DNA Tetrahedron Research Articles

The Current Progress of Tetrahedral DNA Nanostructure for Antibacterial Application and Bone Tissue Regeneration.

Recently, programmable assembly technologies have enabled the application of DNA in the creation of new nanomaterials with unprecedented functionality. One of the most common DNA nanostructures is the tetrahedral DNA nanostructure (TDN), which has attracted great interest worldwide due to its high stability, simple assembly procedure, high predictability, perfect programmability, and excellent biocompatibility. The unique spatial structure of TDN allows it to penetrate cell membranes in abundance and regulate cellular biological properties as a natural genetic material. Previous studies have demonstrated that TDNs can regulate various cellular biological properties, including promoting cells proliferation, migration and differentiation, inhibiting cells apoptosis, as well as possessing anti-inflammation and immunomodulatory capabilities. Furthermore, functional molecules can be easily modified at the vertices of DNA tetrahedron, DNA double helix structure, DNA tetrahedral arms or DNA tetrahedral cage structure, enabling TDN to be used as a nanocarrier for a variety of biological applications, including targeted therapies, molecular diagnosis, biosensing, antibacterial treatment, antitumor strategies, and tissue regeneration. In this review, we mainly focus on the current progress of TDN-based nanomaterials for antimicrobial applications, bone and cartilage tissue repair and regeneration. The synthesis and characterization of TDN, as well as the biological merits are introduced. In addition, the challenges and prospects of TDN-based nanomaterials are also discussed.

Modular DNA Tetrahedron Nanomachine-Guided Dual-Responsive Hybridization Chain Reactions for Discernible Bivariate Assay and Cell Imaging.

Engineering of multivariate biosensing and imaging platforms involved in disease plays a vital role in effectively discerning cancer cells from normal cells and facilitating reliable targeted therapy. Multiple biomarkers such as mucin 1 (MUC1) and nucleolin are typically overexpressed in breast cancer cells compared to normal human breast epithelium cells. Motivated by this knowledge, a dual-responsive DNA tetrahedron nanomachine (drDT-NM) is constructed through immobilizing two recognition modules, MUC1 aptamer (MA) and a hairpin H1* encoding nucleolin-specific G-rich AS1411 aptamer, in two separate vertexes of a functional DT architecture tethering two localized pendants (PM and PN). When drDT-NM identifiably binds bivariate MUC1 and nucleolin, two independent hybridization chain reactions (HCRM and HCRN) as amplification modules are initiated with two sets of four functional hairpin reactants. Among them, one hairpin for HCRM is dually ended by fluorescein and quencher BHQ1 to sense MUC1. The responsiveness of nucleolin is executed by operating HCRN utilizing another two hairpins programmed with two pairs of AS1411 splits. In the shared HCRN duplex products, the parent AS1411 aptamers are cooperatively merged and folded into G-quadruplex concatemers to embed Zn-protoporphyrin IX (ZnPPIX/G4) for fluorescence signaling readout, thereby achieving a highly sensitive intracellular assay and discernible cell imaging. The tandem ZnPPIX/G4 unities also act as imaging agents and therapeutic cargos for efficient photodynamic therapy of cancer cells. Based on drDT-NM to guide bispecific HCR amplifiers for adaptive bivariate detection, we present a paradigm of exquisitely integrating modular DNA nanostructures with nonenzymatic nucleic acid amplification, thus creating a versatile biosensing platform as a promising candidate for accurate assay, discernible cell imaging, and targeted therapy.

DNA Tetrahedra-Based Delivery of MicroRNA-22 to Reduce Depressive Symptoms in Mice.

Major depressive disorder (MDD) is a common illness with an increasing lifetime prevalence. Thus, an increasing number of studies have investigated the association between MDD and microRNAs (miRNAs), which are a novel approach for treating depression. However, the therapeutic potential of miRNA-based strategies has several limitations. To overcome these limitations, DNA tetrahedra (TDNs) have been used as piggyback materials. In this study, we successfully used TDNs as carriers of miRNA-22-3p (miR-22-3p) and synthesized a novel DNA nanocomplex (TDN-miR-22-3p), which was used in a lipopolysaccharide (LPS)-induced depression cell model. The results suggest that miR-22-3p may regulate inflammation by regulating phosphatase and tensin homologue (PTEN), an important regulatory molecule in the PI3K/AKT pathway, and downregulating the expression of NLRP3. We further validated the role of TDN-miR-22-3p in vivo using an LPS-induced animal model of depression. The results indicate that it ameliorated depression-like behavior and attenuated the expression of inflammation-related factors in mice. This study demonstrates the establishment of a straightforward and efficacious miRNA delivery system and the potential of TDNs as therapeutic vectors and tools for mechanistic studies. To the best of our knowledge, this is the first study to use TDNs in combination with miRNAs to treat depression.

DNA tetrahedron-based CRISPR bioassay for treble-self-amplified and multiplex HPV-DNA detection with elemental tagging.

Sensitive quantification of multiple analytes of interest is of great significance for clinical diagnosis. CRISPR Cas platforms offer a strategy for improving the specificity, sensitivity, and speed of nucleic acid-based diagnostics, while their multiplex analysis capability is still limited and challenging. Herein, we develop a novel DNA Tetrahedron (DTN)-supported biosensor based on the spatially separated CRISPR Cas self-amplification strategy and multiple-metal-nanoparticle tagging coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection to improve the sensitivity and feasibility of the platform for multiplex detection of HPV-DNA (HPV-16, HPV-18 and HPV-52). Given target DNA induces robust trans-cleavage activity of the Cas12a/crRNA duplex, and the surrounding corresponding single-stranded DNA (ssDNA) linker are cleaved into short fragments that are unable to bond metal-nanoparticle probes (197Au, 107Ag, 195Pt) onto DTN modified magnetic beads probe (MBs-DTN), resulting in obvious ICP-MS signal change. Of note, compared with ssDNA functionalized MBs, a higher Signal-to-Noise Ratio was obtained by using MBs-DTN in our system, further amplifying the signal by regulating probes on the surface of MBs. As expected, the HPV-DNA could be detected with detection limits as low as 218fM and be multiplexed assayed at one test with high accuracy and specificity by this proposed strategy. Furthermore, we demonstrated that the HPV-DNA in cervical swab samples could be detected, showing high consistency with DNA sequencing results. We believe that this work provides a promising option in designing CRISPR based multiplex detection system for high sensitivity, good specificity, and clinical molecular diagnostics.

Self-Assembly of DNA Nanostructures in Different Cations.

The programmable nature of DNA allows the construction of custom-designed static and dynamic nanostructures, and assembly conditions typically require high concentrations of magnesium ions that restricts their applications. In other solution conditions tested for DNA nanostructure assembly, only a limited set of divalent and monovalent ions are used so far (typically Mg2+ and Na+ ). Here, weinvestigate the assembly of DNA nanostructures in a wide variety of ions using nanostructures of different sizes: a double-crossover motif (76 bp), a three-point-star motif (~134 bp), a DNA tetrahedron (534 bp) and a DNA origami triangle (7221 bp). Weshow successful assembly of a majority of these structures in Ca2+ , Ba2+ , Na+ , K+ and Li+ and provide quantified assembly yields using gel electrophoresis and visual confirmation of a DNA origami triangle using atomic force microscopy. Wefurther show that structures assembled in monovalent ions (Na+ , K+ and Li+ ) exhibit up to a 10-fold higher nuclease resistance compared to those assembled in divalent ions (Mg2+ , Ca2+ and Ba2+ ). Ourwork presents new assembly conditions for a wide range of DNA nanostructures with enhanced biostability.

Cascaded, Feedback-Driven, and Spatially Localized Emergence of Constitutional Dynamic Networks Driven by Enzyme-Free Catalytic DNA Circuits.

The enzyme-free catalytic hairpin assembly (CHA) process is introduced as a functional reaction module for guided, high-throughput, emergence, and evolution of constitutional dynamic networks, CDNs, from a set of nucleic acids. The process is applied to assemble networks of variable complexities, functionalities, and spatial confinement, and the systems provide possible mechanistic pathways for the evolution of dynamic networks under prebiotic conditions. Subjecting a set of four or six structurally engineered hairpins to a promoter P1 leads to the CHA-guided emergence of a [2 × 2] CDN or the evolution of a [3 × 3] CDN, respectively. Reacting of a set of branched three-arm DNA-hairpin-functionalized junctions to the promoter strand activates the CHA-induced emergence of a three-dimensional (3D) CDN framework emulating native gene regulatory networks. In addition, activation of a two-layer CHA cascade circuit or a cross-catalytic CHA circuit and cascaded driving feedback-driven evolution of CDNs are demonstrated. Also, subjecting a four-hairpin-modified DNA tetrahedron nanostructure to an auxiliary promoter strand simulates the evolution of a dynamically equilibrated DNA tetrahedron-based CDN that undergoes secondary fueled dynamic reconfiguration. Finally, the effective permeation of DNA tetrahedron structures into cells is utilized to integrate the four-hairpin-functionalized tetrahedron reaction module into cells. The spatially localized miRNA-triggered CHA evolution and reconfiguration of CDNs allowed the logic-gated imaging of intracellular RNAs. Beyond the bioanalytical applications of the systems, the study introduces possible mechanistic pathways for the evolution of functional networks under prebiotic conditions.

“Repaired and initiated” intramolecular DNA circuit enables the amplified imaging of DNA repair enzyme activity in live cells

Intramolecular catalytic hairpin assembly (intraCHA) has recently been developed. However, non-nucleic acid-initiated intraCHA is rarely explored. The only protein-initiated intraCHA depends on the unwarrantable binding affinity between protein and its aptamer, which generally results in limited initiation efficiency. Herein, a “repaired and initiated” intraCHA (RI-intraCHA) nanosystem was designed and its operation was reported for amplified imaging of DNA repair enzyme activity in live cells. 8-oxoguanine (8-OG) DNA glycosylase was selected as the model DNA repair enzyme. The RI-intraCHA nanosystem was constructed by linking a dsDNA (containing 8-OG sites and trigger strand), two hairpins to different vertexes of DNA tetrahedron. The nanosystem could independently enter into live cells in virtue of cell permeability of DNA tetrahedron. Upon repair action of endogenous 8-OG DNA glycosylase, intraCHA reaction in the nanosystem was initiated efficiently, generating amplified fluorescence signal. The nanosystem provided a detection limit of 0.2443 U/mL for 8-OG DNA glycosylase, which was lower than that of the reported imaging approaches. Furthermore, the nanosystem exhibited satisfactory biosafety and biostability, achieving amplified imaging of intracellular 8-OG DNA glycosylase activity. The designed RI-intraCHA nanosystem provided a promising tool for the research of basic biology of intracellular DNA repair enzymes as well as their clinic correlations.

CRISPR-Cas12a powered multifunctional DNA nanodumbbell lock biosensor for multiple molecular detection

Detection of multiple biomarkers for accurate diagnosis of disease is highly desirable but remains challenging. Here, we developed a versatile diagnostic biosensor (SMARTLOCK) through the unique combination of DNA tetrahedron, nonlinear HCR and CRISPR-Cas12a system for simultaneous detection of multiple nucleic acids, small molecules, proteins and different types of combinations. Two DNA tetrahedrons are assembled into a functional dumbbell lock, which was unlocked by the target molecules, thereby triggering a two-stage signal amplification of nonlinear HCR and CRISPR-Cas12a to generate powerful fluorescence signals. The capability of multi-target simultaneous detection of SMARTLOCK is demonstrated in the detection of miR-141, miR-375, miR-21, ATP, cortisol, insulin and their combinations. SMARTLOCK could selectively (specificity = 93.3%) and sensitively (sensitivity = 90%) distinguish early-stage prostate cancer (PCa) patients (n = 10) from healthy donors (n = 30). Measurement of two PCa-related RNAs (miR-141 and miR-375) shows the potential of SMARTLOCK to be a highly accurate and low-cost tool for the screening, diagnosis and prognosis of various diseases.

MicroRNA-122-functionalized DNA tetrahedron stimulate hepatic differentiation of human mesenchymal stem cells for acute liver failure therapy

As the most abundant liver-specific microRNA, microRNA-122 (miR122) played a crucial role in the differentiation of stem cells into hepatocytes. However, highly efficient miR122 delivery still confronts challenges including poor cellular uptake and easy biodegradation. Herein, we for the first time demonstrated that the tetrahedral DNA (TDN) nanoplatform had great potential in inducing the differentiation of human mesenchymal stem cells (hMSCs) into functional hepatocyte-like cells (HLCs) by transferring the liver-specific miR122 to hMSCs efficiently without any extrinsic factors. As compared with miR122, miR122-functionalized TDN (TDN-miR122) could significantly up-regulate the protein expression levels of mature hepatocyte markers and hepatocyte-specific marker genes in hMSCs, indicating that TDN-miR122 could particularly activate the hepatocyte-specific properties of hMSCs for developing cell-based therapies in vitro. The transcriptomic analysis further indicated the potential mechanism that TDN-miR122 assisted hMSCs differentiated into functional HLCs. The TDN-miR122-hMSCs exhibited hepatic cell morphology phenotype, significantly up-regulated specific hepatocyte genes and hepatic biofunctions in comparison with the undifferentiated MSCs. Preclinical in vivo transplantation appeared that TDN-miR122-hMSCs in combination with or without TDN could efficiently rescue acute liver failure injury through hepatocyte function supplement, anti-apoptosis, cellular proliferation promotion, and anti-inflammatory. Collectively, our findings may provide a new and facile approach for hepatic differentiation of hMSCs for acute liver failure therapy. Further large animal model explorations are needed to study their potential in clinical translation in the future.

DNA tetrahedron–mediated triplex molecular switch for extracellular pH monitoring

This study aimed to construct a novel DNA triplex molecular switch modified with DNA tetrahedron (DTMS-DT) with sensitive response to extracellular pH using a DNA tetrahedron as the anchoring unit and DNA triplex as the response unit. The results showed that the DTMS-DT had desirable pH sensitivity, excellent reversibility, outstanding anti-interference ability, and good biocompatibility. Confocal laser scanning microscopy suggested that the DTMS-DT could not only be stably anchored on the cell membrane but also be employed to dynamically monitor the change in extracellular pH. Compared with the reported probes for extracellular pH monitoring, the designed DNA tetrahedron-mediated triplex molecular switch exhibited higher cell surface stability and brought the pH-responsive unit closer to the cell membrane surface, making the results more reliable. In general, developing the DNA tetrahedron-based DNA triplex molecular switch is helpful for understanding and illustrating the pH dependent cell behaviors and disease diagnostics.

Hierarchical Porous Metal-Organic Framework as Biocatalytic Microreactor for Enzymatic Biofuel Cell-Based Self-Powered Biosensing of MicroRNA Integrated with Cascade Signal Amplification.

Enzymatic biofuel cells have become powerful tools in biosensing, which however generally suffer from the limited loading efficiency as well as low catalytic activity and poor stability of bioenzymes. Herein, the hierarchical porous metal-organic frameworks (MOFs) are synthesized using tannic acid (TA) for structural etching, which realizes co-encapsulation of glucose dehydrogenase (GDH) and nicotinamide adenine dinucleotide (NAD+ ) cofactor in zeolitic imidazolate framework (ZIF-L) and are further used as the biocatalytic microreactors to modify bioanode. In this work, the TA-controlled etching can not only expand the pore size of microreactors, but also achieve the reorientation of enzymes in their lower surface energy form, therefore enhancing the biocatalysis of cofactor-dependent enzyme. Meanwhile, the topological DNA tetrahedron is assembled on the microreactors, which acts as the microRNA-responsive "lock" to perform the cascade signal amplification of exonuclease III-assisted target recycling on bioanode and hybridization chain reaction (HCR) on biocathode. The proposed self-powered biosensor has achieved a detection limit as low as 2 aM (6 copies miRNA-21 in a 5µL of sample), which is further successfully applied to identify cancer cells and clinical serums of breast cancer patients based on the different levels of miRNA-21, holding great potential in accurate disease identification and clinical diagnosis.

Design nanoprobe based on DNA tetrahedron supported hybridization chain reaction and its application to in situ analysis of bacteria

A new nanoprobe (DTAAT) has been well designed based on DNA tetrahedron supported hybridization chain reaction (HCR) and further applied for in situ analysis of bacteria. Antibody-aptamer conjugate (AA) has been coupled with DNA tetrahedron (DT) followed by the linkage of trigger strand (A). Bacteria can be preciously recognized by dual binding of both antibody and aptamer in DTAAT, to release trigger strand which is complementary with aptamer. By virtue of proximity effect, the released trigger strand can further efficiently induce the simultaneous occurrence of arrays of HCR at three vertices of DT, with rapid reaction rate of 359.29 min−1 in comparison with that of 212.60 min−1 for free HCR. DTAAT can be served for in situ imaging of bacteria by confocal laser scanning microscopy and single-cell characterization by flow cytometry. Moreover, using DTAAT as probe, the quantitative analysis of bacteria can be realized with high specificity and anti-interference capability. In a word, the developed DTAAT nanoprobe has a great potential for accurate and sensitive in situ analysis of bacteria.

Binding of combined irinotecan and epicatechin to a pH-responsive DNA tetrahedron for controlled release and enhanced cytotoxicity

pH-Responsive aptamer-linked DNA nanostructures can actively target cancer cells to release drugs in the cells’ acidic environment. Tea polyphenols can be used as cancer-preventive agents to enhance the efficacy of chemotherapeutic drugs. In this study, we constructed a pH-responsive DNA tetrahedron with MUC1 aptamer (MUC1-TD) to co-load irinotecan hydrochloride (CPT-11) and (-)-epicatechin (EC). The thermodynamic parameters for the interaction of CPT-11 and/or EC with MUC1-TD were investigated using fluorescence spectroscopy and calorimetry. The binding of CPT-11 to MUC1-TD was found to be stronger than that of EC. Differential scanning calorimetry and fluorescence quenching experiments demonstrated the intercalative binding between CPT-11/EC and MUC1-TD. The in vitro release rate of CPT-11 was faster at pH 5.0 than at pH 7.4, confirming the pH-responsive of MUC1-TD. In vitro cytotoxicity results indicated that CPT-11 loaded by MUC1-TD was more cytotoxic than free CPT-11. Further, we found that the cytotoxicity of CPT-11 was further enhanced in the presence of EC due to a synergy between them. Additionally, cell uptake experiments showed that CPT-11 and EC loaded by MUC1-TD were mainly distributed in the nucleus of human breast cancer cells (MCF-7). These findings indicate that pH-responsive DNA nanostructures are a promising delivery system for co-loading chemotherapeutic drugs and natural polyphenols.

Spectroscopic, calorimetric and cytotoxicity studies on the combined binding of daunorubicin and acridine orange to a DNA tetrahedron

Chemotherapy–phototherapy (CTPT) combination drugs co-loaded by targeted DNA nanostructures can achieve controlled drug delivery, reduce toxic side effects and overcome multidrug resistance. Herein, we constructed and characterized a DNA tetrahedral nanostructure (MUC1-TD) linked with the targeting aptamer MUC1. The interaction of daunorubicin (DAU)/acridine orange (AO) alone and in combination with MUC1-TD and the influence of the interaction on the cytotoxicity of the drugs were evaluated. Potassium ferrocyanide quenching analysis and DNA melting temperature assays were used to demonstrate the intercalative binding of DAU/AO to MUC1-TD. The interactions of DAU and/or AO with MUC1-TD were analyzed by fluorescence spectroscopy and differential scanning calorimetry. The number of binding sites, binding constant, entropy and enthalpy changes of the binding process were obtained. The binding strength and binding sites of DAU were higher than those of AO. The presence of AO in the ternary system weakened the binding of DAU to MUC1-TD. In vitro cytotoxicity studies demonstrated that the loading of MUC1-TD augmented the inhibitory effects of DAU and AO and the synergistic cytotoxic effects of DAU + AO on MCF-7 cells and MCF-7/ADR cells. Cell uptake studies showed that the loading of MUC1-TD was beneficial in promoting the apoptosis of MCF-7/ADR cells due to its enhanced targeting to the nucleus. This study has important guiding significance for the combined application of DAU and AO co-loaded by DNA nanostructures to overcome multidrug resistance.

Transmembrane capability of DNA origami sheet enhanced by 3D configurational changes

DNA origami-engineered nanostructures are widely used in biomedical applications involving transmembrane delivery. Here, we propose a method to enhance the transmembrane capability of DNA origami sheets by changing their configuration from two-dimensional to three-dimensional. Three DNA nanostructures are designed and constructed, including the two-dimensional rectangular DNA origami sheet, the DNA tube, and the DNA tetrahedron. The latter two are the variants of the DNA origami sheet with three-dimensional morphologies achieved through one-step folding and multi-step parallel folding separately. The design feasibility and structural stability of three DNA nanostructures are confirmed by molecular dynamics simulations. The fluorescence signals of the brain tumor models demonstrate that the tubular and the tetrahedral configurational changes could dramatically increase the penetration efficiency of the original DNA origami sheet by about three and five times, respectively. Our findings provide constructive insights for further rational designs of DNA nanostructures for transmembrane delivery.

Cucurbit[7]uril-Based Supramolecular DNA Nanogel for Targeted Codelivery of Chemo/Photodynamic Drugs.

Nanodrug delivery systems for the delivery of combination therapeutics have shown their exceptionally potential clinical application by facilitating better synergistic anticancer effects. Herein, we developed a universal strategy to fabricate supramolecular DNA nanogels from DNA tetrahedron skeleton and cucurbit[7]uril-based host-guest interaction for codelivery the chemo and photodynamic therapy drugs. The constructed supramolecular DNA nanogels showed the size tunability, host-guest competition and DNA enzyme responsibility. The cell uptake and MTT experiments demonstrated that the nanogel has excellent biocompatibility and specificity, and achieved the enrichment and slow release of drug in cells. Finally, the combined chemo/photodynamic therapy was realized by coloading doxorubicin hydrochloride and methylene blue. It was proven to be a better stragety to promote apoptosis of cancer cells compared to single chemotherapy or photodynamic therapy. These results suggest that our proposed supramolecular nanogels have provided an effective nanoplatform for drug delivery in the combinational therapy for cancer.

A dynamic DNA tetrahedron framework for active targeting.

An active targeting strategy-enabled DNA tetrahedron delivery vehicle could facilitate stable drug encapsulation and stimuli-responsive on-demand release, building a universal platform for different drug delivery requirements. Owing to the excellent biocompatible nature, programmability and remarkable cell and tissue permeability, the tetrahedral DNA nanostructure (TDN) has proven its value in the delivery of various bioactive molecules. We previously described this as a static multifunctional complex in our earlier protocol. However, static structures and passive targeting behavior might introduce off-target effects under complicated biological conditions. Therefore, in this Protocol Extension, we present a major update of the TDN delivery vehicle enabling an active targeting strategy to be used for stimuli-sensitive conformation changes and on-site cargo release, which could avoid drawbacks, including complex and time-consuming fabrication processes and undetermined cell penetration ability of other DNA-based delivery vehicles. Upon exquisite design of TDN size based on cargo type, one-pot annealing is applied to fabricate the Tiamat-designed TDN exoskeleton. Then the design of the dynamic DNA apparatus can be based on the target and environmental stimuli, including DNA strand hybridization-based and pH-sensitive DNA apparatus, and careful titration of strand lengths and mismatches is achieved using polyacrylamide and agarose gel electrophoresis, or fluorophore modifications. Finally, cargo loading strategies are designed, including site and stand titration and cargo encapsulation verification. The dynamic structures show promising targetability and effectiveness in antitumor and anti-inflammatory treatment in vitro and in vivo. Assembly and characterization in the lab takes ~5 d, and the timing for the verification of biostability and biological applications depends on the uses.

Dual-targeting inhibition of TNFR1 for alleviating rheumatoid arthritis by a novel composite nucleic acid nanodrug

Selective suppression of tumor necrosis factor (TNF) α-TNF receptor 1 (TNFR1) signaling is a potent solution for rheumatoid arthritis (RA). Herein, novel composite nucleic acid nanodrugs that simultaneously restrain TNF α binding and TNFR1 multimerization were designed to reinforce inhibition of TNF α-TNFR1 signaling for RA therapy. Towards this end, a novel peptide Pep4‐19 that suppresses TNFR1 clustering was extracted from TNFR1. The resulting peptide and a DNA aptamer Apt2‐55, which inhibits TNF α binding, were integrally or separately anchored on DNA tetrahedron (TD) to obtain nanodrugs with different spatial distribution of Apt2‐55 and Pep4‐19 (TD-3A-3P and TD-3(A-P)). Our results showed that Pep4‐19 enhanced the viability of inflammatory L929 cells. Both TD-3A-3P and TD-3(A-P) suppressed caspase 3, reduced cell apoptosis, and inhibited FLS-RA migration. Compared to TD-3(A-P), TD-3A-3P supplied sufficient flexibility for Apt2‐55 and Pep4‐19, and showed better anti-inflammation properties. Furthermore, TD-3A-3P significantly relieved symptoms in collagen-induced arthritis (CIA) mice, and the anti-RA efficacy through intravenous injection was comparable to transdermal administration via microneedles. Overall, the work provides an effective strategy for RA treatment by dual-targeting TNFR1, and demonstrates that microneedles are promising approach to drug administration in the treatment of RA.

DNA Tetrahedron-Based Valency Controlled Signal Probes for Tunable Protein Detection.

Combined detection of multiple markers related to the same disease could improve the accuracy of disease diagnosis. However, the abundance levels of multiple markers of the same disease varied widely in real samples, making it difficult for the traditional detection method to meet the requirements of a wide detection range. Herein, three kinds of cardiac biomarkers, cardiac troponin I (cTnI), myoglobin (Myo), and C-reaction protein (CRP), which were from the pM level to the μM level in real samples, were selected as model targets. Valency-controlled signal probes based on DNA tetrahedron nanostructures (DTNs) and platinum nanoparticles (PtNPs) were constructed for tunable cardiac biomarker detection. PtNPs with high horseradish peroxidase-like activity and stability served as signal molecules, and DTNs with unique spatial structure and sequence specificity were used for precisely controlling the number of connected PtNPs. By controlling the number of PtNPs connected to DTNs, monovalent, bivalent, and trivalent signal probes were obtained and were used for the detection of cardiac markers in different concentration ranges. The limit of detection of cTnI, Myo, and CRP was 3.0 pM, 0.4 nM, and 6.7 nM, respectively. Furthermore, it performed satisfactorily for the detection of cardiac markers in 10% human serum. It was anticipated that the design of valency-controlled signal probes based on DTNs and nanozymes could be extended to the construction of other multi-target detection platforms, thus providing a basis for the development of a new precision medical detection platform.

The effects of doxorubicin loaded aptamer S3-linked DNA tetrahedrons on nasopharyngeal carcinoma

ObjectiveOur research group in the early stage identified CD109 as the target of aptamer S3 in nasopharyngeal carcinoma (NPC). This study was to use S3 to connect DNA tetrahedron (DT) and load doxorubicin (Dox) onto DT to develop a targeted delivery system, and explore whether S3-DT-Dox can achieve targeted therapy for NPC.MethodsAptamer S3-conjugated DT was synthesized and loaded with Dox. The effects of S3-DT-Dox on NPC cells were investigated with laser confocal microscopy, flow cytometry, and MTS assays. A nude mouse tumor model was established from NPC 5-8F cells, and the in vivo anti-tumor activity of S3-DT-Dox was examined by using fluorescent probe labeling and hematoxylin–eosin staining.ResultsThe synthesized S3-DT had high purity and stability. S3-DT specifically recognized 5-8F cells and NPC tissues in vitro. When the ratio of S3-DT to Dox was 1:20, S3-DT had the best Dox loading efficiency. The drug release rate reached the maximum (0.402 ± 0.029) at 48 h after S3-DT-Dox was prepared and mixed with PBS. S3-DT did not affect Dox toxicity to 5-8F cells, but reduced Dox toxicity to non-target cells. Meanwhile, S3-DT-Dox was able to specifically target the transplanted tumors and inhibit their growth in nude mice, with minor damage to normal tissues.ConclusionOur study highlights the ability and safety of S3-DT-Dox to target NPC cells and inhibit the development NPC.Graphical abstract