Pseudotyped lentiviral vectors:Ready for translation into targeted cancer gene therapy?

Gene therapy holds great promise for curing cancer by editing the deleterious genes of tumor cells,but the lack of vector systems for efficient delivery of genetic material into specific tumor sites in vivo has limited its full therapeutic potential in cancer gene therapy.Over the past two decades,increasing studies have shown that lentiviral vectors(LVs)modified with different glycoproteins from a donating virus,a process referred to as pseudotyping,have altered tropism and display cell-type specificity in transduction,leading to selective tumor cell killing.This feature of LVs together with their ability to enable high efficient gene delivery in dividing and non-dividing mammalian cells in vivo make them to be attractive tools in future cancer gene therapy.This review is intended to summarize the status quo of some typical pseudotypings of LVs and their applications in basic anti-cancer studies across many malignancies.The opportunities of translating pseudotyped LVs into clinic use in cancer therapy have also been discussed.

基因治疗递送系统的研究新进展:遗传性视网膜疾病治疗的曙光

遗传性视网膜疾病是多种先天性视网膜神经退行性疾病的总称,临床上以夜盲、进行性视野缩小、视力下降甚至失明为特点,具有多种遗传形式。由于其病变的根源在于基因突变,通过基因治疗,即利用外源性核苷酸替换或沉默基因缺陷细胞内的致病基因,使细胞表达正确的蛋白质,恢复细胞的功能,就有可能治愈疾病。同时,眼睛具有免疫“豁免”特性,是实现基因治疗的理想器官。为了完成遗传物质的修正,治疗性核苷酸需要进入细胞内发挥作用,携带健康基因的载体递送系统是实现这一过程的有利工具。该文重点总结了包括病毒载体和非病毒载体在内的遗传性视网膜疾病基因治疗递送系统的研究进展及面临的问题。

Improving gene transfection efficiency of highly branched poly(β-amino ester)s through the in-situ conversion of inactive terminal groups

Highly branched poly(β-amino ester)s(HPAEs)have emerged as a safe and efficient type of non-viral gene delivery vectors.However,the presence of inactive terminal secondary amine groups compromises their gene transfection capability.In this study,HPAEs with similar topological structures and chemical compositions but varying numbers of terminal secondary 4-amino-1-butanol(S4)and secondary/tertiary 3-morpholinopropylamine(MPA)groups were synthesized.The results demonstrate that an increased number of secondary/tertiary MPA groups in-situ significantly enhances the DNA binding capability of HPAEs,leading to the formation of smaller HPAE/DNA polyplexes with higher zeta potential,ultimately resulting in superior gene transfection efficiency in bladder epithelial cells.This study establishes a sim-ple yet effective strategy to maximize the gene transfection potency of HPAEs by converting the inactive terminal groups in-situ without the need for complex modifications to their topological structure and chemical composition.

Highly efficient retinal gene delivery with helper-dependent adenoviral vectors

There have been significant advancements in the field of retinal gene therapy in the past several years.In particular,therapeutic efficacy has been achieved in three separate human clinical trials conducted to assess the ability of adeno-associated viruses(AAV)to treat of a type of Leber’s congenital amaurosis caused by RPE65 mutations.However,despite the success of retinal gene therapy with AAV,challenges remain for delivering large therapeutic genes or genes requiring long DNA regulatory elements for controlling their expression.For example,Stargardt’s disease,a form of juvenile macular degeneration,is caused by defects in ABCA4,a gene that is too large to be packaged in AAV.Therefore,we investigated the ability of helper dependent adenovirus(HD-Ad)to deliver genes to the retina as it has a much larger transgene capacity.Using an EGFP reporter,our results showed that HD-Ad can transduce the entire retinal epithelium of a mouse using a dose of only 1
105 infectious units and maintain transgene expression for at least 4 months.The results demonstrate that HD-Ad has the potential to be an effective vector for the gene therapy of the retina.

Recent progress in polymer-based gene delivery vectors

The gene delivery system is one of the three components of a gene medicine, which is the bottle neck of current gene therapy. Nonviral vectors offer advantages over the viral system of safety, ease of manufacturing, etc. As important nonviral vectors, polymer gene delivery systems have gained increasing attention and have begun to show increasing promising. In this review, the fundamental and recent progress of polymer-based gene delivery vectors is reviewed.

Nanoparticle based inner ear therapy

Synthetic nanoparticles can be used to carry drugs, genes, small interfering RNA （siRNA） and growth fac-tors into the inner ear, to repair, restore and induce cellular regeneration. Nanoparticles （NPs） have been developed which are targetable to selected tissue, traceable in vivo, and equipped with controlled drug/gene release. The NPs are coated with a “stealth” layer, and decorated with targeting ligands, markers, transfection agents and endosomal escape peptides. As payloads, genes such as the BDNF -gene, Math1 -gene and Prestin -gene have been constructed and delivered in vitro. Short-hairpin RNA has been used in vitro to silence the negative regulator of Math1, the in-hibitors of differentiation and DNA binding. In order to facilitate the passage of cargo from the middle ear to the inner ear, the oval window transports gadolinium chelate more effciently than the round window and is the key element in introducing therapeutic agents into the vestibule and cochlea. Depending upon the type of NPs, different migration and cellular internalization pathways are employed, and optimal carriers should be designed depending on the cargo. The use of NPs as drug/gene/siRNA carriers is fascinating and can also be used as an intraoperative adjunct to cochlear implantation to attract the peripheral processes of the cochlear nerve.

遗传性听力障碍的基因治疗研究进展

听力障碍是常见的感觉障碍性疾病之一,目前用于治疗遗传性听力障碍的临床选择有限,主要是通过配戴助听器或植入人工耳蜗等补偿或重建听力,并不能恢复自然听力。从病理学来说,恢复生理听觉是听力障碍治疗的必然目标,因此基因治疗才是听力障碍康复的最终方法。目前遗传性听力障碍的基因治疗还处在动物实验阶段,如何强化该基础研究并促进其向临床转化,是未来研究的重点。本文对遗传性听力障碍基因治疗的现状、发展前景和挑战等进行文献复习和发展展望。

Recent advances in polymeric biomaterials-based gene delivery for cartilage repair

Untreated articular cartilage damage normally results in osteoarthritis and even disability that affects millions of people.However,both the existing surgical treatment and tissue engineering approaches are unable to regenerate the original structures of articular cartilage durably,and new strategies for integrative cartilage repair are needed.Gene therapy provides local production of therapeutic factors,especially guided by biomaterials can minimize the diffusion and loss of the genes or gene complexes,achieve accurate spatiotemporally release of gene products,thus provideing long-term treatment for cartilage repair.The widespread application of gene therapy requires the development of safe and effective gene delivery vectors and supportive gene-activated matrices.Among them,polymeric biomaterials are particularly attractive due to their tunable physiochemical properties,as well as excellent adaptive performance.This paper reviews the recent advances in polymeric biomaterial-guided gene delivery for cartilage repair,with an emphasis on the important role of polymeric biomaterials in delivery systems.

Efficient drug and gene delivery to liver fibrosis:rationale, recent advances, and perspectives

Liver fibrosis results from chronic damages together with an accumulation of extracellular matrix,and no specific medical therapy is approved for that until now.Due to liver metabolic capacity for drugs,the fragility of drugs,and the presence of insurmountable physiological obstacles in the way of targeting,the development of efficient drug delivery systems for anti-fibrotics seems vital.We have explored articles with a different perspective on liver fibrosis over the two decades,then collected and summarized the information by providing corresponding in vitro and in vivo cases.We have discussed the mechanism of hepatic fibrogenesis with different ways of fibrosis induction in animals.Furthermore,the critical chemical and herbal anti-fibrotics,biological molecules such as micro-RNAs,siRNAs,and growth factors,which can affect cell division and differentiation,are mentioned.Likewise,drug and gene delivery and therapeutic systems on in vitro and in vivo models are summarized in the data tables.This review article enlightens recent advances in emerging drugs and nanocarriers and represents perspectives on targeting strategies employed in liver fibrosis treatment.

Folate-conjugated polyspermine for lung cancer–targeted gene therapy

Biodegradable polyamines have long been studied as potential recombinant viral gene vectors.Spermine(SPE) is an endogenous tetra-amine with excellent biocompatibility yet poor gene condensation capacity. We have previously synthesized a polyspermine based on SPE and poly(ethylene glycol)(PEG)diacrylate(SPE-alt-PEG) for enhanced transfection performance, but the synthesized SPE-alt-PEG still lacked specificity towards cancer cells. In this study, folic acid(FA) was incorporated into SPE-alt-PEG to fabricate a targeted gene delivery vector(FA-SPE-PEG) via an acylation reaction. FA-SPE-PEG exhibited mild cytotoxicity in both cancer cells and normal cells. FA-SPE-PEG possessed higher transfection efficiency than PEI 25 K and Lipofectamines2000 in two tested cancer cell lines at functional weight ratios, and its superiority over untargeted SPE-alt-PEG was prominent in cells with overexpressed folate receptors(FRs). Moreover, in vivo delivery of green fluorescent protein(GFP) with FA-SPE-PEG resulted in highest fluorescent signal intensity of all investigated groups. FA-SPE-PEG showed remarkably enhanced specificity towards cancer cells both in vivo and in vitro due to the interaction between FA and FRs. Taken together, FA-SPE-PEG was demonstrated to be a prospective targeted gene delivery vector with high transfection capacity and excellent biocompatibility.

Lung gene therapydHow to capture illumination from the light already present in the tunnel

Gene therapy has been considered as the most ideal medical intervention for genetic diseases because it is intended to target the cause of diseases instead of disease symptoms.Availability of techniques for identification of genetic mutations and for in vitro manipulation of genes makes it practical and attractive.After the initial hype in 1990s and later disappointments in clinical trials formore than a decade,light has finally come into the tunnel in recent years,especially in the field of eye gene therapy where it has taken big strides.Clinical trials in gene therapy for retinal degenerative diseases such as Leber’s congenital amaurosis(LCA)and choroideremia demonstrated clear therapeutic efficacies without apparent side effects.Although these successful examples are still rare and sporadic in the field,they provide the proof of concept for harnessing the power of gene therapy to treat genetic diseases and to modernize our medication.In addition,those success stories illuminate the path for the development of gene therapy treating other genetic diseases.Because of the differences in target organs and cells,distinct barriers to gene delivery exist in gene therapy for each genetic disease.It is not feasible for authors to review the current development in the entire field.Thus,in this article,we will focus onwhatwe can learn from the current success in gene therapy for retinal degenerative diseases to speed up the gene therapy development for lung diseases,such as cystic fibrosis.

将目标物质靶向至心脏的研究进展

当前心血管疾病的发病率和死亡率仍位居全球前列。随着分子生物学和细胞心脏病学知识的不断更新,基因治疗已在临床研究中有了长足的进步。然而对于如何将目的细胞或基因成功运送到心脏并发挥作用,仍需克服各种障碍,如解剖、血流机械力、内皮屏障、细胞屏障以及免疫应答等。病毒和非病毒载体,一些细胞及细胞外囊泡、生物材料、外科手术等方法已被广泛运用于各种临床前实验当中。

WHAT CAN WE LEARN FROM VIRUS IN DESIGNING NONVIRAL GENE VECTORS

Gene therapy has emerged as a potential new approach to treat genetic disorders by delivering therapeutic genes to target diseased tissues. However, its clinical use has been impeded by gene delivery systems. The viral vectors are very efficient in delivering and expressing their carried genes, but they have safety issues in clinical use. While nonviral vectors are much safer with very low risks after careful material design, but their gene transcription efficiency is too low to be clinically used. Thus, rational design of nonviral vectors mimicking the viral vectors would be a way to break this bottleneck. This review compares side-by-side how viral/nonviral gene vectors transcend these biological barriers in terms of blood circulation, cellular uptake, endosome escape, nucleus import and gene transcription.

纳米生物技术基因治疗载体研究进展

基因治疗已在治疗多种人类重大疾病如遗传病、肿瘤等方面显示出良好的应用前景,但也面临着巨大的挑战,其中之一就是需要安全、高效、靶向的载体系统。纳米生物材料,如脂质体、聚丙交酯-乙交酯(PLGA),聚乳酸(PLA)等,由于具有良好的生物安全性、可方便有效地实现基因靶向性及高效表达和缓释,成为制备高效、靶向的基因治疗载体系统的良好介质,日益在基因治疗载体系统中受到广泛重视。本文综述了目前在基因治疗领域中常用的纳米载体的生物学特性,以及它们的最新研究进展。

基因治疗导入载体的研究进展

基因治疗在恶性肿瘤、癌症、遗传性疾病和心脑血管等疾病的治疗中开始应用,临床治疗效果明显。基因治疗中的关键技术是选用合适的载体将外源基因高效导入受体靶细胞,综述了基因治疗中病毒和非病毒载体的研究进展。

基因治疗中外源基因的导入

基因治疗是将遗传物质导入靶细胞以达到治疗疾病的目的,目前基因治疗研究中的主要障碍是如何将外源基因导入靶细胞。本文介绍基因治疗的原理和外源基因导入靶细胞时的常用方法,包括显微注射法、电穿孔法、基因枪粒子轰击法等。对基因治疗的现状、存在的问题及未来发展前景作了简要探讨。

心血管疾病的基因治疗

基因治疗在先天遗传性以及后天获得性心血管疾病治疗中均具有广阔的发展前景.对心血管疾病致病机理的深入认识和疾病基因组学研究的发展,进一步促进了临床前基因治疗的研究进展.但基因治疗过程中存在的机体细胞免疫反应、外源基因表达水平不足、在体基因转导效率低下等因素都成为基因治疗临床应用转化的瓶颈.近年来,基因导入载体和基因组编辑技术的发展为上述问题的改善和解决提供了新的思路.目前成族规律间隔短回文重复序列(clustered regularly interspaced short palindromic repeats,CRISPR)/Cas9基因组编辑技术已经成功应用于动物模型的在体基因编辑,达到了显著改善血脂指标的疗效.进一步研究体内组织特异和高效的基因导入方式,提高基因编辑的靶向效率和特异性,并建立全面有效的安全评估实验体系,将推动基因治疗向临床应用的转化.针对心血管疾病基因治疗中基因导入载体的研究以及CRISPR/Cas9基因组编辑技术的应用展开讨论.

靶向基因转移系统的研究进展

基因治疗已在治疗多种人类重大疾病如遗传病、肿瘤等方面显示出良好的应用前景,但也面临着巨大的挑战,主要是如何选择安全、高效、靶向的载体系统。基因治疗的靶向性研究近年来取得了许多新的进展,如应用重组病毒载体,借助抗体或配体将治疗基因定向导入靶细胞。纳米生物材料由于其良好的生物安全性,可方便有效地实现基因的靶向性及高效表达,成为制备高效、靶向的基因治疗载体系统的良好介质,在基因治疗载体系统中日益受到广泛重视。本文综述了目前国内外在靶向基因转移系统中的最新研究进展。

非病毒载体在基因治疗中的发展与应用

构建基因载体并建立安全高效的基因载体体内投递系统是基因治疗的关键。基因载体分病毒与非病毒载体。病毒载体转染高效,已应用于临床,但仍面临安全性低的问题。非病毒载体制备简单、安全性高、潜力大;然而,转染效率低的问题限制了其临床应用。基因治疗领域的研究者一直致力于优化非病毒载体投递系统,提高转染效率,已经出现可应用于临床的基因投递产品。文章旨在回顾非病毒基因载体的研究进展及其临床应用前景。

非病毒基因递送载体的研究进展

目前,基因药物的递送成为药学研究的热点,基因递送载体主要包括病毒载体和非病毒载体。非病毒基因载体的毒性低,生物相容性好,转染效率高,具有潜在的临床应用价值。本文就靶向递送基因载体、多功能基因载体、同时载基因与化疗药物的载体、智能基因载体和脂质体等非病毒基因递送载体的研究进展做一综述。