Prebiotic-chemistry inspired polymer coatings for biomedical and material science applications

In the field of prebiotic chemistry, hydrogen cyanide (HCN)-derived polymers have been studied for many years as a possible source of the precursors that provide the building blocks for proteins as well as nucleic acids, and they have also been associated with the origin of life. The HCN trimer, aminomalononitrile (AMN), polymerizes to give a brown complex nitrogenous polymer. We report the one-step polymerization-deposition of AMN as a simple generic surface-coating method and as an application of prebiotic chemical research to material science. We found that this polymerization, carried out in buffered aqueous solutions, can be used to coat a wide range of organic and inorganic substrate materials. The robust, non-cytotoxic coatings also provide for excellent cell attachment, suggesting potential biomedical applications. Furthermore, the coating chemistry allows for the immobilization of other compounds, including metals, both during coating formation or by performing secondary immobilization reactions. Australian researchers have transformed molecules associated with the origin of life into biocompatible polymers for medical devices. Hydrogen cyanide is a so-called prebiotic chemical that researchers believe acted as a building block for peptide and protein generation during Earth's early history. Richard Evans from Australia's national science agency CSIRO and co-workers developed a simple procedure that spontaneously turns aminomalonitrile, a hydrogen cyanide trimer, into a sticky brown polymer using pH-buffered water. A one-step immersion process then coated a wide range of substrates — glass, plastics and metals — with a robust film having desirable device characteristics. Cell growth experiments showed successful attachment of mouse fibroblasts to the coating with no cytotoxicity. The team also immobilized metals and organic labelling compounds onto the coating using co-polymerization and post-film treatment strategies. We report a generic aqueous coating methodology that provides highly biocompatible surfaces. The method is inspired by prebiotic chemistry that involves the polymerization of hydrogen cyanide (HCN). The neutralization of the commercially available HCN trimer aminomalononitrile toluenesulfonate results in spontaneous polymerization that can be used to coat a wide variety of surfaces with a highly nitrogenous polymer. The non-cytotoxic coating provides excellent cell attachment and its chemistry allows the immobilization of other compounds including metals both during coating formation or by subsequent secondary immobilization reactions. This gives access to bioactive coatings including antimicrobial surfaces. Prebiotic chemistry has always been focussed on the understanding of the chemical origin of life and has remained highly fundamental research. To our knowledge this is the first application of prebiotic chemistry to material science.