Beyond Amber: T-REX Preserves DNA for the Future, Minus the Dinosaurs

The sharp decrease in the cost of DNA sequencing has driven up the demand for nucleic acid extraction in order to unravel genomic information, discover cures for genetic illnesses, and track new biological threats. Current ways to storing large nucleic acid collections rely on continuous energy to maintain low temperatures and intricate cold chain procedures. Inspired by the millennia-long preservation of fossilized biological specimens in calcified minerals or glassy amber, Thermoset-REinforced Xeropreservation (T-REX), is a method for preserving DNA in deconstructable glassy polymer networks. The invention of polyplexes for nucleic acid encapsulation is critical to T-REX, as it streamlines the transfer of DNA from aqueous to organic phases. These polyplexes contain initiators, monomers, cross-linkers, and thionolactone-based cleavable comonomers that are necessary to build the polymer networks.

The degradable thermoset is a polymer that solidifies when heated. The cleavable linkages are easily broken, allowing the polymer to breakdown in a controlled manner. There is a choice in how to degrade them.The researchers chose to synthesize their thermoset polymer using styrene and a cross-linker, resulting in an amber-like thermoset known as cross-linked polystyrene.This thermoset is also incredibly hydrophobic, which prevents moisture from entering and destroying the DNA.To make the thermoset biodegradable, styrene monomers and cross-linkers are copolymerized with thionolactones. These linkages can be disrupted by treating them with a chemical known as cysteamine.Because styrene is so hydrophobic, the researchers had to devise a technique to attract DNA, a hydrophilic, negatively charged molecule, into it. To accomplish this, they identified a mixture of three monomers that might be converted into polymers that disintegrate DNA by facilitating its interaction with styrene. Each monomer has unique properties that work together to transport DNA from water to styrene. There, charged DNA forms spherical complexes, with hydrophobic groups forming an exterior layer that interacts with styrene. When heated, this solution solidifies into a glass-like block containing DNA complexes. To release the DNA, the researchers add cysteamine, which cleaves the bonds that hold the polystyrene thermoset together and breaks it down into smaller bits. Then, a detergent known as SDS (sodium dodecyl sulfate) can be used to extract the DNA from polystyrene without harming it.

This technique successfully encapsulates DNA of varying lengths, from tens of bases to gigabases, in hours rather than days as with standard silica-based encapsulation. Furthermore, T-REX allows for DNA extraction with relatively safe reagents, as opposed to the dangerous hydrofluoric acid necessary for silica recovery. T-REX offers a low-cost, time-efficient, and long-term nucleic acid preservation solution for synthetic biology, genomics, and digital information storage, potentially addressing typical low-temperature storage problems.

REFERENCE:

Prince E, Cheng HF, Banal JL, Johnson JA. Reversible Nucleic Acid Storage in Deconstructable Glassy Polymer Networks. Journal of the American Chemical Society. 2024 Jun 12.

IMAGE SOURCE:

Cover Image: https://encryptedtbn0.gstatic.com/imagesq=tbn:ANd9GcSarMZEGtZRpW9r9UUn9PijHwo1Y5WQVmwFQQ&s

Journal of the American Chemical Society: https://pubs.acs.org/cms/10.1021/jacs.4c01925/asset/images/medium/ja4c01925_0006.gif