UC San Diego

In the field of DNA Nanotechnology, a field that utilizes synthetically designed DNA strands and their inherent complimentary nature to create two and three dimensional structures, there are many approaches to creating structures to act as vehicles for drug delivery and platforms for diagnostics. However, this field holds an expense due to the number of oligonucleotide strands that are required in order to form the structures. These structures are also limited by the amount of therapeutic load they can carry, the density of targeting modalities that can be attached to the surface, and the variability of other proteins or small molecules that we may wish to include. Our approach to this problem was to utilize a natural, bacterial DNA amplification process known as Rolling Circle Amplification, or RCA. With RCA, we can amplify a sequence into a long stranded DNA sequence carrying the complementary sequence repeating multiple times sequentially on one strand. Using these repetitive sequences, we can create structures by binding them to themselves in certain manners. Any unbound sequences can be used to bind to, and capture, many different modalities and carry a large variety of materials or therapeutics to a designated target. They can also be of great use in capturing large quantities of an analyte in detection motifs and modalities. My RCA structures are capable of binding large quantities of materials, thusly delivering them to targeted cell populations through the use of binding many ligands on the surface. These structures are also capable of undergoing morphological changes in order to facilitate delivery or act as a diagnostic modality in the presence of the target analyte or environment. Thusly, these structures, created by amplifying a single DNA strand, as opposed to utilizing many, have a great advantage over current DNA Nanotechnology techniques for creating delivery and diagnostic vehicles due to their great flexibility in binding capabilities and the decreased cost for synthesis.