Development of Physiologically Stable Membrane Wrapped Nanoshells for Endometriosis Targeting

• Ella Miller, Biomedical Engineering, University of North Carolina at Chapel Hill

• Emily Day, Biomedical Engineering, University of Delaware

Endometriosis is a chronic inflammatory disease, affecting 1 in every 10 women, where endometrial-like tissue grows outside the uterus, causing persistent pain. Current treatments offer pain management rather than addressing the underlying inflammation. To specifically target inflammation in endometriotic lesions, I am evaluating biomimetic nanoparticles that are wrapped with plasma membranes derived from macrophages. The inflammation-targeting of these nanoparticles is enabled by various membrane-expressed proteins. Therefore, to maximize targeting efficiency and long-term stability, the coating procedure must be refined such that a majority of the nanoparticle surface is coated by the membrane. Towards this goal, I have extracted membranes from J774A.1 macrophages and coated nanoshells (NS) at a 2:1 or 4:1 membrane-to-NS ratio using sonication and extrusion methods. The resultant 2:1 sonication, 4:1 sonication, and 4:1 extrusion macrophage-wrapped NS (Mac-NS) are analyzed to determine the optimal wrapping ratio and method. The membrane-coated NS have been characterized using dynamic light scattering (DLS), UV-Vis spectroscopy, transmission electron microscopy (TEM), and SDS-PAGE. DLS shows that membrane-coated NS are ~15 nm larger in hydrodynamic diameter than unwrapped NS and have a more neutral zeta potential. UV-Vis spectroscopy displays the extinction spectra and confirms membrane wrapping through evaluating stability in a NaCl solution. TEM images reveal a membrane shell around the NS core. SDS-PAGE confirms membrane proteins are retained during the wrapping process. While both sonication and extrusion can form membrane-coated NS, the 4:1 membrane-to-NS ratio provides more consistent coating than the 2:1 ratio. Future studies will evaluate the optimized mac-NS formulation’s ability to selectively target endometriosis-associated inflammation in vitro and in vivo.