An organic/inorganic composite compound is disclosed, which includes a core of a polyhedron of polyhedral oligomeric silsesquioxane and at least one arm connected to a silicon atom of the polyhedral oligomeric silsesquioxane. The at least one arm includes a vinyl-based first structural unit including at least one ethylene oxide group at a side chain thereof and a vinyl-based second structural unit including at least one anti-biotic functional group at a side chain thereof.
