Actively targeted low-dose camptothecin as a safe, long-acting, disease-modifying nanomedicine for rheumatoid arthritis.

Purpose Camptothecin (CPT), a potent topoisomerase I inhibitor, was originally discovered as an anticancer agent to induce programmed cell death of cancer cells. Recent evidence suggests that, similar to cancer, alterations in apoptosis and over-proliferation of key effector cells in the arthritic joint result in rheumatoid arthritis (RA) pathogenesis. Initial in vitro studies have suggested that camptothecin inhibits synoviocyte proliferation, matrix metalloproteinases expression in chrondrocytes and angiogenesis. This study is one of the first to test, in vivo, RA as a new indication for CPT.