(596g) Diminution of Macrophage Attachment on CD47-Functionalized and Polydopamine-Coated Surface

CD47 is a ubiquitously expressed protein known as â??marker of selfâ?. Recently, CD47 functionalized surface has shown the ability to reduce inflammatory response and platelet adhesion. Polydopamine is an ultrathin but robust film formed by pH-induced polymerization. Polydopamine has been used as a universal surface modification agent capable of further surface functionalization. The purpose of this study is to use polydopamine as a platform to immobilize CD47 onto substratum in order to prevent macrophage attachment. The surface of 6-well cell culture plates was modified with biotin molecules through polydopamine coating. CD47-streptavidin fusion protein was then immobilized onto the biotin-functionalized surface through the high affinity between biotin and streptavidin. The effect of CD47-SIRPα interaction on cell attachment was studied by inoculating J774A.1 macrophages and human mesenchymal stem cells (hMSCs) on CD47 immobilized cell culture plates. Macrophage cells have high amount of SIRPα expressed on the cell surface, while hMSCs do not have any SIRPα. CD47 modified surface deferred macrophage attachment for up to 8 hours. However, hMSCs attached to CD47 immobilized surface within 2 hours. Our results demonstrate that CD47-functionalized surface can prevent macrophage attachment due to CD47-SIRPα interaction.