纳米级分子靶向超声造影剂的制备及其体外肿瘤靶向性实验研究

目的制备针对肿瘤HER2分子的纯纳米粒径分子靶向超声造影剂,观测其理化特性,并在体外肿瘤细胞中验证其特异靶向性。方法利用改良的薄膜水化法直接制备纯纳米粒径微泡,鉴定其基本理化特性、形态学表现及体外超声造影成像效果;利用"亲和素-生物素法"构建"纳米微泡-Affibody",体外多种肿瘤细胞验证其特异靶向性,同时观察其稳定性。结果直接制备出了纯纳米级微泡,粒径为(498.7±55.0)nm,各项理化特性及超声成像效果良好;新构建的"纳米微泡-Affibody"在体外对多种HER2(+)肿瘤细胞具有特异靶向性。结论 "纳米微泡-Affibody"体外特异靶向性强,稳定性好,为进一步进行体内肿瘤分子靶向超声造影及抗肿瘤分子靶向治疗奠定了基础。     

携载PSMA单克隆抗体载药纳米泡的制备及体内显影的实验研究

目的制备携载PSMA单克隆抗体的载阿霉素纳米泡,观察其基本特性和体内显影能力。方法机械震荡法制备靶向载药纳米泡,观察其形态、大小、载阿霉素和偶联PSMA单克隆抗体的情况。检测粒径和电位,检测载药浓度,并在超声波治疗仪辐照下检测药物释放率。将靶向载药纳米泡与临床用微米级声学造影剂对比研究,观察二者在小鼠肝肾的增强造影效果。结果靶向载药纳米泡大小、分布均匀。荧光显微镜显示阿霉素和PSMA单克隆抗体与纳米泡结合。纳米泡粒径(793.80±92.05)nm,电位(8.74±2.41)mV,载药浓度(1.18±0.11)mg/ml。辐照下,阿霉素释放率(48.65±3.99)%。靶向载药纳米泡在小白鼠肝肾显影的达峰时间、上升时间和持续显影时间均长于临床用微米级声学造影剂,且有统计学差异(P0.05),而峰值强度无统计学差异(P0.05)。结论本实验成功制备了性质稳定的携载PSMA单克隆抗体载药纳米泡,且在体内有较好的显影效果,为今后应用靶向纳米泡作为化疗药物载体靶向治疗前列腺癌的研究提供了基础。     

非霍奇金淋巴瘤靶向治疗新进展

肿瘤分子靶向治疗,是指在细胞分子水平上,针对已经明确的致癌位点（该位点可以是肿瘤细胞内部的一个蛋白分子,也可以是一个基因片段）,来设计相应的治疗药物,药物进入体内以后靶向性选择与这些致癌位点相结合并发生作用,导致肿瘤细胞特异性死亡,而较少作用于肿瘤周围的正常组织细胞,所以分子靶向治疗又被称为“生物导弹”。分子靶向治疗的问世,不仅改变了传统化疗药物治疗模式,而且提高了某些肿瘤治愈率。根据药物的作用靶点和性质不同,本文就目前非霍奇金淋巴瘤中靶向治疗及其进展作一综述。     

载顺铂纳米靶向探针的制备及其体外对NPC细胞寻靶能力的实验研究

目的制备一种可载顺铂(CDDP)并具有叶酸分子靶向性的纳米级超声分子探针,研究其基本特性及体外寻靶能力。方法将CDDP、聚乳酸-羟基乙酸(PLGA)按一定比例溶解在有机溶剂中,采用双乳化法制备载有CDDP的纳米级超声造影剂(PLGA/CDDP),观察测量其基本特性及纳米微粒的包封率、载药量,优化CDDP的最佳剂量。通过聚乙二醇亚胺在PLGA表面连接叶酸(FA)分子后,双乳化法制备出载有CDDP,并具有FA分子靶向功能的纳米微粒(PLGA-Fa/CDDP)。将PLGA/CDDP和PLGA-Fa/CDDP分别作用于体外培养的人鼻咽癌(NPC)细胞株HNE-1(FA受体高表达)和CNE-2(FA受体低表达),观察比较其靶向性。结果成功制备了载有CDDP的纳米微粒PLGA/CDDP,该纳米微粒大小均匀,形态圆整,分散性好,直径分布为533.5nm。进一步将FA分子成功连接于PLGA表面成功制备了具有FA分子靶向功能的纳米微粒PLGA-Fa/CDDP,该纳米微粒与FA受体高表达的人NPC细胞株HNE-1细胞可以靶向结合,而与FA受体低表达的人NPC细胞株CNE-2细胞靶向结合不明显。结论成功制备了一种载有CDDP并具有FA分子靶向的纳米级超声造影剂微粒PLGA-Fa/CDDP,其对人NPC细胞株HNE-1细胞具有明显靶向性。     

纳米技术在乳腺癌治疗研究中的进展

近年来,纳米技术作为一项新的技术开拓了医学的新领域,为治疗很多疾病提供了新的方法。在乳腺癌治疗的研究中,发现纳米载体能很好地携带乳腺癌常用化疗药物,并能稳定释放药物。纳米材料在乳腺癌治疗方面有很好的靶向作用。在被动靶向方面,纳米载体能利用肿瘤微环境的改变提高增强渗透滞留效应,增加肿瘤局部药物浓度,进而提高抗乳腺癌效果;在主动靶向方面,乳腺癌分子靶向及磁性纳米微粒介导的靶向可提高乳腺癌细胞对抗癌药物的摄入。此外,纳米载体利用靶向效应部分逆转乳腺癌多药耐药,利用沉默相关耐药基因达到加强逆转的效果的作用。对于乳腺癌转移方面,纳米药物载体可以降低乳腺癌转移的风险,提高治疗乳腺癌骨转移的效果,对乳腺癌相关骨质疏松有一定的治疗效果。纳米技术在乳腺癌治疗中的应用前景越来越广阔。     

纳米级靶向超声造影剂的制备及对兔VX2肝肿瘤的显影试验

目的 制备一种具有靶向性的纳米级超声造影剂,测定其物理特性,并对兔VX2肝肿瘤的靶向性进行评估.方法 采用高速均质法制备纳米级靶向超声造影剂,测定粒径、Zeta电位、稳定性,观察体外显影、对体内肿瘤的显影,对肿瘤组织进行病理切片及荧光共聚焦观察.结果 纳米级靶向超声造影剂的粒径为(474.1±83.5)nm,Zeta电位为+(9.8±5.7)mV,溶液的性质稳定,其沉淀能够增强超声显影,体内能够增强肿瘤的显影,光镜下和荧光共聚焦显微镜下均能够观察到靶向造影剂聚集在肿瘤组织内.结论 自制的纳米级微球符合理想的靶向超声造影剂的要求,性质稳定,能够靶向肿瘤组织显影,有望成为一种新型的靶向超声造影剂及载基因或药物的靶向载体.     

新型多肽聚酰胺-胺型靶向药物载体的载药性能及细胞吸收和毒性

背景:前期研究通过噬菌体展示体内筛选方法获得了一条NCI-H460非小细胞肺癌特异结合的多肽(Lung cancer targetingpe ptide,LCTP),将该多肽与修饰的聚酰胺-胺型(Polyamidoamine,PAMAM)树枝状高分子材料连接制备了纳米靶向药物载体PAMAM-Ac-FITC-LCTP,该载体在体内外对非小细胞肺癌NCI-H460具有很好的靶向性。目的:在前期研究基础上,进一步研究PAMAM-Ac-FITC-LCTP靶向载体对阿霉素的包埋、释放及其细胞吸收和毒性性能。方法:以筛选到的多肽LCTP为靶向剂,构建了PAMAM-Ac-FITC-LCTP靶向载体。采用物理包埋法将PAMAM-Ac-FITC-LCTP与阿霉素连接,通过体外透析实验观察载体对药物的缓释功能,共聚焦显微镜观察细胞对药物的吸收。以游离阿霉素作为对照,MTT法观察载体载药后对NCI-H460细胞的作用。结果与结论:PAMAM-Ac-FITC-LCTP对阿霉素的最大包埋率为7.46%。载体对药物具有明显的缓释作用,离子浓度、pH和温度对药物的释放具有影响,说明PAMAM-Ac-FITC-LCTP主要是通过静电相互作用与阿霉素结合。PAMAM-Ac-FITC-LCTP/阿霉素短时间内较单独药物更高效进入NCI-H460细胞,而复合物24h的细胞毒性与阿霉素对细胞的毒性基本一致。以上结果说明PAMAM-Ac-FITC-LCTP可能是一个肿瘤治疗和诊断中很有用的药物靶向传输载体。     

新型多肽聚酰胺-胺型靶向药物载体的载药性能及细胞吸收和毒性

背景：前期研究通过噬菌体展示体内筛选方法获得了一条NCI-H460非小细胞肺癌特异结合的多肽（Lung cancer targetingpe ptide,LCTP）,将该多肽与修饰的聚酰胺-胺型（Polyamidoamine,PAMAM）树枝状高分子材料连接制备了纳米靶向药物载体PAMAM-Ac-FITC-LCTP,该载体在体内外对非小细胞肺癌NCI-H460具有很好的靶向性。目的：在前期研究基础上,进一步研究PAMAM-Ac-FITC-LCTP靶向载体对阿霉素的包埋、释放及其细胞吸收和毒性性能。方法：以筛选到的多肽LCTP为靶向剂,构建了PAMAM-Ac-FITC-LCTP靶向载体。采用物理包埋法将PAMAM-Ac-FITC-LCTP与阿霉素连接,通过体外透析实验观察载体对药物的缓释功能,共聚焦显微镜观察细胞对药物的吸收。以游离阿霉素作为对照,MTT法观察载体载药后对NCI-H460细胞的作用。结果与结论：PAMAM-Ac-FITC-LCTP对阿霉素的最大包埋率为7.46%。载体对药物具有明显的缓释作用,离子浓度、pH和温度对药物的释放具有影响,说明PAMAM-Ac-FITC-LCTP主要是通过静电相互作用与阿霉素结合。PAMAM-Ac-FITC-LCTP/阿霉素短时间内较单独药物更高效进入NCI-H460细胞,而复合物24h的细胞毒性与阿霉素对细胞的毒性基本一致。以上结果说明PAMAM-Ac-FITC-LCTP可能是一个肿瘤治疗和诊断中很有用的药物靶向传输载体。     

携细胞间黏附分子1抗体的Sono Vue微泡造影剂靶向识别受损内皮的实验研究

目的 探讨静电吸附法制备的携细胞间黏附分子1抗体靶向微泡在体外和体内的寻靶能力.方法 采用静电吸附法制备携ICAM-1抗体的靶向SonoVue微泡.体外培养经IL-1β刺激大量表达ICAM-1的人血管内皮细胞ECV304,采用免疫荧光法检测靶向微泡与其结合能力.构建兔急性心肌梗死模型,进行靶向微泡的心肌造影,采用冷冻切片和免疫荧光法榆测靶向微泡与受损血管内膜结合能力.结果 在体外实验中,可见大量携ICAM-1抗体靶向微泡与刺激后ECV304细胞紧密结合,仅有少量靶向微泡与正常ECV304细胞结合.体内实验中,可见大量携ICAM-1抗体靶向微泡在兔梗死心肌受损血管内膜处黏附,仅可见少量靶向微泡在正常血管内膜处黏附.结论 携ICAM-1抗体靶向微泡在体内、体外均能与受损血管内皮特异性结合,不仅有利于靶向超声造影显像,更为微泡携带药物或基因在局部定向释放开辟良好前景.     

叶酸-顺铂纳米药物的制备及其对人鼻咽癌细胞的靶向治疗作用

目的:制备连接叶酸分子的顺铂纳米药物,并研究该药物对人鼻咽癌细胞的体外靶向治疗作用.方法:采用化学共沉淀法制备顺铂纳米药物并通过聚乙二醇二胺连接叶酸分子合成叶酸-顺铂纳米药物(FA-MNP-CDDP)并对其进行表征.将人鼻咽癌细胞HNE-1和CNE-2与FA-MNP-CDDP体外共培养,采用普鲁士蓝染色法测定细胞摄取纳米药物的情况,采用MTT法测定纳米药物的细胞毒性.结果:合成FA-MNPCDDP纳米药物顺铂含量为(1.6 ±0.1)mg/mL,药物粒子平均直径为(10.1 ±1.5)nm.表达叶酸受体的HNE-1细胞对该纳米药物摄取能力显著强于不表达叶酸受体的CNE-2细胞.FA-MNP-CDDP对HNE-1细胞的体外抑制效果明显,IC50[(1.300±0.10)μg/mL]较单纯顺铂[(2.161±0.85)μg/mL]降低约40%.结论:叶酸-顺铂纳米药物具有针对鼻咽癌细胞的靶向载药和抑制增殖的能力.     

Biofunctionalized targeted nanoparticles for therapeutic applications

Background: The development of nanoparticles for the delivery of therapeutic agents has introduced new opportunities for the improvement of medical treatment. Recent efforts have focused on developing targeted nanoparticles, which are formulated by (for therapeutic delivery) functionalizing nanoparticle surfaces with targeting molecules, such as antibodies, peptides, small molecules and oligonucleotides. Objectives: To review the state of targeted nanoparticles development. Methods: The authors discuss the nanoparticle platforms for therapeutic delivery, targeting molecules and the biofunctionalized targeted nanoparticles currently in development. Results/conclusions: Biofunctionalized targeted nanoparticles have demonstrated exciting results in preclinical studies. With continued improvements, they may fulfill their potential as therapeutics carriers that can deliver the maximum dose to diseased tissue while minimizing effects on normal cells.     

Doxorubicin-loaded mesoporous magnetic nanoparticles to induce apoptosis in breast cancer cells

Selective targeting of chemotherapeutic drugs toward the cancer cells overcomes the limitations involved in chemotherapy. Ideally, targeted delivery system holds great potential in cancer therapy due to specific release of drug in the cancer tissues. In this regard, DOX-loaded chitosan coated mesoporous magnetic nanoparticles (DOX-CMMN) were prepared and evaluated for its physicochemical and biological characteristics. Nanosized magnetic nanoparticles were observed with a high loading capacity for DOX. The drug-loaded nanoparticles exhibited a controlled and sustained release of drug without any burst release phenomenon. The DOX-DMMN showed a concentration-dependent cell proliferation inhibitory action against breast cancer cells. The blank nanoparticles showed excellent biocompatibility with cell viability >85% at the maximum tested concentration. Our results showed that chitosan coated magnetic system has high potential for breast cancer targeting under an alternating current magnetic field (ACMF). The present study showed that magnetic nanoparticles can be targeted to tumor cells under the presence of oscillating magnetic field. The combined effect of chemotherapy and thermotherapy can have a promising clinical potential for the treatment of breast cancer.     

Current advances in ultrasound-combined nanobubbles for cancer-targeted therapy: a review of the current status and future perspectives

The non-specific distribution, non-selectivity towards cancerous cells, and adverse off-target side effects of anticancer drugs and other therapeutic molecules lead to their inferior clinical efficacy. Accordingly, ultrasound-based targeted delivery of therapeutic molecules loaded in smart nanocarriers is currently gaining wider acceptance for the treatment and management of cancer. Nanobubbles (NBs) are nanosize carriers, which are currently used as effective drug/gene delivery systems because they can deliver drugs/genes selectively to target sites. Thus, combining the applications of ultrasound with NBs has recently demonstrated increased localization of anticancer molecules in tumor tissues with triggered release behavior. Consequently, an effective therapeutic concentration of drugs/genes is achieved in target tumor tissues with ultimately increased therapeutic efficacy and minimal side-effects on other non-cancerous tissues. This review illustrates present developments in the field of ultrasound-nanobubble combined strategies for targeted cancer treatment. The first part of this review discusses the composition and the formulation parameters of NBs. Next, we illustrate the interactions and biological effects of combining NBs and ultrasound. Subsequently, we explain the potential of NBs combined with US for targeted cancer therapeutics. Finally, the present and future directions for the improvement of current methods are proposed.

NBs combined with ultrasound demonstrated the ability to enhance the targeting of anticancer agents and improve the efficacy.     

叶酸受体及其在介导药物靶向肿瘤细胞治疗中的应用

肿瘤细胞表面过度表达一系列受体,能与特异性的配体结合并诱导细胞内化.以这些受体为作用靶点,使药物与特异性配体结合即可将药物主动靶向肿瘤细胞.叶酸受体在多种肿瘤细胞特别是髓细胞白血病细胞中都有过度表达,它可通过介导细胞内化将叶酸摄取入细胞胞浆,利用叶酸受体进行肿瘤,特别是白血病的靶向性治疗颇有应用前景.本文就叶酸受体生物学性质、染色体定位及与配体的相互作用,叶酸受体在正常组织、肿瘤组织,特别是白血病细胞中的分布特点,以及叶酸受体介导主动靶向肿瘤细胞,特别是白血病细胞的研究进展进行了概述.     

Cell vehicle targeting strategies

Use of cells as therapeutic carriers has increased in the past few years and has developed as a distinct concept and delivery method. Cell-based vehicles are particularly attractive for delivery of biotherapeutic agents that are difficult to synthesize, have reduced half-lives, limited tissue penetrance or are rapidly inactivated upon direct in vivo introduction. Initial studies using cell-based approaches served to identify some of the key factors for the success of this type of therapeutic delivery. These factors include the efficiency of cell loading with a therapeutic payload, the means of cell loading and the nature of therapeutics that cells can carry. However, one important aspect of cell-based delivery yet to be fully investigated is the process of actual delivery of the cell payload in vivo. In this regard, the potential ability of cell carriers to provide site-specific or targeted delivery of therapeutics deserves special attention. The present review focuses on a variety of targeting approaches that may be utilized to improve cell-based therapeutic delivery strategies. The different aspects of targeting that can be applied to cell vehicles will be discussed, including physical methods for directing cell distribution, intrinsic cell-mediated homing mechanisms and the feasibility of engineering cells with novel targeting mechanisms. Development of cell targeting strategies will further advance cell vehicle applications, broaden the applicability of this delivery approach and potentiate therapeutic outcomes.     

基于超声靶向微泡破坏技术的纳米给药系统的研究进展

纳米给药系统是治疗多种疾病,尤其是肿瘤的一种极具应用潜力的方法。然而,目前其药物输送效率仍难以满足靶向治疗的需要。超声靶向微泡破坏(UTMD)技术作为一种安全的物理靶向方法,可以增强组织渗透性和细胞膜通透性,进而提高纳米给药系统的药物递送效率。本文就UTMD介导的纳米给药系统的研究进行综述。     

脂质体在肿瘤靶向治疗中的应用

随着生物技术、纳米技术和物理技术等多学科的飞速发展，脂质体作为一种载体已经得到了较大程度的发展。脂质体的靶向治疗应用与脂质体的体内生物学行为相一致。因此，对脂质体体内靶向部位的药物控释和持续时间等方面进行研究，从而寻找到体内那些合理的靶向部位。本文就脂质体的特点和各类脂质体的靶向抗肿瘤性进行了探讨，着重讨论脂质体靶向抗肿瘤的实用性和有效性。     

Improving chemotherapeutic drug penetration in tumors by vascular targeting and barrier alteration

Drug delivery and penetration into neoplastic cells distant from tumor vessels are critical for the effectiveness of solid-tumor chemotherapy. We have found that targeted delivery to tumor vessels of picogram doses of TNF-alpha (TNF), a cytokine able to alter endothelial barrier function and tumor interstitial pressure, enhances the penetration of doxorubicin in tumors in murine models. Vascular targeting was achieved by coupling TNF with CNGRC, a peptide that targets the tumor neovasculature. This treatment enhanced eight- to tenfold the therapeutic efficacy of doxorubicin, with no evidence of increased toxicity. Similarly, vascular targeting enhanced the efficacy of melphalan, a different chemotherapeutic drug. Synergy with chemotherapy was observed with 3-5 ng/kg of targeted TNF (intraperitoneally), about 10(6)-fold lower than the LD(50) and 10(5)-fold lower than the dose required for nontargeted TNF. In addition, we have also found that targeted delivery of low doses of TNF to tumor vessels does not induce the release of soluble TNF receptors into the circulation. The delivery of minute amounts of TNF to tumor vessels represents a new approach for avoiding negative feedback mechanisms and preserving its ability to alter drug-penetration barriers. Vascular targeting could be a novel strategy for increasing the therapeutic index of chemotherapeutic drugs.     

Targeted synthetic gene delivery vectors

Synthetic gene delivery vehicles have made significant progress in the past decade in demonstrating strong potential for targeted delivery to specific cells, low toxicity and immunogenicity and large carrying capacity. However, significant advances must still be made to increase the efficiency of both polymer and lipid vehicles. Furthermore, techniques to generate more effective targeting moieties for a variety of cell types, as well as means to consistently assemble vectors containing these targeting ligands, are areas for further improvement. This review focuses on significant recent advances in generating a number of novel targeted vectors, and discusses progress in the development of new genetic and chemical systems to enhance the targeting, assembly and biocompatibility of synthetic vectors.