(78i) Characterizing Synthetic Cell Penetrating Nanodiscs for Therapeutic Delivery

Nanodiscs (NDs) are disc-shaped biomimetic structures composed of lipid bilayers and amphiphilic scaffold proteins wrapped around their outer peripheries. The hydrophobic core of an ND allows for the transport of hydrophobic therapeutics, while the surface is amenable to functionalization with nucleic acids and peptides. These qualities make NDs unique drug delivery vehicles and a promising technology for the delivery of therapeutics to the cytoplasm of cells. A compelling challenge in biophysical research is the efficient delivery of therapeutics across the cellular plasma membrane. To overcome this obstacle, it is necessary to exploit cellular processes that naturally internalize molecules at the plasma membrane interface. We propose the development of NDs that contain an amphiphilic cell-penetrating peptide (CPP) capable of inducing cellular uptake via Clathrin-mediated endocytosis. Towards the development of this novel therapeutic delivery approach, we must first establish a procedure for synthesizing and characterizing cell penetrating NDs. In our procedure, we utilized a self-assembly technique that yields NDs containing phospholipids and CPP-fusion proteins derived from Apolipoprotein-AI. This procedure yields high quality cell penetrating NDs, as characterized by dynamic light scattering, fluorescence measurements, and optical microscopy. The NDs possess nanoscale dimensions, maintain a high-degree of intact protein-lipid interactions, and interact with synthetic biological membranes that mimic the plasma membrane. Future work aims at engineering these NDs to incorporate siRNA and measuring their uptake and therapeutic potential in mammalian cell lines.