DNA ‘glue’ could hold 3D printed organs together

A team of biochemists has proposed using DNA scaffolds to grow human cells, creating a potentially cost-efficient way of "gluing" together 3D printedtissues and organs in the future.

The method, described in the ACS Biomaterials Science & Engineering journal, relies on creating a "smart glue" from plastic (polystyrene or polyacrylamide) nanoparticles containing 40 base pairs of DNA. These are assembled in a gel -- the nanoparticles are held together by DNA interactions, while the gel holds the entire scaffold's shape in place. The team, from the University of Texas at Austin, could then use the gel in a 3D printer to create structures about a centimetre in size. It means that the microscopic DNA strands and nanoparticles suddenly have a tangible presence -- the gel is something that can be used and manipulated at a scale visible to the human eye.

Most importantly, it was proven that the material can act as a scaffold for new cells to flourish. Therefore it could be envisioned as a scaffold for injury repair, whereby the gel helps graft on new 3D printed cells grown in the lab and implanted.

So many of the advances in 3D printing live tissue have been constrained to the small sizes possible. In 2013, for instance, a tiny functioning liver was 3D printed at just half a millimetre thick and four millimetres wide. It survived five days, thanks to an enhanced blood supply and support gel. However, being able to use a support gel that can be manipulated with ease (not at the microscopic gel) and is made from a substance that is easily controlled (depending on the DNA used, the team knows how it will behave), would provide larger, superior scaffolds for growing cells, tissue and eventually organs.

The team concludes: "The ability to control the macroscale shape, the microscale topology by DNA computation-mediated self-assembly, and the ability to choose the chemistry of the 'dumb' substrate material is a unique combination of features for tissue engineering."

Read the rest here:
DNA 'glue' could hold 3D printed organs together