DNA Surface Technology: From Gene Sensors to Integrated Systems for Life and Materials Sciences

Molecular self-assembly offers a ‘bottom-up’ route to fabrication with subnanometre precision of complex structures from simple components1. DNA has proven a versatile building block2–5 for programmable construction of such objects, including two-dimensional crystals6, nanotubes7–11, and three-dimensional wireframe nanopolyhedra12–17. Templated self-assembly of DNA18 into custom two-dimensional shapes on the megadalton scale has been demonstrated previously with a multiple-kilobase ‘scaffold strand’ that is folded into a flat array of antiparallel helices by interactions with hundreds of oligonucleotide ‘staple strands’19, 20. Here we extend this method to building custom three-dimensional shapes formed as pleated layers of helices constrained to a honeycomb lattice. We demonstrate the design and assembly of nanostructures approximating six shapes — monolith, square nut, railed bridge, genie bottle, stacked cross, slotted cross — with precisely controlled dimensions ranging from 10 to 100 nm. We also show hierarchical assembly of structures such as homomultimeric linear tracks and of heterotrimeric wireframe icosahedra. Proper assembly requires week-long folding times and calibrated monovalent and divalent cation concentrations. We anticipate that our strategy for self-assembling custom three-dimensional shapes will provide a general route to the manufacture of sophisticated devices bearing features on the nanometer scale. Show more

Nucleic acid aptamers offer several advantages over traditional antibodies, but their clinical translation has been delayed by several factors, including insufficient potency, lack of safety data and high production costs. Here, Zhou and Rossi provide an overview of aptamer generation, focusing on recent technological advances and clinical development, as well as challenges and lessons learned. Show more

Gold colloids have fascinated scientists for over a century and are now heavily utilized in chemistry, biology, engineering, and medicine. Today these materials can be synthesized reproducibly, modified with seemingly limitless chemical functional groups, and, in certain cases, characterized with atomic-level precision. This Review highlights recent advances in the synthesis, bioconjugation, and cellular uses of gold nanoconjugates. There are now many examples of highly sensitive and selective assays based upon gold nanoconjugates. In recent years, focus has turned to therapeutic possibilities for such materials. Structures which behave as gene-regulating agents, drug carriers, imaging agents, and photoresponsive therapeutics have been developed and studied in the context of cells and many debilitating diseases. These structures are not simply chosen as alternatives to molecule-based systems, but rather for their new physical and chemical properties, which confer substantive advantages in cellular and medical applications. Show more