Inverse Targeting    Immune Thrombocytopenic Purpura    FcRn Inhibitors  

TAT-based Targeted Drug Delivery                   Opsisomes                     Mechanisms of IVIG Action   

Opsisomes for Treatment of ITP

Opsisomes are antibody-coated liposomes that are engineered to inhibit the phagocytosis and destruction of platelets in patients with immune thrombocytopenic purpura (ITP). Our efforts in the development of opsisomes are described in the following papers: Blood 109(6):2470-6, 2007, Int J Pharm. 304(1-2):51-62, 2005. 

Proposed mechanism of action of antibody-coated liposomes in ITP. (A) Platelets and RBCs in healthy individuals. (B) Anti-platelet antibody coated platelets are destroyed by FcγR-mediated and complement-mediated phagocytosis. (C) Antibody coated RBCs compete with antibody-coated platelets for FcγR after anti-D treatment. (D) Antibody-coated liposomes compete with antibody-coated platelets for FcγRs and complement receptors (CR1)