All the small things:
DNA Origami, Nanotechnology and Nanomedicine

Believe it or not, out there somewhere, in a brightly lit laboratory, is a person in a lab coat, folding DNA, proteins and other biological compounds to provide innovative new medicines, tackle microengineering problems and create intriguing art. Welcome to the world of nantechnology.

The structure of DNA

Nanotechnology is the study of materials and devices smaller than 100 nanometers (10-5 or 0.000001 cm), and it is being applied to a diverse set of problems including drug delivery, nanorobotics, gene therapy, microelectronics and molecular computing. DNA nanotechnology involves the construction of self-assembling minute artificial structures from nucleic acids (the building blocks of DNA). DNA can be used to form a functional nanostructure itself, or it can be used as a scaffold to direct the assembly of other molecules (e.g. carbon, protein, peptides) into a functional structure. This is possible because of the strict base pairing rules of DNA, which means that strands will only bind together if they share complementary sequences. Base sequences can be therefore designed that will form specific structures. This is a major advantage over other materials used in nanotechnology such as proteins and nanoparticles. Dynamic DNA nanostructures can also be designed that react to certain chemical or physical stimuli, and DNA engineering is allowing scientists to design sequences that catalyse reactions, influence gene expression and modify the properties of natural DNA. Even more amazingly, DNA ‘printers’ have now been developed which can produce DNA strands with specific sequences, and bind them to a surface.

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The Magic of Medicine: Gene Therapy

In the 60 years since Watson and Crick’s landmark discovery of the structure of DNA, our understanding of how genes influence disease has increased exponentially. For some conditions, an exciting therapeutic prospect exists: gene therapy. Gene therapy attempts to repair faulty genes instead of simply treating symptoms.

For many conditions, the exact genetic mechanisms underlying them have now been elucidated. While a lot of diseases are the result of a complex interaction between multiple genes and environmental factors, others are the result of a single mutation, resulting in the failure to produce an essential functional protein. For such conditions, an exciting therapeutic prospect exists: gene therapy. In principle, the idea behind gene therapy is very simple. Whereas conventional medicine generally attempts to replace the missing gene product or repair the damage caused by its absence, gene therapy attempts to repair the faulty gene itself. Why treat symptoms when you can treat the cause?

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