STTR Phase I: Purification of Mycosporine-like Amino Acids using Aptamers

The broader impact of this STTR Phase I project is to harvest a natural sunscreen for broader distribution. This project will use a group of fast-growing microorganisms that make these ingredients. The challenge will be to harvest enough of the material to make effective and affordable sunscreens. The problem is akin to trying to collect all the "needles in a haystack". New tools that incorporate reusable analogues to "magnets" for capturing and releasing the sunscreen compound will provide a novel way to get the material out of a complex mixture of broken open cells and into the sunscreens. There is a lack of genuinely non-toxic, environmentally safe sunscreens in the U.S. market today. Melanoma, the most common cancer in the U.S., is a deadly form of skin cancer directly attributable to sun damage to skin, and conventional sunscreens are under pressure because of human health concerns and possible impacts on coral reefs. This work will provide a new class of sunscreens safer for people and marine life. Unlocking the potential of this nature-designed sunscreen will improve human health and the environment. This STTR Phase I project will evaluate the technical feasibility of using aptamers (small nucleic acids) to isolate mycosporine-like amino acids (MAAs) from a complex mixture of compounds derived from cyanobacteria. Small molecules present challenges for aptamer development because they can be: difficult to immobilize, have multiple three-dimensional conformations, and few chemically distinguishing features. MAAs present unique challenges due to the similarity of their chemical structure with other cell lysate materials and wide variety of amino acid substitutions. This innovation entails the isolation and identification of the specific MAAs being produced, isolation of aptamers that are highly specific, and assessing process scalability. MAAs are not commercially available so reference standards will be derived from the culture broth. These materials will be utilized as targets in aptamer selection using a proprietary single-stranded DNA library of aptamer sequences to identify suitable candidates by next-generation sequencing and bioinformatics analysis. Those aptamer candidates will then be screened and evaluated using an affinity purification workflow and absorbance-based microplate assay. The end result of this work will be to establish if this is a robust and scalable affinity purification method for MAAs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.