Herein we describe the development of the Red Blood Cell coated nanoparticle, RBC-NP. Purified natural erythrocyte membrane is used to coat drug-loaded poly(lacticco- glycolic acid) (PLGA). Synthetic PLGA co-polymer is biocompatible and biodegradable and has already received US FDA approval for drug-delivery and diagnostics. This work looks specifically at the retention of immunosuppressive proteins on RBC-NPs, right-sidedness of natural RBC membranes interfacing with synthetic polymer nanoparticles, sustained and retarded drug release of RBC- NPs as well as further surface modification of RBC-NPs for increased targeting of model cancer cell lines