具有内部空腔体积大、表面积大、生物相容性好及表面可功能化等特点,能克服一般药物传递系统所存在的载药量较小、药物易发生泄漏等缺陷,是一种极具开发潜力的新型药物传递系统。     

Filled carbon nanotubes in biomedical imaging and drug delivery

Introduction: Carbon nanotubes have been advocated as promising candidates in the biomedical field in the areas of diagnosis and therapy. In terms of drug delivery, the use of carbon nanotubes can overcome some limitations of ‘free’ drugs by improving the formulation of poorly water-soluble drugs, allowing targeted delivery and even enabling the co-delivery of two or more drugs for combination therapy. Two different approaches are currently being explored for the delivery of diagnostic and therapeutic agents by carbon nanotubes, namely attachment of the payload to the external sidewalls or encapsulation into the inner cavities. Although less explored, the latter confers additional stability to the chosen diagnostic or therapeutic agents, and leaves the backbone structure of the nanotubes available for its functionalization with dispersing and targeting moieties. Several drug delivery systems and diagnostic agents have been developed in the last years employing the inner tubular cavities of carbon nanotubes.

Areas covered: The research discussed in this review focuses on the use of carbon nanotubes that contain in their interior drug molecules and diagnosis-related compounds. The approaches employed for the development of such nanoscale vehicles along with targeting and releasing strategies are discussed.

Expert opinion: The encapsulation of both biomedical contrast agents and drugs inside carbon nanotubes is further expanding the possibilities to allow an early diagnosis and treatment of diseases.     

Applications of cyclic peptide nanotubes (cPNTs)

Self-assembled cyclic peptide nanotubes (cPNTs) have recently drawn particular attention as one of the most intriguing nanostructures in the field of nanotechnology. Given their unique features including high surface area, increased drug loading, environmental stability, enhanced permeation, and modifiable drug release, these hollow tubular structures can be constructed with cyclic di-, tri-, tetra-, hexa-, octa-, and decapeptides with various amino acid sequences, enantiomers, and functionalized side chains and can be applied for antiviral and antibacterial drugs, drug delivery and gene delivery vectors, organic electronic devices, and ionic or molecular channels. Recent publications have presented promising results regarding the use of cPNTs as drugs or biomedical devices. However, there is an urgent need for the further in vivo nanotoxicity and safety testing of these nanotubes to evaluate their suitability in different fields.     

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.     

The alluring potential of functionalized carbon nanotubes in drug discovery

Importance of the field: The possibility of carbon nanotube integration into living systems for therapeutic and diagnostic purposes has opened the way to explore their applications in drug delivery and discovery. A wide variety of chemical approaches has been developed to functionalize carbon nanotubes with therapeutic molecules towards different biomedical uses. Areas covered in this review: This review covers the recent advances in the development of functionalized carbon nanotubes to offer improvements for different diseases, in particular for cancer therapy. What the reader will gain: Functionalized carbon nanotubes are able to transport therapeutic agents. Targeted methodologies using carbon nanotube-based conjugates have been investigated to improve the efficacy of some drugs. The capacity of such nanomaterials to seamlessly translocate into cells with alternative various mechanisms and their pharmacokinetic properties is also discussed. Take home message: Although at its infancy, functionalized carbon nanotubes are very promising as a new nanomedicine platform in the field of drug discovery and delivery. They have the capacity to cross biological barriers and can be eliminated via renal and/or fecal excretion. They can transport small drug molecules while maintaining - and in some cases improving - their therapeutic efficacy.     

酸敏释药胶束肿瘤靶向给药系统的研究进展

酸敏释药胶束作为一种新型的靶向给药系统,具有增溶疏水性药物、载药量高,酸敏感释药等优势。可通过物理包埋或酸敏感键共价连接药物的方式包载药物。在肿瘤组织的偏酸环境下,物理包埋载药胶束由于共聚物亲脂嵌段质子化或亲水亲脂嵌段水解分离、共聚物失去两亲性,胶束解聚释药;而以共价连接方式包载的药物经酸敏键断裂释放。现主要从载药方式及释药机制方面探讨酸敏释药胶束作为肿瘤靶向给药系统的研究进展。     

Carbon nanotubes for delivery of small molecule drugs

In the realm of drug delivery, carbon nanotubes (CNTs) have gained tremendous attention as promising nanocarriers, owing to their distinct characteristics, such as high surface area, enhanced cellular uptake and the possibility to be easily conjugated with many therapeutics, including both small molecules and biologics, displaying superior efficacy, enhanced specificity and diminished side effects. While most CNT-based drug delivery system (DDS) had been engineered to combat cancers, there are also emerging reports that employ CNTs as either the main carrier or adjunct material for the delivery of various non-anticancer drugs.     

Analyzing Nanotheraputics-Based Approaches for the Management of Psychotic Disorders

Psychoses are brain disorders clinically manifested by cognitive conditions such as hallucinations, delirium, dementia, schizophrenia, and delusions. Antipsychotic drugs are associated with significant side effects such as dystonia, tardive dyskinesia, involuntary muscle movement, and metabolic disorders. Moreover, those antipsychotics currently available have poor bioavailability, drug-related adverse effects, poor therapeutic efficacy, and poor brain delivery resulting from the blood-brain barrier. Conventional dosage forms, which release the drugs into the general circulation, fail to deliver the drugs directly to the brain efficiently. Thus, a rational approach based on nanotherapeutics may overcome these limitations; such approaches can be used for the delivery of drug molecules to their targeted site. Nanotherapeutics are colloidal systems comprising nanosize-range particles and unique physicochemical properties; these properties include plasticity, biodegradability, bioacceptability, versatile surface modification properties, and protection of drug molecules from degradation. The present review describes various nanoformulations for delivery of antipsychotic drugs to the brain; these include nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsion, nanosuspensions, and carbon nanotubes. The review also considers the ability of these formulations to improve drug bioavailability and targeting affinity, as well as their ability to circumvent the first-pass metabolism.     

Organic nanotubes for drug loading and cellular delivery

Organic nanotubes made of synthetic amphiphilic molecules are novel materials that form by self-assembly. In this study, organic nanotubes with a carboxyl group (ONTs) at the surface were used as a carrier for the anticancer drug doxorubicin, which has a weak amine group. The IC(50) values of ONT for cells were higher than that of conventional liposomes, suggesting that ONTs are safe. The results showed that the drug loading of ONTs was susceptible to the effect of ionic strength and H(+) concentration in the medium, and drug release from ONTs was promoted at lower pH, which is favorable for the release of drugs in the endosome after cellular uptake. ONTs loaded with the drug were internalized, and the drug was released quickly in the cells, as demonstrated on transmission electron microscopy images of ONTs and the detection of a 0.05% dose of ONT chelating gadolinium in the cells. Moreover, ONT could be modified chemically with folate by simply mixing with a folate-conjugate lipid. Therefore, these novel, biodegradable organic nanotubes have the potential to be used as drug carriers for controlled and targeting drug delivery.     

The alluring potential of functionalized carbon nanotubes in drug discovery

Importance of the field: The possibility of carbon nanotube integration into living systems for therapeutic and diagnostic purposes has opened the way to explore their applications in drug delivery and discovery. A wide variety of chemical approaches has been developed to functionalize carbon nanotubes with therapeutic molecules towards different biomedical uses.

Areas covered in this review: This review covers the recent advances in the development of functionalized carbon nanotubes to offer improvements for different diseases, in particular for cancer therapy.

What the reader will gain: Functionalized carbon nanotubes are able to transport therapeutic agents. Targeted methodologies using carbon nanotube-based conjugates have been investigated to improve the efficacy of some drugs. The capacity of such nanomaterials to seamlessly translocate into cells with alternative various mechanisms and their pharmacokinetic properties is also discussed.

Take home message: Although at its infancy, functionalized carbon nanotubes are very promising as a new nanomedicine platform in the field of drug discovery and delivery. They have the capacity to cross biological barriers and can be eliminated via renal and/or fecal excretion. They can transport small drug molecules while maintaining – and in some cases improving – their therapeutic efficacy.