纳米颗粒在基因治疗中的作用——一种转染基因的新载体

基因治疗是将DNA转染进入目的细胞，修复遗传错误或产生治疗因子。反义寡核苷酸的应用是基因治疗的主要手段之一。目前利用纳米颗粒作为特异性基因的载体已成为研究的热点。纳米控释系统使转染基因的胞内摄入量增高，增强其稳定性、靶向性及细胞定位。本就此方面的研究进行了综述。     

β—地中海贫血基因治疗研究进展

基因治疗是根治β地贫的唯一途径。本就目前对β地贫基因治疗研究的β珠蛋白基因转移治疗，药物遥基因治疗，反义核酸技术的治疗作了较为系统的综述，着重介绍了ＲＶ、ＡＡＶ载体介导β基因导入β地贫患造血干／祖细胸以获得细胞和红系组织的稳定整合和正常     

单基因遗传病基因治疗中病毒型载体的应用

摘要：在单基因遗传病的基因治疗中,病毒型载体是较为常用的将目的基因导入靶细胞的有效运载工具之一,分为腺病毒载体、腺相关病毒载体、逆转录病毒载体及慢病毒载体等。在本文中,我们拟就单基因遗传病基因治疗中病毒型载体的应用现状和研究进展做较为系统地阐述。     

Survivin-肿瘤基因治疗的新靶点

基因治疗的本质就是目的基因、载体与转染的问题，基因治疗的关键就是目的基因的选择。随着人类基因组计划的完成，已有不少的基因被发现及克隆，为肿瘤的基因治疗开拓了广阔的运用前景。但基因治疗仍存在许多有待解决的问题，如目的基因的选择、目的基因的组织及细胞特异性、高效率载体的选择等。本文所涉及的survivin是肿瘤基因治疗的新靶点，现就survivin的功能及与肿瘤的关系及其在肿瘤基因治疗中的作用作一综述。     

非病毒型纳米载体在基因治疗中的研究现状及展望

近10年来，新型非病毒载体在基因治疗中日益受到欢迎。其主要代表为纳米载体，具有无毒性及免疫原性的优势，已作为高效阳离子载体用于基因转移。体外基因转移实验表明，纳米载体的基因转移率高于普通脂质体及其它阳离子多聚体，如多聚氮丙及聚赖氨酸。本对纳米载体的结构特点，性能，基因转移机制进行综述，并将其在体内外基因转移效率与其它非病毒载体作以比较。     

β-地中海贫血基因治疗研究进展

基因治疗是根治β地贫的唯一途径。本文就目前对β地贫基因治疗研究的β珠蛋白基因转移治疗、药物的基因治疗、反义核酸技术的治疗作了较为系统的综述，着重介绍了ＲＶ、ＡＡＶ载体介导β基因导入β地贫患者造血干／祖细胞以获得细胞和红系组织的稳定整合和正常表达、ＨＵ等药物激活γ珠蛋白基因表达及提高β６５４突变基因转录本正常剪接水平、反义核酸修复β６５４突变基因转录本正常剪接等研究的新进展及其作用机制和临床治疗的探索。     

逆转录病毒介导人胰岛素基因感染pT67、Phoenix和HepG2细胞的表达

十余年前，第一例腺苷酸脱氨酶缺陷症的基因矫正作用为多种疾病的基因治疗带来了极大希望和鼓舞。基因治疗是解决人类遗传缺陷症极有希望的途径。寻找可靠、高效、安全的载体仍是当前基因治疗的关键任务。本研究的目的在于探讨构建人胰岛素基因逆转录病毒载体并检测逆转录病毒介导人胰岛素基因感染pT67、Phoenix和HepG2细胞后胰岛素蛋白质的表达。     

基因治疗的安全性评价

基因治疗的安全性日益引起重视,基因作为一种全新的药物,其安全性的评价具有特异性,本主要从基因治疗研究常用载体及表达产物两方面总结了基因治疗的安全性。     

非病毒基因载体材料的研究进展

非病毒材料可成为基因治疗中的基因载体，使目的基因持续有效地表达。非病毒基因载体主要有脂质体、人工合成聚合物载体、天然聚合物载体、局部基因释放载体等。其中壳聚糖及其衍生物是一种优良的基因释放载体，局部基因释放载体技术将基因治疗与组织工程结合起来，在组织修复与重建方面将发挥重要作用。     

基因治疗中的基因调控研究进展

基因治疗的目的是将导入的外源基因能够得到时序上、水平上的正确表达,其产物发挥治疗作用。目的基因表达的调控是影响基因治疗效果的一个重要因素。本文系统介绍了基因靶技术在基因治疗中的地位,提高逆转录病毒载体滴度的方法,逆转录病毒载体与目的基因序列的影响,反式激活提高目的基因应用以及对基因治疗中目的基因表达调控的展望。     

Molecular therapeutics of HBV

The hepatitis B virus (HBV) infection is a public health problem worldwide, particularly in East Asia. The current therapy of HBV infection is mostly based on chemical agents and cytokines that have been shown to provide limited efficacy and are also toxic to the human body. Gene therapy is a new therapeutic strategy against HBV infection, involving the transmission of gene drugs into liver cells by specific delivery systems and methods. Although this new anti-HBV infection technique is under active investigation, various promising anti-HBV viral gene drugs have been developed for gene therapy, including antisense RNA and DNA, hammerhead ribozymes, dominant negative HBV core mutants, single chain antibody, co-nuclease fusion protein, and antigen. In order to optimize their antiviral effects and/or enhance anti-HBV immunity, various novel gene delivery systems have also been developed to (specifically) deliver such DNA constructs into liver cells; some of them are viral vectors, such as adenoviral vectors, retroviral vectors and poxviral vectors, and even hepatitis B viral for its hepatocellular specificity. Others are non-viral vectors, in which naked DNA and liposomes are frequently used for DNA vaccine or nucleotide analogs for inhibiting HBV DNA polymerase. This review addresses various aspects of gene therapy for HBV infection, including gene drugs, delivery methods, animal model, and liver transplantation with combination therapy. It also discusses the problems that remain to be solved.     

Synthetic and natural polycations for gene therapy: state of the art and new perspectives

Currently, the major drawback of gene therapy is the gene transfection rate. The two main types of vectors that are used in gene therapy are based on viral or non-viral gene delivery systems. There are several non-viral systems that can be used to transfer foreign genetic material into the human body. In order to do so, the DNA to be transferred must escape the processes that affect the disposition of macromolecules. These processes include the interaction with blood components, vascular endothelial cells and uptake by the reticuloendothelial system. Furthermore, the degradation of therapeutic DNA by serum nucleases is also a potential obstacle for functional delivery to the target cell. Cationic polymers have a great potential for DNA complexation and may be useful as non-viral vectors for gene therapy applications. The objective of this review was to address the state of the art in gene therapy using synthetic and natural polycations and the latest strategies to improve the efficiency of gene transfer into the cell.     

Mannan-mediated gene delivery for cancer immunotherapy

Recent years have seen a resurgence in interest in the development of efficient non-viral delivery systems for DNA vaccines and gene therapy. We have previously used oxidized and reduced mannan as carriers for protein delivery to antigen-presenting cells by targeting the receptors that bind mannose, resulting in efficient induction of cellular responses. In the present study, oxidized mannan and reduced mannan were used as receptor-mediated gene transfer ligands for cancer immunotherapy. In vivo studies in C57BL/6 mice showed that injection of DNA encoding ovalbumin (OVA) complexed to oxidized or reduced mannan-poly-L-lysine induced CD8 and CD4 T-cell responses as well as antibody responses leading to protection of mice from OVA+ tumours. Both oxidized and reduced mannan delivery was superior to DNA alone or DNA-poly-L-lysine. These studies demonstrate the potential of oxidized and reduced mannan for efficient receptor-mediated gene delivery in vivo, particularly as DNA vaccines for cancer immunotherapy.     

Laboratory formulated magnetic nanoparticles for enhancement of viral gene expression in suspension cell line

One factor critical to successful gene therapy is the development of efficient delivery systems. Although advances in gene transfer technology including viral and non-viral vectors have been made, an ideal vector system has not yet been constructed. Due to the growing concerns over the toxicity and immunogenicity of viral DNA delivery systems, DNA delivery via improve viral routes has become more desirable and advantageous. The ideal improve viral DNA delivery system should be a synthetic materials plus viral vectors. The materials should also be biocompatible, efficient, and modular so that it is tunable to various applications in both research and clinical settings. The successful steps towards this improve viral DNA delivery system is demonstrated: a magnetofection system mediated by modified cationic chitosan-coated iron oxide nanoparticles. Dense colloidal cationic iron oxide nanoparticles serve as an uptake-enhancing component by physical concentration at the cell surface in presence of external magnetic fields; enhanced viral gene expression (3-100-fold) due to the particles is seen as compared to virus vector alone with little virus dose.     

Nonviral gene therapy

The last 10 years have seen substantial progress in the development and application of nonviral vectors in gene therapy. Several novel nonviral methods have been developed that approach viruses with respect to transfection efficiency. A variety of nonviral delivery systems that can be used for gene therapy in different clinical settings are also available. In this review article, we will detail all of the major nonviral vectors that are currently used in gene therapy while highlighting some recent developments, particularly the progress towards the understanding of the cellular and in vivo barriers in gene transfer. Recent advancement in achieving sustained and regulated gene expression will also be addressed. Finally, this review will briefly cover targeted gene repair using nonviral delivery systems. Their impact in gene therapy will also be discussed.     

Polysaccharide gene transfection agents

Gene delivery is a promising technique that involves in vitro or in vivo introduction of exogenous genes into cells for experimental and therapeutic purposes. Successful gene delivery depends on the development of effective and safe delivery vectors. Two main delivery systems, viral and non-viral gene carriers, are currently deployed for gene therapy. While most current gene therapy clinical trials are based on viral approaches, non-viral gene medicines have also emerged as potentially safe and effective for the treatment of a wide variety of genetic and acquired diseases. Non-viral technologies consist of plasmid-based expression systems containing a gene associated with the synthetic gene delivery vector. Polysaccharides compile a large family of heterogenic sequences of monomers with various applications and several advantages as gene delivery agents. This chapter, compiles the recent progress in polysaccharide based gene delivery, it also provides an overview and recent developments of polysaccharide employed for in vitro and in vivo delivery of therapeutically important nucleotides, e.g. plasmid DNA and small interfering RNA.     

DNA疫苗递送系统研究进展

DNA疫苗是在基因治疗和转基因技术基础上产生的第三代疫苗,已成为当前疫苗研究领域的热点.因裸DNA疫苗直接接种存在诸多不足之处,故研制新的给药系统,保护DNA免受生物环境破坏,将其有效导人靶细胞,使之具有更强的免疫效能是研究的主要内容之一.目前研究较多的非病毒递送系统有脂质体、天然高分子载体、人工合成聚合物载体、减毒胞内菌等,其中分别以阳离子脂质体、壳聚糖、聚乙烯亚胺、伤寒沙门菌较为常用.现有研究结果 已显示出上述递送系统的巨大应用潜力,它们各自的优势必将对DNA疫苗的推广起到很好的促进作用.     

Adenovirus as an integrating vector

Recombinant adenoviral vectors have served as one of the most efficient gene delivery vehicles in vivo thus far. Multiply attenuated or completely gutless adenoviral vectors have been developed to achieve long-term gene expression in animal models by overcoming cellular immunity against de novo synthesized adenoviral proteins. However, since adenovirus lacks native integration machinery, the goal of gene therapy obtaining permanent expression cannot be realized with current adenoviral vector systems. Recent studies have shown that replication-incompetent adenoviral vectors randomly integrate into host chromosomes at frequencies of 0.001-1% of infected cells. To improve the integration frequencies of adenoviral vectors, a variety of hybrid vectors combining the highly efficient DNA delivery of adenovirus with the integrating machinery of retroviruses, adeno-associated viruses, and transposons, have been emerging. These hybrid vectors have shown promise, at least in in vitro systems. Furthermore, adenoviral vectors have shown potential as gene targeting vectors. These developments should eventually lead to more effective gene therapy vectors that can transduce a myriad of cell types stably in vivo.     

Enabling customization of non-viral gene delivery systems for individual cell types by surface-induced mineralization

Delivering genes to mediate functions of cells is a crucial technology for both basic science and clinical applications. Though numerous non-viral gene delivery systems have been developed, the diversity of mammalian cells poses a great challenge to the material design. Here, we demonstrate that surface-induced mineralization represents a promising approach to systematically customize DNA delivery with respect to the characteristics of cells. We initially examined gene transfer in nine cell types derived from different tissues and organisms by surface-induced DNA-doped calcium carbonate nanocomposites derived from a library of mineral solutions. Subsequently, we correlated gene transfer efficiency with cellular uptake, pH responsiveness of nanocomposites, and phagosomal pH of individual cell types. Based on the correlation, we were able to optimize the DNA delivery to the cell types of interest. Surface-induced mineralization possesses great potential for customizing gene transfer in realizing gene- and cell-based therapy and probing functions of genes.