Periodically Ordered, Nuclease-Resistant DNA Nanowires Decorated with Cell-Specific Aptamers as Selective Theranostic Agents

Functional Aptamer-Embedded Nanomaterials for Diagnostics and Therapeutics

In the past decades, various nanomaterials with unique properties have been explored for bioapplications. Meanwhile, aptamers, generated from the systematic evolution of ligands by exponential enrichment technology, are becoming an indispensable element in the design of functional nanomaterials because of their small size, high stability, and convenient modification, especially endowing nanomaterials with recognition capability to specific targets. Therefore, the incorporation of aptamers into nanomaterials offers an unprecedented opportunity in the research fields of diagnostics and therapeutics. Here, we focus on recent advances in aptamer-embedded nanomaterials for bioapplications. First, we briefly introduce the properties of nanomaterials that can be functionalized with aptamers. Then, the applications of aptamer-embedded nanomaterials in cellular analysis, imaging, targeted drug delivery, gene editing, and cancer diagnosis/therapy are discussed. Finally, we provide some perspectives on the challenges and opportunities that have arisen from this promising area.

Hierarchical Fabrication of DNA Wireframe Nanoarchitectures for Efficient Cancer Imaging and Targeted Therapy

Though small-molecule drugs play a crucial role in cancer treatment, intrinsic issues such as poor solubility and systematic toxicity have considerably mitigated their anticancer functions and caused unwanted side effects. To achieve satisfying therapeutic efficiency, it is essential to develop innovative targeting systems for precise and efficient delivery of anticancer drugs. In this work, a hierarchical self-assembly strategy was applied to fabricate a core-shell nanoarchitecture composed of a DNA octahedral wireframe and chemodrug-functionalized Sgc8c aptamer. The integrated enhanced permeability and retention effect of the DNA nanostructure and active targeting ability of the Sgc8c aptamer allowed the highly selective chemodrug delivery and in vivo efficient imaging and treatment. The advantage of our multifunctional nanostructure was further highlighted by its impressive serum stability, excellent accumulation ability, deep penetration capability, significantly improved therapeutic efficacy, and favorable biosafety. This study showed promising potential of such a core-shell DNA nanoarchitecture in precise drug loading control, drug delivery, and personal medicine.

Cascade Circuits on Self-Assembled DNA Polymers for Targeted RNA Imaging In Vivo

DNA molecular probes have emerged as a powerful tool for RNA imaging. Hurdles in cell-specific delivery and other issues such as insufficient stability, limited sensitivity, or slow reaction kinetics, however, hinder the further application of DNA molecular probes in vivo. Herein, we report an aptamer-tethered DNA polymer for cell-specific transportation and amplified imaging of RNA in vivo via a DNA cascade reaction. DNA polymers are constructed through an initiator-triggered hybridization chain reaction using two functional DNA monomers. The prepared DNA polymers show low cytotoxicity and good stability against nuclease degradation and enable cell-specific transportation of DNA circuits via aptamer-receptor binding. Moreover, assembling the reactants of hairpins C1 and C2 on the DNA polymers accelerates the response kinetics and improves the sensitivity of the cascade reaction. We also show that the DNA polymers enable efficient imaging of microRNA-21 in live cells and in vivo via intravenous injection. The DNA polymers provide a valuable platform for targeted and amplified RNA imaging in vivo, which holds great implications for early clinical diagnosis and therapy.