Oregon Health & Science University

Michael Stowell

Milton Yatvin

Michael J Meredith

Vincent S Gallicchio

This invention provides novel methods and reagents for specifically delivering biologically active compounds to phagocytic mammalian cells. The invention also relates to specific uptake of such biologically active compounds by phagocytic cells and delivery of such compounds to specific sites intracellularly. The invention specifically relates to methods of facilitating the entry of antiviral and antimicrobial drugs and other agents into phagocytic cells and for targeting such compounds to specific organelles within the cell. The invention specifically provides compositions of matter and pharmaceutical embodiments of such compositions comprising conjugates of such antimicrobial drugs and agents covalently linked to particulate carriers generally termed microparticles. In particular embodiments, the antimicrobial drug is covalently linked to a microparticle via a cleavable linker moiety that is non-specifically cleaved in a phagocytic cell. In additional embodiments, the biologically-active compound is provided in an inactive, prodrug form that is activated by a chemical or enzymatic activity specific for cells infected by a microorganism, particularly a pathological or disease-causing microorganism. Thus, the invention provides cell targeting of drugs wherein the targeted drug is only activated in cells infected with a particular microorganism. Alternative embodiments of such specific drug delivery compositions also contain polar lipid carrier molecules effective in achieving intracellular organelle targeting in infected phagocytic mammalian cells. Particular embodiments of such conjugates comprise antimicrobial drugs covalently linked both to a microparticle via a cleavable linker molecule and to a polar lipid compound, to facilitate targeting of such drugs to particular subcellular organelles within the cell. Also provided are porous microparticles impregnated with antiviral and antimicrobial drugs and agents wherein the surface or outside extent of the microparticle is covered with a degradable coating that is degraded within a phagocytic mammalian cell. Also provided are nonporous microparticles coated with an antiviral or antimicrobial drug and further coated wherein the surface or outside extent of the microparticle is covered with a degradable coating that is degraded within a phagocytic mammalian cell. Methods of inhibiting, attenuating, arresting, combating and overcoming microbial infection of phagocytic mammalian cells in vivo and in vitro are also provided.

Nonporous microparticle-prodrug conjugates for treatment of infection

Methods and reagents are provided for specifically targeting biologically active compounds such as antiviral and antimicrobial drugs, or prodrugs containing the biologically active compound to specific sites such as specific organelles in phagocytic mammalian cells. The biologically active compound or prodrug is linked to a microparticle with a linker that is non-specifically or specifically cleaved inside a phagocytic mammalian cell. Alternatively, the biologically active compound or prodrug is impregnated into a porous microparticle or coated on a nonporous microparticle, and then coated with a coating material that is non-specifically or specifically degraded inside a phagocytic mammalian cell. The prodrug contains the biologically active compound linked to a polar lipid such as ceramide with a specific linker such as a peptide that is specifically cleaved to activate the prodrug in a phagocytic mammalian cell infected with a microorganism. A microparticle linked antimicrobial drug or prodrug may be used for killing a microorganism infecting a phagocytic mammalian cell in vivo or in vitro.

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Fulbourn, United Kingdom

Michael Stowell