rhIL-2与阿霉素长循环热敏脂质体靶向治疗肿瘤的协同作用

目的:观察重组人白细胞介素-2(rhIL-2)与阿霉素长循环热敏脂质体(ALTSL)联合靶向治疗荷H22瘤小鼠的协同作用,并探讨其抑瘤作用的机制。方法:以荷H22瘤小鼠的瘤重为指标,评价药物的抑瘤活性。以荷H22瘤小鼠的存活天数计算生命延长率。以乳酸脱氢酶释放法测定NK细胞的杀伤活性。以MTT比色法检测淋巴细胞的转化率。以流式细胞术检测肿瘤细胞的凋亡及p53、Fas、FasL和caspase-3的表达。用RT PCR法测定IL-2mRNA及IL-12mRNA的表达。镜下观察荷H22瘤小鼠肿瘤、心、肝及肾脏组织的病理变化。结果:rhIL2 ALTSL的抑瘤率显著高于单用ALTSL,分别为73.5%和67.0%;ALTSL和rhIL2 ALTSL均可显著延长荷瘤小鼠的存活时间(P<0.05～P<0.01)与对照组和游离阿霉素(FADM)组相比较,ALTSL组NK细胞的杀伤活性显著增加,rhIL2 ALTSL组NK细胞的杀伤活性更高。与FADM组比较,rhIL-2 ALTSL组淋巴细胞的转化率明显提高(P<0.01)。应用ALTSL组和rhIL-2 ALTSL组均可增强脾细胞中IL-2mRNA和IL-12mRNA的表达,但后者的增强作用高于前者。病理切片检查显示,热敏脂质体配合肿瘤局部加热,使肿瘤细胞凝固坏死,联合应用rhIL-2肿瘤组织溶解,细胞破碎,可见大量的淋巴细胞浸润。结论:ALTSL能提高ADM的抑瘤效果,降低ADM心肺的毒性。rhIL-2 ALTSL可诱导肿瘤     

肿瘤的靶向治疗不同途径的研究进展

肿瘤的靶向治疗是一种恶性肿瘤的生物治疗方法之一，其原理是借助高度特异的亲肿瘤物质作为载体，以有细胞毒作用的物质如放射性核素、化疗药、毒素等与载体结合，依靠载体的特异性和肿瘤的亲和力，将细胞毒物质尽量集中在肿瘤部位发挥稳定地杀伤作用，而对宿主正常组织无害。近20多年来的研究已取得了很大的进展。开辟了多条不同的靶向治疗途径。本文就此方面的研究进展作一综述。     

纳米磁性阿霉素人血白蛋白微球的制备与表征

目的：制备用于肿瘤靶向治疗的纳米Fe3O4磁性粒子和磁性阿霉素靶向抗癌微球。方法：采用液相共沉淀法制备纳米Fe3O4颗粒，采用XRD、HRTEM等测试手段埘该纳米粉进行表征；随后制备磁性阿霉素白蛋白微球，利用HRTEM对其包裹性能进行表征，同时采用荧光光谱法对其载药量进行测试。结果：纳米Fe，O。磁性粒子的平均粒径为16．3nm，分布宽度为5．8nm；磁性阿霉素微球的有效载药量为2．65％、表观载药量为3．Ol％。结论：该研究为肿瘤的药物化疗提供了一种新型的方法和材料，即磁件靶向微球定向治疗肿瘤的方法。     

空载磁性壳聚糖微球的靶向性研究

药物磁性微球是由超顺磁性纳米磁粒子、抗癌药物和其它成分共同包埋于高分子聚合物载体中构成,它为抗癌药物的靶向性提供了一种新的途径.本文探讨了空载磁性壳聚糖微球(MCMs)的体内分布.将25只家兔分为A组,靶向组;B组,非靶向组;C组,空白对照组;D组,改变磁场加载时间靶向组;E组,改变磁场距离靶向组.检测各组织中Fe的浓度.结果表明靶向组肺组织中分布百分率高于其它各组,磁场距离的改变对Fe在肺组织中的浓度有很大影响,磁场加载时间对其影响较小.     

磁性阿霉素纳米微球的制备及在高频磁场中的发热研究

制备一种在高频磁场中能感应发热的用于治疗肿瘤的阿霉素纳米微球，研究其在磁场中的热效应。用超声搅拌冷冻干燥的方法制备药物微球，平均粒径200nm左右。电镜观察其形态为球囊状。将其置于不同介质中于高频磁场中测其温度变化值，实验表明该微球在交变磁场中使介质升温。升温速度与平稳时的温度和微球的量及磁场强度成正比，介质流动性好，升温快。     

用微球白蛋白栓塞肾动脉的临床观察

为观察人白蛋白微球用于微小动脉栓塞的效果,给进一步的临床应用提供依据。将自行制备的粒径为80-140μm的人白蛋白微球在22只雌性杂种家犬经肾动脉插管注入,致成栓塞,观察在栓塞后不同时间段,肾动脉造影所见和病理变化。结果表明人白蛋白微球可栓塞至肾终末小动脉。在栓塞后14周仍可见微球的存在,未见明显侧枝循环形成。提示可以应用人白蛋白微球有效地进行肾微小动脉的栓塞。     

高温与阿霉素对兔VX-2细胞的协同作用

以体外长期培养的兔ＶＸ－２细胞为靶细胞,采用水浴加法进行体外细胞毒试验,（ＭＴＴ法）,观察了热疗,化疗及热化疗对兔ＶＸ－２细胞的生长抑制规律的影响,结果表明：（１）温热和阿纱对ＶＸ－２均有一定的抑制和杀伤作用两者一定方式的联合具有协同或相加作用。（２）热化疗加热温度以４２～４３℃为柱,加热时间以３０ｍｉｎ以上为佳。     

磁性阿霉素纳米微球在磁场中磁感应的发热研究

目的：制备一种在高频磁场中能感应发热的用于治疗肿瘤的阿霉素纳米微球，研究其在磁场中的热效应。材料与方法：用超声搅拌冷冻干燥的方法制备药物微球，电镜观察其形态及粒径估测。将其置于不同介质中于高频磁场中测其温度变化值。结果：磁性阿霉素微球为球囊状，平均粒径200nm左右，最小为150nm，最大为350nm，该微球在交变磁场中使介质升温。升温速度与平稳时的温度和微球的量，磁场强度成正比，介质流动性好，升温快。结论：可通过调节磁场强度和磁性阿霉素微球的量使周围温度达到所需值。     

阿霉素磁性蛋白微球联合外磁场对恶性肿瘤细胞的毒性试验

为了观察恒定磁场诱导下阿霉素磁性蛋白微球体外对恶性肿瘤细胞生长的抑制作用,将体外培养的Waleker-256细胞分为阿霉素磁性微球联合磁场组,阿霉素磁性微球组及阿霉组三组,倒置显微镜观察细胞的生长状态,改良MTT法检测各组细胞的抑制率,结果表明：阿霉素磁性微球组与游离阿霉素组抑制率（P＞0．05）,联合磁场组抑制率明显提高（P＜0．01）,细胞形态出现显著变化,显示阿霉素磁性蛋白 球与游离阿霉素对恶性肿瘤细胞具有相似的抑制作用,联合恒定磁场可增强其抑瘤效应。     

基于纳米材料与纳米技术的肿瘤靶向治疗

结合多学科的力量、特别是借助新技术的发展对肿瘤进行有效治疗,是目前肿瘤治疗研究方面的一个重要趋势。本文在肿瘤靶向治疗的定义和对主要几类方法说明的基础上,重点介绍和分析纳米材料和纳米技术的被动靶向、场致靶向和分子靶向等方面的最新研究进展,并讨论存在的一些问题和今后可能的努力方向。     

静磁场靶向药物递送系统在肿瘤诊疗中的研究进展

化疗是治疗肿瘤的传统手段之一,但其具有组织非特异性,在抑制肿瘤细胞生长的同时也会对正常细胞产生毒副作用.磁靶向药物递送系统可通过具有生物相容性的、稳定的磁性纳米颗粒载体将抗癌药物在外磁场的引导下,靶向运输和浓聚在肿瘤组织.该技术不仅提高了药物运输的效率和药物的抗癌活性,还能降低药物用量和减轻毒副作用.载药磁性纳米颗粒和所应用的外磁场的性质是影响磁性纳米颗粒靶向肿瘤组织的重要影响因素.载药磁性纳米颗粒的靶向递送是否有效,主要依赖靶向目标位置处所应用的磁场和磁场强度是否足够吸引束缚载药磁性纳米颗粒在肿瘤组织中停留以及释放.对静磁场在引导磁性纳米颗粒靶向肿瘤组织研究的新进展进行综述,为静磁场在靶向肿瘤治疗方面提供一定的科研基础支持.     

Programmed packaging of mesoporous silica nanocarriers for matrix metalloprotease 2-triggered tumor targeting and release

The development of multifunctional nanocarrier with each unit functioning at the correct time and location is a challenge for clinical applications. With this in mind, a type of intelligent mesoporous silica nanocarrier (PGFMSN) is proposed for matrix metalloprotease 2 (MMP 2)-triggered tumor targeting and release by integrating programmed packing and MMP 2-degradable gelatin. Mesoporous silica nanoparticles (MSN) are first functionalized with folic acid (FA) as a target ligand to improve cell uptake. Then gelatin is introduced onto FA-MSN via temperature-induced gelation, where gelatin layer blocks drugs inside the mesopores and protects the targeting ligand. To prolong blood-circulation lifetime, PEG is further decorated to obtain PGFMSN. All units are programmatically incorporated in a simple way and coordinated in an optimal fashion. Cells, multicellular spheroids and in vivo results demonstrate that PGFMSN is shielded against nonspecific uptake. After circulating to tumor tissue, the up-regulated MMP-2 hydrolyzes gelatin layer to deshield PEG and switch on the function of FA, which facilitate the selective uptake by tumor cells through folate-receptor-mediated endocytosis. Meanwhile, the packaged drug is released due to the shedding of gelatin layer. It is shown that doxorubicin (DOX)-loaded exhibits superior tumor targeting, drug internalization, cytotoxicity, and antitumor efficacy over free DOX, non-PEGylated and non-targeted nanoparticles, which provides potential applications for targeted cancer therapy.     

Doxorubicin-loaded human serum albumin nanoparticles surface-modified with TNF-related apoptosis-inducing ligand and transferrin for targeting multiple tumor types

Human serum albumin (HSA) nanoparticles (NPs) surface modified with tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and transferrin, and containing doxorubicin were designed and prepared. Surface amines of HSA were reversibly protected with dimethylmaleic anhydride (DMMA), and HSA-NPs were prepared using a desolvation technique. Furthermore, the surfaces of HSA-NPs were modified with thiolated TRAIL or transferrin using sulfosuccinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (Sulfo-SMCC). The prepared TRAIL/transferrin plus doxorubicin HSA-NPs were characterized by TEM, FE-SEM, and particle size analysis, and their cytotoxic and apoptotic activities were evaluated in several cancer cell lines, namely, HCT 116, doxorubicin-resistant MCF-7, and CAPAN-1. In addition, the tumor-targeting abilities of NPs were assessed using an infrared imaging system in HCT 116-xenografted nu/nu mice. Results showed that the TRAIL/transferrin/doxorubicin HSA-NPs had remarkable cytotoxic and apoptotic activities in all cancer cells examined with a general or a drug-resistant character, and that these NPs had obvious synergistic cytotoxic effects particularly on CAPAN-1 cells. Moreover, these HSA-NPs were effectively localized to tumors in a HCT 116-xenografted nu/nu mouse over 32 h. The findings of this study suggest that the described TRAIL/transferrin/doxorubicin HSA-NPs are a useful targeting agent capable of killing different types of tumor cells in various tissue organs.     

The effect of multistage nanovector targeting of VEGFR2 positive tumor endothelia on cell adhesion and local payload accumulation

Nanovectors are a viable solution to the formulation of poorly soluble anticancer drugs. Their bioaccumulation in the tumor parenchyma is mainly achieved exploiting the enhanced permeability and retention (EPR) effect of the leaky neovasculature. In this paper we demonstrate that multistage nanovectors (MSV) exhibit rapid tumoritropic homing independent of EPR, relying on particle geometry and surface adhesion. By studying endothelial cells overexpressing vascular endothelial growth factor receptor-2 (VEGFR2), we developed MSV able to preferentially target VEGFR2 expressing tumor-associated vessels. Static and dynamic targeting revealed that MSV conjugated with anti-VEGFR2 antibodies displayed greater than a 4-fold increase in targeting efficiency towards VEGFR2 expressing cells while exhibiting minimal adherence to control cells. Additionally, VEGFR2 conjugation bestowed MSV with a significant increase in breast tumor targeting and in the delivery of a model payload while decreasing their accumulation in the liver. Surface functionalization with an anti-VEGFR2 antibody provided enhanced affinity towards the tumor vascular endothelium, which promoted enhanced adhesion and tumoritropic accumulation of a reporter molecule released by the MSV.     

Near-infrared dye bound albumin with separated imaging and therapy wavelength channels for imaging-guided photothermal therapy

Development of theranostic agent for imaging-guided photothermal therapy has been of great interest in the field of nanomedicine. However, if fluorescent imaging and photothermal ablation are conducted with the same wavelength of light, the requirements of the agent's quantum yield (QY) for imaging and therapy are controversial. In this work, our synthesized near-infrared dye, IR825, is bound with human serum albumin (HSA), forming a HSA-IR825 complex with greatly enhanced fluorescence under 600 nm excitation by as much as 100 folds compared to that of free IR825, together with a rather high absorbance but low fluorescence QY at 808 nm. Since high QY that is required for fluorescence imaging would result in reduced photothermal conversion efficiency, the unique optical behavior of HSA-IR825 enables imaging and photothermal therapy at separated wavelengths both with optimized performances. We thus use HSA-IR825 for imaging-guided photothermal therapy in an animal tumor model. As revealed by in vivo fluorescence imaging, HSA-IR825 upon intravenous injection shows high tumor uptake likely owing to the enhanced permeability and retention effect, together with low levels of retentions in other organs. While HSA is an abundant protein in human serum, IR825 is able to be excreted by renal excretion as evidenced by high-performance liquid chromatography (HPLC). In vivo tumor treatment experiment is finally carried out with HSA-IR825, achieving 100% of tumor ablation in mice using a rather low dose of IR825. Our work presents a safe, simple, yet imageable photothermal nanoprobe, promising for future clinical translation in cancer treatment.     

抗肝癌单链抗体融合TNFα导向作用的初步实验研究

目的 获得有效果的抗肝癌基因工程单链免疫细胞因子（TNFα）。方法 将抗肝癌单克隆抗体（mAb)HAb25的单链抗体（scFv25)与人TNFα基因偶联,构建抗肝癌免疫细胞因子（scFv25-TNFα,亚克隆人原核GST融合表达载体pGEX4T-1中,在大杆菌中进行表达。对肝癌细胞SMMC-7721涂片进行间接免疫荧光染色,测定纯化后目的蛋白的活性,通过对荷肝癌（SMMC-7721）裸鼠进行的初步抑瘤实验,检测scFv25-TNFα的导向治疗效果。结果scFv25-TNFα具有与亲本抗体HAb25类似的抗原结合特异性。scFv25-TNFα对荷肝癌裸鼠体内直径2mm左右的肿瘤具有明确的导向杀伤作用,达到3/3完全缓解,明显强于TNFα对照组。该组有交待得只有2/3,且无完全缓解。结论 scFv250-TNFα为具有一定效果的抗肝癌双功能抗体。     

PE重组免疫毒素在肿瘤导向治疗中的应用

绿脓杆菌外毒素A(PE)经过修饰后失去了与细胞结合的能力,将单克隆抗体的Fv段或细胞因子作为导向分子与修饰后的PE通过DNA重组技术融合,获得重组的免疫毒素,这种免疫毒素通过导向分子将毒素带到靶细胞,并杀伤靶细胞,因而被广泛运用于肿瘤的导向治疗。     

Self-assembled PEG-IR-780-C13 micelle as a targeting,safe and highly-effective photothermal agent for in vivo imaging and cancer therapy

IR-780, a representative hydrophobic near-infrared (NIR) fluorescence dye, is capable of fluorescently imaging and photothermal therapy in vitro and in vivo. However, insolubility in all pharmaceutically acceptable solvents limits its further biological applications. To increase solubility, we developed a novel self-assembled IR-780 containing micelle (PEG-IR-780-C13) based on the structural modification of IR-780. Briefly, a hydrophilic PEG₂₀₀₀ was modified on the one side of IR-780, and the hydrophobic carbon chain on the other side was extended from C3 to C16 (additional C13 carbon chain). The modification provides a better self-assemble capability, improved water solubility and higher stability. In addition, PEG-IR-780-C13 micelles are specifically targeted to the tumor after intravenous injection and can be used for tumor imaging. The in vitro cell viability assays and in vivo photothermal therapy experiments indicated that CT-26 cells or CT-26 xenograft tumors can be effectively ablated by combining PEG-IR-780-C13 micelles with 808 nm laser irradiation. More importantly, no significant toxicity can be observed after intravenous administration of the therapeutic dose of generated micelles. Overall, our micelles may have the least safety concern while showing excellent treatment efficacy, and thus may be a new photothermal agent potentially useful in clinical applications.     

pH-Responsive polymer-liposomes for intracellular drug delivery and tumor extracellular matrix switched-on targeted cancer therapy

This study presents a tumor-extracellular matrix pH-induced targeting liposome (ECM-targeting liposomes), crosslinked from methoxy-poly(ethylene glycol)-b-poly(N-2-hydroxypropyl methacrylamide-co-histidine)-cholesterol copolymers and biotin2-polyethylene glycol crosslinkers by hydrogen bonds to overcome the defects of liposomes. In this study, ECM-targeting liposomes were completely investigated their pH-responsibility, drug releasing behaviors, anticancer efficiencies and the time-dependent organ distribution and toxic effects. Experimental results indicate that ECM-targeting liposomes showed rapid drug releasing profiles in acidic conditions. Because the ECM-targeting liposomes accumulated preferentially in tumor, the ECM-targeting liposomes exhibited exceptional anticancer activity in vivo and lower hepatic and renal toxicity. The ECM-targeting liposomes which are switched on the targeting ability in tumor ECM possess potential for future application in anticancer therapy.