Methods of making polycationic nanofibers by grafting cationic polymers onto electrospun neutral nanofibers and polycationic nanofibers produced by the methods are provided herein. In addition, methods of using the polycationic nanofibers to reduce inflammation, to adsorb anionic compounds such as heparin or nucleic acids, to inhibit the growth of microbes or inhibit the formation of a biofilm are also provided. The polycationic nanofibers may be in a mesh and may be included in a medical device, wound dressing, bandage, or as part of a graft.