| AVS 64th International Symposium & Exhibition | |
| Biomaterial Interfaces Division | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterial Interfaces Poster Session with Flash presentations |
| Presenter: | Telmo Díez, University of New Mexico |
| Authors: | T. Díez, University of New Mexico P.A.H. Nguyen, University of New Mexico N. Carroll, University of New Mexico J. Satterfield, University of New Mexico G.P. Lopez, University of New Mexico |
| Correspondent: | Click to Email |
Intrinsically disordered proteins (IDPs) are dynamic biomaterials used by mammalian cells in cell signaling, transcription, and chromatin remodeling functions. In native cells, they are frequently used in packaging and un-packaging of nucleic acids (NAs), making them promising biomaterials for drug delivery and gene delivery. Elastin Like Polypeptides (ELPs) are synthetic biopolymers that have similar structural features to natural IDPs with many similar associated functions. In this research, we focus on replicating IDPs’ ability to assemble into hierarchal phase-separated granular structures and interact with nucleic acids using cationic ELPs. Importantly, ELPs condense to form coacervates above a lower critical solution temperature (LCST). Below this temperature, ELPs exist as a fully soluble random coil polymer. In this study, we use an ELP comprising 8 positive charges due the presence of 8 lysines interspersed within the chain. We demonstrate that condensed ELP coacervates provide the necessary charge density to attract and encapsulate nucleic acids. Here, ELP coacervates are incubated with fluorescently labeled DNA containing a Cy3 fluorophore on its 5’ end. We characterize the amount of DNA captured by fluorescence intensity measurements that are taken prior to and following formation of a phase-separated ELP coacervate in aqueous solution. Furthermore, we use microfluidics to form aqueous microdroplets comprising ELP and fluorescent DNA to visualize DNA capture within ELP coacervate spheres via fluorescence microscopy. ELP coacervates formed by heating the microdrops above the ELP transition temperature are shown to electrostatically complex with- and capture DNA. We characterize the thermodynamic binodal boundary (i.e. temperature-dependent phase boundary) of the ELP to resolve the ELP volume fraction within the coacervate to determine the optimal temperature to maximize DNA capture. These initial studies will inform our future work to engineer smart, programmable nanoparticles for the delivery of nucleic acids for gene therapy applications.