Efficacy of various water-soluble chelator molecules in the liposome-mediated macrophage "suicide" technique.

In earlier studies, we described a technique for the "in vivo" depletion of macrophages, using liposome-encapsulated dichloromethylene bisphosphonate (C12MBP). The aim of the present study was to compare the effects on macrophages of various other liposome-delivered Ca2+ chelators: EDTA, DTPA, and EGTA. It appeared that both EDTA and DTPA as well as Ca(2+)-and Cu(2+)-EDTA complexes were also effective in the elimination of splenic macrophages when encapsulated in liposomes and intravenously injected. EGTA, a well-known and frequently used Ca2+ chelator, had no effect.