(616f) Engineering Antiphagocytic Drug Carriers Using CD47-Streptavidin Fusion Protein

Despite the remarkable advances and successes in the efficacy of the synthetic carriers such as polymer and lipid particles, they often struggle to meet clinical expectations such as fast clearance from blood circulation. Natural particulates, which range from pathogens to mammalian cells, are therefore worth examining in more depth, as they are highly optimized for their specific functions in vivo and possess features that are often desired in drug delivery carriers. To extend the blood circulation time of drug delivery carriers, many strategies have been used in particle surface modifications to avoid clearance by mononuclear phagocyte system. Here we report a biomimetic approach of functionalizing synthetic particulates with CD47 self-marker proteins to endow drug delivery carriers with phagocytosis-resistant features. CD47-streptavidin fusion protein was constructed and attached to the biotinylated particles. Our results revealed that CD47 could reduce macrophage-mediated clearance of particles via its interaction with signal regulatory protein alpha on macrophages.