DNA: From Carrier of Genetic Information to Polymeric Materials

Research has shown that the DNA molecule can not only store genetic information but also serve as a polymeric biomolecule for the fabrication of functional materials. The unique precise molecular recognition capability and sequence programmability, combined with its good biocompatibility and biodegradability, impart the DNA molecule considerable potential for use in the construction of multifunctional materials. Depending on the composition, DNA-based materials have been generally categorized into pure DNA materials that are entirely composed of DNA and hybrid DNA materials that are composed of DNA and other functional compositions. Recently, we have developed a series of DNA-based materials that can be applied in diagnosis and therapy, and this review summarizes the relative work. Although challenges still exist regarding the real applications of DNA-based materials such as the high cost of DNA, the difficulty in scale-up, and the low resistance to nuclease, we believe that these drawbacks will be overcome with the development of technology, and new opportunities will emerge in the fi eld of diagnosis and treatment.

A Programmable Hybrid DNA Nanogel for Enhanced Photodynamic Therapy of Hypoxic Glioma

Photodynamic therapy(PDT)is a promising cancer therapy due to the evident advantages of a rapid curative eff ect,minimal or non-invasiveness,and circumvention of drug resistance.However,the hydrophobicity of photosensitizers and the hypoxic tumor microenvironment in solid tumors reduce the therapeutic eff ect of PDT immensely.Herein,we construct a programmable hybrid mesoporous silica nanoparticle/DNA nanogel(H-DNA nanogel)for enhanced PDT.The H-DNA nanogel is constituted with a virus-like mesoporous silica nanoparticle(VMSN)as the core to provide an appropriate nano-interface and a self-assembly programmable DNA hydrogel layer based on rolling circle amplifi cation(RCA)as the shell.Two kinds of G-quadruplex structures inserted with a hemin and zinc phthalocyanine(ZnPc)photosensitizer are introduced into the H-DNA nanogel by base pairing.The two modules of G-quadruplex structure work as an oxygen supplement in the hypoxic tumor microenvironment and increase the yield of singlet oxygen,respectively.Our hybrid DNA nanogel system provides a modular platform for effi cient cancer PDT and has great potential in the broader biomedical fi eld.

Aptamer-Based DNA Materials for the Separation and Analysis of Biological Particles

DNA is a biological macromolecule that carries genetic information in organisms.It provides a series of predominant bio-logical advantages,such as sequence programmability,high biocompatibility,and low biotoxicity.As such,it is a unique polymer material that shows great potential for application in biological and medical fields.DNA aptamers are short DNA sequences with a specific ability of molecular recognition.With its discovery,the application prospect of DNA materials has broadened,especially for the separation and analysis of biological particles.In this review,the functions and characteristics of DNA aptamers are introduced,and the applications of DNA materials in cell/exosome separation and cancer detection are summarized.The application prospect and possible challenges of DNA materials are predicted.

Hybridization chain reaction-based DNA nanomaterials for biosensing,bioimaging and therapeutics

DNA nanomaterials hold great promise in biomedical fields due to its excellent sequence programmability,molecular recognition ability and biocompatibility.Hybridization chain reaction(HCR)is a simple and efficient isothermal enzyme-free amplification strategy of DNA,generating nicked double helices with repeated units.Through the design of HCR hairpins,multiple nanomaterials with desired functions are assembled by DNA,exhibiting great potential in biomedical applications.Herein,the recent progress of HCR-based DNA nanomaterials for biosensing,bioimaging and therapeutics are summarized.Representative works are exemplified to demonstrate how HCR-based DNA nanomaterials are designed and constructed.The challenges and prospects of the development of HCR-based DNA nanomaterials are discussed.We envision that rationally designing HCR-based DNA nanomaterials will facilitate the development of biomedical applications.

DNA纳米技术应用于水环境污染示踪

水环境污染是当前人类社会所面临的严峻挑战之一,阻碍了全球生态环境和社会经济的可持续发展.潜在污染源众多和水文地质条件的复杂性导致对污染源追溯、污染范围界定和污染程度量化等问题的研判十分棘手.针对这些难题,已发展了多种水环境污染物迁移示踪系统,例如离子化合物、有色染料和同位素等,这些示踪系统的应用对水环境污染治理起到了重要的推动作用.近年来,快速发展的基于脱氧核糖核酸(deoxyribo nucleic acid,DNA)纳米技术的示踪方法(DNA示踪技术)逐渐崭露头角,其是应用DNA片段作为特异性标记物进行水环境污染示踪.与已有的示踪技术相比,DNA示踪技术具有示踪剂数量巨大、特异性强、检测灵敏、运移及降解特性可控和环境友好等诸多优势,是极具潜力的新一代示踪技术.DNA示踪技术的研发与应用集成了生物化学、材料科学、环境工程和水文地质等多学科知识,是典型的交叉研究领域.为促进DNA示踪技术体系的长足发展以及水环境污染防治能力的不断增强,本文重点阐述了DNA片段作为水环境污染示踪剂的原理与方法,全面梳理了DNA示踪技术体系的发展脉络,总结探讨了DNA示踪技术在水环境污染示踪研究中的典型应用,最后展望了未来重要的研究方向.

A DNA micro-complex containing polyaptamer for exosome separation and wound healing

Exosomes(EXOs)have showed great potential in regenerative medicine.The separation of EXOs from complex biological media is essential for the down-stream applications.Herein,we report a deoxyribonucleic acid(DNA)-based micro-complex(DMC)containing polyaptamers,which realized the specific separation of EXOs from cell culture media and the significant promotion of wound healing.The synthesis of DMCs was based on a biomineralization process via rolling circle amplification(RCA)under the catalysis of phi29 DNA polymerase.To endow DMCs with the ability to capture EXOs,the DNA template of RCA was integrated with complementary sequence of aptamer that specifically recognized the CD63 proteins on EXOs.The obtained DMCs contained polyaptamers that can specifically capture the EXOs in cell culture media.The EXOs-capturing DMCs were collected by centrifugation,achieving the separation of EXOs.Mesenchymal stem cell(MSC)-derived EXOs(MSC-EXOs)were separated by this DMC-based strategy,and the separated MSC-EXOs significantly enhanced the migration ability of cells.In particular,the significant therapeutic efficacy of the DMCs with MSC-EXOs was verified in full-thickness wound excision mouse models,in which the wounds completely healed in 10 days.We envision that this DMC-based separation strategy can be a promising route to promote the development of EXOs in biomedicine.

Light-Mediated Spatiotemporally Dynamic Assembly of DNA Nanostructures in Living Cells Regulates Autophagy

The assembly of exogenous artificial architectures inside cells can regulate a series of biological events,which heavily relies on the development of spatiotemporally controlled molecular assembly systems.We herein report a designer deoxyribonucleic acid(DNA)nanostructure that enables light-mediated spatiotemporally dynamic assembly in living cells and consequently achieves efficient regulation of cell autophagy.The DNA nanostructure was constructed from i-motif moiety-containing branched DNA,photocleavable bond-containing linker,and tumor cell-targeting aptamer.After cellular uptake mediated by aptamers,under the spatiotemporal control of both UV light and late endosomal/lysosomal acidic environments,disassembly/reassembly of DNA nanostructure occurred via two rationally designed routes,generating microsized DNA assembly.As a result,autophagy was significantly enhanced with the increase of DNA assembly size.The enhanced autophagy showed an impact on related biological effects.Our system is expected to be a powerful tool for the regulation of intracellular events and cellular behaviors.

Engineering CRISPR/Cas-based nanosystems for therapeutics, diagnosis and bioimaging

CRISPR/Cas system has been utilized to rationally manipulate intracellular genes,and it has been engineered as versatile and efficient gene editing tools with precise site-specificity and excellent targeting ability for therapeutics,diagnostics,and bioimaging.Here,the evolution and application of CRISPR/Cas systems were sketched chronologically.Landmark works were exemplified to illustrate the design principles of CRISPR/Cas systems.Furthermore,the delivery vectors of CRISPR/Cas system especially DNA nanomaterials-based vectors were categorized and illuminated.DNA nanomaterials are suitable for CRISPR/Cas system delivery via base pairing due to its sequence programmability and biocompatibility.Then the applications of CRISPR/Cas in diagnosis and genomic imaging were highlighted.At the end of the review,the challenges and opportunities of CRISPR/Cas systems were deeply discussed.We envision that the grant advances on CRISPR/Cas systems will promote the development of interdisciplinary fields in chemistry,biology and medicine.

Construction of Polymeric DNA Network and Application for Cell Manipulation

Comprehensive Summary Deoxyribonucleic acid(DNA)is a biomacromolecule,as well as a polymeric material,whose sequences with different manipulative structures enable them to implement a series of functions,such as reorganization,target,and catalysis.Compared to existing traditional materials incapable of multifunctional integration,the polymeric DNA network is a form of material that can achieve functional integration while maintaining specific DNA properties.Furthermore,precise target enabled by DNA network is one of the most essential components of cellular manipulation.Hence,the DNA network is indispensable and irreplaceable to cell manipulation that it is a versatile tool for the understanding of basic laws of living life and treatments of diseases,such as cell isolation,cell delivery,and cell interference.Herein,the construction of polymeric DNA network is briefly introduced from the aspects of assembly modules,construction methods,and properties.

Construction of DNA aggregates in cell milieu for bio-interference

Precise assembly of biomolecules into functional aggregate structures represents a key characteristic of nature living cells,and is critical for the cellular processes.The construction of artificial aggregates in living cells by responding to intracel-lular specific stimuli has been applied in elucidating molecular mechanisms of naturally cellular processes and interfering with cellular processes,which is poten-tial and significant in biomedicine.DNA(deoxyribonucleic acid)features sequence programmability,precise assembly and versatility,and therefore is regarded as the potential candidate for constructing versatile functional aggregates in living cells.In this review,we summarize our recent efforts of employing DNA to in situ construct versatile aggregates in living cells via responding intracellular triggers,and the sub-sequent bio-interference of the DNA aggregates.Finally,we discuss the remaining challenges and opportunities in thefield,and envision that rational design and con-struction of versatile DNA aggregates in living system would be a promising solution for precision and personalized therapeutics.

索拉非尼联合卡培他滨治疗肝细胞肝癌的效果及对血清miR-212和miR-132水平的影响

目的探讨索拉非尼联合卡培他滨治疗肝细胞肝癌(HCC)的效果及对患者血清miR-212和miR-132水平的影响。方法抽取2018年2月至2020年6月郑州人民医院收治的HCC患者126例,采用随机数字表法分为单一组和联合组,每组63例。单一组给予卡培他滨治疗,联合组给予索拉非尼联合卡培他滨治疗。比较两组的化疗效果、近期生存率、血清miR-212和miR-132水平及不良反应发生率。结果联合组总有效率(79.36%,50/63)高于单一组(61.90%,39/60),P<0.05。治疗后,两组血清miR-212和miR-132 mRNA、蛋白水平高于治疗前,且联合组高于单一组(P<0.05);治疗后1年,联合组无进展生存率为73.02%(46/63),高于单一组的52.38%(33/63),P<0.05。联合组不良反应总发生率(26.98%,17/63)与单一组(17.46%,11/63)比较差异未见统计学意义(P>0.05)。结论索拉非尼联合卡培他滨治疗HCC在调节患者血清miR-212和miR-132水平、提高疗效和近期生存率方面有积极作用,且联合用药未明显增加不良反应的发生。

Construction and applications of DNA-based nanomaterials in cancer therapy

As a biologically active macromolecule, deoxyribonucleic acid(DNA) has the advantages of sequence programmability and structure controllability and can accurately transmit sequence information to specific biological functions. Facing the complex internal microenvironment and heterogeneity in tumor treatment, the construction and applications of DNA-based nanomaterials have become a focus point of research. In particular, the hybridization of DNA molecules with other materials endows DNA-based nanomaterials with multiple functions such as targeting, stimulus responsiveness and regulations of biological activities, making DNA nanostructures great potential in the treatment of major human diseases.In this review, the construction and characteristics of DNA-based nanomaterials are introduced. Then,the functions and applications of DNA-based nanomaterials in the delivery of chemotherapy drugs and gene drugs, stimulus-responsive release and regulation of cell homeostasis are reviewed. Finally, the future development and challenges of DNA-based nanomaterials are prospected. We envision that DNAbased nanomaterials can enrich the nanomaterial system by rational design and synthesis and address the growing demands on biological and biomedical applications in the real world.

Preparation of biomimetic gene hydrogel via polymerase chain reaction for cell-free protein expression

Deoxyribonucleic acid(DNA)hydrogels,a three-dimensional(3 D)network made from DNA chains,have attracted great attention because of its molecular programmability,excellent biocompatibility and wide biomedical applications.Construction of hydrogel incorporating genetic function is still a challenge because of the limitations in available preparation methods.Herein,we develop a polymerase chain reaction(PCR)based strategy to construct gene integrated hydrogel to mimic the biofunction of nucleus zone.DNA primers were chemically modified by methacrylamide,which were used as modular primers in PCR to hybridize with template plasmid DNA,yielding methacrylamide functionalized gene(Acry-gene).Afterwards,Acry-gene was chemically cross-linked and compressed via free radical polymerization of terminal group methacrylamide to form a threedimensional gene network,namely gene hydrogel.The gene hydrogel retained the genetic function and expressed protein successfully in a cell free protein expression system.This work provides a general approach for the construction of biofunctional gene hydrogel which mimics bioprocesses,showing great potential in biomedicine and biomimetic fields.

Cell lysates and egg white create homeostatic microenvironment for gene expression in cell-free system

Homeostasis widely exists in living systems,and plays essential roles for maintaining normal physiological activities,enabling to preserve their functionalities against variations.Gene expression is a crucial process that allows cells to produce the necessary protein,giving cells the flexibility to adapt to variations.Herein we study homeostasis of gene expression in cell-free system.Heat-inactivated cell lysates and egg white are utilized to create homeostatic microenvironment.Results show that both in cell lysates and egg white,gene expression is maintained at relatively stable levels upon variations including gene amount,magnesium ions and temperature.Our work presents a nascent concept and experimental evidence for the homeostasis in cell-free systems,and provides implication for living systems.

Self-assembly of artificial architectures in living cells-design and applications

Self-assembly exists widely in natural living system and artificial synthetic material system.Administration of self-assemblies of artificial architectures in living cells can be used to explore the molecular physicochemical fundamentals and operating mechanisms of living system,and consequently promote the development of biomedicine.In order to mimic naturally occurring self-assemblies and realize controllable functions,great efforts have been devoted to constructing dynamic assembly of artificial architectures in living cells by responding to intracellular specific stimuli,which can be used to regulate morphology,behaviors and fate of living cells.This review highlights the recent progress on artificial self-assembly in living cells.The molecular fundamentals and characteristics of intracellular environment that can induce the self-assembly of artificial architectures are introduced,and the representative work on dynamic artificial self-assembly in living cells is sketched chronologically.Moreover,intracellular stimuli-mediated pathways of artificial assembly in living cells are categorized,biological effects caused by intracellular self-assembly are summarized,and biomedical applications focusing on therapy and imaging are described.In the end,the perspective and challenges of artificial self-assembly in living cells are fully discussed.It is believed that the grand advances on artificial self-assembly in living cells will contribute to elaborating the molecular mechanisms in cells,and further promoting the biologically and medically-related applications in the future.

Gene-like Precise Construction of Functional DNA Materials

CONSPECTUS:Developing a new system of material chemistry is an important molecular foundation for the design and preparation of functional materials,which resembles the preparation of raw materials such as bricks for constructing a building that determines the quality of the building.However,precisely controlling the synthesis processes and structures of functional materials always remains a grand challenge.It is expected to propose a paradigm of“gene-like”precise construction to realize the rational synthesis of functional materials,i.e.,a“structure-function-application”principle for the precise construction.As the core genetic material of life,the DNA molecule is a bioactive macromolecule that can accurately encode genetic information and also can act as the generic molecular building block for the precise construction of functional materials.In this Account,we describe our work on the design and construction of functional DNA materials,to illustrate the principle of“gene-like”construction of functional DNA materials.The DNA molecule shows the unique advantages in the“gene-like”construction of functional materials,mainly including the precise arrangement of bases(monomers),the controllable design and assembly of structure,the precise transmission of sequence information,and customization of function.First,the number and sequence of four deoxynucleotide monomers that constitute the DNA strand can be rationally designed and accurately synthesized.Second,the sequence information on DNA endows the precise and efficient assembly of DNA molecules and ensures the precise regulation on the specific biological functions of functional DNA materials.Third,the functions of DNA materials can couple with the biological environments,so as to achieve the predetermined applications.Based on the scale of the constructed DNA materials,we categorize DNA materials into three classes:molecular scale,nanoscale,and macroscale.At the molecular scale,the representative material is branched DNA-based materials;the construction strategies mainly include targettriggered polymerization,enzymatic extension,and hybrid coupling;the applications mainly include the nonenzymatic detection of base mutation,the construction of artificial cells for the study of compartmentalization and the confinement effect,and the regulation of optical and antibacterial properties of supernanoclusters.At the nanoscale,the representative material is the DNA nanocomplex;the construction strategies mainly include hybridization with polymer,small molecule,and metal ions;the applications mainly include gene drug delivery and luminescence bioimaging.At the macroscale,the representative material is the DNA hydrogel;the construction strategies mainly include double-rolling circle amplification(double-RCA),multistage-RCA,and chemical cross-linking;the applications mainly include cell isolation,cell delivery,antibacterial agents,and self-healing electric circuits.Based on the“gene-like”paradigm,we expect to develop a wider variety of functional DNA materials by the precise regulation of DNA assembly behaviors and topological structures.We further envision that our work on the design,synthesis,and applications of functional DNA materials is a typical paradigm for the“gene-like”precise construction of functional materials and hopefully will promote the development of materials genome.

A smart DNA hydrogel for isolation of bacterial outer membrane vesicles and localized cancer immunotherapy

Bacterial outer membrane vesicles(OMVs)have shown great potential in cancer immunotherapy.The isolation of OMVs from complex media with high purity and high bioactivity is the prerequisite of therapeutic applications,which remains highly challenging.Herein,we report a smart DNA hydrogel for the efficient isolation of OMVs from bacterial culture medium,which is further applied for localized cancer immunotherapy.The DNA hydrogel is constructed through the cross-linking of two ultralong DNA chains generated via rolling circle amplification(RCA).One chain contains polyvalent GN6 aptamer for the specific capture of OMVs,and the other contains polyvalent programmed death-1(PD-1)aptamer for the blocking of PD-1 immune checkpoint on the surface of T lymphocytes.The OMVs capsulated by DNA hydrogel maintain high immunostimulatory bioactivity.In the mouse model of melanoma,this OMVs-containing DNA hydrogel shows a remarkable tumor inhibition rate of∼95%.This smart DNA hydrogel represents a promising biomedical platform for the efficient isolation of bacterial-derived OMVs,and provides a powerful strategy for cancer immunotherapy.