An Ingenious New Delivery System For Antioxidant SOD

Scientists in Georgia are reporting successful lab tests of new polymer microparticles that show promise as a long-sought way to deliver drugs directly into the cell structures responsible for inflammation.

Those immune system structures, macrophages, devour and destroy foreign substances such as invading bacteria and cellular debris. However, they also release so-called reactive oxygen species that help cause arthritis, acute liver failure and other inflammatory diseases. In a report scheduled for the Jan. 17 issue of ACS' Bioconjugate Chemistry, a bi-monthly journal, Georgia Tech's Niren Murthy and colleagues at Emory University School of Medicine describe successful cell culture experiments with microparticles encapsulating superoxide dismutase (SOD). That compound is getting wide attention as a potential treatment for inflammatory diseases because it scavenges reactive oxygen species. One roadblock to clinical use of SOD, the researchers note, is the lack of a delivery system for SOD. The new polymer microparticles have several advantages over other potential delivery systems, the researchers state. The particles remain intact until reaching acid environments such as the phagosomes -- literal death chambers -- that form after macrophages engulf bacteria and other particles. Then the polymers breakdown, releasing their SOD directly at the site where inflammation begins.(Source: Bioconjugate Chemistry : Georgia Tech University : January 2007.)