磁性脂质体在肿瘤治疗研究中的应用

磁性脂质体(magnetic liposomes,ML)是近年来发展起来的一种重要的靶向新剂型，是在脂质体中掺入磁性物质而制成。在体外磁场引导下，ML可携载药物，选择性到达肿瘤靶区，实现靶向给药。ML中的磁性粒子对电磁涟有特殊吸收率，在交变磁场作用下，可强烈吸收能量而升温，抑制肿瘤组织生长，县至使肿瘤消失。进一步深入对磁性脂质体的研究县有重要意义。     

热敏脂质体在肿瘤热疗中的应用研究

在一定温度下,当脂质膜由凝胶态转变为液晶态时,其磷脂的脂酰链紊乱度及活动度增加,膜的流动性也增大,此时包封的药物释放速率亦增大,根据这一原理制备的脂质体称为热敏脂质体（又称温度敏感脂质体）。现介绍热敏脂质体在肿瘤热疗中应用的原理以及国内外的研究现状。     

纳米磁性热敏脂质体在肿瘤热化疗中的应用研究

口腔颌面肿瘤手术已达到较高的水平，但手术根治和功能保存的矛盾仍然存在。热化疗的抗癌效应以其毒副作用小的特点备受青睐。口腔颌面部肿瘤位置表浅，其解剖特点有利于热化疗过程中的加温、测温及控温。但是热疗过程中热场分布，细胞的热耐受性，以及化疗药物的利用度问题难以解决，这使热化疗应用受到一定的限制。随着纳米技术的迅猛发展，将磁性纳米材料应用于肿瘤热疗能够基本克服上述问题，再加之口腔颌面肿瘤的解剖特点将更有利于纳米磁性热敏脂质体在靶向部位发挥作用，使其成为生物医学界的研究热点。     

热敏脂质体在肿瘤热疗中的应用研究

在一定温度下,当脂质膜由凝胶态转变为液晶态时,其磷脂的脂酰链紊乱度及活动度增加,膜的流动性也增大,此时包封的药物释放速率亦增大,根据这一原理制备的脂质体称为热敏脂质体(又称温度敏感脂质体).现介绍热敏脂质体在肿瘤热疗中应用的原理以及国内外的研究现状.     

纳米磁性热敏脂质体在肿瘤热化疗中的应用研究

口腔颌面肿瘤手术已达到较高的水平,但手术根治和功能保存的矛盾仍然存在.热化疗的抗癌效应以其毒副作用小的特点备受青睐.口腔颌面部肿瘤位置表浅,其解剖特点有利于热化疗过程中的加温、测温及控温.但是热疗过程中热场分布,细胞的热耐受性,以及化疗药物的利用度问题难以解决,这使热化疗应用受到一定的限制.随着纳米技术的迅猛发展,将磁性纳米材料应用于肿瘤热疗能够基本克服上述问题,再加之口腔颌面肿瘤的解剖特点将更有利于纳米磁性热敏脂质体在靶向部位发挥作用,使其成为生物医学界的研究热点.     

携带磁性纳米颗粒载药微囊的制备及肿瘤治疗的应用研究进展

通过磁场操控使携带磁性纳米颗粒的微囊富集在生物体特定部位,可实现微囊对特定组织或器官的靶向输送。负载抗肿瘤药物的磁性微囊既可以磁靶向到肿瘤组织,又有缓释、控释药物的优点,已成为实现肿瘤靶向治疗的新型药物载体。本文综述了脂质体、聚合物电解质微囊、聚合物微球等药物载体携带磁性纳米颗粒的制备方法,及其用于抗肿瘤药物载体的基础研究进展。      

免疫脂质体在肿瘤治疗中的应用

免疫脂质体具有主动靶向性、降低肿瘤药物的治疗毒性、提高药物治疗指数等特点,在肿瘤治疗研究中被广泛使用作为肿瘤化疗和放疗药物、基因治疗和肿瘤影像学诊断治疗的载体。作为常见肿瘤药物治疗靶向载体,免疫脂质体可提高药物疗效,降低毒性;作为肿瘤基因治疗载体,免疫脂质体可提高siRNA的稳定性与靶向性;作为放射治疗的载体,免疫脂质体可在细胞或者亚细胞水平对肿瘤组织进行靶向显影,具有影像监测和放射性治疗的双重潜能。随着功能结构复合化、靶标优化筛选等方面的进展,免疫脂质体在肿瘤治疗领域将有更广阔的应用前景。     

脂质体在肿瘤治疗和示踪研究中的新进展

脂质体(liposome, LP)是一种人工制备的球形磷脂双分子层囊泡, 由于生物体质膜的基本结构也是磷脂双分子层膜, 脂质体具有与生物体细胞相似的结构, 因此有较好的生物相容性, 同时也具有生物可降解性、免疫原性小及无明显毒性等优势。脂质体作为药物的有效载体已经得到广泛应用, 近年来其封装荧光染料进行肿瘤方面的示踪研究也有所报道。随着表面修饰材料及制备方法的不断发展, 脂质体作为一种运输载体将更具明显优势, 目前研究热衷以长循环和靶向脂质体封装药物和荧光染料的研究。本文将主要讨论长循环和靶向脂质体在肿瘤研究的应用和进展。      

磁性氧化铁纳米颗粒在肿瘤靶向治疗中的应用及进展

近年来,磁性纳米颗粒由于其独特的表面比效应、小尺寸和量子尺寸效应以及磁性特性受到人们的关注,它们在生物科学和医学中的潜在应用也在过去的数十年间得到迅速发展。其中,经过适当表面修饰的磁性氧化铁纳米颗粒应用前景最为光明,已经被广泛运用于众多的体内实验性应用研究,如磁共振成像、组织修复、免疫测定、生物液体制品的解毒、药物递送、过热疗法以及细胞分离等。本文重点综述磁性氧化铁纳米颗粒的研究现状与进展,阐述其药物递送及磁致过热效应在肿瘤靶向治疗方面的应用,以及磁性纳米铁颗粒长期发展面临的挑战及可能的发展前景。     

磁性药物靶向治疗肿瘤

近年来，随着生物技术、纳米技术和物理化学等多学科的飞速发展，磁性药物靶向治疗有了长足进步。本文对其历史、现状及发展作了简要介绍。     

The use of dendritic cells in cancer therapy

Although the immune system evolved to protect the host from infection, what fires the popular imagination is its potential to recognise and destroy cancer. The immune system can generate potent cytotoxicity (eg transplant rejection), but can these mechanisms be harnessed for therapeutic benefit in patients with cancer? The discovery of an ever-increasing array of tumour antigens shows clearly that the targets exist. The challenge lies in generating a sufficiently potent response towards them. Central to the processes of antigen recognition, processing, and presentation to the immune system are dendritic cells. Understanding of the relation between these and the cellular immune response is crucial to elucidation of how to manipulate immune responses. The past 20 years have witnessed a dramatic expansion in this understanding and led to the first early-phase clinical trials of dendritic cells for the treatment of cancer. These studies have established the safety and feasibility of this approach and have produced encouraging evidence of therapeutic efficacy. This paper reviews the biology of dendritic cells and their use in clinical trials, as well as highlighting issues for future trial design.     

The use of gene therapy in cancer research and treatment

Gene therapy involves identifying a gene of interest and then manipulating the expression of this gene through a variety of techniques. Here we specifically address gene therapy's role in cancer research. This paper will encompass thoroughly investigated techniques such as cancer vaccines and suicide gene therapy and the latest advancements in and applications of these techniques. It will also cover newer techniques such as Antisense Oligonucleotides and small interfering RNAs and how these technologies are being developed and used. The use of gene therapy continues to expand in cancer research and has an integral role in the advancement of cancer treatment.     

The use of roncoleukin for LAK therapy in ovarian cancer

Roncoleukin--recombinant IL-2--was studied with a view to application for LAK therapy. Lymph of ductus thoracicus from ovarian cancer patients receiving adjuvant autolymphochemotherapy was used as source of lymphocytes. Immunobiologic activity of lymphocytes was assayed after 30-minutes incubation with roncoleukin and 24- or 48-hours culturing. The investigation established an increase in T-cell proliferation, autocrine stimulation of IL-2 production, growth of NK-cells cytotoxicity, immediate cytotoxic effect on K562 target cells culture and such sensitizing effect as roncoleukin's potential to boost its susceptibility to NK-lysis. LAK-therapy was used as a component of complex treatment of ovarian cancer (8). Our method has a future in dealing with the present pathology.     

Biomarker use in colorectal cancer therapy

Biomarkers reflective of the molecular and genetic heterogeneity in colorectal cancers now guide certain aspects of clinical management and offer great potential for enrichment, stratification, and identification of novel therapeutic targets in drug development. Using case-based examples, this article reviews biomarkers that have an established role in the clinical management of colorectal cancer: mismatch repair protein testing and KRAS and BRAF mutational analysis. A selection of biomarkers undergoing validation for future clinical application is presented, and the dynamic and challenging interface between biomarkers in research and clinical practice is discussed.     

磁共振影像在乳腺癌放疗中的作用

近年来,随着磁共振定位和放疗设备的临床开发和应用,越来越多的研究开始关注磁共振的良好软组织分辨能力,力图探索磁共振影像在乳腺癌患者放疗中潜在的应用价值。本文就磁共振影像在乳腺癌保乳术后放疗中的研究进展进行综述,以期为未来研究提供一定思路和参考。     

The use of capecitabine in the combined-modality therapy for rectal cancer

Locally advanced rectal adenocarcinoma is treated by combined-modality therapy, which consists of surgery, chemotherapy, and radiation therapy. A series of randomized trials established a preferred treatment sequence of preoperative radiation therapy and 5-fluorouracil(5-FU)-based chemotherapy, total mesorectal excision, and adjuvant 5-FU-based chemotherapy for patients with stage II/III disease. Capecitabine is an oral prodrug of 5-FU that has potential advantages compared with intravenous 5-FU, including ease of administration and potentially increased therapeutic effect. Capecitabine is converted by a 3-step enzymatic process; the last step involves the enzyme thymidine phosphorylase, which is overexpressed in tumor tissues and is stimulated by concurrent radiation therapy. Over the past 5 years, several phase I/II trials of capecitabine-based therapy were reported. This review discusses the evolution of combined-modality therapy for rectal cancer with specific attention given to the use of capecitabine in conjunction with radiation therapy.     

The case for routine use of adjuvant therapy in pancreatic cancer

Pancreatic cancer is a devastating disease with a poor prognosis for most patients. Surgical resection remains the cornerstone of treatment, providing the only realistic hope of long-term survival. Even with optimal surgical management, 5-year survival averages 15% to 20% for resectable disease. Progress is being made, however. Currently, the benefits of postoperative therapy for resected pancreatic ductal adenocarcinoma appear clear, and recommendations for such therapy appear to us to be well justified. Additional benefit to patients awaits the development of new agents, molecular targeted drugs, and novel approaches such as immunotherapy.     

The use of aromatase inhibitors in adjuvant therapy for early breast cancer

Clinical evidence supporting the use of aromatase inhibitors (AIs) in adjuvant therapy for hormone-sensitive early breast cancer (EBC) has grown rapidly over the past few years and is reviewed in this article. The results of two studies-the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial and the Breast International Group (BIG) 1-98 trial-support the use of AIs as primary adjuvant therapy for EBC, with significantly prolonged disease-free survival, time to recurrence, and time to distant recurrence for both anastrozole and letrozole over tamoxifen. Furthermore, anastrozole has an established beneficial risk:benefit ratio compared with tamoxifen with mature data over the full 5-year recommended treatment period. For women who have already received 2-3 years of tamoxifen, switching studies with anastrozole [the Italian Tamoxifen Anastrozole (ITA) trial and the Austrian Breast and Colorectal Cancer Study Group (ABCSG) 8/Arimidex-Nolvadex (ARNO 95) trial] and exemestane [the Intergroup Exemestane Study (IES)] have also shown that 5 years of primary adjuvant tamoxifen therapy is not optimal and that switching to an AI should be considered. Finally, for those women who have completed 5 years of tamoxifen, based on the results of the MA 17 trial, extended adjuvant treatment with letrozole should be considered. Although no sequencing data are available yet, current evidence suggests that an AI should be the adjuvant treatment of choice over tamoxifen, and anastrozole is the only AI with mature adjuvant data to date.     

Formulation and characterisation of magnetic resonance imageable thermally sensitive liposomes for use with magnetic resonance-guided high intensity focused ultrasound

Thermal radiosensitization was tested in a pair of mouse cells (MB⁺ wild-type and MB^?, DNA polymerase β knockout cells) and in human breast carcinoma cells (MCF7 wild-type and C716 transfected to give elevated DNA polymerase β expression). Results showed that neither reducing DNA polymerase β (involved in base excision repair) nor increasing it had any significant effect on thermal radiosensitization. The data indicated that polymerase β was not involved in thermal radiosensitization, and since hyperthermia is known as a radiation damage repair inhibitor, other repair pathways might be involved and need to be explored.     

Targeting cancer gene therapy with magnetic nanoparticles

Recent advances in cancer genomics have opened up unlimited potential for treating cancer by directly targeting culprit genes. However, novel delivery methods are needed in order for this potential to be translated into clinically viable treatments for patients. Magnetic nanoparticle technology offers the potential to achieve selective and efficient delivery of therapeutic genes by using external magnetic fields, and also allows simultaneous imaging to monitor the delivery in vivo. Compared to conventional gene delivery strategies, this technique has been shown to significantly increase gene delivery to human xenograft tumors models, as well as various internal organs (e.g. liver, kidney) and the central nervous system. Magnetic nanoparticle technology, therefore, has the potential to turn the challenge of gene therapy in vivo into a new frontier for cancer treatment.