Nebulized Inhalation of Peptide-Modified DNA Origami To Alleviate Acute Lung Injury.

Acute lung injury (ALI) is a severe inflammatory lung disease, with high mortality rates. Early intervention by reactive oxygen species (ROS) scavengers could reduce ROS accumulation, break the inflammation expansion chain in alveolar macrophages (AMs), and avoid irreversible damage to alveolar epithelial and endothelial cells. Here, we reported cell-penetrating R9 peptide-modified triangular DNA origami nanostructures (tDONs-R9) as a novel nebulizable drug that could reach the deep alveolar regions and exhibit an enhanced uptake preference of macrophages. tDONs-R9 suppressed the expression of pro-inflammatory cytokines and drove polarization toward the anti-inflammatory M2 phenotype in macrophages. In the LPS-induced ALI mouse model, treatment with nebulized tDONs-R9 alleviated the overwhelming ROS, pro-inflammatory cytokines, and neutrophil infiltration in the lungs. Our study demonstrates that tDONs-R9 has the potential for ALI treatment, and the programmable DNA origami nanostructures provide a new drug delivery platform for pulmonary disease treatment with high delivery efficiency and biosecurity.

Self-Assembled DNA Composite-Engineered Mesenchymal Stem Cells for Improved Skin-Wound Repair.

The direct use of mesenchymal stem cells (MSCs) as therapeutics for skin injuries is a promising approach, yet it still faces several obstacles, including limited adhesion, retention, and engraftment of stem cells in the wound area, as well as impaired regenerative and healing functions. Here, DNA-based self-assembled composites are reported that can aid the adhesion of MSCs in skin wounds, enhance MSC viability, and accelerate wound closure and re-epithelialization. Rolling-circle amplification (RCA)-derived DNA flowers, equipped with multiple copies of cyclic Arg-Gly-Asp (cRGD) peptides and anti-von Willebrand factor (vWF) aptamers, act as robust scavengers of reactive oxygen species (ROS) and enable synergistic recognition and adhesion to stem cells and damaged vascular endothelial cells. These DNA structure-aided stem cells are retained at localized wound sites, maintain repair function, and promote angiogenesis and growth factor secretion. In both normal and diabetes-prone db/db mice models with excisional skin injuries, facile topical administration of DNA flower-MSCs elicits rapid blood vessel formation and enhances the sealing of the wound edges in a single dose. DNA composite-engineered stem cells warrant further exploration as a new strategy for the treatment of skin and tissue damage.

Genetically Encoded DNA Origami for Gene Therapy In Vivo.

DNA origami has played an important role in various biomedical applications, including biosensing, bioimaging, and drug delivery. However, the function of the long DNA scaffold involved in DNA origami has yet to be fully exploited. Herein, we report a general strategy for the construction of a genetically encoded DNA origami by employing two complementary DNA strands of a functional gene as the DNA scaffold for gene therapy. In our design, the complementary sense and antisense strands can be directly folded into two DNA origami monomers by their corresponding staple strands. After hybridization, the assembled genetically encoded DNA origami with precisely organized lipids on the surface can function as the template for lipid growth. The lipid-coated and genetically encoded DNA origami can efficiently penetrate the cell membrane for successful gene expression. After decoration with the tumor-targeting group, the antitumor gene (p53) encoded DNA origami can elicit a pronounced upregulation of the p53 protein in tumor cells to achieve efficient tumor therapy. The targeting group-modified, lipid-coated, and genetically encoded DNA origami has mimicked the functions of cell surface ligands, cell membrane, and nucleus for communication, protection, and gene expression, respectively. This rationally developed combination of folding and coating strategies for genetically encoded DNA origami presents a new avenue for the development of gene therapy.

DNA Nanomaterials-Based Platforms for Cancer Immunotherapy.

The past few decades have witnessed the evolving paradigm for cancer therapy from nonspecific cytotoxic agents to selective, mechanism-based therapeutics, especially immunotherapy. In particular, the integration of nanomaterials with immunotherapy is proven to improve the therapeutic outcome and minimize off-target toxicity in the treatment. As a novel nanomaterial, DNA-based self-assemblies featuring uniform geometries, feasible modifications, programmability, surface addressability, versatility, and intrinsic biocompatibility, are extensively exploited for innovative and effective cancer immunotherapy. In this review, the successful employment of DNA nanoplatforms for cancer immunotherapy, including the delivery of immunogenic cell death inducers, adjuvants and vaccines, immune checkpoint blockers as well as the application in immune cell engineering and adoptive cell therapy is summarized. The remaining challenges and future perspectives regarding the pharmacokinetics/pharmacodynamics, in vivo fate and immunogenicity of DNA materials, and the design of intelligent DNA nanomedicine for individualized cancer immunotherapy are also discussed.

A DNA-Based Plasmonic Nanodevice for Cascade Signal Amplification.

Here, we describe a DNA circuit-aided, origami nanodevice-based plasmonic system, which performs DNA-regulated, cascade amplification of faint chemical/biological signals. In this system, two gold-nanorods (GNRs) are co-assembled onto a DNA lock-containing, tweezer-like DNA origami template. Logic circuits serve as recognition and amplification elements for specific messengers, producing DNA keys for driving conformational changes of the plasmonic nanodevices. In the presence of input signals including nucleic acids, adenosines, chiral tyrosinamides or specific receptors expressed by tumor cells, the plasmonic nanodevices can be activated to perform dynamic structural motions, reporting robust responses via plasmonic circular dichroism (CD) spectral changes. This DNA nanodevice-based system provides a different design to enrich the strategies for constructing synthetic nanomachines, enabling the customized bottom-up nanostructure construction for sensitive biological signaling.

Stimuli-Responsive DNA Origami Nanodevices and Their Biological Applications.

DNA origami nanotechnology has provided predictable static nanoarchitectures and dynamic nanodevices with rationally designed geometries, precise spatial addressability, and marked biocompatibility. Multiple functional elements, such as peptides, aptamers, nanoparticles, fluorescence probes, and proteins, etc. can be easily integrated into DNA origami templates with nanoscale precision, leading to a variety of promising applications. Triggered by chemical/physical stimuli, dynamic DNA origami nanodevices can switch between defined conformations or translocate autonomously, providing powerful tools for intelligent biosensing and drug delivery. In this minireview, we summarize the recent progress of dynamic DNA origami nanodevices with desired reconfigurability and feasibility to perform multiple biological tasks. We introduce varieties of DNA nanodevices that can be controlled by different molecular triggers and external stimuli. Subsequently, we highlight the recent advances in employing DNA nanodevices as biosensors and drug delivery vehicles. At last, future possibilities and perspectives are also discussed.

An RNA/DNA hybrid origami-based nanoplatform for efficient gene therapy.

Nucleic acid nanostructures are promising biomaterials for the delivery of homologous gene therapy drugs. Herein, we report a facile strategy for the construction of target mRNA (scaffold) and antisense (staple strands) co-assembled RNA/DNA hybrid "origami" for efficient gene therapy. In our design, the mRNA was folded into a chemically well-defined nanostructure through RNA-DNA hybridization with high yield. After the incorporation of an active cell-targeting aptamer, the tailored RNA/DNA hybrid origami demonstrated efficient cellular uptake and controllable release of antisenses in response to intracellular RNase H digestion. The biocompatible RNA/DNA origami (RDO) elicited a noticeable inhibition of cell proliferation based on the silencing of the tumor-associated gene polo-like kinase 1 (PLK1). This RDO-based nanoplatform provides a novel strategy for the further development of gene therapy.

A DNA nanodevice-based vaccine for cancer immunotherapy.

A major challenge in cancer vaccine therapy is the efficient delivery of antigens and adjuvants to stimulate a controlled yet robust tumour-specific T-cell response. Here, we describe a structurally well defined DNA nanodevice vaccine generated by precisely assembling two types of molecular adjuvants and an antigen peptide within the inner cavity of a tubular DNA nanostructure that can be activated in the subcellular environment to trigger T-cell activation and cancer cytotoxicity. The integration of low pH-responsive DNA 'locking strands' outside the nanostructures enables the opening of the vaccine in lysosomes in antigen-presenting cells, exposing adjuvants and antigens to activate a strong immune response. The DNA nanodevice vaccine elicited a potent antigen-specific T-cell response, with subsequent tumour regression in mouse cancer models. Nanodevice vaccination generated long-term T-cell responses that potently protected the mice against tumour rechallenge.

A Tubular DNA Nanodevice as a siRNA/Chemo-Drug Co-delivery Vehicle for Combined Cancer Therapy.

Using the DNA origami technique, we constructed a DNA nanodevice functionalized with small interfering RNA (siRNA) within its inner cavity and the chemotherapeutic drug doxorubicin (DOX), intercalated in the DNA duplexes. The incorporation of disulfide bonds allows the triggered mechanical opening and release of siRNA in response to intracellular glutathione (GSH) in tumors to knockdown genes key to cancer progression. Combining RNA interference and chemotherapy, the nanodevice induced potent cytotoxicity and tumor growth inhibition, without observable systematic toxicity. Given its autonomous behavior, exceptional designability, potent antitumor activity and marked biocompatibility, this DNA nanodevice represents a promising strategy for precise drug design for cancer therapy.

Cofactor-free oxidase-mimetic nanomaterials from self-assembled histidine-rich peptides.

Natural oxidases mainly rely on cofactors and well-arranged amino acid residues for catalysing electron-transfer reactions but suffer from non-recovery of their activity upon externally induced protein unfolding. However, it remains unknown whether residues at the active site can catalyse similar reactions in the absence of the cofactor. Here, we describe a series of self-assembling, histidine-rich peptides, as short as a dipeptide, with catalytic function similar to that of haem-dependent peroxidases. The histidine residues of the peptide chains form periodic arrays that are able to catalyse H2O2 reduction reactions efficiently through the formation of reactive ternary complex intermediates. The supramolecular catalyst exhibiting the highest activity could be switched between inactive and active states without loss of activity for ten cycles of heating/cooling or acidification/neutralization treatments, demonstrating the reversible assembly/disassembly of the active residues. These findings may aid the design of advanced biomimetic catalytic materials and provide a model for primitive cofactor-free enzymes.

Enzyme Mimic Nanomaterials and Their Biomedical Applications.

Nanomaterials with enzyme-mimicking behavior (nanozymes) have attracted a lot of research interest recently. In comparison to natural enzymes, nanozymes hold many advantages, such as good stability, ease of production and surface functionalization. As the catalytic mechanism of nanozymes is gradually revealed, the application fields of nanozymes are also broadly explored. Beyond traditional colorimetric detection assays, nanozymes have been found to hold great potential in a variety of biomedical fields, such as tumor theranostics, antibacterial, antioxidation and bioorthogonal reactions. In this review, we summarize nanozymes consisting of different nanomaterials. In addition, we focus on the catalytic performance of nanozymes in biomedical applications. The prospects and challenges in the practical use of nanozymes are discussed at the end of this Minireview.

Efficient Intracellular Delivery of RNase A Using DNA Origami Carriers.

Delivery of proteins to carry out desired biological functions is a direct approach for disease treatment. However, protein therapy is still facing challenges due to low delivery efficiency, poor targeting during trafficking, insufficient therapeutic efficacy, and possible toxicity induced by carriers. Here, we present a novel delivery platform based on DNA origami nanostructure that enables tumor cell transportation of active proteins for cancer therapy. In our design, cytotoxic protein ribonuclease (RNase) A molecules are organized on the rectangular DNA origami nanosheets, which work as nanovehicles to deliver RNase A molecules into the cytoplasm and execute their cell-killing function inside the tumor cells. Cancer cell-targeting aptamers are also integrated onto the DNA origami-based nanoplatform to enhance its targeting effect. This DNA origami-protein coassembling strategy can be further developed to transport other functional proteins and therapeutic components simultaneously for synergistic effects and be adapted for integrated diagnostics and therapeutics.