Surface Geometry of Cargo-less Gold Nanoparticles Is a Driving Force for Selective Targeting of Activated Neutrophils to Reduce Thrombosis in Antiphospholipid Syndrome.

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by recurrent arterial, venous, and microvascular thrombosis where activated neutrophils play a determinant role. However, neutrophils are challenging to target given their short lifespan in circulation and spontaneous activation. Screening of a small library of gold nanoparticles (AuNPs) led to the discovery of a formulation capable of targeting activated neutrophil attachment and has demonstrated that star-shaped, anti-PSGL-1-antibody-coated AuNPs (aPSGL-1-AuNPs) were more efficacious compared with other shapes of AuNPs. Our findings further revealed an exciting and safe targeting mode toward activated neutrophils in the APS mouse model induced by human-patient-derived antiphospholipid IgGs. Our studies demonstrate that targeting is dependent on the specific topographical features of the highly segregated PSGL-1 on the activated neutrophil surface for which a high affinity shape-driven nanomedicine can be designed and implemented. As such, star-shaped aPSGL-1-AuNPs serve as a promising nanoimmunotherapy for immunothrombosis associated with neutrophil adhesion in APS.