Synthesis and in vitro activity of new biguanide-containing dendrimers on pathogenic isolates of Acanthamoeba polyphaga and Acanthamoeba griffini.

The genus Acanthamoeba can cause Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). The treatment of these illnesses is hampered by the existence of a resistance stage that many times causes infection relapses. In an attempt to add new agents to our chemotherapeutic arsenal against acanthamebiasis, two Acanthamoeba isolates were treated in vitro with newly synthesized biguanide dendrimers. Trophozoite viability analysis and ultrastructural studies showed that dendrimers prevent encystment by lysing the cellular membrane of the amoeba. Moreover, one of the dendrimers showed low toxicity when tested on mammalian cell cultures, which suggest that it might be eventually used as an amoebicidal drug or as a disinfection compound in contact lens solutions.