Acoustically shaped DNA-programmable materials

DNA-based hydrogels for bone regeneration: A promising tool for bone organoids

DNA-based hydrogels stand out for bone regeneration due to their exceptional biocompatibility and programmability. These hydrogels facilitate the formation of spatial bone structures through bulk hydrogel fabricating, microsphere formatting, and 3D printing. Furthermore, the bone microenvironment can be finely tuned by leveraging the degradation products, nanostructure, targeting, and delivery capabilities inherent to DNA-based materials. In this review, we underscore the advantages of DNA-based hydrogels, detailing their composition, gelation techniques, and structure optimization. We then delineate three critical elements in the promotion of bone regeneration using DNA-based hydrogels: (i) osteogenesis driven by phosphate ions, plasmids, and oligodeoxynucleotides (ODNs) that enhance mineralization and promote gene and protein expression; (ii) vascularization facilitated by tetrahedral DNA nanostructures (TDNs) and aptamers, which boosts gene expression and targeted release; (iii) immunomodulation achieved through loaded factors, TDNs, and bound ions that stimulate macrophage polarization and exhibit antibacterial properties. With these advantages and properties, these DNA-based hydrogels can be used to construct bone organoids, providing an innovative tool for disease modeling and therapeutic applications in bone tissue engineering. Finally, we discuss the current challenges and future prospects, emphasizing the potential impacts and applications in regenerative medicine.

Functional Nucleic Acid Nanostructures for Mitochondrial Targeting: The Basis of Customized Treatment Strategies

Mitochondria, as vital organelles, play a central role in subcellular research and biomedical innovation. Although functional nucleic acid (FNA) nanostructures have witnessed remarkable progress across numerous biological applications, strategies specifically tailored to target mitochondria for molecular imaging and therapeutic interventions remain scarce. This review delves into the latest advancements in leveraging FNA nanostructures for mitochondria-specific imaging and cancer therapy. Initially, we explore the creation of FNA-based biosensors localized to mitochondria, enabling the real-time detection and visualization of critical molecules essential for mitochondrial function. Subsequently, we examine developments in FNA nanostructures aimed at mitochondrial-targeted cancer treatments, including modular FNA nanodevices for the precise delivery of therapeutic agents and programmable FNA nanostructures for disrupting mitochondrial processes. Emphasis is placed on elucidating the chemical principles underlying the design of mitochondrial-specific FNA nanotechnology for diverse biomedical uses. Lastly, we address the unresolved challenges and outline prospective directions, with the goal of advancing the field and encouraging the creation of sophisticated FNA tools for both academic inquiry and clinical applications centered on mitochondria.

Structural transitions of ionic microgel solutions driven by circularly polarized electric fields

In this work, a theoretical approach is developed to investigate the structural properties of ionic microgels induced by a circularly polarized (CP) electric field. Following a similar study on chain formation in the presence of linearly polarized fields [T. Colla et al., ACS Nano, 2018, 12, 4321-4337], we propose an effective potential between microgels which incorporates the field-induced interactions via a static, time averaged polarizing charge at the particle surface. In such a coarse-graining framework, the induced dipole interactions are controlled by external parameters such as the field strength and frequency, ionic strength, as well as microgel charge and concentration, thus providing a convenient route to induce different self-assembly scenarios through experimentally adjustable quantities. In contrast to the case of linearly polarized fields, dipole interactions in the case of CP light are purely repulsive in the direction perpendicular to the polarization plane, while featuring an in-plane attractive well. As a result, the CP field induces layering of planar sheets arranged perpendicularly to the field direction, in strong contrast to the chain formation observed in the case of linear polarizations. Depending on the field strength and particle concentration, in-plane crystallization can also take place. Combining molecular dynamics (MD) simulations and the liquid-state hypernetted-chain (HNC) formalism, we herein investigate the emergence of layering formation and in-plane crystal ordering as the dipole strength and microgel concentration are changed over a wide region of parameter space.

Crystalline Assemblies of DNA Nanostructures and Their Functional Properties

Self-assembly presents a remarkable approach for creating intricate structures by positioning nanomaterials in precise locations, with control over molecular interactions. For example, material arrays with interplanar distances similar to the wavelength of light can generate structural color through complex interactions like scattering, diffraction, and interference. Moreover, enzymes, plasmonic nanoparticles, and luminescent materials organized in periodic lattices are envisioned to create functional materials with various applications. Focusing on structural DNA nanotechnology, here, we summarized the recent developments of two- and three-dimensional lattices made purely from DNA nanostructures. We review DNA-based monomer design for different lattices, guest molecule assembly, and inorganic material coating techniques and discuss their functional properties and potential applications in photonic crystals, nanoelectronics, and bioengineering as well as future challenges and perspectives.

Electrochemical Quantification of miRNA Based on Strain-Promoted Azide-Alkyne Cycloaddition Ligated Tetrahedral DNA Nanotags

Highly sensitive and accurate detection of disease biomarkers is of great importance for diagnosis, staging, and treatment of certain diseases. Herein, we report a novel electrochemical method for the quantification of miRNA biomarkers with DNA tetrahedrons as the signal reporters. Upon the initiation of DNA hairpin opening by miRNA at the electrode interface, the hidden click reaction group is exposed for the bioconjugation with a tetrahedral DNA nanostructure, which carries multiple electrochemical species. Strand displacement polymerization and reductant-mediated amplification are integrated for improved analytical performance. The established method achieves accurate quantitative detection of miRNA in the range from 100 aM to 10 pM. More importantly, it exhibits exceptional selectivity and stability, making it a highly convenient approach to monitor miRNA biomarkers, meeting the requirements of point-of-care testing.