Liposome-mediated therapy of human immunodeficiency virus type-1 and mycobacterium infections

Abstract

We review our recent work on the use of liposomes for the delivery of antiviral agents to human immunodeficiency virus type-1 (HIV-1) infected cells, and antimycobactcrial drugs to cells harboring Mycobacterium avium complex or Mycobacterium tuberculosis. Soluble CD4 has been used to target liposomes to HIV-1-infected cells. Antisense oligodeoxynucleotides have been effectively delivered into HIV-1-infected macrophages using pH-sensitive liposomes. pH-sensitive liposomes with serum stability are being developed as in vivo delivery vehicles. Liposomes encapsulating an HIV-1 protease inhibitor were more effective in inhibiting virus production in infected macrophages than the free drug. Anionic liposomes were found to inhibit HIV-1 infectivity, while cationic liposomes had a differential toxicity for HIV-1-infected macrophages. Lipophilic sulfated cyclodextrins have been synthesized as novel antiviral agents. Liposome-encapsulated ciprofloxacin treatment reduced the number of viable M. avium in macrophages more than the free antibiotic. Liposome-encapsulated paromomycin and sparfloxacin were effective against M. tuberculosis inside macrophages, including multi-drug-resistant strains. Streptomycin encapsulated in liposomes and delivered intravenously or subcutaneously reduced the number of viable M. tuberculosis in infected mice and prevented mortality.