9-硝基喜树碱叶酸聚合物胶束肿瘤靶向给药系统的表征及体外药效评价

背景：近年来,两亲性聚合物胶束作为难溶性药物载体和叶酸介导的肿瘤细胞靶向给药系统在药剂学研究领域受到极大的关注。 目的：制备包载9-硝基喜树碱的叶酸聚合物胶束并进行理化表征及体外药效评价。 方法：采用薄膜-水化法制得载药胶束,利用激光粒度分析仪检测胶束粒径大小,反相高效液相层析法检测载药量,透析法进行体外释放试验;利用肿瘤细胞摄取及体外生长抑制试验,对叶酸聚合物胶束作体外药效评价。 结果与结论：制得的9-硝基喜树碱叶酸聚合物胶束粒径为24~26 nm,载药量为3.24%,24 h累积释放百分率约90%。叶酸修饰的聚合物胶束对肿瘤细胞的亲和性及抗肿瘤活性显著高于普通胶束。提示叶酸修饰的聚合物胶束可为难溶性药物提供一种具有良好应用前景的肿瘤主动靶向纳米载药系统。     

叶酸靶向载紫杉醇磷脂-聚合物杂化纳米粒的制备及其体外细胞评价

目的 制备具有叶酸靶向性的载紫杉醇磷脂-聚合物杂化纳米粒(PTX-FLPNPs),并研究其对乳腺癌细胞EMT-6的细胞毒性及体外细胞吞噬.方法 以聚己内酯-聚乙二醇-聚己内酯(PCL-PEG-PCL)、二硬脂酰基磷脂酰乙醇胺-甲氧基聚乙二醇(DSPE-mPEG2000)和叶酸偶联的磷脂(Folate-PEG(2000)-DSPE)为药物载体,通过薄膜水化法自组装制备PTX-FLPNPs,并对其进行表征;使用激光扫描共聚焦显微镜观察比较叶酸受体高表达的乳腺癌细胞EMT-6对叶酸靶向及无靶向杂化纳米粒的吞噬作用;采用MTS法研究PTX-FLPNPs对EMT-6细胞的细胞毒性.结果 成功制备了PTX-FLPNPs,其呈球形,粒径均匀,具有明显的“核-壳”结构.投药量为30％的PTX-FLPNPs的平均粒径为(279.9±8.7)nm,多分散系数为0.173±0.021,Zeta电位为(-17.5±1.1)mV,载药量为(27.36±0.91)％,包封率为(91.16±1.12)％.细胞吞噬实验表明,叶酸受体高表达的EMT-6细胞对叶酸靶向的杂化纳米粒的吞噬作用明显强于无靶向的杂化纳米粒(P＜0.05).细胞毒性实验结果表明,PTX-FLPNPs的细胞毒性低于紫杉醇注射剂,且对肿瘤细胞的抑制效果优于无靶向的杂化纳米粒.结论 PTX-FLPNPs具有较高载药量及包封率,粒径均匀,可通过主动靶向作用介导肿瘤细胞内吞,并增加药物在肿瘤细胞内的浓度,是一种能有效抑制肿瘤的靶向载药纳米制剂.     

药物控释载体材料的研究与应用

背景：作为控制释放体系的药物载体材料大多是高分子材料,但部分纳米无机材料也正逐步应用到药物控释材料体系中并取得了很好的研究成果。因此,药物控释用载体材料的设计与研究应用越来越受到重视。 目的：对国内外药物控释载体材料的应用及最新研究进展作一综述。 方法：应用计算机检索CNKI和Elsevier SD数据库中1999-01/2011-01关于药物控缓释材料的文章,在标题和摘要中以“高分子,介孔材料,无机硅,磷酸盐,控释”或“polymer,mesoporous materials,Inorganic silicon ,calcium phosphate,controlled release”为检索词进行检索。选择文章内容与药物控缓释有关者,同一领域文献则选择近期发表或发表在权威杂志文章。纳入25篇文献进行综述。 结果与结论：药物控缓释载体材料以用药量小、作用时间长、靶向作用好等特点被广泛关注,但是仍存在载药后药物失活,丧失生物活性等缺陷,目前随着复合药物载体材料和经皮给药装置研究的发展,控缓释材料在临床治疗中的应用必将更加广泛。     

叶酸受体功能变异对叶酸代谢的影响及其在肿瘤治疗中的应用

叶酸为体内DNA合成、修复及甲基化所必需的微营养素,其缺乏可诱发DNA单双链断裂、染色体畸变等基因组稳定性下降事件及DNA甲基化异常、改变基因表达.叶酸受体是一类高亲和力叶酸结合蛋白,其在正常组织和恶性组织中的表达范围、表达量及功能存在很大差异,常被用于肿瘤靶向治疗.细胞表面叶酸受体的数量和类型影响叶酸的摄取效率,同时,叶酸-药物复合物靶向叶酸受体的作用也受到循环过程中叶酸含量的干扰.据此,该文将对叶酸代谢与叶酸受体表达之间的关系及其在肿瘤治疗中的应用现状作一概述.     

叶酸分子靶向载顺铂磁性纳米药物制备及表征

背景：醛基化海藻酸钠具有良好的水溶性和组织相容性,利用其改性Fe3O4磁性纳米颗粒可增加表面活性和稳定性,叶酸的修饰可赋予载体分子靶向性。 目的：制备具有叶酸受体靶向及磁靶向的载顺铂磁性纳米药物(CDDP-FA-ASA-MNPs)。 方法：采用高碘酸钠氧化法制备醛基化海藻酸钠,叶酸的羧基经二环己基碳二亚胺和N-羟基琥珀酰亚胺活化后合成FA与双端氨基聚乙二醇的耦连产物FA-PEG,化学共沉淀法制备Fe3O4,海藻酸钠侧链含有大量羧基,85 ℃下与Fe3O4纳米颗粒表面的羟基形成化学键结合,然后通过雪夫氏碱将FA-PEG与醛基化海藻酸钠相连接,最后根据配位络合的原理,顺铂分子中的-Cl被海藻酸钠的羧基取代,形成稳定的叶酸和醛基化海藻酸钠改性载顺铂磁性纳米复合物。 结果与结论：所制备的磁性纳米药物呈颗粒状,稳定分散于水溶液中,Fe3O4磁核平均粒径为(8.116±0.24) nm,流体力学直径为(110.9±1.7) nm,zeta电位为(-26.45±1.26) mV,最大饱和磁化强度为56.2 emu/g,顺铂包封率为(49.05±1.58)%,载药量为(14.31±0.49)%。体外实验证实,叶酸分子靶向载顺铂磁性纳米药物能被叶酸受体表达阳性的鼻咽癌细胞HNE-1和喉癌细胞Hep-2选择性摄取,而叶酸受体表达阴性的鼻咽癌细胞CNE-2则不摄取。提示所制备的CDDP-FA-ASA-MNPs具有良好的水溶性和稳定性,能被叶酸受体表达阳性的鼻咽癌和喉癌细胞摄取。     

阳离子脂质体介导的基因转移机制

背景：与病毒载体相比,许多天然与合成的阳离子类脂以脂质体的形式用于基因转移,具有无免疫原性、易生产、质粒免受核酸酶降解和无致瘤性等优点,并且作为病毒载体的有效替代物,阳离子脂质体能用于细胞的体内和体外转染。 目的：介绍阳离子脂质体介导的基因转移机制研究进展。 方法：由第一作者用计算机检索中国期刊全文数据库(CNKI：1987/2010)和PubMed (1987/2010)数据库,检索词分别为“基因治疗、阳离子脂质体、基因转移、机制”和“gene therapy, cationic liposome, gene transfer, mechanism”,语言分别设定为中文和英文。从阳离子脂质体基因转染和基因转移机制进行总结,综述了阳离子脂质体介导的基因转移机制。 结果与结论：共检索到108篇,按纳入和排除标准对文献进行筛选,共纳入20篇文章。综述了阳离子脂质体介导的基因转移机制,包括阳离子脂质体/DNA复合物的形成、细胞吸收、内含体释放和复合物解体以及细胞核摄入等方面的研究内容。结果提示,对类脂构效关系和基因转移机制的研究,是提高阳离子脂质体转染效率和优化基因治疗的关键。     

口服胰岛素载体的高分子生物材料

背景：利用具有生物相容性和生物可降解性的高分子材料作为载体,通过化学结合或物理包裹胰岛素,可提高胰岛素在体内的稳定性和生物利用度。 目的：从类型、制备方法、特征、药理作用等方面综述国内外口服胰岛素载体的高分子材料的研究进展。 方法：由作者应用计算机检索中国知网数据库、PubMed数据库和Elsevier 数据库2002年1月至2013年2月,与高分子生物材料和口服胰岛素载体相关的文章,中文关键词为“高分子生物材料、口服胰岛素、载体”,英文关键词为“polymeric biomaterials,oral insulin,carrier”。 结果与结论：目前,主要用于口服胰岛素系统控缓释的高分子生物材料可分为天然高分子生物材料和合成高分子生物材料两大类。用于口服胰岛素载体研究的天然高分子材料,以壳聚糖、藻酸盐多见。合成高分子生物材料中聚酯类、聚丙烯酸酯类及其共聚物,因具有良好的生物相容性、生物降解性和生理性能,被用作口服胰岛素制剂的载体材料的研究报道较多。国内外有关口服胰岛素制剂的研究报道虽多,也有一些商品型口服胰岛素进入临床试验阶段,但至今尚未见到实际应用的临床报告。其主要原因是作为载体的高分子材料、胰岛素的生物利用度低、制剂的质量标准及稳定性问题尚未解决。因此,未来的研究将主要集中在：载体材料的选择或者对现有高分子聚合物进行物理和化学的修饰,研发出新型的聚合物基材料作为载体,以避免胃肠道对胰岛素的破坏和改善胰岛素在体内的吸收,获得理想的释药速度和良好缓控释效果。     

精氨酸-甘氨酸-天冬氨酸肽类似物与新生血管内皮靶向治疗

背景：血管内皮是缺血、血栓、炎症、水肿、氧化应激等病理损伤中的重要部位,选择特异性的内皮细胞靶点成为药物介入治疗的关键。 目的：分析和总结近年来精氨酸-甘氨酸-天冬氨酸肽及精氨酸-甘氨酸-天冬氨酸多肽类似物作为特异性的内皮细胞靶点的研究。 方法：分别以“RGD、整合素、靶向治疗”,“RGD、integrin 、targeted therapy” 为检索词,应用计算机检索Pubmed 数据库1998年1月至2011年12月有关文章。纳入有关血管新生的文献。排除与研究目的无关和内容重复者。保留42篇文献做进一步分析。 结果与结论：整合素αvβ3是内皮细胞病理损伤及血管新生时的特异靶点,参与内皮细胞的迁移、增殖、分化过程。精氨酸-甘氨酸-天冬氨酸肽及精氨酸-甘氨酸-天冬氨酸多肽类似物作为整合素和其配体相互作用的识别位点,能结合肿瘤或者病理损伤时新生血管表达增高的整合素αvβ3,介导细胞与细胞外基质及细胞之间的相互作用,可在新生血管显影、靶向药物递送、载体材料修饰中发挥重要作用。     

抗肿瘤药物载体的主动靶向策略

背景：抗肿瘤药物给药后,在机体内往往非特异性分布,毒副作用大,生物利用度低,具有主动靶向功能的药物载体可成功解决这一问题。 目的：综合论述了近年来国内外制备主动靶向药物载体应用于抗肿瘤药物输送的最新研究,归纳总结出药物载体的各类主动靶向策略。 方法：应用计算机检索平台ISI Web of Knowledge检索2004/2011各英文数据库,检索词采用与抗肿瘤药物载体靶向给药密切相关的关键词,如“tumor,drug carrier,active targeting”等,共检索到文献58篇,最终纳入符合标注的文献26篇。 结果与结论：主动靶向策略是设计抗肿瘤药物载体时首先需要考虑也是最为重要的环节,它决定了药物载体实际的药物输送效果以及药物的生物利用度。具有主动靶向策略的药物载体可携带抗肿瘤药物到达肿瘤部位,显著减少机体内其他部位药物的非特异性分布,从而降低其毒副作用,提高生物利用度。     

脂质体在基因治疗中的应用研究及进展***

背景：脂质体是常用的安全的基因载体,然而由于其本身组成及结构的原因,应用和发展受到了限制,其转染效率和治疗效果成为基因治疗研究中最为重要的参考因素。 目的：回顾脂质体在基因治疗中的应用以及研究进展。 方法：由第一作者计算机检索1995/2011中国期刊全文数据库、CALIS全国医学文献/服务系统以及康健循证医学知识仓库,中英文检索词分别为“脂质体、基因、转染”和“liposome、gene、transfection”。 结果与结论：脂质体作为基因载体较病毒载体具有安全性高,免疫原性小,毒性小,容易制备等优点已成功应用于很多体外及动物体内实验,但由于其转染效率低,靶向性低等缺点使其发展受到了很大限制,所以目前脂质体在基因治疗中的研究热点在于提高脂质体的转染效率,在靶细胞和靶器官达到治疗浓度才能有更好的治疗效果。     

胰岛素缓释载体材料应用研究与问题

BACKGROUND: Sustained-release carriers of insulin shaped as microspheres made of different biomaterials have become an issue of concern. OBJECTIVE: To summarize the carrier materials and methods to prepare sustained-release microspheres of insulin. METHODS: Wanfang and PubMed databases were retrieved by computer for articles related to sustained-release carriers of insulin published from 1997 to 2015. The search terms were “insulin, controlled-release carrier, biomaterials” in Chinese and English, respectively. RESULTS AND CONCLUSION: Natural biodegradable polymer materials are preferred to prepare sustained-release microspheres of insulin, including gelatin, alginate, chitosan and its derivatives. These natural materials have good biocompatibility, degradability, film-forming and microsphere-forming abilities. Synthetic biodegradable polymer materials as carrier materials can promote drug stability and effective utilization, and realize targeted drug delivery. According to different physicochemical properties of materials, sustained-release carriers of insulin that meet different requirements can be prepared using emulsion-chemical crosslinking, spray drying and solvent evaporation methods. This review provides new insight into the development of stable drug carriers.     

Drug delivery with upconversion nanoparticles for multi-functional targeted cancer cell imaging and therapy

Upconversion nanoparticles (UCNPs) with unique multi-photon excitation photoluminescence properties have recently been intensively explored as novel contrast agents for low-background biomedical imaging. In this work, we functionalize UCNPs with a polyethylene glycol (PEG) grafted amphiphilic polymer. The PEGylated UCNPs are loaded with a commonly used chemotherapy molecule, doxorubicin (DOX), by simple physical adsorption via a supramolecular chemistry approach for intracellular drug delivery. The loading and releasing of DOX from UCNPs are controlled by varying pH, with an increased drug dissociation rate in acidic environment, favorable for controlled drug release. Upconversion luminescence (UCL) imaging by a modified laser scanning confocal microscope reveals the time course of intracellular delivery of DOX by UCNPs. It is found that DOX is shuttled into cells by the UCNP nano carrier and released inside cells after endocytosis. By conjugating nanoparticles with folic acid, which targets folate receptors over expressed on various types of cancer cells, we further demonstrate targeted drug delivery and UCL cell imaging with UCNPs. Besides DOX, this non-covalent drug loading strategy can also be used for loading of photosensitizer molecules on UCNPs for potential near-infrared light induced photodynamic therapy. Our results suggest the promise of UCNPs as interesting nano carriers for multi-functional cancer therapy and imaging.     

药物缓释载体材料在医药领域中的研究及应用

背景：药物缓释就是将小分子药物与高分子载体以物理或化学方法结合,在体内通过扩散、渗透等控制方式,将小分子药物以适当的浓度持续地释放出来,从而达到充分发挥药物功效的目的。 目的：总结药物缓释载体材料特征及其在医药领域中的应用。 方法：以“药物缓释、载体材料、生物降解、壳聚糖、聚乳酸、海藻酸钠”为中文关键词,以“Drug delivery,carrier material,biodegradable,chitosan,polylactic acid, sodium alginate”为英文关键词,采用计算机检索中国期刊全文数据库、PubMed数据库(1993-01/2010-11)相关文章。纳入高分子生物材料-药物缓释载体等相关的文章,排除重复研究或Meta分析类文章,共入选31篇文章进入结果分析。 结果与结论：壳聚糖和聚乳酸是当前在药物缓释体系中应用较多的材料,它是将小分子药物与高分子载体以物理或化学方法结合, 以适当的浓度持续地释放出来,从而达到充分发挥药物功效的目的,较单一生物材料具有显著优越性,具有更好的生物相容性和生物可降解性。目前很多研究仍处于实验阶段,还有一些问题有待于解决,如制剂质量方法不成熟,剂量较难控制,成本较高等。     

Folate mediated l-arginine modified oligo (alkylaminosiloxane) graft poly (ethyleneimine) for tumor targeted gene delivery

Folate receptor mediated gene targeting provides several advantages such as delivery of high concentration of gene at specific tumor sites including brain, lung, ovary, uterus and kidney where folate receptors are over expressed. In the present study for both systemic stability and tumor targeting ability, poly (ethylene glycol)-folic acid (PEG-FA) conjugate was coupled with an arginine modified oligo (alkylaminosiloxane) graft poly (ethyleneimine) having enhanced transfection efficiency compared to poly (ethyleneimine). The resultant polymer P(SiDAAr)5FP2 complexed pDNA effectively and showed protection against nuclease degradation. The PEG group provided improved blood compatibility and cell viability. Uniformly oriented arginine moiety helped to enhance cellular and nuclear localisation, which led to improved transfection. The polymer was capable of releasing pDNA at the nucleus and being cleared from the cell after its purpose. Transfection in presence of cellular uptake inhibitors showed multiple pathways for cellular uptake of the targeted polymer, out of which folate receptor mediated uptake was more prominent. The folate mediated cellular uptake of P(SiDAAr)5FP2 was then confirmed by flow cytometric evaluation. The high accumulation of targeted polymers in the tumor tissues of tumor bearing mice from 2nd hour onwards proved the active targeting effect of the polymer. Besides tumor accumulation, the material showed capability to diffuse through the vascular endothelium. This property is expected to be beneficial for brain targeting experiments.     

Preparation and characterization of methoxy poly(ethylene glycol)/poly(epsilon-caprolactone) amphiphilic block copolymeric nanospheres for tumor-specific folate-mediated targeting of anticancer drugs

Biodegradable methoxy poly(ethylene glycol)/poly(-caprolactone) (MPEG/PCL) amphiphilic block copolymer nanospheres coupled to folic acid have been designed to target a folate-binding protein that is overexpressed on the surface of many tumoral cells. For this purpose, hydroxy groups terminated on the MPEG/PCL copolymer were converted into primary amino groups, which were used to conjugate with the carboxylic group of folic acid. Nanospheres were prepared by the formation of micelles of the copolymer with or without the anticancer agent paclitaxel. Folate-mediated MPEG/PCL nanospheres were compared with hydroxyl- and amino-terminated nanospheres in terms of their size, surface characteristics, and drug-loading efficiency. Regardless of the type of terminal group, the MPEG/PCL nanospheres showed a narrow size distribution with an average diameter <80 nm without paclitaxel, and an average diameter of 115 nm when loaded with the drug. The results from zeta potential and X-ray photoelectron spectroscopy measurements revealed that the folate molecules were partially exposed, and were expressed on the surface of the nanospheres allowing folate receptor recognition. In in vitro, cytotoxicity tests, the nanospheres loaded with paclitaxel showed a higher cell viability than in cases where paclitaxel was absent. Thus, folate-mediated nanospheres composed of MPEG and PCL are potentially new drug carriers for tumor cell-selective targeting treatments.     

缓释药物的研究进展及临床应用

背景：各种制备缓释制剂的缓释材料很多,目前可用于生产的缓释材料有40多种,广泛应用于临床多种疾病的治疗。 目的：对目前国内外几种重要的缓释药物载体材料及临床上常用的缓释药物进行总结。 方法：应用计算机检索CNKI和PubMed数据库2000-01/2010-12关于缓释药物研究的文章,在标题和摘要中以“缓释,药物,生物材料”或“sustained release,drug,biomaterials”为检索词进行检索。选择文章内容与缓释药物密切相关的文章。排除Meta分析及重复性研究,最终纳入23篇文献进入结果分析。 结果与结论：可生物降解的合成高分子材料受到普遍重视并得到广泛应用,壳聚糖以其良好的性能备受青睐,成为药物缓释的一种重要载体,生物降解高分子聚乳酸在药物缓释方面的应用,起到重要的治疗作用;纤维蛋白胶生物相容性高,能有效延缓药物释放,在临床很多领域广泛应用。     

Conjugated Polymer‐Based Nanoparticles for Cancer Cell‐Targeted and Image‐Guided Photodynamic Therapy

Multifunctional materials with cell imaging and therapeutic functions are anticipated to provide promising agents in cancer treatment. Herein, folic acid modified conjugated polymer nanoparticles (FA‐CPNs) are exploited to target cancer cells and destroy the neighboring cancer cells. Folic acid in FA‐CPNs enables the strong binding with high affinity to folate receptor, a cancer‐cell‐associated protein, to target cancer cells. FA‐CPNs are able to produce cytotoxic reactive oxygen species upon irradiation 600 nm light, and therefore cause the cell death of folate receptor‐overexpressed cancer cells effectively. Therefore, the conjugated polymer‐based nanoparticles provide a multifunctional system for targeting cancer cells and photodynamic therapy.     

Synthesis and characterization of chitosan-g-poly(ethylene glycol)-folate as a non-viral carrier for tumor-targeted gene delivery

Poor water solubility and low transfection efficiency of chitosan are major drawbacks for its use as a gene delivery carrier. PEGylation can increase its solubility, and folate conjugation may improve gene transfection efficiency due to promoted uptake of folate receptor-bearing tumor cells. The aim of this study was to synthesize and characterize folate-poly(ethylene glycol)-grafted chitosan (FA-PEG-Chi) for targeted plasmid DNA delivery to tumor cells. Gel electrophoresis study showed strong DNA binding ability of modified chitosan. The pH(50) values, defined as the pH when the transmittance of a polymer solution at 600 nm has reached 50% of the original value, suggested that the water solubility of PEGylated chitosan had improved significantly. Regression analysis of pH(50) value as a function of substitution degree of PEG yielded an almost linear correlation for PEG-Chi and FA-PEG-Chi. The solubility of PEGylated chitosan decreased slightly by further conjugation of folic acid due to the relatively more hydrophobic nature of folic acid when compared to PEG. In addition, the chitosan-based DNA complexes did not induce remarkable cytotoxicity against HEK 293 cells. FA-PEG-Chi can be a promising gene carrier due to its solubility in physiological pH, efficiency in condensing DNA, low cytotoxicity and targeting ability.