DNA nanotechnology can be used to create intricate DNA structures due to the ability to direct the molecular assembly of nanostructures through a bottom-up approach. Here, we propose nanocarriers composed of both synthetic and natural DNA for drug delivery. The topological, optical characteristics, and interaction studies of Cu2+/Ni2+/Zn2+-curcumin-conjugated DNA complexes were studied using atomic force microscopy (AFM), UV-vis spectroscopy, Fourier transform infrared and mass spectroscopy. The maximum release of metallo-curcumin conjugates from the DNA complexes, triggered by switching the pH, was found in an acidic medium. The bacterial growth curves of E. coli and B. subtilis displayed a prolonged lag phase when tested with the metallo-curcumin-conjugated DNA complexes. We also tested the in vitro cytotoxicity of the metallo-curcumin-conjugated DNA complexes to prostate cancer cells using an MTS assay, which indicated potent growth inhibition of the cells. Finally, we studied the cellular uptake of the complexes, revealing that DNA complexes with Cu2+/Ni2+-curcumin exhibited brighter fluorescence than those with Zn2+-curcumin.

Due to its predictable self-assembly and structural stability, structural DNA nanotechnology is considered one of the main interdisciplinary subjects encompassing conventional nanotechnology and biotechnology. Here we have fabricated the mucin aptamer (MUC1)-conjugated DNA nano-ring intercalated with doxorubicin (DNR-DOX) as potential therapeutics for breast cancer. DNR-DOX exhibited significantly higher cytotoxicity to the MCF-7 breast cancer cells than the controls, including DOX alone and the aptamer deficient DNA nano-ring (DNR) with doxorubicin. Interactions between DOX and DNR were studied using spectrophotometric measurements. Dose-dependent cytotoxicity was performed to prove that both DNR and DNR were non-toxic to the cells. The drug release profile showed a controlled release of DOX at normal physiological pH 7.4, with approximately 61% released, but when exposed to lysosomal of pH 5.5, the corresponding 95% was released within 48 h. Owing to the presence of the aptamer, DNR-DOX was effectively taken up by the cancer cells, as confirmed by confocal microscopy, implying that it has potential for use in targeted drug delivery.

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Due to its unique physical and chemical characteristics, DNA, which is known only as genetic information, has been identified and utilized as a new material at an astonishing rate. The role of DNA has increased dramatically with the advent of various DNA derivatives such as DNA–RNA, DNA–metal hybrids, and PNA, which can be organized into 2D or 3D structures by exploiting their complementary recognition. Due to its intrinsic biocompatibility, self‐assembly, tunable immunogenicity, structural programmability, long stability, and electron‐rich nature, DNA has generated major interest in electronic and catalytic applications. Based on its advantages, DNA and its derivatives are utilized in several fields where the traditional methodologies are ineffective. Here, the present challenges and opportunities of DNA transformations are demonstrated, especially in biomedical applications that include diagnosis and therapy. Natural DNAs previously utilized and transformed into patterns are not found in nature due to lack of multiplexing, resulting in low sensitivity and high error frequency in multi‐targeted therapeutics. More recently, new platforms have advanced the diagnostic ability and therapeutic efficacy of DNA in biomedicine. There is confidence that DNA will play a strong role in next‐generation clinical technology and can be used in multifaceted applications.

DNA is an excellent and extraordinarily versatile building block that can be used to construct nanoscale objects and arrays of increasing complexity, and as a result, a considerable amount of progress has been made in DNA-directed molecular self-assembly. Here, we demonstrate the sequential fabrication of three-dimensional multilayered DNA nanostructures by utilizing single-strand and doublecrossover tile (DX) designs via substrate-assisted growth and multistep annealing methods. We used both layering and connector tiles to synthesize the base layer for both the single strand-based and DX tile-based designs. Layering without and with connector tiles was used to produce double-layer and multi-layer designs for single strandbased designs, but only layering tiles were used for the DX tilebased design. Connector tiles provided appropriate sticky-end sets to form the designed lattice structures. Atomic force microscopy revealed that the spacing between the tiles was in good agreement with the design scheme, but the heights of the multi-layered nanostructures were found to be slightly lower than expected due to suppression by the substrate. This kind of step-wise multi-layer assembly may produce a variety of spacings to incorporate different guest molecules or aid the attachment of various types of biomolecules and nanomaterials in parallel arrays along the layers. † Electronic supplementary information (ESI) available: Schematic diagram and DNA sequences for tiles forming single-, double-and multi-layers; height proles of multi-layer assembly; a 2% agarose gel image. See