US scientists near development of self-replicating materials

The scientists claim they have developed artificial structures that can self replicate — a process that has the potential to yield new types of materials.

‘This is the first step in the process of creating artificial self-replicating materials of an arbitrary composition,’ said Paul Chaikin, a professor within New York University’s (NYU’s) physics department and one of the study’s co-authors.

The results of the research could lead to the first steps towards a general process for the self replication of a wide variety of arbitrarily designed seeds, which are made from DNA tile motifs that serve as letters arranged to spell out a particular word.

The replication process preserves the letter sequence and the shape of the seed and hence the information required to produce further generations.

In the natural world, the DNA replication process involves complementary matches between bases — adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C) — to form its familiar double helix. By contrast, the NYU researchers developed an artificial tile or motif called BTX (bent triple-helix molecules containing three DNA double helices), with each BTX molecule composed of 10 DNA strands.

Unlike DNA, the BTX code is not limited to four letters — in principle, it can contain quadrillions of different letters and tiles that pair using the complementarity of four DNA single strands, or ‘sticky ends’, on each tile, to form a six-helix bundle.

NYU’s Prof Nadrian Seeman told The Engineer that one of the strengths of the new technology is that DNA can be decorated at any cycle of replication with almost anything on the same nano-scale (~20 nm).

Seeman, from NYU’s chemistry department and co-author of the study added that anything from metallic or semi-conducting nanoparticles, biological species (DNAzymes or ribozymes or aptamers or enzymes or antibodies), or polymer components can - in principle - be attached, mixed and matched and replicated at any cycle.

The work, conducted by researchers in NYU’s departments of chemistry and physics and its Center for Soft Matter Research, appears in the latest issue of the journal Nature.

The research was supported by grants from the WM Keck Foundation, the MRSEC Program of the National Science Foundation, the National Institute of General Medical Sciences, the US Army Research Office, NASA and the US Office of Naval Research.