Nanosize stucture plays an important role in inflammatory potential in lung

High ranked manufacturers of drugs consider the lungs to be an important route through which to administer drugs.Several studies revealed that inhaled nanoparticles, including those from natural sources, can trigger inflammation in the lungs, raising concerns that have slowed efforts to develop inhalable nanoparticle drug delivery systems for anticancer agents. Those concerns may be alleviated thanks to new findings that nanoparticles made of biodegradable materials do not trigger inflammation. A team of investigators of the University of Giessen (Germany) compared the inflammatory effects of biodegradable and non-biodegradable nanoparticles delivered into the lungs. The researchers tested nanoparticles made of biostable polystyrene, biodegradable polylactic-co-glycolic acid (PLGA), and a novel biodegradable polymer made of PLGA linked to a second polymer known as polyvinyl alcohol (PVA). This latter polymer is considered a strong candidate for pulmonary delivery of pharmaceuticals. Using both cultured lung cells and mice, the investigators found that polystyrene triggers a substantial inflammatory reaction. In comparison, PLGA nanoparticles of the same size produced no more of an inflammatory response than did a dilute salt solution. PLGA-PVA nanoparticles did not trigger any signs of inflammation, either. The researchers noted, however, that the larger PLGA-PVA nanoparticles were cleared more rapidly from the lungs by macrophages, which would not be desirable for a drug delivery vehicle.