Ionizable drug delivery systems for efficient and selective gene therapy

Gene therapy has shown great potential to treat various diseases by repairing the abnormal gene function.However,a great challenge in bringing the nucleic acid formulations to the market is the safe and effective delivery to the specific tissues and cells.To be excited,the development of ionizable drug delivery systems(IDDSs)has promoted a great breakthrough as evidenced by the approval of the BNT162b2 vaccine for prevention of coronavirus disease 2019(COVID-19)in 2021.Compared with conventional cationic gene vectors,IDDSs can decrease the toxicity of carriers to cell membranes,and increase cellular uptake and endosomal escape of nucleic acids by their unique pH-responsive structures.Despite the progress,there remain necessary requirements for designing more efficient IDDSs for precise gene therapy.Herein,we systematically classify the IDDSs and summarize the characteristics and advantages of IDDSs in order to explore the underlying design mechanisms.The delivery mechanisms and therapeutic applications of IDDSs are comprehensively reviewed for the delivery of plasmid DNA(pDNA)and four kinds of RNA.In particular,organ selecting considerations and high-throughput screening are highlighted to explore efficiently multifunctional ionizable nanomaterials with superior gene delivery capacity.We anticipate providing references for researchers to rationally design more efficient and accurate targeted gene delivery systems in the future,and indicate ideas for developing next generation gene vectors.

Nucleic Acid Aptamers as Potential Therapeutic and Diagnostic Agents for Lymphoma

Lymphomas are cancers that arise from white blood cells and usually present as solid tumors. Treatment of lymphoma often involves chemotherapy, and can also include radiotherapy and/or bone marrow transplantation. There is an unquestioned need for more effective therapies and diagnostic tool for lymphoma. Aptamers are single stranded DNA or RNA oligonucleotides whose three-dimensional structures are dictated by their sequences. The immense diversity in function and structure of nucleic acids enable numerous aptamers to be generated through an iterative in vitro selection technique known as Systematic Evolution of Ligands by EXponential enrichment (SELEX). Aptamers have several biochemical properties that make them attractive tools for use as potential diagnostic and pharmacologic agents. Isolated aptamers may directly inhibit the function of target proteins, or they can also be formulated for use as delivery agents for other therapeutic or imaging cargoes. More complex aptamer identification methods, using whole cancer cells (Cell-SELEX), may identify novel targets and aptamers to affect them. This review focuses on recent advances in the use of nucleic acid aptamers as diagnostic and therapeutic agents and as targeted delivery carriers that are relevant to lymphoma. Some representative examples are also discussed.

小核酸类药物的修饰和靶向递送研究进展

小核酸类药物是在基因水平上发挥作用的小RNA分子,包括小干扰RNA、反义寡核苷酸、核酸适配体、微RNA等。小核酸类药物研发中面临易被核酸酶降解、半衰期短、易被血液循环中的免疫细胞识别、跨膜转运困难等难题。利用化学修饰和末端修饰可提高小核酸的抗酶解能力和稳定性,延长半衰期,降低免疫原性,提高靶向性。利用核酸类药物载体可协助核酸类药物到达病灶,增加靶向性,并实现溶酶体逃逸,提高药效。常用的载体包括病毒载体、脂质体、无机纳米粒子、聚合物纳米粒子和外泌体等。本文综述小核酸药物的修饰和递送技术研究进展,探讨提高小核酸类药物药效和靶向性的策略,以期为小核酸类药物的临床应用转化提供参考。

pH响应型DOX@R_(9)-PEC-NP药物载体的合成及释药性能研究

利用天然果胶(PEC)和九聚精氨酸(R_(9))构建一种具有穿膜效果及pH响应型的载药纳米球(R_(9)-PEC-NP),用于目标药物的靶向递送。以PEC和R_(9)为原料,合成了具有穿膜效果的九聚精氨酸修饰的果胶衍生物(R_(9)-PEC),并用元素分析仪(EA)和傅里叶红外光谱仪(FT-IR)对R_(9)-PEC进行了表征;在R_(9)-PEC溶液中CaCO_(3)自组装形成一种具有pH响应型的纳米球(R_(9)-PEC-NP),并用Zeta电位与粒度分析仪和扫描电子显微镜(SEM)对其形貌、尺寸和电位进行了测定,用紫外-可见分光光度计(UV-Vis)和倒置荧光显微镜分析了R_(9)-PEC-NP对阿霉素(DOX)的装载及释放情况。研究结果表明:R_(9)和PEC成功连接,呈现规则的球形,平均粒径为215 nm;所制备的R_(9)-PEC-NP微粒可对DOX实现有效装载,包封率为(88.70±3.56)%,载药量为(8.15±0.12)%;该纳米球可以缓控释放DOX,且具有较好的pH响应性,同时,因R_(9)的连接赋予其细胞穿膜性能,使其成为潜在的智能给药系统载体材料。

核酸类药物的修饰和递送研究进展

核酸类药物是在基因水平上发挥作用的RNA或DNA。目前应用较多的有核酸适配体、反义寡核苷酸、信使RNA、微RNA、小干扰RNA、小激活RNA等。核酸类药物临床应用面临稳定性差、靶向性弱、难以跨越体内屏障等难题。通过核酸化学结构修饰可以提高部分核酸药物在体内的稳定性、靶向性,提高递送效率,同时降低药物的免疫原性;应用核酸类药物载体可以帮助药物到达病灶,有助于核酸类药物实现更高效的内体逃逸,促进药物在体内发挥作用。目前应用较多的递送载体有病毒载体、脂质纳米粒、聚合物纳米载体、无机纳米载体、蛋白载体、外泌体等。目前,单独的修饰或递送载体尚不足以克服众多障碍,将核酸化学结构修饰与药物递送系统相结合有望实现更好的治疗效果,但后者技术难度和临床转化成本也随之增加。针对更加简单实用、低毒高效、精准递送核酸药物载体和核酸化学结构修饰的研发将成为核酸药物研发的热点方向。本文综述了核酸类药物的修饰和递送研究进展,讨论了提高核酸类药物递送效率的对策,以期为核酸类药物的转化应用提供参考。

信使RNA药物修饰及其递送系统研究进展

信使RNA(mRNA)药物在多种疾病的预防和治疗中展现了巨大的应用价值。最大程度提高mRNA的稳定性和翻译效率,保证mRNA免受核酸酶的降解并靶向特定组织和细胞是临床转化的要求。通过修饰核苷酸降低mRNA免疫原性,密码子优化增加mRNA翻译效率,5'帽结构和3'多聚腺苷酸尾结构增加mRNA稳定性,以及添加5'和3'非翻译区功能调控mRNA稳定性和翻译效率。通过纳米粒递送系统保护mRNA不被核酸酶降解,增加mRNA血液循环,并帮助mRNA进入细胞质发挥治疗和预防作用。本文综述了mRNA药物的制剂工程技术进展,讨论了提高mRNA稳定性和翻译效率的方法及设计原理,总结了具有产业转换潜力的mRNA递送系统的设计要求及其临床应用,并展望了mRNA药物未来可能的研究方向,以满足实现个性化精准医疗的需求。

Functionalization of silica nanoparticles for nucleic acid delivery

Silica nanoparticles （SiNPs） have been widely engineered for biomedical applications, such as bioimaging and drug delivery, because of their high tunability, which allows them to perform specific functions. In this review, we discuss the functionalization and performance of SiNPs for nucleic acid delivery. Nucleic acids, including plasmid DNA （pDNA） and small interfering RNA （siRNA）, constitute the next generation molecular drugs for the treatment of intractable diseases. However, their low bioavailability requires delivery systems that can circumvent nuclease attack and kidney filtration to ensure efficient access to the target cell cytoplasm or nucleus. First, we discussed the biological significance of nucleic acids and the parameters required for their successful delivery. Next, we reviewed SiNP designing for nucleic acid delivery with respect to nucleic acid loading and release, cellular uptake, endosomal escape, and biocompatibility. In addition, we discussed the co-delivery potential of SiNPs. Finally, we analyzed the current challenges and future directions of SiNPs for advanced nucleic acid delivery.

跨越溶酶体途径的核酸药物递送策略

核酸药物通过在细胞质或细胞核中发挥作用,调控基因表达,在获得性或遗传性疾病治疗以及疫苗开发等方面有重要意义。目前开发的多种核酸递送载体,通过细胞内吞经内体/溶酶体途径入胞,转染效率较低。本文介绍和分析了跨越溶酶体途径的核酸药物递送策略,包括膜易位、膜融合、受体/转运体介导的非内吞摄取和小窝介导的细胞摄取等,讨论了目前此类策略面临的问题和挑战,为核酸药物跨越溶酶体途径递送的发展提供参考。

基因治疗中的核酸药物及非病毒递送载体的研究进展

基因治疗是针对基因异常相关疾病的终极治疗技术,各种具有不同机制的核酸药物的出现为基因治疗带来了更多的可能性。但是,由于存在体内稳定性差、难以高效进入靶细胞等问题,核酸药物需要载体的帮助而进入目标细胞并到达特定的胞内位置,因此,开发安全高效的核酸递送系统是基因治疗的基石。与病毒载体相比,非病毒载体具有更高的安全性,但转染效率较低。随着纳米技术的发展,非病毒载体的效率得到了显著的提升,进入临床研究的数量逐渐增多。本文简要介绍基因治疗中的核酸药物及其递送载体,对非病毒核酸药物递送技术的瓶颈及进展做综合评述。

核苷酸适体在靶向给药系统中的应用进展

适体,即体外合成筛选得到的能特异性地与靶分子结合的一段寡核苷酸序列。由于其独特的性质,在靶向给药系统中有着广阔的应用前景,目前已成为靶向给药研究领域的热点。综述了适体在靶向给药系统中的优势及其应用进展,并对其应用前景和面临的问题进行分析。

智能响应型纳米载体用于核酸类药物递送的研究进展

核酸类药物可以直接对特定蛋白表达相关基因进行调控,同时因其序列设计简单、合成修饰方便、作用机制明确,已受到越来越多的关注,且有望成为肿瘤治疗等领域最有前景的药物之一。然而,核酸类药物必须依赖有效载体才能克服自身局限性以及各种跨膜障碍进而发挥疗效。目前,非病毒核酸类递送载体多存在转染效率较低的缺点,为此,研究者们设计了一系列针对体内病理环境和体外物理刺激的智能响应型纳米载体,该类载体可通过响应体内pH、氧化还原条件等特定变化或者温度、光照、超声波、磁场等外部刺激,来实现核酸类药物的精准调控释放,并提高其在靶细胞内的转染效率,降低其对正常组织和细胞的毒副作用。本文综述了当前智能响应型纳米载体在核酸类药物递送领域的研究进展,对智能响应型核酸类药物载体的功能设计及作用特点进行了介绍,以期为核酸类药物及其递送系统的研究提供参考。

Multifunctional nucleic acid nanostructures for gene therapies

Nucleic acid nanotechnology has been developed to be a promising strategy to construct various nano-biomaterials with structural programmability, spatial addressability, and excellent biocompatibility. Self-assembled nucleic acid nanostructures have been employed in a variety of biomedical applications, such as bio-imaging, diagnosis, and therapeutics. In this manuscript, we will review recent progress in the development of multifunctional nucleic acid nanostructures as gene drug delivery vehicles. Therapeutic systems based on RNA interference （RNAi）, clustered regularly interspaced short palindromic repeat associated proteins 9 system （CRISPR/Cas9） genome editing, gene expression, and CpG-based immunostimulation will be highlighted. We will also discuss the challenges and future directions of nucleic acid nanotechnology in biomedical research.

ZIF-8递送生物大分子的研究进展

类沸石咪唑酯骨架-8(zeolitic imidazolate framework-8,ZIF-8)是一种由Zn^(2+)和2-甲基咪唑组成的新型金属有机骨架材料,它具有孔隙率高、比表面积大、化学和热稳定性好、表面性质可调及pH诱导生物降解性等优点,这些优点赋予了ZIF-8多种功能,使其能广泛应用于气体吸附与分离、催化、药物传递等领域。近年来,研究人员通过原位合成的方法使ZIF-8可包封蛋白质、酶、核酸等生物大分子,生物大分子主要通过交联、键合与ZIF-8骨架结合,并包埋在ZIF-8晶体内部或位于其表面。ZIF-8作为运载体可递送蛋白质和酶以保持其生物学活性,提高其功能表现和稳定性;同时,ZIF-8亦可负载核酸药物使其在胞内表达用于基因治疗。综述了这些方面的研究进展和应用,并对ZIF-8在相关生物医学领域的应用进行了展望。

Erythromycin loaded by tetrahedral framework nucleic acids are more antimicrobial sensitive against Escherichia coli(E.coli)

Erythromycin is a commonly used broad-spectrum antibiotic,but resistance to this antibiotic makes its use less effective.Considerable efforts,beside finding alternatives,are needed to enhance its antimicrobial effect and stability against bacteria.Tetrahedral framework nucleic acids(tFNAs),a novel delivery vehicle with a three-dimensional nanostructure,have been studied as a carrying platform of antineoplastic drugs.In this study,the use of tFNAs in delivering erythromycin into Escherichia coli(E.coli)was investigated for the first time.The tFNAs vehicle increased the bacterial uptake of erythromycin and promoted membrane destabilization.Moreover,it increased the permeability of the bacterial cell wall,and reduced drug resistance by improving the movement of the drug across the membrane.The tFNAs-based delivery system enhanced the effects of erythromycin against E.coli.It may therefore provide an effective delivery vehicle for erythromycin in targeting antibiotic-resistant bacteria with thick cell wall.

Pharmaceutical applications of framework nucleic acids

DNA is a biological polymer that encodes and stores genetic information in all living organism. Particularly, the precise nucleobase pairing inside DNA is exploited for the self-assembling of nanostructures with defined size, shape and functionality. These DNA nanostructures are known as framework nucleic acids(FNAs) for their skeleton-like features. Recently, FNAs have been explored in various fields ranging from physics, chemistry to biology. In this review, we mainly focus on the recent progress of FNAs in a pharmaceutical perspective. We summarize the advantages and applications of FNAs for drug discovery, drug delivery and drug analysis. We further discuss the drawbacks of FNAs and provide an outlook on the pharmaceutical research direction of FNAs in the future.

核酸自组装纳米递送载体的研究进展

随着核酸纳米技术的飞速发展,核酸自组装纳米载体已成为药物递送领域的研究热点。针对核酸自组装纳米载体在药物递送中的应用进展进行了系统综述,讨论了不同的核酸自组装策略,阐述了多种靶向递送和药物控制释放方法,同时,总结了核酸自组装纳米递送载体在蛋白质药物、核酸药物、小分子药物和纳米药物递送中的应用,并针对该领域的挑战和未来发展趋势进行了总结和展望,以期为药物递送领域和新型药物系统研究提供参考。

顺铂前药接枝修饰硫代DNA及其自组装靶向纳米药物研究

选用具有良好生物相容性的硫代修饰嵌段核酸为载体,将其非硫代修饰部分设计为靶向MUC-1蛋白的核酸适配体序列,同时在其硫代修饰部分通过硫代磷酸酯基团(Phosphorothioate, PS)接枝修饰四价顺铂前药,制备了两亲性核酸-顺铂前药缀合物MUC-1/PODNA-b-(PSDNA-g-Pt),并进一步自组装成类似球形核酸(Spherical nucleic acid, SNA)的含铂靶向纳米药物(MUC-1/Pt-SNAs).结果表明,该纳米药物递送体系载药率高、形貌稳定、分散性好,能够高效靶向MUC-1蛋白过表达的MCF-7乳腺癌细胞,并在体内外实验中表现出优异的抗肿瘤效果和极低的毒副作用.

基于核酸适体模板的稀土纳米载体用于靶向成像及治疗

核酸是一种结构和功能都比较复杂的生物大分子,它们在生物体内细胞周期的不同阶段以不同的构象存在,以确保各项生命活动的顺利进行。基于纳米材料多功能化的纳米器件已经广泛地应用到生物医药领域的诊断和治疗。借助核酸适体为生物模板,经过一步便利的溶剂热法可以设计并合成多功能的镧系元素掺杂的多孔纳米材料。基于材料自身极好的水溶性及生物特性,该材料可用于细胞层面的靶向成像与药物运载。因核酸适体针对靶细胞特殊的结合功能,研究者的工作将为纳米探针于生物应用方面开辟天窗,相关领域可涉及到时间分辨的生物检测,多模式生物成像或标记,以及癌症或其他疾病的靶向治疗。

Recent progress of aptamer-drug conjugates in cancer therapy

Aptamers are single-stranded DNA or RNA sequences that can specifically bind with the target protein or molecule via specific secondary structures.Compared to antibody-drug conjugates(ADC),aptamer-drug conjugate(ApDC)is also an efficient,targeted drug for cancer therapy with a smaller size,higher chemical stability,lower immunogenicity,faster tissue penetration,and facile engineering.Despite all these advantages,several key factors have delayed the clinical translation of ApDC,such as in vivo off-target effects and potential safety issues.In this review,we highlight the most recent progress in the development of ApDC and discuss solutions to the problems noted above.

Spherical nucleic acids:Organized nucleotide aggregates as versatile nanomedicine

Spherical nucleic acids(SNAs)are composed of a nanoparticle core and a layer of densely arranged oligonucleotide shells.After the first report of SNA by Mirkin and coworkers in 1996,it has created a significant interest by offering new possibilities in the field of gene and drug delivery.The controlled aggregation of oligonucleotides on the surface of organic/inorganic nanoparticles improves the delivery of genes and nucleic acid–based drugs and alters and regulates the biological profiles of the nanoparticle core within living organisms.Here in this review,we present an overview of the recent progress of SNAs that has speeded up their biomedical application and their potential transition to clinical use.We start with introducing the concept and characteristics of SNAs as drug/gene delivery systems and highlight recent efforts of bioengineering SNA by imaging and treatmenting various diseases.Finally,we discuss potential challenges and opportunities of SNAs,their ongoing clinical trials,and future translation,and how they may affect the current landscape of clinical practices.We hope that this review will update our current understanding of SNA,organized oligonucleotide aggregates,for disease diagnosis and treatment.