Application Progress of DNA Nanostructures in Drug Delivery and Smart Drug Carriers

CRISPR/Cas systems combined with DNA nanostructures for biomedical applications

DNA nanostructures are easy to design and construct, have good biocompatibility, and show great potential in biosensing and drug delivery. Numerous distinctive and versatile DNA nanostructures have been developed and explored for biomedical applications. In addition to DNA nanostructures that are completely assembled from DNA, composite DNA nanostructures obtained by combining DNA with other organic or inorganic materials are also widely used in related research. The CRISPR/Cas system has attracted great attention as a powerful gene editing technology and is also widely used in biomedical diagnosis. Many researchers are committed to exploring new possibilities by combining DNA nanostructures with CRISPR/Cas systems. These explorations provide support for the development of new detection methods and cargo delivery pathways, provide inspiration for improving relevant gene editing platforms, and further expand the application scope of DNA nanostructures and CRISPR/Cas systems. This paper mainly reviews the design principles and biomedical applications of CRISPR/Cas combined with DNA nanostructures based on the types of DNA nanostructures. Finally, the application status, challenges and development prospects of CRISPR/Cas combined with DNA nanostructures in detection and delivery are summarized. It is expected that this review will enable researchers to better understand the current state of the field and provide insights into the application of CRISPR/Cas systems and the development of DNA nanostructures.

Dynamic DNA nanostructures in biomedicine: Beauty, utility and limits

DNA composite materials are at the forefront, especially for biomedical science, as they can increase the efficacy and safety of current therapies and drug delivery systems. The specificity and predictability of the Watson-Crick base pairing make DNA an excellent building material for the production of programmable and multifunctional objects. In addition, the principle of nucleic acid hybridization can be applied to realize mobile nanostructures, such as those reflected in DNA walkers that sort and collect cargo on DNA tracks, DNA robots performing tasks within living cells and/or DNA tweezers as ultra-sensitive biosensors. In this review, we present the diversity of dynamic DNA nanostructures functionalized with different biomolecules/functional units, imaging smart biomaterials capable of sensing, interacting, delivery and performing complex tasks within living cells/organisms.

Biomimetic DNA Nanotubes: Nanoscale Channel Design and Applications

Biomacromolecular nanotubes play important physiological roles in transmembrane ion/molecule channeling, intracellular transport, and inter-cellular communications. While genetically encoded protein nanotubes are prevalent in vivo, the in vitro construction of biomimetic DNA nanotubes has attracted intense interest with the rise of structural DNA nanotechnology. The abiotic use of DNA assembly provides a powerful bottom-up approach for the rational construction of complex materials with arbitrary size and shape at the nanoscale. More specifically, a typical DNA nanotube can be assembled either with parallel-aligned DNA duplexes or by closing DNA tile lattices. These artificial DNA nanotubes can be tailored and site-specifically modified to realize biomimetic functions including ionic or molecular channeling, bioreactors, drug delivery, and biomolecular sensing. In this Minireview, we aim to summarize recent advances in design strategies, including the characterization and applications of biomimetic DNA nanotubes.

A pH-controlled bidirectionally pure DNA hydrogel: reversible self-assembly and fluorescence monitoring

A concept for a pure DNA hydrogel has been demonstrated in which triplex structures act as the core components and are assisted by single strands and artfully designed Y-shaped structures. Typically, the triplex structure which is based on protonated cytosine-guanine-cytosine (C-G·C+) is formed at pH 5.0 and disassembles at pH 7.0, whereas the thymine-adenine-thymine (T-A·T)-based triplex structure is formed at pH 7.0 and disassembles at pH 10.0. Therefore, such triplex DNA structure-based pure DNA hydrogels provide pH-controlled reversible self-assembly of DNA structures with a transition between gel and liquid states. More significantly, the introduction of both a fluorophore (FAM) and a quencher (BHQ1) to the hydrogels provides an innovative method for monitoring the self-assembly and disassembly processes through a fluorescence technology.

Magnesium-Stabilized Multifunctional DNA Nanoparticles for Tumor-Targeted and pH-Responsive Drug Delivery

Functional nucleic acids, which can target cancer cells and realize stimuli-responsive drug delivery in tumor microenvironment, have been widely applied for anticancer chemotherapy. At present, high cost, unsatisfactory biostability, and complicated fabrication process are the main limits for the development of DNA-based drug-delivery nanocarriers. Here, a doxorubicin (Dox)-delivery nanoparticle for tumor-targeting chemotherapy is developed taking advantage of rolling circle amplification (RCA) technique, by which a high quantity of functional DNAs can be efficiently collected. Furthermore, Mg²⁺, a major electrolyte in human body showing superior biocompatibility, can sufficiently condense the very long sequence of an RCA product and better preserve its functions. The resultant DNA nanoparticle exhibits a high biostability, making it a safe and ideal nanomaterial for in vivo application. Through cellular and in vivo experiments, we thoroughly demonstrate that this kind of Mg²⁺-stabilized multifunctional DNA nanoparticles can successfully realize tumor-targeted Dox delivery. Overall, exploiting RCA technique and Mg²⁺ condensation, this new strategy can fabricate nanoparticles with a nontoxic composition through a simple fabrication process and provides a good way to preserve and promote DNA functions, which will show a broad application potential in the biomedical field.