Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 66.927
1.
J Nanobiotechnology ; 22(1): 274, 2024 May 22.
Article En | MEDLINE | ID: mdl-38773614

Small extracellular vesicle-derived microRNAs (sEV-miRNAs) have emerged as promising noninvasive biomarkers for early cancer diagnosis. Herein, we developed a molecular probe based on three-dimensional (3D) multiarmed DNA tetrahedral jumpers (mDNA-Js)-assisted DNAzyme activated by Na+, combined with a disposable paper-based electrode modified with a Zr-MOF-rGO-Au NP nanocomplex (ZrGA) to fabricate a novel biosensor for sEV-miRNAs Assay. Zr-MOF tightly wrapped by rGO was prepared via a one-step method, and it effectively aids electron transfer and maximizes the effective reaction area. In addition, the mechanically rigid, and nanoscale-addressable mDNA-Js assembled from the bottom up ensure the distance and orientation between fixed biological probes as well as avoid probe entanglement, considerably improving the efficiency of molecular hybridization. The fabricated bioplatform achieved the sensitive detection of sEV-miR-21 with a detection limit of 34.6 aM and a dynamic range from100 aM to 0.2 µM. In clinical blood sample tests, the proposed bioplatform showed results highly consistent with those of qRT-PCRs and the signal increased proportionally with the NSCLC staging. The proposed biosensor with a portable wireless USB-type analyzer is promising for the fast, easy, low-cost, and highly sensitive detection of various nucleic acids and their mutation derivatives, making it ideal for POC biosensing.


Biosensing Techniques , Extracellular Vesicles , Limit of Detection , Metal-Organic Frameworks , MicroRNAs , Paper , Metal-Organic Frameworks/chemistry , Extracellular Vesicles/chemistry , Humans , Biosensing Techniques/methods , DNA, Catalytic/chemistry , Graphite/chemistry , Gold/chemistry , DNA/chemistry , Metal Nanoparticles/chemistry , Nucleic Acid Hybridization , Electrochemical Techniques/methods , Electrodes , Zirconium/chemistry
2.
J Nanobiotechnology ; 22(1): 230, 2024 May 08.
Article En | MEDLINE | ID: mdl-38720322

Tumor vaccines, a crucial immunotherapy, have gained growing interest because of their unique capability to initiate precise anti-tumor immune responses and establish enduring immune memory. Injected tumor vaccines passively diffuse to the adjacent draining lymph nodes, where the residing antigen-presenting cells capture and present tumor antigens to T cells. This process represents the initial phase of the immune response to the tumor vaccines and constitutes a pivotal determinant of their effectiveness. Nevertheless, the granularity paradox, arising from the different requirements between the passive targeting delivery of tumor vaccines to lymph nodes and the uptake by antigen-presenting cells, diminishes the efficacy of lymph node-targeting tumor vaccines. This study addressed this challenge by employing a vaccine formulation with a tunable, controlled particle size. Manganese dioxide (MnO2) nanoparticles were synthesized, loaded with ovalbumin (OVA), and modified with A50 or T20 DNA single strands to obtain MnO2/OVA/A50 and MnO2/OVA/T20, respectively. Administering the vaccines sequentially, upon reaching the lymph nodes, the two vaccines converge and simultaneously aggregate into MnO2/OVA/A50-T20 particles through base pairing. This process enhances both vaccine uptake and antigen delivery. In vitro and in vivo studies demonstrated that, the combined vaccine, comprising MnO2/OVA/A50 and MnO2/OVA/T20, exhibited robust immunization effects and remarkable anti-tumor efficacy in the melanoma animal models. The strategy of controlling tumor vaccine size and consequently improving tumor antigen presentation efficiency and vaccine efficacy via the DNA base-pairing principle, provides novel concepts for the development of efficient tumor vaccines.


Cancer Vaccines , Lymph Nodes , Manganese Compounds , Mice, Inbred C57BL , Nanoparticles , Ovalbumin , Oxides , Animals , Cancer Vaccines/immunology , Lymph Nodes/immunology , Mice , Ovalbumin/immunology , Ovalbumin/chemistry , Oxides/chemistry , Nanoparticles/chemistry , Manganese Compounds/chemistry , Immunity, Cellular , Female , Cell Line, Tumor , DNA/chemistry , DNA/immunology , Immunotherapy/methods , Melanoma, Experimental/immunology , Melanoma, Experimental/therapy , Particle Size , Antigens, Neoplasm/immunology
3.
Biotechnol J ; 19(5): e2300734, 2024 May.
Article En | MEDLINE | ID: mdl-38719571

Self-assembly of biological elements into biomimetic cargo carriers for targeting and delivery is a promising approach. However, it still holds practical challenges. We developed a functionalization approach of DNA origami (DO) nanostructures with neuronal growth factor (NGF) for manipulating neuronal systems. NGF bioactivity and its interactions with the neuronal system were demonstrated in vitro and in vivo models. The DO elements fabricated by molecular self-assembly have manipulated the surrounding environment through static spatially and temporally controlled presentation of ligands to the cell surface receptors. Our data showed effective bioactivity in differentiating PC12 cells in vitro. Furthermore, the DNA origami NGF (DON) affected the growth directionality and spatial capabilities of dorsal root ganglion neurons in culture by introducing a chemotaxis effect along a gradient of functionalized DO structures. Finally, we showed that these elements provide enhanced axonal regeneration in a rat sciatic nerve injury model in vivo. This study is a proof of principle for the functionality of DO in neuronal manipulation and regeneration. The approach proposed here, of an engineered platform formed out of programmable nanoscale elements constructed of DO, could be extended beyond the nervous system and revolutionize the fields of regenerative medicine, tissue engineering, and cell biology.


DNA , Ganglia, Spinal , Nerve Growth Factor , Nerve Regeneration , Animals , Rats , PC12 Cells , DNA/chemistry , Ganglia, Spinal/cytology , Nerve Growth Factor/chemistry , Nerve Growth Factor/pharmacology , Nanostructures/chemistry , Neurons , Sciatic Nerve , Tissue Scaffolds/chemistry , Rats, Sprague-Dawley
4.
Sci Rep ; 14(1): 10826, 2024 05 11.
Article En | MEDLINE | ID: mdl-38734799

Sequencing the DNA nucleobases is essential in the diagnosis and treatment of many diseases related to human genes. In this article, the encapsulation of DNA nucleobases with some of the important synthesized chiral (7, 6), (8, 6), and (10, 8) carbon nanotubes were investigated. The structures were modeled by applying density functional theory based on tight binding method (DFTB) by considering semi-empirical basis sets. Encapsulating DNA nucleobases on the inside of CNTs caused changes in the electronic properties of the selected chiral CNTs. The results confirmed that van der Waals (vdW) interactions, π-orbitals interactions, non-bonded electron pairs, and the presence of high electronegative atoms are the key factors for these changes. The result of electronic parameters showed that among the CNTs, CNT (8, 6) is a suitable choice in sequencing guanine (G) and cytosine (C) DNA nucleobases. However, they are not able to sequence adenine (A) and thymine (T). According to the band gap energy engineering approach and absorption energy, the presence of G and C DNA nucleobases decreased the band gap energy of CNTs. Hence selected CNTs suggested as biosensor substrates for sequencing G and C DNA nucleobases.


DNA , Guanine , Nanotubes, Carbon , Nanotubes, Carbon/chemistry , DNA/chemistry , Guanine/chemistry , Density Functional Theory , Adenine/chemistry , Cytosine/chemistry , Thymine/chemistry , Sequence Analysis, DNA/methods , Electrons , Models, Molecular , Humans
5.
Anal Chem ; 96(19): 7747-7755, 2024 May 14.
Article En | MEDLINE | ID: mdl-38691774

Accurate classification of tumor cells is of importance for cancer diagnosis and further therapy. In this study, we develop multimolecular marker-activated transmembrane DNA computing systems (MTD). Employing the cell membrane as a native gate, the MTD system enables direct signal output following simple spatial events of "transmembrane" and "in-cell target encounter", bypassing the need of multistep signal conversion. The MTD system comprises two intelligent nanorobots capable of independently sensing three molecular markers (MUC1, EpCAM, and miR-21), resulting in comprehensive analysis. Our AND-AND logic-gated system (MTDAND-AND) demonstrates exceptional specificity, allowing targeted release of drug-DNA specifically in MCF-7 cells. Furthermore, the transformed OR-AND logic-gated system (MTDOR-AND) exhibits broader adaptability, facilitating the release of drug-DNA in three positive cancer cell lines (MCF-7, HeLa, and HepG2). Importantly, MTDAND-AND and MTDOR-AND, while possessing distinct personalized therapeutic potential, share the ability of outputting three imaging signals without any intermediate conversion steps. This feature ensures precise classification cross diverse cells (MCF-7, HeLa, HepG2, and MCF-10A), even in mixed populations. This study provides a straightforward yet effective solution to augment the versatility and precision of DNA computing systems, advancing their potential applications in biomedical diagnostic and therapeutic research.


DNA , Epithelial Cell Adhesion Molecule , MicroRNAs , Humans , Epithelial Cell Adhesion Molecule/metabolism , DNA/chemistry , MicroRNAs/analysis , MicroRNAs/metabolism , Mucin-1/metabolism , Mucin-1/analysis , Computers, Molecular , MCF-7 Cells , Biomarkers, Tumor/metabolism , Biomarkers, Tumor/analysis , Cell Membrane/metabolism , Cell Membrane/chemistry , Hep G2 Cells
6.
Anal Chem ; 96(19): 7679-7686, 2024 May 14.
Article En | MEDLINE | ID: mdl-38698534

Despite the success of surface-enhanced Raman spectroscopy (SERS) for detecting DNA immobilized on plasmonic metal surfaces, its quantitative response is limited by the rapid falloff of enhancement with distance from the metal surface and variations in sensitivity that depend on orientation and proximity to plasmonic "hot spots". In this work, we assess an alternative approach for enhancing detection by immobilizing DNA on the interior surfaces of porous silica particles. These substrates provide over a 1000-fold greater surface area for detection compared to a planar support. The porous silica substrate is a purely dielectric material with randomly oriented internal surfaces, where scattering is independent of proximity and orientation of oligonucleotides relative to the silica surface. We characterize the quantitative response of Raman scattering from DNA in porous silica particles with sequences used in previous SERS investigations of DNA for comparison. The results show that Raman scattering of DNA in porous silica is independent of distance of nucleotides from the silica surface, allowing detection of longer DNA strands with constant sensitivity. The surface area enhancement within particles is reproducible (<4% particle-to-particle variation) owing to the uniform internal pore structure and surface chemistry of the silica support. DNA immobilization with a bis-thiosuccinimide linker provides a Raman-active internal standard for quantitative interpretation of Raman scattering results. Despite the high (30 mM) concentrations of immobilized DNA within porous silica particles, they can be used to measure nanomolar binding affinities of target molecules to DNA by equilibrating a very small number of particles with a sufficiently large volume of low-concentration solution of target molecules.


DNA , Silicon Dioxide , Spectrum Analysis, Raman , Surface Properties , Silicon Dioxide/chemistry , Spectrum Analysis, Raman/methods , Porosity , DNA/chemistry , DNA/analysis
7.
Langmuir ; 40(19): 10157-10170, 2024 May 14.
Article En | MEDLINE | ID: mdl-38700902

I-Motif (iM) DNA structures represent among the most significant noncanonical nucleic acid configurations. iM-forming DNA sequences are found in an array of vital genomic locations and are particularly frequent in the promoter islands of various oncogenes. Thus, iM DNA is a crucial candidate for anticancer medicines; therefore, binding interactions between iM DNA and small molecular ligands, such as flavonoids, are critically important. Extensive sets of spectroscopic strategies and thermodynamic analysis were utilized in the present investigation to find out the favorable interaction of quercetin (Que), a dietary flavonoid that has various health-promoting characteristics, including anticancer properties, with noncanonical iM DNA structure. Spectroscopic studies and thermal analysis revealed that Que interacts preferentially with HRAS1 iM DNA compared with VEGF, BCL2 iM, and duplex DNA. Que, therefore, emerged as a suitable natural-product-oriented antagonist for targeting HRAS1 iM DNA. The innovative spectroscopic as well as mechanical features of Que and its specific affinity for HRAS1 iM may be useful for therapeutic applications and provide crucial insights for the design of compounds with remarkable medicinal properties.


DNA , Promoter Regions, Genetic , Proto-Oncogene Proteins p21(ras) , Quercetin , Quercetin/chemistry , Quercetin/pharmacology , Quercetin/metabolism , DNA/chemistry , DNA/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/chemistry , Proto-Oncogene Proteins p21(ras)/antagonists & inhibitors , Proto-Oncogene Proteins p21(ras)/metabolism , Thermodynamics , Humans , Nucleotide Motifs , Binding Sites
8.
ACS Nano ; 18(19): 12401-12411, 2024 May 14.
Article En | MEDLINE | ID: mdl-38701333

Accurate identification of single nucleotide variants (SNVs) in key driver genes holds a significant value for disease diagnosis and treatment. Fluorescent probes exhibit tremendous potential in specific, high-resolution, and rapid detection of SNVs. However, additional steps are required in most post-PCR assays to convert double-stranded DNA (dsDNA) products into single-stranded DNA (ssDNA), enabling them to possess hybridization activity to trigger subsequent reactions. This process not only prolongs the complexity of the experiment but also introduces the risk of losing target information. In this study, we proposed two strategies for enriching active double-stranded DNA, involving PCR based on obstructive groups and cleavable units. Building upon this, we explored the impact of modified units on the strand displacement reaction (SDR) and assessed their discriminatory efficacy for mutations. The results showed that detection of low variant allele frequencies (VAF) as low as 0.1% can be achieved. The proposed strategy allowed orthogonal identification of 45 clinical colorectal cancer tissue samples with 100% specificity, and the results were generally consistent with sequencing results. Compared to existing methods for enriching active targets, our approach offers a more diverse set of enrichment strategies, characterized by the advantage of being simple and fast and preserving original information to the maximum extent. The objective of this study is to offer an effective solution for the swift and facile acquisition of active double-stranded DNA. We anticipate that our work will facilitate the practical applications of SDR based on dsDNA.


DNA , Polymorphism, Single Nucleotide , Polymorphism, Single Nucleotide/genetics , Humans , DNA/genetics , DNA/chemistry , Colorectal Neoplasms/genetics , Polymerase Chain Reaction , Fluorescent Dyes/chemistry , DNA, Single-Stranded/genetics , DNA, Single-Stranded/chemistry
9.
Mikrochim Acta ; 191(6): 298, 2024 05 06.
Article En | MEDLINE | ID: mdl-38709403

As a real-time fluid biopsy method, the detection of circulating tumor cells (CTCs) provides important information for the early diagnosis, precise treatment, and prognosis of cancer. However, the low density of CTCs in the peripheral blood hampers their capture and detection with high sensitivity and selectivity using currently available methods. Hence, we designed a sandwich-type electrochemical aptasensor that utilizes holothurian-shaped AuPd nanoparticles (AuPd HSs), tetrahedral DNA nanostructures (TDNs), and CuPdPt nanowire networks (NWs) interwoven with a graphdiyne (GDY) sheet for ultrasensitive non-destructive detection of MCF-7 breast cancer cells. CuPdPt NW-GDY effectively enhanced the electron transfer rate and coupled with the loaded TDNs. The TDNs could capture MCF-7 cells with precision and firmness, and the resulting composite complex was combined with AuPd HSs to form a sandwich-type structure. This novel aptasensor showed a linear range between 10 and 106 cells mL-1 and an ultralow detection limit of 7 cells mL-1. The specificity, stability, and repeatability of the measurements were successfully verified. Moreover, we used benzonase nuclease to achieve non-destructive recovery of cells for further clinical studies. According to the results, our aptasensor was more sensitive measuring the number of CTCs than other approaches because of the employment of TDNs, CuPdPt NW-GDY, and AuPd HSs. We designed a reliable sensor system for the detection of CTCs in the peripheral blood, which could serve as a new approach for cancer diagnosis at an early stage.


Aptamers, Nucleotide , Biosensing Techniques , DNA , Electrochemical Techniques , Gold , Limit of Detection , Metal Nanoparticles , Neoplastic Cells, Circulating , Palladium , Neoplastic Cells, Circulating/pathology , Humans , MCF-7 Cells , Metal Nanoparticles/chemistry , Electrochemical Techniques/methods , Aptamers, Nucleotide/chemistry , Gold/chemistry , DNA/chemistry , Biosensing Techniques/methods , Palladium/chemistry
10.
Cryo Letters ; 45(3): 177-184, 2024.
Article En | MEDLINE | ID: mdl-38709189

BACKGROUND: Ovarian tissue cryopreservation for fertility preservation carries a risk of malignant cell re-seeding. Artificial ovary is a promising method to solve such a problem. However, ovary decellularization protocols are limited. Hence, further studies are necessary to get better ovarian decellularization techniques for the construction of artificial ovary scaffolds. OBJECTIVE: To establish an innovative decellularization technique for whole porcine ovaries by integrating liquid nitrogen with chemical agents to reduce the contact time between the scaffolds and chemical reagents. MATERIALS AND METHODS: Porcine ovaries were randomly assigned to three groups: novel decellularized group, conventional decellularized group and fresh group. The ovaries in the novel decellularized group underwent three cycles of freezing by liquid nitrogen and thawing at temperatures around 37 degree C before decellularization. The efficiency of the decellularization procedure was assessed through histological staining and DNA content analysis. The maintenance of ovarian decellularized extracellular matrix(ODECM) constituents was determined by analyzing the content of matrix proteins. Additionally, we evaluated the biocompatibility of the decellularized extracellular matrix(dECM) by observing the growth of granulosa cells on the ODECM scaffold in vitro. RESULTS: Hematoxylin and eosin staining, DAPI staining and DNA quantification techniques collectively confirm the success of the novel decellularization methods in removing cellular and nuclear components from ovarian tissue. Moreover, quantitative assessments of ODECM contents revealed that the novel decellularization technique preserved more collagen and glycosaminoglycan compared to the conventional decellularized group (P<0.05). Additionally, the novel decellularized scaffold exhibited a significantly higher number of granulosa cells than the conventional scaffold during in vitro co-culture (P<0.05). CONCLUSION: The novel decellularized method demonstrated high efficacy in eliminating DNA and cellular structures while effectively preserving the extracellular matrix. As a result, the novel decellularized method holds significant promise as a viable technique for ovarian decellularization in forthcoming studies. Doi.org/10.54680/fr24310110212.


Cryopreservation , Decellularized Extracellular Matrix , Nitrogen , Ovary , Tissue Scaffolds , Animals , Female , Nitrogen/chemistry , Swine , Ovary/cytology , Tissue Scaffolds/chemistry , Cryopreservation/methods , Decellularized Extracellular Matrix/chemistry , Tissue Engineering/methods , Granulosa Cells/cytology , Fertility Preservation/methods , Extracellular Matrix/chemistry , DNA/analysis , DNA/chemistry
11.
Methods Mol Biol ; 2800: 35-53, 2024.
Article En | MEDLINE | ID: mdl-38709476

Clustering of type II tumor necrosis factor (TNF) receptors (TNFRs) is essential for their activation, yet currently available drugs fail to activate signaling. Some strategies aim to cluster TNFR by using multivalent streptavidin or scaffolds based on dextran or graphene. However, these strategies do not allow for control of the valency or spatial organization of the ligands, and consequently control of the TNFR activation is not optimal. DNA origami nanostructures allow nanometer-precise control of the spatial organization of molecules and complexes, with defined spacing, number and valency. Here, we demonstrate the design and characterization of a DNA origami nanostructure that can be decorated with engineered single-chain TNF-related apoptosis-inducing ligand (SC-TRAIL) complexes, which show increased cell killing compared to SC-TRAIL alone on Jurkat cells. The information in this chapter can be used as a basis to decorate DNA origami nanostructures with various proteins, complexes, or other biomolecules.


DNA , Nanostructures , Nanostructures/chemistry , Humans , Jurkat Cells , DNA/chemistry , DNA/metabolism , TNF-Related Apoptosis-Inducing Ligand/chemistry , TNF-Related Apoptosis-Inducing Ligand/metabolism , Receptors, Tumor Necrosis Factor/metabolism , Receptors, Tumor Necrosis Factor/chemistry , Nanotechnology/methods , Nucleic Acid Conformation
12.
Methods Mol Biol ; 2800: 103-113, 2024.
Article En | MEDLINE | ID: mdl-38709481

The spatial resolution of conventional light microscopy is restricted by the diffraction limit to hundreds of nanometers. Super-resolution microscopy enables single digit nanometer resolution by circumventing the diffraction limit of conventional light microscopy. DNA point accumulation for imaging in nanoscale topography (DNA-PAINT) belongs to the family of single-molecule localization super-resolution approaches. Unique features of DNA-PAINT are that it allows for sub-nanometer resolution, spectrally unlimited multiplexing, proximity detection, and quantitative counting of target molecules. Here, we describe prerequisites for efficient DNA-PAINT microscopy.


DNA , Single Molecule Imaging , DNA/chemistry , Single Molecule Imaging/methods , Microscopy, Fluorescence/methods , Proteins/chemistry , Nanotechnology/methods
13.
Sci Rep ; 14(1): 10157, 2024 05 02.
Article En | MEDLINE | ID: mdl-38698072

Extraction of nucleic acids (NAs) is critical for many methods in molecular biology and bioanalytical chemistry. NA extraction has been extensively studied and optimized for a wide range of applications and its importance to society has significantly increased. The COVID-19 pandemic highlighted the importance of early and efficient NA testing, for which NA extraction is a critical analytical step prior to the detection by methods like polymerase chain reaction. This study explores simple, new approaches to extraction using engineered smart nanomaterials, namely NA-binding, intrinsically disordered proteins (IDPs), that undergo triggered liquid-liquid phase separation (LLPS). Two types of NA-binding IDPs are studied, both based on genetically engineered elastin-like polypeptides (ELPs), model IDPs that exhibit a lower critical solution temperature in water and can be designed to exhibit LLPS at desired temperatures in a variety of biological solutions. We show that ELP fusion proteins with natural NA-binding domains can be used to extract DNA and RNA from physiologically relevant solutions. We further show that LLPS of pH responsive ELPs that incorporate histidine in their sequences can be used for both binding, extraction and release of NAs from biological solutions, and can be used to detect SARS-CoV-2 RNA in samples from COVID-positive patients.


COVID-19 , Elastin , Peptides , SARS-CoV-2 , Elastin/chemistry , Hydrogen-Ion Concentration , Peptides/chemistry , COVID-19/virology , SARS-CoV-2/isolation & purification , SARS-CoV-2/genetics , Humans , Intrinsically Disordered Proteins/chemistry , Liquid-Liquid Extraction/methods , Nucleic Acids/isolation & purification , Nucleic Acids/chemistry , DNA/chemistry , DNA/isolation & purification , Elastin-Like Polypeptides , Phase Separation
14.
J Nanobiotechnology ; 22(1): 218, 2024 May 02.
Article En | MEDLINE | ID: mdl-38698435

Approximately 80 percent of the total RNA in cells is ribosomal RNA (rRNA), making it an abundant and inexpensive natural source of long, single-stranded nucleic acid, which could be used as raw material for the fabrication of molecular origami. In this study, we demonstrate efficient and robust construction of 2D and 3D origami nanostructures utilizing cellular rRNA as a scaffold and DNA oligonucleotide staples. We present calibrated protocols for the robust folding of contiguous shapes from one or two rRNA subunits that are efficient to allow folding using crude extracts of total RNA. We also show that RNA maintains stability within the folded structure. Lastly, we present a novel and comprehensive analysis and insights into the stability of RNA:DNA origami nanostructures and demonstrate their enhanced stability when coated with polylysine-polyethylene glycol in different temperatures, low Mg2+ concentrations, human serum, and in the presence of nucleases (DNase I or RNase H). Thus, laying the foundation for their potential implementation in emerging biomedical applications, where folding rRNA into stable structures outside and inside cells would be desired.


Nanostructures , Nucleic Acid Conformation , RNA, Ribosomal , RNA, Ribosomal/chemistry , Nanostructures/chemistry , Humans , RNA Folding , DNA/chemistry , Polylysine/chemistry , Polyethylene Glycols/chemistry
15.
J Am Chem Soc ; 146(19): 12925-12932, 2024 May 15.
Article En | MEDLINE | ID: mdl-38691507

Technological breakthroughs in cryo-electron microscopy (cryo-EM) methods open new perspectives for highly detailed structural characterizations of extracellular vesicles (EVs) and synthetic liposome-protein assemblies. Structural characterizations of these vesicles in solution under a nearly native hydrated state are of great importance to decipher cell-to-cell communication and to improve EVs' application as markers in diagnosis and as drug carriers in disease therapy. However, difficulties in preparing holey carbon cryo-EM grids with low vesicle heterogeneities, at low concentration and with kinetic control of the chemical reactions or assembly processes, have limited cryo-EM use in the EV study. We report a straightforward membrane vesicle cryo-EM sample preparation method that assists in circumventing these limitations by using a free-standing DNA-affinity superlattice for covering holey carbon cryo-EM grids. Our approach uses DNA origami to self-assemble to a solution-stable and micrometer-sized ordered molecular template in which structure and functional properties can be rationally controlled. We engineered the template with cholesterol-binding sites to specifically trap membrane vesicles. The advantages of this DNA-cholesterol-affinity lattice (DCAL) include (1) local enrichment of artificial and biological vesicles at low concentration and (2) isolation of heterogeneous cell-derived membrane vesicles (exosomes) from a prepurified pellet of cell culture conditioned medium on the grid.


Cryoelectron Microscopy , DNA , Cryoelectron Microscopy/methods , DNA/chemistry , Extracellular Vesicles/chemistry , Humans , Cholesterol/chemistry , Liposomes/chemistry
16.
J Am Chem Soc ; 146(19): 13126-13132, 2024 May 15.
Article En | MEDLINE | ID: mdl-38696488

Cisplatin, a cornerstone in cancer chemotherapy, is known for its DNA-binding capacity and forms lesions that lead to cancer cell death. However, the repair of these lesions compromises cisplatin's effectiveness. This study investigates how phosphorylation of HMGB1, a nuclear protein, modifies its binding to cisplatin-modified DNA (CP-DNA) and thus protects it from repair. Despite numerous methods for detecting protein-DNA interactions, quantitative approaches for understanding their molecular mechanism remain limited. Here, we applied click chemistry-based single-molecule force spectroscopy, achieving high-precision quantification of the interaction between phosphorylated HMGB1 and CP-DNA. This method utilizes a synergy of click chemistry and enzymatic ligation for precise DNA-protein immobilization and interaction in the system. Our results revealed that HMGB1 binds to CP-DNA with a significantly high rupture force of ∼130 pN, stronger than most natural DNA-protein interactions and varying across different DNA sequences. Moreover, Ser14 is identified as the key phosphorylation site, enhancing the interaction's kinetic stability by 35-fold. This increase in stability is attributed to additional hydrogen bonding suggested by molecular dynamics (MD) simulations. Our findings not only reveal the important role of phosphorylated HMGB1 in potentially improving cisplatin's therapeutic efficacy but also provide a precise method for quantifying protein-DNA interactions.


Cisplatin , Click Chemistry , DNA , HMGB1 Protein , Molecular Dynamics Simulation , HMGB1 Protein/metabolism , HMGB1 Protein/chemistry , Cisplatin/chemistry , Cisplatin/pharmacology , Cisplatin/metabolism , Phosphorylation , DNA/chemistry , DNA/metabolism , Humans , Protein Binding , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology
17.
Nano Lett ; 24(19): 5808-5815, 2024 May 15.
Article En | MEDLINE | ID: mdl-38710049

In multicellular organisms, individual cells are coordinated through complex communication networks to accomplish various physiological tasks. Aiming to establish new biological functions in the multicellular community, we used DNA as the building block to develop a cascade of nongenetic reaction circuits to establish a dynamic cell-cell communication network. Utilizing membrane-anchored amphiphilic DNA tetrahedra (TDN) as the nanoscaffold, reaction circuits were incorporated into three unrelated cells in order to uniquely regulate their sense-and-response behaviors. As a proof-of-concept, this step enabled these cells to simulate significant biological events involved in T cell-mediated anticancer immunity. Such events included cancer-associated antigen recognition and the presentation of antigen-presenting cells (APCs), APC-facilitated T cell activation and dissociation, and T cell-mediated cancer targeting and killing. By combining the excellent programmability and molecular recognition ability of DNA, our cell-surface reaction circuits hold promise for mimicking and manipulating many biological processes.


Antigen-Presenting Cells , Cell Communication , DNA , DNA/chemistry , Humans , Antigen-Presenting Cells/immunology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Lymphocyte Activation , Neoplasms/pathology , Neoplasms/genetics
18.
J Am Chem Soc ; 146(19): 13046-13054, 2024 May 15.
Article En | MEDLINE | ID: mdl-38710657

Common in biomacromolecules, kinetically trapped misfolded intermediates are often detrimental to the structures, properties, or functions of proteins or nucleic acids. Nature employs chaperone proteins but not nucleic acids to escort intermediates to correct conformations. Herein, we constructed a Jablonski-like diagram of a mechanochemical cycle in which individual DNA hairpins were mechanically unfolded to high-energy states, misfolded into kinetically trapped states, and catalytically relaxed back to ground-state hairpins by a DNA chaperone. The capacity of catalytic relaxation was demonstrated in a 1D DNA hairpin array mimicking nanoassembled materials. At ≥1 µM, the diffusive (or self-walking) DNA chaperone converted the entire array of misfolded intermediates to correct conformation in less than 15 s, which is essential to rapidly prepare homogeneous nanoassemblies. Such an efficient self-walking amplification increases the signal-to-noise ratio, facilitating catalytic relaxation to recognize a 1 fM DNA chaperone in 10 min, a detection limit comparable to the best biosensing strategies.


DNA , Molecular Chaperones , Nucleic Acid Conformation , DNA/chemistry , Kinetics , Molecular Chaperones/chemistry , Catalysis
19.
ACS Appl Mater Interfaces ; 16(19): 24162-24171, 2024 May 15.
Article En | MEDLINE | ID: mdl-38696548

Molecular carriers are necessary for the controlled release of drugs and genes to achieve the desired therapeutic outcomes. DNA hydrogels can be a promising candidate in this application with their distinctive sequence-dependent programmability, which allows precise encapsulation of specific cargo molecules and stimuli-responsive release of them at the target. However, DNA hydrogels are inherently susceptible to the degradation of nucleases, making them vulnerable in a physiological environment. To be an effective molecular carrier, DNA hydrogels should be able to protect encapsulated cargo molecules until they reach the target and release them once they are reached. Here, we develop a simple way of controlling the enzyme resistance of DNA hydrogels for cargo protection and release by using cation-mediated condensation and expansion. We found that DNA hydrogels condensed by spermine are highly resistant to enzymatic degradation. They become degradable again if expanded back to their original, uncondensed state by sodium ions interfering with the interaction between spermine and DNA. These controllable condensation, expansion, and degradation of DNA hydrogels pave the way for the development of DNA hydrogels as an effective molecular carrier.


DNA , Hydrogels , Spermine , Hydrogels/chemistry , DNA/chemistry , DNA/metabolism , Spermine/chemistry , Drug Carriers/chemistry
20.
Anal Methods ; 16(19): 3118-3124, 2024 May 16.
Article En | MEDLINE | ID: mdl-38699853

Small extracellular vesicles (sEVs) are a type of extracellular vesicle that carries many types of molecular information. The identification of sEVs is essential for the non-invasive detection and treatment of illnesses. Hence, there is a significant need for the development of simple, sensitive, and precise methods for sEV detection. Herein, a DNA tweezers-based assay utilizing a "turn-on" mechanism and proximity ligation was suggested for the efficient and rapid detection of sEVs through amplified fluorescence. The target facilitates the proximity combination of the C1 probe and C2 probe, resulting in the formation of a complete extended sequence. The elongated sequence can cyclically initiate the hairpin probe (HP), leading to the activation of DNA tweezers. An excellent linear correlation was achieved, with a limit of detection of 57 particles per µL. Furthermore, it has been effectively employed to analyze sEVs under intricate experimental conditions, demonstrating a promising and pragmatic prospect for future applications. Given that the identification of sEVs was successfully accomplished using a single-step method that exhibited exceptional sensitivity and strong resistance to interference, the proposed technique has the potential to provide a beneficial platform for accurate recognition of sEVs and early detection of diseases.


Extracellular Vesicles , Nucleic Acid Hybridization , Extracellular Vesicles/chemistry , Humans , DNA/chemistry , Limit of Detection , Biosensing Techniques/methods
...